Miyuki Torashima

Liver parenchymal changes after transcatheter arterial embolization therapy for hepatoma: CT evaluation

We retrospectively reviewed computed tomographic (CT) findings of 118 patients with hepatoma who received sequential follow-up CT after transcatheter arterial embolization (TAE). Thirty-five patients received TAE using Gelfoam particles with cisplatin, 37 patients using Gelfoam particles and iodized oil (Lipiodol) with cisplatin, and 46 patients using iodized oil with cisplatin. Liver atrophy was observed in 33 patients, lobarly or focally, depending on the embolized area. It was frequently associated with portal vein occlusion by the tumor, usage of iodized oil, and repeated embolization therapy. The lobar atrophy was seen in patients who had portal vein occlusion and/or received repeated embolization therapy. The focal atrophy was observed in patients who were administered iodized oil. Infarction developed in four patients who had a thrombus in the portal vein and received peripheral embolization therapy using iodized oil. We conclude that liver parenchymal changes occur frequently in patients who have portal vein occlusion and/or receive peripheral embolization using iodized oil.

Characterization of Sonographically Indeterminate Ovarian Tumors with MR Imaging A logistic regression analysis

Purpose: The goal of this study was to maximize the discrimination between benign and malignant masses in patients with sonographically indeterminate ovarian lesions by means of unenhanced and contrast-enhanced MR imaging, and to develop a computer-assisted diagnosis system. Material and Methods: Findings in precontrast and Gd-DTPA contrast-enhanced MR images of 104 patients with 115 sonographically indeterminate ovarian masses were analyzed, and the results were correlated with histopathological findings. of 115 lesions, 65 were benign (23 cystadenomas, 13 complex cysts, 11 teratomas, 6 fibro-thecomas, 12 others) and 50 were malignant (32 ovarian carcinomas, 7 metastatic tumors of the ovary, 4 carcinomas of the fallopian tubes, 7 others). A logistic regression analysis was performed to discriminate between benign and malignant lesions, and a model of a computer-assisted diagnosis was developed. This model was pro-spectively tested in 75 cases of ovarian tumors found at other institutions. Results: From the univariate analysis, the following parameters were selected as significant for predicting malignancy (p<0.05): a solid or cystic mass with a large solid component or wall thickness greater than 3 mm; complex internal architecture; ascites; and bilaterality. Based on these parameters, a model of a computer-assisted diagnosis system was developed with the logistic regression analysis. To distinguish benign from malignant lesions, the maximum cut-off point was obtained between 0.47 and 0.51. In a prospective application of this model, 87% of the lesions were accurately identified as benign or malignant. Conclusion: Benign and malignant ovarian lesions can be distinguished in most sonographically indeterminate lesions by means of parameters obtained from contrast-enhanced MR imaging.

MR imaging of atypical polypoid adenomyoma

The magnetic resonance (MR) appearances of three cases of atypical polypoid adenomyoma are reported. The signal intensity of the tumor was similar to that of adenomyosis on T2-weighted MR Imaging (MRI). On contrast-enhanced study, irregular enhancement was seen in hyperintense areas on T2-weighted images. Atypical polypoid adenomyoma can be characterized as a hypointense polypoid mass with hyperintense foci on T2-weighted MR images, resembling the appearance of adenomyosis.

Contrast-Enhanced Dynamic MR Imaging of Postmolar Gestational Trophoblastic Disease

Conventional spin-echo (SE) and contrast-enhanced dynamic MR imaging were performed on a 1.5 T superconductive unit for evaluation of myometrial lesions in postmolar gestational trophoblastic disease (GTD) in 10 women. MR imaging was done at the time of the initial examination (n=10), during (n=6), and after repeated courses of chemotherapy (n=10). The T2-weighted SE image revealed an enlarged uterus (n=7), disappearance of zonal anatomy (n=6), and heterogeneous signal intensities (n=8) with prominent flow voids (n=7). However, these abnormalities remained after repeated courses of chemotherapy, when the S-β-HCG level returned to the normal range. Myometrial lesions characteristically had marked enhancement with areas of unenhancement on dynamic MR images in patients with highly elevated S-β-HCG. Areas of contrast enhancement correlated with changes in S-β-HCG level. The enhancement was reduced with decrease in S-β-HCG level after repeated courses of chemotherapy. Six of 8 masses seen on T2-weighted images proved to be active trophoblastic lesions and 2 masses proved to be hematoma or necrosis. In 2 patients, abnormal myometrial lesions were detected only on contrast-enhanced dynamic MR imaging. These preliminary data indicate that contrast-enhanced dynamic MR imaging more clearly demonstrates myometrial involvement of postmolar GTD than conventional SE imaging.

Unruptured interstitial pregnancy: A pitfall of MR imaging

We report two cases with interstitial pregnancy, which showed completely different MR appearances. In case 1, a gestational sac was demonstrated and the diagnosis of ectopic pregnancy was straightforward. In case 2, a hypervascular mass was shown without demonstration of a gestational sac, the findings usually seen in gestational trophoblastic disease (GTD). MR imaging may play some role in the diagnosis of interstitial pregnancy when sonography is insufficient or equivocal. If GS is visualized, diagnosis is easy. However, if not, the appearance may have a spectrum and can be similar to GTD.

Invasive adenocarcinoma of the uterine cervix: MR imaging

The detection of adenocarcinoma of the cervix is difficult in clinical examination, leading to poor prognoses. We evaluated MR appearances of 23 patients with adenocarcinoma of the cervix and appearances of 65 patients with cervical SCCs were also evaluated for comparison. Both T2-weighted spin echo, dynamic and postcontrast Gd-DTPA enhanced techniques were obtained at a 1.5 Tesla MR unit. The results of our study showed that adenocarcinoma of the cervix have MR imaging features which may permit distinction from SCCs which include: large tumors with preservation of endocervical epithelium, lesser contrast enhancement, and greater enhancement of the tumor periphery. Understaging may be more problematic with adenocarcinoma than SCC.