Assessment of Focal Liver Lesions with 4-Phase Dynamic FLASH MR Imaging: Usefulness of Early Image Acquisitionfor Characterization of Arterial Phase

PURPOSE: To document the usefulness of early image acquisition using the contrast-enhanced dynacic MR imagingfor characterization of various focal hepatic lesions during the arterial phase. MATERIALS AND METHODS:Seventy-nine patients with 145 focal liver lesions (71 hemangiomas, 59 hepatocellular carcinomas and 15metastases) underwent breathhold dynamic MR imaging using a fast low-angle shot sequence. After obtainingunenhanced T1-weighted images, four phase MR images were obtained 10, 35, 60 and 300 seconds after starting theinjection. Patterns of contrast enhancement were analyzed for each lesion, with an emphasis on first phase images. RESULTS: Forty-two of the 59 HCCs (71%) showed prominent contrast enhancement during the first phase. HCCssmaller than 2cm in diameter showed a more homogeneous enhancement pattern than those which measured 2cm ormore(24/25 vs 12/17;P<.05). Hemangiomas showed a globular enhancement pattern during the same phase in 51 of 71cases (72%), a finding which was more apparent in those whose diameter was 2cm or more(35/54 vs 16/17, p<.05).During the first phase of imaging, 12 of the 15 metastases showed peripheral enhancement of their thick rim. CONCLUSION: The use of early image acquisition on dynamic MR sequences is helpful in character-izing lesionsaccrding to their pattern of contrast enhancement.

Radiologic Findings of Lobular Carcinoma of the Breast

PURPOSE: To analyze and characterize the radiologic findings of lobular carcinoma of the breast, a carcinoma which is very rare in Korea. MATERIALS AND METHODS: Twelve patients with pathologically proven lobular carcinoma were included in this study. Mammography was performed in all patients and ultrasonography in six. Clinical manifestations, mammographic findings and ultrasonographic findings were retrospectively analysed. RESULTS: Mean age of the patients was 45.9 years and the most common clinical manifestation was palpable breast mass (9/12). Radiologic findings of lobular carcinoma were spiculation (11/12), mass density (8/12), asymmetric vessel (6/12), and microcalcifications (6/12). Ultrasonography showed intermediate or lower echoic mass (4/6). Posterior enhancements and shadowings were noted in the same proportion. Breast MRI in two patients showed mass lesion with rapid strong enhancement at 1 minute after contrast injection on dynamic study. Tumor stages were stage II (6/12) followed by stage I (3/12), and most advanced case was stage IIIb. CONCLUSION: On mammogram, the most common finding of lobular carcinoma of the breast was spiculation, and calcifications showed more frequently than in other reports. Ultrasound study showed ellipsoid mass with transverse long axis. Internal echogenicity and posterior sonic enhancement or shadowing of the mass were not characteristic of the tumor.