Inflammatory Pseudotumor of the Liver: CT Findings

PURPOSE: To evaluate the CT features of inflammatory pseudotumor of the liver with histopathologiccorrelation. MATERIALS AND METHODS: The CT features of 14 cases (ten patients) with pathologically proveninflammatory hepatic pseudotumor were retrospectively analyzed and correlated with resected and biopsy specimens. RESULTS: The size of lesions ranged between 2.0 and 7.0cm (mean, 3.7cm); On unenhanced CT, the masses were seenas ill-defined hypodense lesions, while on contrast-enhanced CT they were heterogeneous and multiseptated, withenhancement of internal septa and peripheral wall (n=10). In four lesions, central low density and peripheralhomogeneous enhancement were seen. On histopathological correlation, the central hypoattenuated area correspondedto chronic inflammalory cell infiltrates with foamy histiocytes, plasmacytes, and lymphocytes, while thehyperattenuated peripheral wall and internal septa represented dense fibrosis. CONCLUSION: In patients in whon CTshows a heterogeneous enhancing mass, inflammatory pseudotumor of the liver should be included in differentialdiagnosis.

Biodistribution and Scintigraphy of Iodine-131-Iododeoxyadenosine in Rats Bearing Breast Cancer / 대한핵의학회잡지

PURPOSE: I-131 labeled (2'-deoxy-2-iodo-p-D-arabinofuranosyl) adenine (IAD) may be involved in DNA synthesis during active proliferation of tumor cells. We conducted this study to find out the biodistribution of IAD and its feasibility for scintigraphic tumor imaging. MATERIALS AND METHODS: Tosyl acetyl-adenosine was dissolved in acetonitrile, and I-131-NaI was added and heated to synthesize IAD. Female Fisher 344 rats innoculated with breast tumor cells were injected witb 0.27 MBq of IAD. Rats were sacrificed at 0.5, 1, 2, 4, 24h and the % of injected dose per gram of tissue (%ID/g) was determined. For scintigraphy, rats bearing breast cancer were administered with 1.11 MBq of IAD and imaging was perforrned after 2 and 24h. Then, rat body was fixed and rnicrotomized slice was placed on radiographic film for autoradiography, RESULTS: %ID/g of tumor wa.' 0.74 (0.5h), 0.73 (1h), 0.55 (2h), 0.38 (4h), and 0.05 (24h), respectively. At 1h after injection, %ID/g of tumor was higher than that of heart (0.34), liver (0.42), spleen (0.47), kidney (0,69), muscle (0.14), bone (0.33) and intestine (0.51). However, %1D/g of tumor was lower than blood (1.06), lung (0.77), and thyroid (177.71). At 4h, %ID/g of tumor in comparison with other tissue did not change. Tumor contrast expressed by tumor to blood ratio was 0.69 and tumor to muscle ratio was 5.11 at 1h. However, these ratios did not improve through 24h. On autoradiogram and scintigraphy at 2 and 24 hour, the tumor was well visualized. CONCLUSION: This results suggest that Ial) may have a potential for tumor scintigraphy. However, further work is needed to improve localization in tumor tissue.

MR Imaging of the Denvervated Skeletal Muscles in Rabbits

PURPOSE: To determine the time of magnetic resonance(MR) signal intensity changes in denervated skeletal muscle and to compare MR imaging with electromyography(EMG) in the evaluation of peripheral nerve injury. MATERIALS AND METHODS: We evaluated MR imagings of denervated muscles after experimental transection of the sciatic nerve in five rabbits using 1.0T MR unit. MR imaging and EMG were performed 3 days and 1, 2 and 3 weeks after denervation. T1-weighted images(T1-WI), T2-WI and Short Tau Inversion Recovery(STIR) images were obtained. The signal intensity (SI) of muscles in the denervated and normal sides were visually and quantitatively compared. After measuring the SI of the normal and abnormal areas, the time of SI change was determined when there was significant difference (P<0.05) of SI between the normal and denervated sides. RESULTS: On STIR images, two of the five rabbits showed significant SI changes at the third day(P<0.05) and all showed significant changes(P<0.05)at the first week. On T2-WI, one rabbit showed significant SI changes at the third day, and all showed significant SI changes at the first week. On T1-WI, significant SI changes were seen in one rabbit at the second week and in one at the third. One week after denervation, all showed denervation potential on EMG. CONCLUSION: This study suggests that MR imaging using STIR images is a useful method in the evaluation of denervated muscle, and that MR signal changes of denervated muscle may precede EMG changes after denervation. To localize and to determine the severity of the peripheral nerve injury, future analysis of the distribution of abnormal MR SI in denervated muscles would be helpful.