[Studies on utility of MR T2-weighted images using multishot echo-planar imaging for hepatic mass lesions]
Department of Radiology, Osaka Medical College.
MR T2-weighted images using multishot echo-planar imaging (EPI) and fast spin-echo (FSE) sequences were obtained in 22 patients with hepatic masses. Multishot EPI sequences included eight-shot breath-hold EPI and 16-shot EPI without breath-hold, while FSE sequences included nonfat-suppressed respiratory-triggered FSE, fat-suppressed respiratory-triggered FSE, and nonfat-suppressed breath-hold FSE. Signal-to-noise ratio, contrast-to-noise ratio and artifacts were compared between EPI and FSE images of 47 hepatic masses. In evaluating solid tumors, EPI provided image quality equal or superior to that of FSE, whereas in the evaluation of nonsolid tumors FSE showed better image quality than EPI. In conclusion, it was demonstrated that in the evaluation of hepatic solid tumors T2-weighted eight-shot breath-hold EPI can replace both nonfat-suppressed respiratory-triggered FSE and breath-hold FSE, and it was suggested that eight-shot breath-hold EPI can replace fat-suppressed respiratory-triggered FSE to reduce patient discomfort and increase examination throughput.
[Placing two parallel catheters by Seldingers approach through the femoral artery for CT angiography and CT during arterioportography: evaluation of efficacy and safety]
Saito K. Goto Y. Wakabayashi Y. Saito T. Abe K.
Department of Radiology, Musashino Red Cross Hospital.
The purpose of this study was to evaluate the efficacy and safety of placing two parallel catheters by Seldinger's approach through the femoral artery for CT angiography (CTA) and CT during arterioportography (CTAP). We performed an analysis of 30 patients. Two introducers were successfully placed in all cases. Only one minor complication was observed, a localized inguinal hematoma. The CTA/CTAP procedures were successful in all patients except six who had anatomical variations of the hepatic arterial supply. Our methods proved to be useful and safe for patients with standard hepatic arterial supply.
[Three-dimensional MR angiography of HCC and portal and hepatic veins using superparamagnetic iron oxide]
Ono Y. Marukawa T. Ashikaga R. Inoue M. Fujii K. Araki Y. Ishida O.
Department of Radiology, Kinki University School of Medicine.
We examined a new MR technique for obtaining 3D-MRA images of the liver that simultaneously depicts HCC and the portal and hepatic veins. Five patients with clinically suspected HCC were studied with superparamagnetic iron oxide (SHU-555A) used as a negative contrast medium for the liver. In our study, a 3D-rotational display was provided on the CTR monitor from 2D-TOF images by computed reconstruction, clearly showing HCC and portal and hepatic veins on the same image. Our method was found to be of great value in planning surgery of the liver.
[Three-dimensional gadolinium-enhanced dynamic MRI of whole liver using spectrally selected enhanced fast gradient recall sequence]
Takahashi S. Kim T. Murakami T. Hori M. Okada A. Nakata S. Tsuda K. Narumi Y. Tomoda K. Oi H. Nakamura H.
Department of Radiology, Osaka University Medical School.
Three-dimensional gadolinium-enhanced dynamic MRI of whole liver using the spectrally selected enhanced fast gradient recall sequence (spec IR-efgre3d) was performed in five patients with HCC. Ten HCC nodules were confirmed by CTA, CTAP and Lipiodol CT, and all of them were detected with dynamic MRI. MIP images reconstructed from 3D gadolinium-enhanced dynamic MR studies clearly showed the main portal vein and its branches in all cases. Portal vein thrombosis was also demonstrated with the MIP images.
[Gd-DTPA enhanced multi-shot echo-planar MRI: improvement of contrast between metastatic liver cancer and liver parenchyma]
Kim T. Murakami T. Takahashi S. Okada A. Hori M. Nobuhiro M. Tomoda K. Narumi Y. Oi H. Nakamura H.
Department of Radiology, Osaka University School of Medicine.
In six patients with metastatic liver cancer, spin-echo multi-shot echo-planar MR imaging 8/2000/80/1 (shot/TR/TE/excitation) of the liver was performed before and 30, 60, 90 and 120 sec after the intravenous injection of Gd-DTPA. Signal-to-noise ratios (SNR) of the liver tumor and liver parenchyma were measured in each phase. The contrast-to-noise ratios (CNR) between the tumor and liver parenchyma were also calculated. While the SNR of the tumor did not change after the injection of Gd-DTPA, the SNR of the liver parenchyma decreased and the CNR between the tumor and liver parenchyma increased.
[Prognosis of residual spleen after partial splenic embolization for the treatment of hypersplenism in cirrhosis]
Iida T. Sakino I. Akagi K.
Department of Radiology, Saiseikai Yahata General Hospital.
The aim of this study was to elusidate the change in residual spleen volume after partial splenic embolization (PSE) in 43 cirrhotic patients with marked hypersplenism. Residual spleen volume was indicated as the rate (%) of residual spleen to initial spleen before PSE. Furthermore, the platelet count after PSE was observed in 23 patients followed up for 2 years. Residual spleen volume in patients with infarction rates of more than 80% (group A) had been maintained within 20 % even after 2 years, while they had obviously increased during the early stage after PSE in patients with infarction rates under 80% (group B), especially in patients with lower infarction rates (under 60%). Mean platelet count improved significantly in both groups after PSE (p < 0.001, respectively), but increased more in group A than in group B (p < 0.01). High fever and abdominal pain were observed in all cases of PSE. Other adverse effects such as pleural effusion and ascites that were frequent in group A were transient. These results suggest that PSE performed with a high infarction rate of the spleen provides effective, long-lasting results in the treatment of hypersplenism in cirrhosis.
[Arterial redistribution of extrahepatic collaterals to the liver under temporary balloon occlusion of the proper hepatic artery]
Takeuchi Y. Arai Y. Inaba Y. Ohno K. Maeda T. Itai Y.
Department of Diagnostic Radiology, Aichi Cancer Center.
Three patients with liver metastases receiving transarterial chemotherapy underwent embolization of extrahepatic collaterals to the liver under temporary balloon occlusion of the proper hepatic artery. Enhancement in the liver and tumors was observed at CT arteriography through the right inferior phrenic artery and was accentuated under balloon occlusion in all patients. A Cyanoacrylate-Lipiodol mixture was infused through the right inferior phrenic artery to occlude arterial communications with intrahepatic arteries. Better contrast agent distribution was obtained in all patients after embolization. It is suggested that this procedure can be effective for arterial redistribution against extrahepatic collaterals to the liver.
[Detection of recurrent rectal cancer using helical CT with SmartPrep: a new technique for obtaining optimal contrast enhancement]
Tanaka J. Tsukuda S. Amanuma M. Nishi N. Negishi C. Kozawa E. Yuasa M. Heshiki A.
Department of Radiology, Saitama Medical School.
Seven patients with suspected recurrent rectal cancer underwent Helical CT using SmartPrep. SmartPrep is a software application developed by GE in which the ROI is placed at the desired level of the aorta prior to contrast injection. Using a low-dose continuous scan, the time density curve was obtained instantly, and the optimal timing of scanning was judged from the curve. Four patients who demonstrated intense enhancement at the anastomotic site had local recurrence. No intense enhancement was observed in these areas on conventional delayed CT. Thus, SmartPrep appears to be useful for the accurate diagnosis of recurrent rectal cancer.