Yoshimitsu Ohgiya MD, Presenter: Nothing to Disclose

Toshi Hashimoto MD, Abstract Co-Author: Nothing to Disclose

Takehiko Gokan MD, Abstract Co-Author: Nothing to Disclose

Masaki Oka, Abstract Co-Author: Nothing to Disclose

Sven Ekholm MD, Abstract Co-Author: Nothing to Disclose

Per-Lennart Alwe Westesson MD, PhD, Abstract Co-Author: Nothing to Disclose

To establish MR imaging features that may distinguish hemangiomas from high-flow and low-flow vascular malformations (VMs).

Twentyseven patients with peripheral vascular anomalies (5 hemangiomas, 6 high-flow VMs and 16 low-flow VMs) underwent conventional and dynamic MR imaging. The temporal resolution of the dynamic MR imaging was 5 sec. Enhancement was calculated by the formula: percentage enhancement = (signal intensity after enhancement – signal intensity before enhancement)/ signal intensity before enhancement ×100. Time intervals between onset of enhancement of the lesion and the maximal percentage enhancement of the lesion were measured and was defined as contrast rise time. Lesions were assessed for presence of flow voids, phleboliths and skin involvement on conventional MR images. Margins, internal homogeneity and signal intensity on T2-weighted images were compared on conventional MR images.

The mean contrast rise time for hemangiomas was 6.0 sec (range 0-10 sec). The mean contrast rise time for high-flow VMs was 4.2 sec (range 0-5 sec). The mean contrast rise time for low-flow VMs was 83.3 sec (range 50-105 sec). The mean contrast rise time for low-flow VMs was significantly longer than those for hemangiomas and high-flow VMs (Scheffe; P<0.01). There was no significant difference between hemangiomas and high-flow VMs. When compared with high-flow VMs, a significantly greater proportion of hemangiomas consisted of a defined margin (Scheffe; P<0.01), but they did not differ in internal homogeneity and signal intensity on T2-weighted images. Flow voids were observed in 1 hemangioma and 3 high-flow VMs. Phleboliths were seen in 4 low-flow VMs. Involved skin was noted in 4 high-flow VMs and 3 low-flow VMs.

The long contrast rise time separates low-flow VMs from the other lesions. The presence of defined margins and absence of skin involvement is suggestive of a hemangioma when compared with VMs.

To establish MR imaging features that may distinguish hemangiomas from high-flow and low-flow vascular malformations (VMs).

Twentyseven patients with peripheral vascular anomalies (5 hemangiomas, 6 high-flow VMs and 16 low-flow VMs) underwent conventional and dynamic MR imaging. The temporal resolution of the dynamic MR imaging was 5 sec. Enhancement was calculated by the formula: percentage enhancement = (signal intensity after enhancement – signal intensity before enhancement)/ signal intensity before enhancement ×100. Time intervals between onset of enhancement of the lesion and the maximal percentage enhancement of the lesion were measured and was defined as contrast rise time. Lesions were assessed for presence of flow voids, phleboliths and skin involvement on conventional MR images. Margins, internal homogeneity and signal intensity on T2-weighted images were compared on conventional MR images.

The mean contrast rise time for hemangiomas was 6.0 sec (range 0-10 sec). The mean contrast rise time for high-flow VMs was 4.2 sec (range 0-5 sec). The mean contrast rise time for low-flow VMs was 83.3 sec (range 50-105 sec). The mean contrast rise time for low-flow VMs was significantly longer than those for hemangiomas and high-flow VMs (Scheffe; P<0.01). There was no significant difference between hemangiomas and high-flow VMs. When compared with high-flow VMs, a significantly greater proportion of hemangiomas consisted of a defined margin (Scheffe; P<0.01), but they did not differ in internal homogeneity and signal intensity on T2-weighted images. Flow voids were observed in 1 hemangioma and 3 high-flow VMs. Phleboliths were seen in 4 low-flow VMs. Involved skin was noted in 4 high-flow VMs and 3 low-flow VMs.

The long contrast rise time separates low-flow VMs from the other lesions. The presence of defined margins and absence of skin involvement is suggestive of a hemangioma when compared with VMs.

Ohgiya, Y, Hashimoto, T, Gokan, T, Oka, M, Ekholm, S, Westesson, P, Peripheral Vascular Malformations and Hemangiomas: Value of Dynamic MR Imaging for Diagnosis.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4415164.html