Type:
Educational Exhibit
Keywords:
Musculoskeletal soft tissue, MR, Computer Applications-3D, Fistula
Authors:
A. Nobre, M. Wagels, E. McMeniman, T. Lloyd
DOI:
10.26044/ranzcr2022/R-0064
Imaging findings OR Procedure details
Three complex HS cases demonstrating extent of the disease, associated complications, and manifestations of HS on MRI, have been selected by a musculoskeletal radiologist, dermatologist, and plastic surgeon at a large tertiary hospital in Australia. The extent of disease can often be underestimated both clinically and radiologically and these annotated cases will demonstrate the complex and interconnected nature of the subcutaneous fistulas that characterise the severe end of the disease spectrum. Imaging findings will be displayed with reference to the clinical Hurley staging system. [4] These image findings include, but are not limited blind ending sinus tracts and extensive ramifying fistulating disease.
Additionally, these cases will demonstrate the utility of 3D rendering and modelling of these cases using a commercially available 3D segmentation program commonly used for 3D printing applications. Currently, on demand 3D virtual models are being presented at tertiary level HS multidisciplinary team meetings for perioperative planning and to measure disease progression. This exciting development opens the opportunity for further research, clinical collaboration, and integration of complex imaging into wider clinical practice.
Colour Key of 3D segmentations
- Yellow: fistula, cyan: chronically inflamed tissue, purple: anus, red: sciatic nerve, pink/tan: outer skin
Case 1:
38-year-old male– Hurley Stage 3 Hidradenitis Suppurativa.
3D-Segmentation created to guide surgical deroofing
MRI
- 3T MRI, Gadolinium contrast
- Tunnelling fistulous disease seen ramifying across both buttocks within the subcutaneous tissue planes.
- Right: Tunnelling fistulous disease from right buttocks to ischial tuberosity and sacrum. Close proximity to sciatic nerve.
- Left: Deep extension to ischial anal fossae with disease seen tracking anterior to perineum on both sides of midline
3D segmentation of Axial T2 Fat saturation sequence
Case 2:
30-year-old male who presented with Hurley Stage 3 Hidradenitis Suppurativa. 3D-Segmentation created to guide surgical deroofing
MRI
- MRI parameters: 3T MRI, Gadolinium contrast
- Large bilateral fistulous disease extending from bilateral buttocks anteriorly with the involvement of medial thighs. Multiple fistulous tracts demonstrated.
3D segmentation of Coronal T2 Fat saturation sequence
Case 3:
57-year-old male with Hurley Stage 3 Hidradenitis Suppurativa.
3D-Segmentation created to guide surgical deroofing
MRI
- MRI parameters: 3T, Gadolinium contrast
- Peroneal disease - Multiple ramifying fistulous involving the perineum and around the external and opening of the medial folds of the buttocks.
- There is a second area of cutaneous and subcutaneous chronic disease tissue which extends laterally over the right buttock.
3D segmentation of Axial T2 Fat saturation sequence