Magnetic resonance imaging study is a useful diagnostic tool, when a discrete pulmonary nodule demonstrates neither fat nor calcification on CT, for detecting the quite typical cleftlike structure in a pulmonary hamartoma and could provide diagnostic confidence.

Steatocystoma multiplex is manifest by multiple clinically palpable skin-colored or yellow nodules scattered on the axillae and the anterior chest wall. Steatocystoma multiplex is included in the differential diagnoses of lipoma, fat necrosis, galactocele, epidermal cyst, and so on, so radiologists need to be aware of its distinguishing features. The findings of a well-circumscribed round fat-density nodule on mammography or an intradermal hypoechoic nodule on sonography, combined with a family history of steatocystoma multiplex (40%) and an extensive bilateral spatial distribution of nodules, confirm the diagnosis of steatocystoma multiplex.

ObjectiveTo investigate the relationships between the apparent diffusion coefficients (ADCs) on diffusion-weighted imaging (DWI) and the speed of contrast-enhancement in hepatic hemangiomas.Materials and MethodsSixty-nine hepatic hemangiomas (≥ 1 cm) were evaluated with DWI, by using multiple b values (b = 50, 400, 800 s/mm2), followed by a gadolinium-enhanced dynamic MRI. The lesions were classified into three groups, according to the speed of contrast-enhancement on the portal phase. ADCs were measured on the ADC map automatically, and were calculated by using the two different b values (mADC50-400 with b values = 50 and 400; mADC400-800 with b values = 400 and 800 s/mm2).ResultsThe mean ADCs (× 10-3 mm2/s) were significantly higher in the rapid group (1.9 ± 0.44) than in the intermediate (1.7 ± 0.35, p = 0.046) or the slow groups (1.4 ± 0.34, p = 0.002). There were significant differences between the rapid and the slow groups in mADC50-400 (2.12 vs. 1.48; p = 0.008) and mADC400-800 (1.68 vs. 1.22, p = 0.010), and between the rapid and the intermediate groups in mADC50-400 (2.12 vs. 1.79, p = 0.049). Comparing mADC50-400 with mADC400-800, there was a significant difference only in the rapid group (p = 0.001).ConclusionHigher ADCs of rapidly-enhancing hemangiomas may be related to richer intralesional vascular perfusion. Also, the restricted diffusion may be attributed to the difference of structural characteristics of hemangioma.