Abstract
BACKGROUND:
Soft tissue vascular malformations are not uncommonly encountered in clinical practice and are often mistaken for other pathologies. Vascular anomalies are divided into vascular tumors and malformations. Vascular malformations progressively increase in size with increasing age and are classified into the low‑flow (venous, lymphatic, venous-lymphatic, capillary, and capillary venous) and high‑flow malformations (arteriovenous malformations (AVM) and arteriovenous fistula (AVF)) depending on the presence or absence of arterial flow. Vascular Malformations belong to the spectrum of orphan diseases and can involve all segments of the vascular tree: arteries, capillaries, and veins, and similarly the lymphatic vasculature. The classification according to the International Society for the Study of Vascular Anomalies (ISSVA) is of major importance to guide proper treatment. Imaging plays a crucial role to classify vascular malformations according to their dominant vessel type, anatomical extension, and flow pattern.
AIM: Aim of this study is to evaluate the Magnetic resonance imaging (MRI) features of the soft tissue vascular malformations and to classify the lesions depending on the flow pattern.
MATERIAL AND METHOD:
The study was an Observational study has been conducted in the Department of Radiology. A total of 50 patients with soft tissue vascular malformations who reported to our hospital. The patients underwent detailed clinical examinations prior to the imaging. All patients underwent MRI on a 1.5 tesla GE MRI scanner. The sequences done included T1WI, T2WI, fat-saturated T2WI, STIR, and gradient recalled echo (GRE) sequences in 3 planes (axial, coronal, and sagittal). Pre-contrast fat-saturated T1W and 3D postcontrast dynamic imaging were done in all cases. The contrast used was Gadoterate Meglumine (0.1 mmol/kg). Specialized coils (head, body, extremity, etc.) were used depending on the part evaluated. Patients with contraindications to MR evaluation were excluded from the study.
RESULTS:
Venous malformations were the most common malformation seen in this study. Of the 30 cases, 18 cases were seen involving the extremities and 12 cases were seen in the head and neck region. The lesions appeared hypointense on T1WI and hyperintense on T2WI, STIR, and fat-saturated T2W sequences. Phleboliths were seen in 13 cases appearing as hypointense foci on T1WI, T2WI, GRE, and post-contrast images. On dynamic postcontrast images, the majority of these lesions showed diffuse contrast enhancement on delayed images. No case of high-flow malformations was imaged in this study. The low-flow malformations included 32 cases of venous malformations, 10 cases of lymphatic malformations, and eight cases of venous-lymphatic malformations.
CONCLUSION:
Soft tissue vascular malformations are not infrequently encountered and are often mistaken for other lesions. Dynamic contrast-enhanced MRI is the modality of choice for classifying the lesions, mapping their entire extent, and helping in deciding the management and in follow-up of the lesions. Special emphasis needs to be laid on the inclusion of the correct sequences during the MR examination. Heavily T2 weighted and STIR sequences are very helpful to detect the extent of the lesions.
KEYWORDS: Dynamic Post Contrast, Magnetic Resonance Imaging and Vascular Malformation