The Significance of Postangiographic CT for Differentiation of Hepatic Masses

PURPOSE: To identify the longterm hemodynamics of various hepatic masses and to determine any differential findings by using postangiographic CT performed with increased amount of contrast media and time than conventional contrast CT. MATERIALS AND METHODS: 50 confirmed masses consisted of 22 hepatocellular carcinoma, 10 cholangiocarcinoma, 9 metastasis, and 9 cavernous hemangioma were included. The changes of the density of internal viable tumor portion relative to surrounding normal liver parenchyma in postangiographic CT from that in conventional CT were classified as 3 patterns; no specific changes, increase, or decrease. RESULTS: in 22 cases of hepatoceilular carcinoma, six cases showed no relative density change, four cases increase, and twelve cases decrease. In ten cases of cholangiocarcinoma, one case showed no change, nine cases increase. In nine cases of metastasis, four cases showed no change, five cases increase. In nine cases of hemangioma, all cases showed increase. CONCLUSION: In postangiographic CT which emphasize the significance of postequilibrium and delayed phase, other hemodynamic changes undetected in angiography could more easily be comprehended. Considering the differing amount of consumed contrast media and time duration, and with reference of other imaging modalities, differential diagnosis of hepatic masses based on longterm hemodynamics could easily be made.

Enhancement Patterns of Hepatic Metastasis from Stomach Cancer at Multi-phase Incremental Bolus Dynamic CT

PURPOSE: The purpose of our study was to characterize the enhancing patterns of hepatic metastasis from gastric adenocarinoma using multi-phase incremental bolus dynamic CT with obtained both in early and late phase contrast scan and to evaluate the its advantages. METHODS AND MATERIALS: Of 33 cases of multi-phase incremental bolus dynamic CT with proved hepatic~metastasis from gastric adenocarinoma, we classified dynamic enhancement patterns as three types according to early phase contrast enhancement, and then analized the late phase contrast enhancement, more metastasis detection, segmental abnormal arterial perfusions and correlation between pathologic type. RESULTS: Type I (totally hypodense lesion) was in 18 patients(55%), type II (peripheral high density area) was seen in 13 patients (39%), and type III (near totally hyperdense lesion) was seen in two patients(6%). But in late phase, masses showed totally hypodense area in 26 patients(79%), central high with peripheral low density area(PLDA) in six patients(18%) and totally isodense in one patient(3%). More metastatic masses were detected with early phase in 11 patients(33%) as compared with late phase contrast. Segmental arterial hyperperfusion around the lesions, which could represent intrahepatic portal branch invasion, was seen in 10 patients(30%). There was no correlation between pathologic type and enhancement pattern of lesions. CONCLUSION: Multi-phase incremental bolus dynamic CT could represent variable hemodynamic changes of hepatic metastatic masses and was useful to evaluate the qualitative and quantitative analysis of hepatic metastases.

Superiority of IV bolus CT in evaluation of metastatic lymphadenopathy in th stomach cancer

Differentiation of lymph node from vessels or bowel wall with similar clearity is often difficult in conventional contrast-enhanced computed tomography (CCCT). For optimal differentiation of these structures, arterial-phase dominent CT images by IV bolus injection and rapid scan were obtained. The images were compared from those by CCCT in evaluation of lymphadenopathy. Seventy patients, diagnosed as stomach cancer by pathology, were selected for this study. There were 14 cases of equivocal lymphadenopathy on CCCT while IV bolus CT revealed lymphadenopathy in 9 of there and no lymphadenopathy in the rest. Among the 38 cores without lymphadenopathy on CCCT, IV bolus CT detected 4 lymphadenopathy. In 30 node dissection cases, when we decided 1cm as CT criterion for lymphatic enlargement, the sensitivity and the specificity that there were lymphatic enlargement in gross of lymphatic infiltration above one fourth in pathology even though no lymphatic enlargement in gross were 100%. On conclusion, IV bolus CT is more helpful method to evaluate lymphadenopathy than CCCT and compatible with pathologic findings when we decide 1cm as CT criterion for lymphadenopathy. In conclusion, IV bolus CT is superior to CCCT in evaluation of metastatic Lymphadenopathy when using CT Criferion of 1cm as the diameter of enlarged lymph node.

Analysis of the result and merit of computed tomography guided percutaneous needle aspiration biopsy of focal lung lesion / 영남의대학술지

Percutaneous needle biopsy of pulmonary lesion with use of fluoroscopic guidance is well estabilished as a diagnostic tool but limited by the small size and inaccessibility of certain lesions. However, percutaneous needle biopsy'has been used increasingly in relation to advance and the salty of smaller biopsy needle and new imaging modalities such as ultrasound and CT. CT, because of its characteristics of high resolution, allows tissue sampling with considerable safty from area that heretofore could not be visualized under fluoroscopy. The authors summarized 44 pulmonary lesions that underwent CT-guided transthoracic biopsy with fine-needle over a 14 month period and analyzed the sensitivity of PTNB. -CT-guided PTNB was done with 20 gauge or 22 gauge Westcott biopoy needle (Mann medical products, USA). A diagnosis was made in 27 of 44 cases (61%) including malignany in 19 of 24 cases and benignancy in 8 of 20 cases. The pulmonary mass lesions were located at the peripheral zone of the lung field in 33 cases and at the central zone in 11 cases. Complications were observed in 2 cases which were pneumothorax and hemoptysis each but specific therapy was not required The sensitivity of PTNB by one session was 61% (27/44). The sensitivity of malignancy was 79% (19/24) and benignancy was 40% (8/20). These results suggest the usefulness of PTNB using fine needles be increased in eariler diagnosis and improved staging of pulmonary nodular lesions without significant complications.

Multiple hepatic adenomatosis: a case report

We expirenced multiple hepatocellular adenomatosis, which was proved by pathology, in 38 years old man who had no prior history of predisposing factors. The radiologic findings were different by the size of tumor mass and intratumoral hemorrhage. Ultrasound demonstrated inhomogeneous hyperechoic large mass in segment 5 of right lobe and hyperechoic or isoechoic multiple small nodules in right lobe. Computed tomography demonstrated low density mass without contrast enhacement. Central high density is noted in hemorrhagic portion. Magnetic resonance T1-weighted image demonstrated high signal intensity in mass and hemorrhagic portion. T2-weighted image demonstrated slightly high signal intensity in mass portion, high signal intensity in hemorrhagic portionand double-layered peripheral rim. Gradient echo image well demonstrated inhomogenesity of mass.

Radiologic findings of mediastinal fibromatosis / 영남의대학술지

The fibromatosis is a rare timorous with local invasion, but is not metastasized distantly. This term should not be applied to nonspecific reactive fibrous proliferations that are part of an inflammatory process of are secondary to injury of hemorrhage and have no tendency toward growth or recurrence. It arises principally from the connective tissue of muscle and overlying fascia or aponeurosis (musculoaponeurotic fibromatosis), and chiefly affects the muscle of shoulder, pelvic girdle, and extremity. The term 'aggressive fibromatosis' is also employed to describe this disease, but it is impossible to predict the clinical course in the individual case. The fibromatosis arising in the mediastinum is very rare, and the report about it is nearly absent. The plain radiography shows merely mass with soft tissue density. The CT demonstrates a poorly defined homogenous or heterogeneous mass, isodense with skeletal muscle on precontrast-images, and slightly hyperdense to muscle on postcontrast-scan. Accurate delineation between the tumor & surrounding tissue is vague or frequently impossible. The authors experienced one case of the mediastinal fibromatosis recently and report the case with review of concerned literature.