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Hong Kong J Radiol 2024 Sep;27(3):e140-6 | Epub 4 September 2024

 

 

Department of Radiology and Imaging, Queen Elizabeth Hospital, Hong Kong SAR, China

 

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Breast cancer is one of the commonest cancers in Hong Kong, comprising 28.4% of female cancers in 2020.[1] In Hong Kong, mammography and sonography are the preferred initial modalities in the evaluation of breast lesions.[2] In some other countries, mammography is the mainstay for breast cancer screening.[3] In an era with increasing utilisation of computed tomography (CT), more breast lesions are detected incidentally when CT scanning is performed for other indications such as pulmonary or cardiac conditions.[4] [5] [6] Although dedicated mammography and sonography are still required for a better evaluation of the lesions, it is still important for radiologists to detect imaged breast lesions and to characterise them when such lesions are encountered on a CT scan. With an increased detection of undiagnosed breast cancer, a prompt referral of suspicious lesions for further investigation can help improve patient outcome. We aimed to investigate the yield of breast cancers from incidentally detected breast lesions on CT in Hong Kong. Their imaging features were correlated and compared with the final pathological diagnoses.

 

A retrospective analysis of the CT examinations scanned in Queen Elizabeth Hospital from 1 January 2018 through 31 December 2020 was performed. Patients whose CT reports contained the keyword ‘breast’ and were referred for a formal breast examination were included. The CT reports were derived from the Radiological Information System and Picture Archiving and Communication System, which is a system managed by Hospital Authority. Patients who had a history of breast diseases or breast surgeries were excluded from the study.

 

The CT scanners used in this study included SOMATOM Force Ultra-Fast Dual Source CT Scanner (Siemens Healthcare, Erlangen, Germany), Aquilion CXL 128 Slice CT Scanner (Toshiba, Tochigi, Japan), and Aquilion Prime CT Scanner (Canon Medical Systems, Tochigi, Japan), with a section thickness of 5 mm. The types of contrast used for enhanced procedures were iohexol (Omnipaque 350; GE HealthCare, Milwaukee [WI], US) and iodixanol (Visipaque 320; GE HealthCare, Milwaukee [WI], US), with a standard adult dose of 90 mL, administered via a pump injector. In examinations of the abdomen requiring injected contrast material imaged in different phases, the contrast was administered for the arterial phase at 3.5 mL/s or in the portal venous phase at 2.5 mL/s with a standard 70-second delay.

 

The CT images were reviewed by and commented on by two experienced radiologists (with 6 and 8 years’ experience in breast imaging, respectively) who were blinded to the diagnostic outcome. As there is no formal lexicon for breast lesions detected in a CT scan, the descriptors used in this study were adapted from the Breast Imaging and Reporting Data System terminology for magnetic resonance imaging lexicons (5th edition).[7] [8] The axillary lymph nodes were considered abnormal if: (1) their longest-to-shortest axis ratio was <2; (2) they lacked a fatty hilum; (3) there was cortical thickening of >3 mm; or (4) their cortices were eccentric.[9]

 

Continuous variables were presented as mean ± standard deviation, and categorical variables were presented as frequencies. The Mann-Whitney U test was used to evaluate the distribution of continuous data. Fisher’s exact test was performed to assess the correlation of the CT features with final pathological diagnosis. The specificity and sensitivity for malignancy were calculated for the significant CT features. A p value of < 0.05 was considered to be statistically significant.

 

A total of 22,255 CT studies of the thorax with or without abdominal regions were performed during the study period. Among these CT examinations, 2,575 of the reports contained the keyword ‘breast’. A total of 347 patients without history of prior breast disease or surgery were noted to have one or more incidental breast lesions in the CT studies; 345 were women and two were male. A total of 224 patients were referred for further formal breast assessment and investigation, among which 188 had subsequent formal breast investigations, nine had defaulted appointments, and 27 were still pending appointments at the time of the study. Among these 188 patients (186 female and 2 male), 164 patients had a solitary lesion, while 17 patients had two lesions and seven patients had three lesions, for a total of 219 incidentally detected breast lesions (Figure 1).

 

Figure 1. Patient selection

 

The overall referral rate for formal breast investigations during the study period was 64.6%. It was lowest in 2018 (61.0%) and highest in 2019, which was 70.8%.

 

Among the 219 breast lesions undergoing formal breast assessment, 88 were classified as ‘normal’ or ‘with benign appearance’ by clinical examination, mammography, and ultrasonography. The remaining 100 patients have undergone ultrasound-guided biopsy in our institute. In these patients, 83 lesions were found to be benign and 48 lesions were malignant (Figure 2), most of which were invasive ductal carcinoma (Table 1).

 

Figure 2. Results of formal breast assessments

 

The malignancy rate was 21.9% (48 out of 219 lesions). Patients with malignant lesions were likely to be older in age compared with those with benign findings (mean age: 67.58 vs. 56.60 years, p = 0.05).

 

Table 1. Core biopsy pathology of incidental breast lesions (n = 131).

 

CT measurement showed that the malignant lesions (mean size: 1.56 cm) were larger than the benign lesions (mean size: 1.23 cm) but not statistically significant (p = 0.08). Among the morphological characteristics of the breast lesions (Table 2), more lesions with an irregular shape or non-circumscribed margin were diagnosed as malignant (p ≤ 0.001). The malignancy rate (i.e., positive predictive value [PPV]) of all irregular lesions was 80%. The sensitivity and specificity of an irregular shape were 25% and 98.2%, respectively, while the malignancy rate of all non-circumscribed lesions was 53.1%. The calculated sensitivity and specificity of a non-circumscribed margin were 54% and 86.5%, respectively. Among the two descriptors for non-circumscribed margins, a spiculated margin had a malignancy rate of 100% with sensitivity and specificity of 16.6% and 100%, respectively, and is more indicative of malignancy (p < 0.05) [Table 3 and Figure 3].

 

Table 2. Morphology and enhancement patterns of the breast lesions (n = 219)

 

Table 3. Diagnostic performance of suspicious computed tomography features in the differentiation of malignant from benign incidental breast lesions

 

Figure 3. A 67-year-old woman underwent a plain computed tomography (CT) scan of the thorax for prolonged cough. (a) Axial CT scan reveals an incidental irregular shaped mass with spiculated margins in the upper outer quadrant of the right breast (arrow), with suspicious involvement of the right pectoralis muscle. (b) Ultrasound scan of the right breast confirms the hypoechoic mass with irregular shape and spiculated margin at the right 9 o'clock position (arrow). (c, d) Mammograms showing the right breast mass as a high-density irregular mass with spiculated margins that closely abuts the pectoralis muscle (arrows). Biopsy was performed and pathological examination confirmed invasive ductal carcinoma

 

Four biopsy-proven malignant lesions contained calcification. However, the association between calcification and malignancy of the lesions was not statistically significant (p > 0.05) [Table 4 and Figure 4].

 

Table 4. Presence of abnormal axillary lymph nodes or calcifications in the breast lesions (n = 219)

 

Figure 4. A 59-year-old woman underwent a contrast-enhanced computed tomography scan of the thorax for shortness of breath. An incidental breast mass showing peripheral enhancement is seen in the upper part of the left breast (arrow). Subsequently she underwent biopsy in the private sector that revealed invasive ductal carcinoma

 

A total of 172 lesions were evaluated in contrast-enhanced CT scans, with 113 of them showing contrast enhancement (Table 2). All of the malignant lesions showed enhancement. The sensitivity and specificity of contrast enhancement were 100% and 44.4%, respectively, for a negative predictive value of 100% for lack of enhancement (Table 3). Furthermore, all lesions that showed rim enhancement were malignant, giving a malignancy rate of 100% (p < 0.05) with specificity of 100% (Table 2 and Figure 5).

 

Figure 5. A 60-year-old woman with a contrast-enhanced computed tomography scan of the abdomen for abdominal pain. (a) An incidental breast mass with lobulated shaped and circumscribed margins is seen at the upper outer quadrant of the left breast with subtle internal calcifications (arrow). (b) Mammography showing a high-density, irregularly shaped mass with spiculated margins and internal pleomorphic calcifications (arrow). (c) Sonography showing the large left breast mass with internal echogenic foci suggestive of calcifications. This mass was later biopsied and confirmed to be invasive ductal carcinoma.

 

The axillary regions were included in the CT scan range in 126 patients. A total of 19 patients were found to have abnormal axillary lymph nodes, of which 12 of them have biopsy-proven malignant breast lesions. The association between presence of abnormal-looking axillary lymph nodes and breast malignancy was found to be statistically significant (p < 0.001) [Table 4].

 

Our study shows an increase in referral rate for dedicated breast imaging from 2018 to 2020, with increased reporting of CT-detected breast lesions. Despite a similar number of total CT scans done in our institute annually, this may be due to an increased awareness of CT-detected breast lesions leading to referral to the breast imaging units for characterisation.

 

In our study, 21.9% of the incidental CT-detected breast lesions were proven to be malignant after biopsy in the breast unit, i.e., out of the 22,255 CT studies performed in 2018 to 2020, 43 patients (five of them with more than one incidental breast tumour) were ultimately diagnosed with unsuspected breast cancer. Hence, the extrapolated breast cancer detection rate by CT scans is 1.9 cases per 1000 population based on our findings. A retrospective review by a local public hospital performed in the 5-year period from 1998 to 2002 showed that the breast cancer detection rate by mammogram is 5 cases per 1000 population,[2] in agreement with the concept that CT scan alone is not a better screening test than mammography.

 

Of the incidentally detected breast cancers in our study, most cases were invasive ductal carcinoma (70.8%) [Table 1], similar to the incidence of invasive ductal carcinoma in the general population of 75%.[10] [11] Ductal carcinoma in situ accounted for 20.8% of the incidentally detected breast cancers in our study (Table 1). Although CT lacks the resolution for microcalcifications, these cases were detected as breast masses.[12]

 

The most suspicious features for malignancy were found to be an irregular shape (malignancy rate of 80%) and spiculated margin (malignancy rate of 100%) [Table 2]. These results were in keeping with other studies across different modalities including mammography and sonography. Liberman et al[13] reported a PPV for malignancy of 73% for irregular shape and 81% for spiculated margins for mammographic studies. Inoue et al[14] reported a PPV for malignancy of 99% for irregular shape and 100% for spiculated margins for CT using dynamic dedicated breast CT. Stavros et al[15] reported a PPV for malignancy of 91.8% for spiculated lesions on sonography.

 

On the other hand, we found that oval shape (malignancy rate of 9.8%) and circumscribed margins (malignancy rate of 12.9%) are more indicative of benignity (Table 2). These results are also similar in the study by Moyle et al.[16]

 

The presence of CT-detected calcifications in breast lesions does not show a statistically significant association with the final pathology diagnosis (Table 4). In this study, only four biopsy-proven malignant lesions contained calcification, while the other visible calcifications were associated with benign entities. This is likely due to the fact that CT has limited spatial resolution. Microcalcifications <0.5 mm that are more likely associated with malignancy cannot be detected on non-dedicated CT.[17] Lindfors et al[18] found that CT was worse than mammography for visualisation of microcalcifications.

 

In our study, all of the biopsy-proven breast malignancies showed contrast enhancement with different enhancement patterns. Among these patterns, rim enhancement and heterogeneous enhancement were more indicative of malignancy (malignancy rate of 100% and 81.8%, respectively) [Table 2]. These results are similar to the findings by Moyle et al[16] and Agrawal et al[19] but are opposite from the study by Inoue et al,[14] who made use of dedicated breast CT for their study. The discrepancy can be due to the difference in timing of image acquisition in the CT studies in our study. Also, malignant breast tumours show rapid contrast uptake and washout, which is well known as a type 3 curve.[20] However, one limitation of our study is that the timing of the contrast administration was not fixed for all the CT studies, therefore such contrast enhancement pattern cannot be demonstrated.

 

In our study, the association between the presence of abnormal-looking axillary lymph nodes and breast malignancy was found to be statistically significant (Table 4). Therefore, evaluation of axillary lymph nodes is essential as part of the triple assessment and before sentinel lymph node biopsy. Although axillary ultrasound is more convenient, it is found that the combination of axillary ultrasound, breast CT, and magnetic resonance imaging of the breast yields a better accuracy rate than the use of a single imaging modality.[21]

 

The breasts are an area for review by CT radiologists, as more breast lesions are being detected incidentally in CT examinations. This study has shown that nearly one in four incidental breast lesions leads to a diagnosis of breast cancer, particularly in older adults, lesions demonstrating spiculation, irregularity or rim enhancement, and in the presence of abnormal axillary lymph nodes. The detection of these incidental lesions can facilitate a timely referral for a formal breast examination, prompt patient management, and better disease outcome.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hong Kong J Radiol 2024 Sep;27(3):e156-63 | Epub 28 August 2024

 

 

Department of Diagnostic and Interventional Radiology, Queen Elizabeth Hospital, Hong Kong SAR, China

 

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The management of bone tumours is complex and requires a multidisciplinary approach. In general, the best line of treatment is surgical resection. Bone tumours with impending or completed pathological fractures require early surgical intervention to prevent or stabilise the fractures. Nevertheless, surgery may be technically difficult due to large or hypervascular tumours, difficult anatomical locations, or close proximity to adjacent vital structures such as the spine. In these scenarios, arterial embolisation plays a pivotal role as a preoperative methodology to achieve devascularisation of the tumour, thus minimising intraoperative bleeding and complications. In this study, we aimed to evaluate the technical success, efficacy, and safety of preoperative embolisation of bone tumours in our tertiary musculoskeletal tumour centre.

 

This retrospective study evaluated 19 patients who underwent preoperative embolisation of bone tumours followed by surgery at our centre from December 2010 to July 2022. Patient demographics, tumour histology and location, presence of pathological fractures or spinal cord compression, and choice of primary embolic agent were recorded. The technical success of embolisation, defined as reduction of tumour arterial blush by ≥70% on postoperative angiography,[1] [2] as shown in our case (Figure 1), was assessed. In cases of no definite tumoural staining identified on preoperative angiography, which was seen in one of our patients, technical success could not be reliably evaluated. Clinical notes as well as operative and anaesthetic records were reviewed for major surgical complications, intraoperative blood loss, and requirements for transfusion. Categorical data are presented as percentages, while numerical data are presented as medians with ranges.

 

Figure 1. (a) Bone metastasis from renal cell carcinoma in the left proximal tibia manifests as a large expansile lytic bone lesion (arrow) on radiograph. (b) It shows significant hypervascularity (arrow) on angiogram with supply from multiple genicular arteries and the anterior recurrent tibial artery. (c) Post-embolisation angiogram confirms technical success of the procedure with minimal residual tumoral vascularity (arrow).

 

Case selection for preoperative embolisation requires a multidisciplinary team discussion. Factors to consider include tumour histology, location, size and vascularity, and the risk of significant intraprocedural haemorrhage.[2] Tumour histology is confirmed by image-guided core needle biopsy. The location, size, and vascularity of the tumour are assessed on imaging. Preprocedural review of imaging, in particular computed tomography angiography, is important for identifying blood supply and drainage, tumour extension into adjacent structures, and proximity to vital structures potentially sharing the arterial supply. Before the embolisation procedure, the results of laboratory tests including clotting profile, platelet count, haemoglobin level, and creatinine values are reviewed. Abnormal coagulation should be corrected since many of the embolic agents require a functioning intrinsic clotting mechanism.

 

All patients in our centre had surgery performed 1 day following the embolisation. In view of potential revascularisation with a prolonged interval between embolisation and surgery, the timing of embolisation should be as close as possible to that of the operation, ideally within 3 days after embolisation.[2] The procedure was performed by radiologists with 8 to 26 years of experience in vascular interventional radiology. The embolisation procedure was done under local anaesthesia in the angiography suite. Vascular access was obtained via femoral arterial puncture. A 5-Fr or 6-Fr vascular sheath and a 4-Fr or 5-Fr pre-shaped catheter were used. A pre-embolisation angiogram was obtained to assess the degree of tumour vascularity, identify the major supplying arteries, and confirm the safety of embolisation. For instance, careful attention must be paid to ensure there is no opacification of a spinal pial artery such as the artery of Adamkiewicz. If embolisation was not contraindicated for any of these reasons, a microcatheter was introduced coaxially through the catheter to achieve superselective catheterisation of tumour feeding arteries and reduce the chance of non-target embolisation. Micron-sized solid embolic particles were primarily used in all cases. They lodged in the tumour vessels proximal to or at capillary level, thus occluding vessels within the tumour to achieve distal tumour microvasculature penetration. The particles were suspended in non-ionic contrast medium to enable visualisation during the angiographic procedure. The choice of particle diameter was determined by vessel size and desired distal embolisation. Injection of embolic agents must be performed under fluoroscopic guidance to guard against reflux into non-target vessels. All embolisation procedures were performed under continuous fluoroscopic guidance. Multiple angiograms were acquired to evaluate the degree of vessel occlusion. The endpoint of the procedure was reached when all the major tumour-supplying vessels were occluded with near-complete obliteration of tumour blush. Finally, a post-embolisation angiogram was performed to assess the technical success of embolisation, which was defined as catheterisation of the major tumour feeding arteries with reduction of the tumour blood supply by ≥70%.[1] [2]

 

There were 10 female and nine male patients who underwent preoperative embolisation during the study period (Table). Patient age ranged between 22 and 77 years and the median age was 61 years. The majority of the tumours were bone metastases (n = 14, 74%) and most of them were either metastases from renal cell carcinoma (n = 6, 32%) or thyroid carcinoma (n = 5, 26%). The rest of the bone tumours (n = 5, 26%) included vertebral haemangioma (n = 2, 11%), plasmacytoma (n = 2, 11%), and chordoma (n = 1, 5%). More than half (n = 11, 58%) of the tumours were located within multiple vertebrae. The rest were located in the extremities (n = 6, 32%) or the pelvis (n = 2, 11%). Pathological fractures were present in 58% of the patients (n = 11). Among the 11 vertebral tumours, cord compression was seen in eight (73%) of them.

 

Table. Demographics, clinical, and pathological characteristics of patients (n = 19).

 

Technical success was achieved in 16 out of 18 (89%) patients and selected case examples are shown in Figures 2, 3, and 4. Only partial embolisation could be performed in two patients due to the proximity of the tumour feeding arteries to the spinal artery in one patient and the occurrence of chest pain during the procedure in another patient. Technical success could not be reliably evaluated in one patient since no definite tumour staining was evident on pre-embolisation angiogram for comparison. The primary embolic agents used included trisacryl gelatin microspheres (Embosphere; Merit Medical, Warrington [PA], US) [n = 8], polyvinyl alcohol (PVA) particles (Contour; Boston Scientific, Marlborough [MA], US) [n = 7], and PVA hydrogel microspheres (Bead Block; Terumo Medical, Tokyo, Japan) [n = 4].

 

Figure 2. (a) Preoperative embolisation performed for bone metastasis from renal cell carcinoma at the right femoral intertrochanteric region (arrow) with pathological fracture. (b) Angiogram of the right femoral artery shows the hypervascular tumour (arrow) supplied by branches of lateral and medial circumflex femoral arteries. (c) Post-embolisation angiogram demonstrates >90% reduction in tumour vascularity (arrow), suggestive of technical success. (d) The patient underwent bipolar hip arthroplasty on the subsequent day with intraoperative blood loss of around 100 mL.

 

Figure 3. Histologically proven spinal metastasis from solitary fibrous tumour undergoing preoperative embolisation. Computed tomography shows the L5 spinal tumour (arrows) with intraspinal (a) and paraspinal (b) extension. Pre-embolisation angiograms confirm the hypervascular tumour (arrows) to be supplied by branches of the left fourth lumbar artery (c) and iliac branch of the left iliolumbar artery (d). Superselective pre-embolisation angiograms by microcatheters advanced into the branches of the left fourth lumbar artery (e) and the branches of the iliac branch of the left iliolumbar artery (f) reveal significant tumour blush (arrows). Post-embolisation angiograms of branches of the left fourth lumbar artery (g) and the iliac branch of the left iliolumbar artery (h) demonstrate absent tumour blush, suggestive of technical success.

 

Figure 4. (a) Pathological fracture through a renal cell metastasis in the distal left humerus (arrow) is seen on the radiograph. (b) Brachial angiogram shows the hypervascular tumour (arrow) with arterial feeders from the brachial artery and radial recurrent artery. (c) Completion angiogram demonstrates successful devascularisation. (d) The patient underwent partial resection of the humerus and total elbow replacement with minimal blood loss.

 

There was no mortality related to embolisation. Minor complications in the form of post-embolisation syndrome and pain from ischaemic necrosis of tumours occurred in six patients (32%) and these were treated with analgesics and fluid. In patients with embolisation of vertebral tumours, there were no procedure-related neurological deficits. The median of intraprocedural blood loss was 700 mL (range, 20-14,000). Two patients (11%) suffered major haemorrhages requiring massive intraprocedural blood transfusions. One of them had a spinal metastasis from renal cell carcinoma with supply from the bilateral T6 segmental arteries. However, successful embolisation was only achieved at the right T6 segmental artery because the spinal artery was seen in repeated angiograms of the left T6 segmental artery (Figure 5). To minimise the risk of spinal cord infarction, the procedure was abandoned after only light embolisation of the left T6 segmental artery and the target of technical success could not be achieved. The patient had significant intraprocedural blood loss requiring massive transfusion and the transfused blood volume was around 3 L. Postoperatively, there was diplegia of the lower limbs, suggestive of spinal cord injury. Another patient had sacral chordoma with no definite tumour staining on preoperative angiography. As a result, technical success of the embolisation procedure could not be reliably evaluated. Embolisation was performed pre-emptively in view of the possibility of massive intraoperative bleeding. Unfortunately, major intraprocedural haemorrhage was still encountered, necessitating massive transfusion with transfused blood volume of around 4 L.

 

Figure 5. (a) Sagittal view of computed tomography of the thoracic spine reveals a T6 bone metastasis from renal cell carcinoma with extension into the spinal canal (arrow). (b) Superselective catheterisation of the right T6 segmental artery shows significant tumour staining (arrow) and non-visualisation of the spinal artery. (c) Post-embolisation angiogram of the right T6 segmental artery shows absent tumour blush. (d) The spinal artery (arrow) was visualised on repeated angiogram of the left T6 segmental artery after initial light embolisation, therefore no further embolisation was performed.

 

Successful embolisation of bone tumours may potentially decrease intraoperative blood loss and improve visualisation of the surgical field, thus minimising risks of major complications and enabling safer and more complete resection. It is particularly beneficial when there is a high risk of intraoperative bleeding, spinal involvement with cord or neural encroachment or in technically difficult locations with expected prolonged surgery,[3] such as hypervascular spinal and pelvic bone metastases. In our case series, the median estimated intraprocedural blood loss was 700 mL, which was lower than that reported in other studies.[4] [5]

 

Apart from its role as an adjuvant therapy to surgery, embolisation may also be performed as a palliative treatment for symptomatic relief of bone metastases. It may be done as a standalone treatment or combined with ablation or cementoplasty.[6] It has been used successfully to achieve neurological improvement in patients with hypervascular vertebral metastases causing acute spinal cord compression[7] and symptomatic relief in patients with painful bone metastases from renal cell carcinoma.[8] There have been studies supporting embolisation as a primary treatment for benign bone tumours such as aneurysmal bone cysts and giant cell tumours.[9] [10] [11] It is particularly beneficial in tumours located in the spine or pelvis, where surgery and radiation are associated with high rates of morbidity and recurrence. Serial embolisation of these tumours is usually performed until there is symptomatic relief or near complete resolution of tumour vascularity.[10] Radiological response can also be assessed and it manifests as reduction in tumour vascularity and increase in ossification. In patients with vertebral haemangiomas complicated with spinal cord compression or spinal pain, surgery or radiotherapy has been the traditional treatment of choice. However, surgery alone is associated with risk of significant bleeding from these highly vascular tumours. Preoperative embolisation has been shown to be a useful adjunctive therapy to minimise bleeding risk.[12] [13]

 

Particulate materials, namely PVA particles and microspheres, are primarily used for embolisation. PVA is water-soluble synthetic polymer made from polyvinyl acetate through partial or full hydrolysis to remove the acetate groups, with size ranging from 50 to 1000 μm. It has the ability to penetrate and occlude the tumour blood supply. It is compressible after drying and will expand to up to 15 times its compressed size after rehydration.[14] Most interventional radiologists have extensive experience in using it and it is relatively easy to deliver. It is safe without any long-term side-effects. The conventional preparation (Contour PVA) has irregular outlines and therefore occludes vessels larger than its diameter due to aggregation of particles. Some newer preparations, e.g., Bead Block PVA hydrogel microspheres, are engineered PVA particles with relatively uniform size. Their microporous nature also enables them to be compressible and facilitates delivery through small catheters. Embosphere microspheres are trisacryl gelatin microspheres with size ranging from 40 to 1200 μm. Their compressibility allows smooth passage through microcatheter with a diameter smaller than its size. They are more uniform in size than PVA and their sizes do not change in liquids. They also have less tendency to clump after injection. The choice of the primary particulate embolic agent is mainly determined by the operator’s experience and preference. There is currently little published literature comparing the efficacy of different embolic materials in preoperative embolisation of bone tumours. A study performed to assess the intraprocedural blood loss post-embolisation showed no clinically significant difference between trisacryl gelatin microspheres and PVA particles.[15] Liquid embolic agents may induce more tumour necrosis than particles and be beneficial when definitive treatment is aimed. Nonetheless, they are technically more difficult to handle and their use requires an experienced operator. They are also associated with a higher risk of non-target embolisation and non-target necrosis compared with particles.[6] As a general rule, if embolisation is performed as preoperative or palliative treatment, liquid agents have little advantage over particulate agents.

 

Complications of embolisation of bone tumours include arterial dissection, pain due to ischaemic necrosis of tumour, non-target embolisation, infection, haemorrhage, and post-embolisation syndrome.[8] [16] Post-embolisation syndrome is a common but usually self-limiting side-effect. Patients present with symptoms such as pain, fever, and malaise, which could be treated with analgesics and fluid. Non-target embolisation is another potential complication. Aside from the use of microcatheters to reduce its risk, coils may be employed to embolise and protect the non-target vessels more proximally, which could not be navigated beyond to get close to the tumour feeding vessels.[7]

 

There were limitations in our study. First, it was retrospective in nature and a non-embolisation group was not available for comparison. With reference to other studies from the literature, it still offered a reasonable view of preoperative embolisation as a potentially helpful procedure in the management of bone tumours. Another limitation was the heterogeneous study population with different tumour pathologies and surgeries performed, but this reflected the diversity of primary and metastatic bone tumours that could be considered for preoperative embolisation. Ideally, a prospective randomised controlled trial with a larger study population would be optimal for determining the exact value of preoperative embolisation compared with non-embolisation. Other factors that could affect intraprocedural blood loss, including patient factors, and the surgery performed, should also be taken into account.

 

Preoperative embolisation is safe, technically feasible, and potentially useful in the treatment of bone tumours, although a high risk of intraoperative bleeding should be taken into consideration.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hong Kong J Radiol 2024 Sep;27(3):e176-82 | Epub 2 September 2024

 

 

¹ Department of Radiology, Pamela Youde Nethersole Eastern Hospital, Hong Kong SAR, China

² Department of Orthopaedics and Traumatology, Pamela Youde Nethersole Eastern Hospital, Hong Kong SAR, China

 

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Ectrodactyly, also known as split hand and foot deformity, is a rare congenital skeletal deformity characterised by deficiency or absence of the central digital rays. The central cleft simulates the appearance of a lobster claw.[1] It can present as an isolated deformity or part of a syndrome—usually with autosomal dominance inheritance—such as the ectrodactyly-ectodermal dysplasia-clefting syndrome or limb-mammary syndrome.[2] [3]

 

We present a case with non-syndromic pedal ectrodactyly. The patient presented with chronic pain over the lateral ankle. To the best of our knowledge, this is the first report of imaging findings, highlighting consequent soft tissue findings in an adult with split foot deformity.

 

A 31-year-old female with known left foot deformity since birth presented with a 2-year history of increasing pain over the lateral ankle. The pain was worse on movement and weight-bearing. There was no preceding injury. She was born full term by normal spontaneous delivery. She enjoyed good past health and had no other known congenital anomalies. Physical examination revealed clefting deformity and abnormal configuration of the left foot. The lateral ankle joint was tender with mild local swelling.

 

Radiographs and reconstructed three-dimensional computed tomography of the left foot and ankle revealed the presence of two complete rays and a singular tarsal bone articulating with the first ray. An incomplete ray was seen in between, comprised of two phalanges and a metatarsal head. The base of the proximal phalanx and the metatarsal head formed anomalous articulation with the first metatarsal head (Figure 1).

 

Figure 1. (a) Dorsopalmar oblique view of X-ray of the left foot. An incomplete ray and a single metatarsal articulating with the first ray are demonstrated. Synostosis of the talus and calcaneum is evident. (b) Frontal view of X-ray of the bilateral ankle joints shows abnormal configuration of the left calcaneum (notched arrow) and shortened and widened left distal fibula (arrow). Osteoarthritic changes of the left calcaneofibular neo-facet are evident. (c) Reformatted computed tomography in bone window of the left foot. The proximal phalanx (PP) and metatarsal head (MT) of the incomplete ray articulate with the first metatarsal head.

 

The left hindfoot was formed by a single bony structure with anterior bifid appearance, simulating non-segmentation of the talus and calcaneus (hereby termed the talocalcaneal complex) [Figures 1 and 2]. A calcaneofibular neo-facet was demonstrated. The distal fibula was shortened while the lateral malleolus appeared widened (Figures 1 and 2).

 

Figure 2. Reconstructed three-dimensional computed tomography of the left foot and the ankle, demonstrating the bony anatomy in lateral oblique (a) and frontal (b) projections, as well as the soft tissue components in the lateral (c) and frontal (d) projections.

 

Pes planar deformity was evident with loss of both medial and lateral longitudinal arches. The talus-first metatarsal angle (Meary’s angle) measured 15° while the calcaneal inclination angle approached 0°, signifying loss of the medial and lateral arches, respectively (Figure 3a). There was widening of the talocalcaneal angle, suggestive of hindfoot valgus deformity (Figure 3b). Osteophytes and subchondral sclerosis were seen around the first tarsalmetatarsal joint, suggestive of midfoot arthrosis (Figure 3b).

 

Figure 3. (a) Lateral view of X-ray of the left foot showing pes planar deformity and a talus-first metatarsal angle of 15˚ convex downwards (Meary’s angle in normal individuals is normally 0˚) [black dotted lines]. The calcaneal inclination angle, measured between the calcaneal inclination axis and the supporting horizontal surface, approaches 0˚ (normal, 20-30˚) [white dotted line]. (b) Dorsopalmar view of X-ray of the bilateral feet. Widened talocalcaneal angle (38˚) [black solid lines] is compared with normal right side (20˚) [white solid lines] (Kite’s angle in normal individuals is normally 25-40˚). It also shows arthrosis of the first tarsal-metatarsal joint (white arrow).

 

Computed tomography of the left ankle joint revealed bony remodelling with flat neo-facets at the calcaneofibular articulation. Secondary osteoarthritic changes and osteophytes were observed (Figure 4a). Magnetic resonance imaging showed associated marrow oedema, moderate synovial thickening, and interposed soft tissue oedema. Mild thickening of the adjacent peroneus brevis and longus tendon sheaths was observed (Figures 4b to 4e). Overall features were suggestive of lateral hindfoot impingement syndrome.

 

Figure 4. (a) Computed tomography and (b-e) magnetic resonance imaging of the left ankle joint. (a) Reformatted coronal projection showing osteophytosis (black arrows) and osteoarthritic changes of the calcaneofibular neo-facet. (b) Sagittal proton density (PD)–weighted short tau inversion recovery image. Increased marrow signals (hollow notched arrows) over distal fibula (DF) and talocalcaneal complex are suggestive of oedema. (c) Coronal PD-weighted fat-saturation image showing moderate soft tissue oedema and thickened sheath of the peroneus longus tendon (solid notched arrow). (d, e) Sequential PD-weighted axial slides through the talofibular joint showing moderate synovial thickening and interposed soft tissue oedema (black arrows).

 

Normal anterior talofibular ligament and calcaneofibular ligament were not well delineated, possibly due to either congenital absence or secondary to chronic impingement-related tearing (Figure 5a and 5b). The posterior talofibular ligament and anterior inferior tibiofibular ligament were small in calibre. Moderate thickening and high heterogeneous short tau inversion recovery signals of the peroneus longus tendon was seen, suggestive of tendinosis and interstitial tear (Figure 5c and 5d). It was possibly a sequala of the altered hindfoot biomechanics.

 

Figure 5. (a) Proton density (PD)–weighted axial view through the right distal calf for comparison. (b) PD-weighted axial view through the left distal calf. Normal anterior talofibular ligament (white arrow) is not well demonstrated. All muscles in the anterior, lateral, and posterior compartments are atrophic. (c) PD-weighted reformatted sagittal image and (d) PD-weighted fat-saturated sequence axial image showing thickening of the plantar portion of the peroneus longus tendon (notched arrows), with high heterogeneous signals suggestive of tendinosis and interstitial tear.

 

The left peroneus longus and brevis muscles were atrophic compared with the right side. Normal infra-malleolar portion of the peroneus brevis tendon was not demonstrated (Figure 6). Other calf muscles had smaller bulk than the right side, most evident at the lateral and posterior compartments (Figure 5b). The plantar portions of the tendons in the anterior and posterior compartment were attenuated.

 

Figure 6. Proton density–weighted axial magnetic resonance images through the right (a) and left (b) distal calves, with the anterior, posterior, and lateral compartments highlighted in green, blue, and yellow, respectively. The left peroneal brevis (PB) and peroneal longus (PL) muscles are atrophic. Muscles in the posterior compartment (tibialis posterior [PT], flexor digitorum longus [FDL], and flexor hallucis longus [FHL]) are also atrophic. Muscle bulks in the anterior compartment (left extensor hallucis longus [EHL] and extensor digitorum longus [EDL]) are preserved. The plantar portion of the anterior and posterior compartment tendons are mostly attenuated (not shown).

 

Ectrodactyly derives from the Greek words ‘ektromo’ and ‘daktylos’, meaning abortion and fingers, respectively. It is nonetheless not limited to the digits or upper limbs. Reportedly it represents a spectrum of limbic deformity, from aphalangia, adactylia and acheiria, to hemimelia or amelia. Most cases of sporadic ectrodactyly are unilateral.[4] The pathogenesis involves failure of initiation of apical ectodermal ridge, or subsequent signalling pathways, that contributes to truncation of all skeletal elements over the distal developing limb bud.[3]

 

Although ectrodactyly commonly presents as an isolated finding, it may form part of a syndrome. Ectrodactyly-ectodermal dysplasia-clefting syndrome is the most reported. It is an autosomal dominant condition, affecting structures derived from the ectoderm such as hair, skin, nails, and teeth, with such presentations as skin hypopigmentation, sparse hair, and dental defects. Genitourinary and lacrimal duct anomalies are also common. Limb-mammary syndrome is also well studied. It is characterised by mammary gland and nipple hypoplasia.[5] Other less common syndromes associated with ectrodactyly include Karsch–Neugebauer-syndrome (congenital nystagmus), Patterson-Stevenson- Fontaine syndrome (mandibulofacial dysostosis), and Adams-Oliver syndrome (scalp defect).[5] [6] Despite the characteristic features, marked phenotypic variability is reported, possibly related to variable expression and incomplete penetrance.

 

Blauth and Borisch[7] proposed a radiological classification for cleft foot that describes a spectrum of metatarsal defects ranging from types I to VI. The characteristics and possible associated features are shown in the Table.[7] With an incomplete metatarsus and two absent rays, our patient fell between type IV and V. In line with the findings, our patient demonstrates possible synostosis of the talus and calcaneum. From the case series, the authors suggested that cleft formation begins at the second or third ray, then proceeds in a distal to proximal fashion.[7] The fifth ray is usually the last affected (Table). Synostosis is commonly seen at the margin of the cleft. Associated features such as syndactyly, polydactyly and cross-bone deformities may be observed, yet appear widely variable.

 

Table. Radiological classification for cleft foot[7]

 

The presence of an incomplete ray caught our attention. According to the known pattern of deformation, the distal portion of the ray should be first affected. For the incomplete ray, provided the absence of a proximal metatarsal, the development of the distal metatarsal and phalanges are not to be expected. In split-hand deformities, syndactyly of the remaining digits is reportedly common. There are also rare cases of triphalangeal thumbs.[5] In the case series by Blauth and Borisch,[7] a few cases displaying central polydactylous element were also reported. Two of the cases showed duplicated phalanges of the second digit.[7] We remain open to the possibility that the incomplete metatarsal head in our patient might arise from the first ray as a polydactylous deformity.

 

The Bluman-Myerson classification stages adult acquired flatfoot deformity (AAFD) based on severity and rigidity of the flatfoot deformity.[8] The bony deformities in our patient caused severe and irreversible hindfoot valgus and rigid flatfoot deformity, classified as stage III AAFD. The altered bony configuration leads to lateral hindfoot (or subfibular) impingement with associated soft tissue fibrosis, midfoot arthrosis, peroneal tendinopathy, and calcaneofibular ligament entrapment.[9] Stage III AAFD is also not uncommonly present in patients with congenital tarsal coalition due to arch flattening and associated rigid hindfoot valgus.[10] The principles of treating stage III AAFD include correcting hindfoot valgus, realigning the midfoot from abduction deformity, and relieving the lateral compartment. In normal individuals, arthrodesis of the talonavicular and subtalar joints is usually performed, where most deformities are found. The calcaneocuboid joint may also be fused, after balancing against the risks of ankle valgus, failure of the deltoid ligament and worsened foot rigidity.[11] In our case, the aim of surgical treatment will be to relieve lateral compartment pressure and the associated pain. A bony procedure is needed as the primary pathology is bone anomaly. Treatment options are limited by a deformed talocalcaneal complex, the absence of few mid- and hind-foot bony structures and hence such joints as the subtalar and calcaneocuboid joints. Medialising calcaneal (talocalcaneal complex, in our case) osteotomy is the most feasible option. In view of the osteoarthritis of the calcaneofibular neo-facet, this procedure may not completely relieve the pain. Ankle fusion would be the last resort to treat the arthritic pain since severe functional disability would result.

 

Common features of ectrodactyly, including absent metatarsals and tarsal synostosis, are present in this case. The presence of an incomplete distal ray around the cleft is nonetheless discordant with current knowledge; we propose that it may arise from the first ray as a polydactylous deformity. Pes planus deformity and associated lateral hindfoot impingement syndrome were well demonstrated across different imaging modalities and consistent with the clinical presentation. Future case series directed at associated soft tissue injuries may be helpful in planning rehabilitation programmes and surgical interventions.

 

 

 

 

 

 

 

 

 

 

 

 

 

Hong Kong J Radiol 2024 Sep;27(3):e183-91 | Epub 12 September 2024

 

 

¹ Department of Radiodiagnosis, Sri Ramachandra Institute of Higher Education and Research, Chennai, India

² Department of Intervention Radiology, Sri Ramachandra Institute of Higher Education and Research, Chennai, India

 

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Osler-Weber-Rendu syndrome (OWRS), also known as hereditary haemorrhagic telangiectasia (HHT), is characterised by multiple mucocutaneous telangiectasias and multiorgan arteriovenous malformations (AVMs) due to abnormal vascular remodelling traceable to a genetic defect in a binding protein for transforming growth factor. The telangiectasias and AVMs have a propensity to bleed due to their fragile nature. The multisystemic involvement of OWRS makes it imperative for clinicians and radiologists to identify the different clinical manifestations and radiological features of this syndrome. In this pictorial essay, we give an overview of the radiological features found in patients with OWRS and the role of interventional radiology in management.

 

Three patients with a radiological diagnosis of OWRS were included (Table 1). [1] [2] [3] They underwent contrastenhanced computed tomography (CECT) and magnetic resonance imaging (MRI) examinations followed by vascular interventions at our hospital from February 2019 to September 2020.

 

Table 1. Curaçao clinical criteria for diagnosis of hereditary haemorrhagic telangiectasia.[1] [2] [3]

 

CECT examinations of the abdomen and the pelvis were acquired using a Revolution EVO Gen 2 128-slice unit (GE HealthCare, Beijing, China). CT images were obtained with parameters of 120 kV and current in auto mode. Axial thin sections were acquired from the dome of the diaphragm to the symphysis pubis and the data were processed into multiplanar reconstruction (MPR) images with 5-mm slice thickness and three-dimensional images. The reconstruction interval was 0.625 mm. Approximately 80 mL of non-ionic contrast material (iohexol 350 mg iodine/mL; GE HealthCare, Milwaukee [WI], US) was administered with a power injector at a rate of 3.5 mL/s. Image data were acquired 18 to 20 seconds (arterial phase) and 60 seconds (portal venous phase) post contrast injection. For CT pulmonary angiography, 60 mL of non-ionic contrast was administrated intravenously at the rate of 5 mL/s followed by 30 mL of a normal saline chaser. Axial thin sections acquired from the sternal notch to the xiphisternum were used to reconstruct three-dimensional and MPR images.

 

For MRI of the brain, the sequences were axial T1-weighted, T2-weighted, diffusion-weighted imaging, sagittal T1-weighted, coronal fast fluid-attenuated inversion recovery, two-dimensional time-of-flight, and three-dimensional time-of-flight acquired on a Signa HDxt 1.5T scanner (GE HealthCare, Milwaukee [WI], US). The CT and MRI images were sent to a picture archiving and communication system and interpreted at workstations. Interventional procedures were performed using a biplane system (Allura Biplane FD20/20; Philips, Best, the Netherlands).

 

A 43-year-old female, who had three pregnancies and three live births previously, presented with abnormal uterine bleeding for 1 month. On pelvic ultrasound, an anterior wall uterine fibroid and a right ovarian cyst was noted. A CT of the abdomen and pelvis showed a right paraovarian cyst and a heterogeneous lesion within the right lobe of the liver. CECT of the abdomen showed extensive telangiectasias[4] (Figure 1a, 1b, and Tables 2 and 3) and confluent masses[5] [6] within both lobes of the liver, with the right one larger than the left one. Early opacification of the left portal vein was noted in the arterial phase, suggestive of AVMs[5] (arteriovenous shunts) [Figure 1c]. The extra- and intrahepatic arteries were dilated, with the common hepatic artery measuring around 10 mm in diameter.[5] [6] On clinical examination, telangiectasias were noted in the fingertips and oral cavity of the patient.

 

Figure 1. Case 1. Axial views of the abdomen in arterial phase at the level of the liver. (a) Multiple tiny areas of vascular puddling (arrowheads) in the hepatic parenchyma are evident, suggestive of telangiectasias. There is also early opacification of the left portal vein (yellow arrow), suggesting an arteriovenous malformation (Tables 2 and 3). (b) Medium-to-large sized vascular abnormalities representing confluent vascular masses (blue arrows) involving the right lobe of the liver are shown. (c) Multiple tortuous corkscrew-like vessels (yellow arrows) scattered in the hepatic parenchyma and the hepatic artery is dilated (white arrow), suggestive of telangiectatic vessels in Osler-Weber-Rendu syndrome.

 

Table 2. Salient features of arteriovenous malformations within different organs with presenting signs/symptoms and treatment options.[4] [8] [11]

 

Table 3. Different types of hepatic shunts on radiological imaging.[5] [6]

 

The diagnosis of OWRS was made (Table 1). The patient needed intervention in the liver AVMs to prevent development of portal hypertension as a complication. However, due to logistical reasons and the patient’s financial difficulties, follow-up imaging was suggested.

 

A 2-year-old boy presented with a sudden onset episode of generalised seizures. His father had a history of brain AVMs. On brain MRI, a bilobed extra-axial lesion was seen in the right transverse temporal sulcus with blooming on gradient echo sequences and flow void on other sequences. A prominent feeder from the M4 segment of the right middle cerebral artery and a prominent vein from the superior anastomotic vein of Trolard were seen draining the lesion into the superior sagittal sinus, suggestive of AVM (Figure 2a and 2b).[1] [7]

 

Figure 2. Case 2. (a) Axial magnetic resonance angiography showing a well-defined extra-axial lesion (star) in the right transverse temporal sulcus communicating with a prominent feeder from the M4 segment of the right middle cerebral artery (white arrow). There is associated left cerebral hemisphere atrophy. (b) Reformatted magnetic resonance venography showing a bilobed extra-axial lesion with a prominent vein representing the superior anastomotic vein of Trolard (curved yellow arrow) seen draining the lesion into the superior sagittal sinus. (c) Axial T2-weighted image (T2WI) showing a pachygyria-polymicrogyria complex (white arrows) involving the right parietal lobe adjacent to the abovementioned lesion. The lesion appears hypointense on T2WI, likely due to flow voids, suggestive of a high-flow arteriovenous fistula. (d) Axial T2WI shows an associated porencephalic cyst (star) involving the left cerebral hemisphere communicating with the frontal horn of the left lateral ventricle. (e) Preprocedural digital subtraction angiography image showing pial arteriovenous fistula involving the right fronto-parietal region fed by a right middle cerebral artery–M4 branch (yellow arrow) and draining via the vein of Trolard (blue arrow) into the superior sagittal sinus with a large venous sac (star). (f) The arteriovenous malformation (AVM) was embolised and post-procedure angiography image shows complete exclusion of the AVM from the circulation (blue arrow). (g) A non-contrast axial computed tomography of the brain shows streak artifacts secondary to post-embolisation status of the AVM (yellow star). Associated left cerebral hemisphere atrophy is noted (curved green arrow).

 

A pachygyria-polymicrogyria complex involved the right parietal lobe adjacent to the lesion (Figure 2c and 2d).[7] A large left-sided porencephalic cyst[7] communicating with the ipsilateral lateral ventricle exerted mass effect in the form of a midline shift of 7 mm to the right. There was associated left cerebral hemiatrophy (Figure 2c and 2d). The diagnosis of OWRS was made (Table 1). In view of the high-flow AVM, embolisation was advised. Endovascular glue embolisation of the right parietal pial arteriovenous fistula was performed by administering iodixanol contrast (GE HealthCare, Milwaukee [WI], US) using a microcatheter (Excelsior XT-17; Stryker, Fremont [CA], US), microwire combination (Transcend; Meditech, Watertown [MA], US) and a HyperGlide balloon (eV3 Endovascular Inc, Irvine [CA], US) to inject 66% glue [n-butyl-2-cyanoacrylate liquid embolic system (Trufill; Cordis Neurovascular, Miami Lakes [FL], US)] as an embolisation agent mixed with ethiodised oil in various dilution ratios depending on the application to control polymerisation rate. Post-procedure angiography and brain CT were performed, which showed complete exclusion of the AVM from the circulation (Figure 2e to 2g). The patient was started on antiepileptic drugs and did not have any other seizure episode during the course in the hospital.

 

A 43-year-old male presented with one episode of haemoptysis (around 10 mL of blood) and two episodes of generalised tonic-clonic seizures. Multiple scattered non-haemorrhagic lacunar infarcts were noted in the right occipital lobe and both fronto-parietal regions. Chest radiography showed multiple homogenous mass lesions in the right lower zone and left upper and lower zones (Figure 3a). Subsequent CT pulmonary angiography revealed multiple AVMs involving the anterior basal segment of the right lower lobe, the apicoposterior segment of the left upper lobe, and the lateral basal segment of the left lower lobe. Multiple tiny AVMs were identified in the right lower lobe.[8] [9] The feeding artery diameter of a few of the AVMs was >3 mm[10] (Figure 3b). The diagnosis of OWRS was made (Table 1). In view of feeding artery diameter size being >3 mm, the patient was advised to undergo curative embolisation to prevent pulmonary as well as cerebral complications. The preprocedural angiogram (Figure 3c and 3d) showed pulmonary AVMs supplied from the basal segmental arteries. Endovascular glue embolisation of the pulmonary AVMs was performed by administering iohexol contrast using a microcatheter and/or microwire and coils with 50% glue as an embolisation agent mixed with ethiodised oil in various dilution ratios. Post-embolisation angiography (Figure 3e) showed complete exclusion of the AVMs from the circulation.

 

Figure 3. Case 3. (a) Chest radiograph showing multiple homogenous mass lesions (stars) seen in the right lower zone and left upper and lower zones. (b) Reformatted coronal maximum intensity projection image showing multiple arteriovenous malformations (AVMs) involving the antero-basal segment of the right lower lobe, apicoposterior segment of the left upper lobe, and the lateral basal segment of the left lobe (red arrows). Multiple tiny AVMs are seen in the right lower lobes (yellow arrowheads). (c) Pre-procedure digital subtraction angiography image of the right lung showing pulmonary AVM (star) with supply from the basal segmental arteries (blue arrow). (d) The AVM nidus (star) was progressively embolised using micro coils with 60% glue and subsequent opacification was seen. Blue arrow indicates vascular supply to the nidus from the basal segmental arteries. (e) Post-procedure angiogram shows complete exclusion of AVM from circulation (blue arrow).

 

Aetiologically, OWRS has been classified into different types based on the genetic mutations found in these patients. HHT type 1, found in nearly 61% of cases,[8] shows a mutation in the endoglin gene located on chromosome 9 and is found on the inner cell membrane of the endothelial cells lining the blood vessels. Patients with these mutations are generally predisposed to cerebral and pulmonary AVMs.[8] HHT type 2, found in nearly 37% of cases, shows a mutation in the activin A receptor-like type 1 (ACVRL-1) gene or the activin receptor-like kinase-1 (ALK-1) gene located on chromosome 12.[8] [11] These patients have been shown to have liver AVMs.[4] Mutations in the mothers against decapentaplegic homolog 4 (SMAD4) gene,[9] which encodes protein for signal transmission from the transforming growth factor beta receptor, has been implicated in 2% of cases of HHT with juvenile gastrointestinal polyposis.[9] Patients having bone morphogenetic protein-9 (BMPR-9) and RSA-1 gene mutations have also shown phenotypic overlap with telangiectasia.[9]

 

The clinical diagnosis of OWRS is made using the four Curaçao clinical criteria,[1] [2] [3] namely: (1) recurrent epistaxis; (2) telangiectasias involving sites including the lips, oral cavity, nose, and fingers; (3) visceral lesions with the gastrointestinal tract, liver, pulmonary, cerebral or spinal involvement; and (4) family history of HHT in a first-degree relative (Table 1).

 

Recurrent epistaxis is the most common symptom which can begin in childhood or adolescensce.[8] Low-pressure packing techniques can be used to manage such episodes. Telangiectasias affected individuals can present post puberty or in adulthood. It happens when capillaries fail to develop between arterioles and venules, commonly involving the face, lips, tongue, palm, and fingers (periungual and nail bed).[8] Telangiectasias can also develop in the gastrointestinal tract, presenting most commonly in the fourth decade of life with stomach and duodenum being the most common sites.[6] [8] AVMs, which are direct communications between blood vessels having a calibre greater than telangiectatic vessels, are also seen in the patients.[9] [11]

 

Distal emboli containing blood clots or bacteria from pulmonary AVMs may result in abscess formation and ischaemic stroke (Table 2).[4] [8] [11]

 

The brain abscesses are generally multiple and recurrent, and involve the superficial layers of the cerebral lobes, most commonly occurring in the parietal lobe. A higher incidence is seen between the third and the fifth decades of life, corresponding to increased pulmonary AVMs.[4] [11]

 

Cerebral AVMs are seen as serpiginous areas of flow void with invasion into the brain parenchyma on MRI. The feeding artery and the draining veins can be identified on different sections (Figure 2a and 2b). Some patients may have high signal intensity on T1-weighted imaging within the basal nuclei that can be a result of the metabolic disorder caused by hepatic artery-portal venous shunting. In equivocal lesions, cerebral angiography is performed, which may show high flow pial AVFs occurring due to the lack of an intervening capillary bed (Figure 2a and 2b).[1]

 

Cortical developmental malformation is another feature which can be seen in the paediatric population. It involves two main entities: polymicrogyria and heterotopia.[7]

 

Patients with polymicrogyria can present with developmental delay, cognitive abnormalities, and epilepsy (about 78% of cases).[4] Epilepsy shows earlier onset in patients having higher degrees of polymicrogyria.[7] A favourable prognosis is present in patients with unilateral and localised polymicrogyria. The imaging features of polymicrogyria on MRI are smaller gyri with thin, shallow sulci separating them (Figure 2c and 2d). The cortex appears thickened, with an irregular surface and abnormal vasculature in close proximity. It is most commonly seen in the perisylvian region, followed by parietal, parietotemporal, and frontal regions.[7]

 

Heterotopia is an abnormal location of normal neuronal cells due to abnormal migration. The most commonly seen variant in OWRS is the periventricular nodular type. Bilateral occurrence is more common in the frontal lobes.[7]

 

Brain and pulmonary AVMs seem to have a higher incidence in patients with cortical developmental malformations.[7] [8]

 

Pulmonary AVMs are the most striking features of lung involvement, seen in nearly 50% of HHT cases (Table 2).[8] The anatomical structure of AVMs can be simple, with one feeding artery and one draining vein, or complex with ≥ 2 arterial branches and draining veins.[12]

 

Chest radiography shows well-defined nodules within the lung (Figure 3a). Cardiomegaly and prominent pulmonary arteries can also be seen (Table 2).

 

Chest CT with MPR and maximum intensity projections show one or multiple serpiginous masses/nodules with ≥1 enlarged feeding artery (diameter of ≥3 mm) and draining vein (Table 2 and Figure 3b).[10] [12] Contrast-enhanced magnetic resonance angiography can show all pulmonary AVMs with feeding arteries having a diameter >3 mm.[10]

 

The treatment of choice is transarterial pulmonary AVM vaso-occlusion with coils (Table 2).[9]

 

Ultrasound imaging can show an increase in common hepatic artery calibre (>7 mm) and intrahepatic hypervascularity.[6] Doppler imaging shows pulsatile portal flow in cases of arterioportal shunting and pulsatile hepatic venous flow in cases of arteriovenous shunting.[6]

 

Focal nodular hyperplasia and hepatic AVMs are more commonly seen in patients with ALK-1 gene mutation. Increased sinusoidal blood flow leads to portal hypertension, pseudocirrhosis of the liver, and hepatic encephalopathy in later stages.[4] [6]

 

CECT of the abdomen with MPR and maximum intensity projections can show telangiectasias in proximity to large vessels[5] and also in the subcapsular regions. These are seen as focal hyperattenuating rounded nodular lesions in the arterial and late arterial phases, which become isodense with the hepatic parenchyma in the hepatic phase (Figure 1a, 1b, and Tables 2 and 3).[4] [5] [6] MRI shows high signal intensity on T2-weighted imaging and appears hypointense on T1-weighted imaging.

 

On CECT of the abdomen, large confluent masses within the liver (>10 mm) may be seen enhancing in enhancing arterial phase with persistent enhancement in hepatic phase.

 

The differentiating features between HHT and cirrhosis on imaging for hepatic perfusion abnormalities are listed in Table 4.[5]

 

Table 4. Important differentiating points between hereditary haemorrhagic telangiectasia and cirrhosis on radiological imaging.[5]

 

Pancreatic AVMs are the most common extrahepatic AVMs. CT imaging shows focal lesions (diameter: 5-10 mm) with increased vascularity. Arteriovenous shunting to the splenic vein or superior mesenteric vein may be noted.[5] [6]

 

The most common manifestation is telangiectasias, both in the small bowel (around 60%) and the stomach (around 30%). Patients with HHT have an increased incidence of small bowel polyps as compared to the general population.[6] [8] Gastrointestinal haemorrhage is a common presentation, usually seen in the fourth to the fifth decades[6] (Table 2). On colonoscopy, 31% to 32% of OWRS patients show colonic AVMs associated with the HHT1 genotype having the endoglin mutation.[4] SMAD4 mutations in OWRS patients result in juvenile polyposis, which is difficult to differentiate from the juvenile polyposis caused by BMPR1A mutations in the general population. Rarely, OWRS cases show intramural haematomas on endoscopic evaluation.[6] [8] [9]

 

The ocular signs and symptoms include conjunctival telangiectasias or AVMs, bloody tears, conjunctival post-haemorrhagic granulomatous lesions, and the recently described association of choriocapillaris atrophy with HHT. However, retinal involvement prevalence is only around 1%.[3] [9]

 

Embolisation of pulmonary and cerebral AVMs is important to avoid serious complications. Pulmonary AVMs having a feeding artery diameter >3 mm are ideal candidates for embolisation to decrease the risk of pulmonary haemorrhages and paradoxical emboli to the brain.[10] Patients should be advised about the side-effects related to embolotherapy for pulmonary AVMs, such as transient post-procedural chest pain and self-limiting pleurisy. Brain AVMs need treatment to prevent the occurrence of stroke and abscess. Microsurgical resection, stereotactic radiation surgery, and endovascular embolisation can be performed. Embolisation can be pre-microsurgical, pre-radiation surgery, curative, or palliative depending on the patient. Preprocedural CT angiography and antibiotic prophylaxis for the risk of bacteraemia is advised. Digital subtraction angiography is used for the procedure.[13] In our patients, since the AVMs were relatively small with few feeding pedicles and without perinidal angiogenesis, curative embolisation was performed (Table 2).

 

Follow-up is an important step in management of these patients. A baseline post-embolisation scan is performed at 6 months and then repeated at 12 months to ensure sac involution, followed by follow-up intervals of 2 years to detect growth of untreated pulmonary AVMs and reperfusion of treated AVMs.[14] Chest CT or contrast-enhanced MRI are used for follow-up post-coiling to look for reperfusion of occluded pulmonary AVMs.[15] The risk of reperfusion increases with larger feeding artery diameter, using less number of coils, oversized coils, or more proximal placement of the coil within the feeding artery. In such cases, it is increasingly difficult to treat these reperfused AVMs, resulting in higher recurrence rates.[15]

 

AVMs associated with OWRS are ticking time bombs which can result in catastrophic events such as pulmonary haemorrhages, brain abscess, stroke, chronic gastrointestinal bleeds, high-output cardiac failure, paraparesis, and, rarely, paraplegia. Since affected individuals are generally asymptomatic, the lesions are often discovered incidentally. Radiologists must always be on the lookout for such classical findings to not only aid the diagnosis but also lower the risk of complications.