Detection of Hepatocelluar Carcinoma on Triple-Phase Images of Liver Using Multi-Detector Row Helical CT

PURPOSE: To determine whether triple-phase multi-detector-row helical CT images of the liver improves the detection rate of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Forty-one patients with 103 HCCs underwent triple-phase multi-detector-row helical CT imaging of the entire liver after contrast administration. Early and late arterial phase images were obtained serially during a single breath-hold, and portal venous-phase images were then obtained. Each image set was independently assessed for the presence of HCC by two radiologists unaware of the possible presence of tumors, and for each phase the detection rate was determined. For each arterial-phase image, lesion conspicuity (attenuation of a tumor compared with that of its parenchyma) was calculated. RESULTS: For reader 1, the detection rates for the early arterial, late arterial, and portal venous phase were 81%, 77%, and 55%, respectively, and for reader 2 were 83%, 81%, and 68%, respectively (p>0.05). When triplephase imaging findings were combined, the detection rate was significantly higher than when only those of the early or late arterial, and portal venous, phase were used (p0.05). CONCLUSION: Triple-phase imaging of the liver, involving the early arterial, late arterial, and portal venous phase, and using multi-detector-row helical CT, increases the detection rate of HCC.

Assessment of Hepatic Arterial Variation Using Multidetector Helical CT-Angiography

PURPOSE: To evaluate the anatomy of the hepatic artery and normal variants using oblique thick-slab maximal intensity projection (MIP) 3-D CT angiography and multidetector helical CT technology. MATERIALS AND METHODS: In 70 patients, axial three-phase CT together with multidetector helical CT and a non-ionic contrast agent was used to evaluate liver disease. During the early arterial phase, the parameters were as follow: slice thickness, 2.5 mm; table speed, 15 mm/rotation, pitch, 6; contrast material, 4 ml/sec; total 120 ml. Using the MIP technique and an Advantage window voxtal 3.03 system (GE), the images obtained were reconstructed as 3D angiograms. In each case, the arterial anatomy and its variants were recorded. RESULTS: A typical anatomy was found in 53 cases (75.7 %). Common variants were a left hepatic artery arising from the left gastric artery(8 cases, 11.4 %) and a right hepatic artery arising from the superior mesenteric artery(3 cases, 4.3 %). Other variant cases were a right hepatic artery arising from the gastroduodenal artery(2 cases, 2.9%), a proper hepatic artery arising from the left gastric artery (1 case, 1.4%), a hepatomesenteric trunk (1 case), a hepatogastric / splenomesenteric trunk(1 case), and a celiomesenteric trunk (1 case). CONCLUSION: 3-D hepatic angiography using multidetector helical CT technology is non-invasive and as accurate as conventional angiography for the evaluation of hepatic arterial anatomy. It is thus considered that 3-D CT angiography is very helpful for the evaluation of hepatic arterial anatomy prior to liver surgery such as transplantation or the treatment of hepatocellular carcinoma.

Diagnostic Usefulness of the Multimodality Study with Mammography, Ultrasonography,99mTc-MIBI Scan in Breast Cancer

PURPOSE: To assess the diagnostic usefulness of multimodality study in the diagnosis of breast cancer. MATERIALS AND METHODS: Eighty-one patients between January 1998 to December 1999 were involved in this study, and who underwent mammography, breast ultrasonography, and 99mTc-MIBI scintimammography in all cases the findings were retrospectively reviewed. Each modality was graded by two physicians specializing in nuclear medicine and two radiologists, all unaware of the pathologic results. A four-grade system(1=definitely benign, 2=probably benign, 3=probably malignant, 4=definitely malignant) was applied to those ofbreast ultrasonography and 99m Tc-MIBI scintimammography and BIRADS was applied to those ofmammography. All breast masses were confirmed by surgery (n=67) or FNA (n=14). Findings of grade 3 or 4 the four-grade system, BIRADS category 4 or 5, or positive coincidence in double and triple combination studies were defined as positive results, and on the basis of the data thus obtained, the sensitivity, specificity, positive and negative predictive value and diagnostic accuracy were calculated for each modality and for multimodality studies. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of 99mTc-MIBI scintimammography were 83.6%, 88.5%, 93.9%, 71.9% and 85.2%, respectively. For ultrasonography, the corresponding figure were 94.5%, 65.3%, 85.2%, 85.0%, and 85.2%, and these for mammography, they were 87.3%, 69.2%, 87.3%, 81.8% and 80.2%. For the ultrasonography and mammography combination, the figures were 83.6%, 50.0%, 93.9%, 100.0% and 95.2%, respectively, and for 99mTc-MIBI scinti-mammography and mammography, the corresponding findings were 72.7%, 69.2%, 95.2%, 100.0% and 96.7%. For the 99mTc-MIBI scintimammography and ultrasonography combination, respective findings of were 80.0%, 61.5%, 95.7%, 94.1% and 95.2%, respectively, and in the triple modality study, respective findings of 70.9%, 50.0%, 97.5%, 100.0% and 98.1% were recorded. CONCLUSION: Among multimodality studies, sensitivity was greatest in the ultrasonography and mammography combination, which is thus extremely suitable for the diagnosis of breast cancer. The findings of two series suggest that in equivocal cases, 99mTc-MIBI scintimammography with its higher specificity and positive predictive value, is a useful adjunctive tool.