2015 HSC Section 1 Book of Articles

A. Tekes et al. / Clinical Radiology 69 (2014) 443 e 457

Figure 13 (a) A 4-year-old female patient with extensive blueness to her left leg and buttock region. She had no leg length discrepancy on measurement. (b e c) Coronal T2-weighted image shows extensive VM in fi ltrating the muscle groups in the left lower extremity and buttock. Note in fi ltration in the skin. (d) DCE-MRA shows enhancement of the VM in the venous phase.

US of VMs demonstrate a sponge-like network of tubular structures with low velocity or no venous fl ow. The vessels are easily compressible with the US probe. MRI is the best imaging method to de fi ne the full anatomical extent of VMs. 31 VMs are serpiginous T2 hyperintense lesions, which often show phleboliths. Hae- morrhage, thrombosis, or phleboliths may reveal variable degree of pre-contrast high T1 hyperintensity. Some degree of fat tissue or muscle tissue may be observed interspersed between the venous channels. Spontaneous thrombosis and thrombolysis can occur with VMs, which results in elevated D -dimer levels ( > 0.5 m g/ml) in approximately 42% of pa- tients. D -dimer levels are often very high even in otherwise healthy patients. 32 Phleboliths are often observed (round/ oval shaped T2 hypointense foci) representing calci fi cation within the veins. DCE-MRA demonstrates enhancement in the venous phase that may be progressive in nature, typical for VMs ( Figs 1 and 6 ). 33 Lymphatic malformation Lymphatic malformations (LMs) are soft, compressible lesions of lymphatic origin ( Figs 1 and 7 ). These have also been referred to as cystic hygromas or lymphangiomas, but

these terms are confusing and should be avoided. LMs are collections of cystic spaces fi lled with chylous material. 34 These cystic spaces may be macrocystic, microcystic, or mixed. Microcystic LMs are not as compressible as macro- cystic LMs. The microcysts may be so small that they are indistinguishable on cross-sectional imaging. US evaluation shows no fl ow within the major spaces, although small arteries and veins can traverse the intersti- tial spaces. MRI appearance can be variable on T1-weighted imaging for LMs depending on internal haemorrhage and in fl ammation, but usually of high signal on T2 weighting and shows mild peripheral enhancement with no internal enhancement with gadolinium. Diffuse microcystic LM may result in mild diffuse enhancement of the cyst walls and may be challenging diagnosis for the radiologist. Capillary malformation Capillary malformations (CMs) are commonly known as “ port wine stains ” as well as nevus fl ammeus and can be confused with IH. They are typically red or pink in infancy and may darken with age. They grow in proportion with the patient and do not resolve spontaneously. CMs in certain locations can be associated with other abnormalities. For

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