Nihon Igaku Hoshasen Gakkai zasshi. Nippon acta radiologica最新文献

Purpose: To evaluate the usefulness of diffusion-weighted MRI in distinguishing different components and in differentiating benign from malignant musculoskeletal tumors.

Materials and methods: Fifty-seven patients with musculoskeletal tumors underwent MR at our institution from October 1999 to April 2002. We evaluated 57 tumors (9 bone tumors and 48 soft tissue tumors). All tumors were classified into 8 groups (myxomatous, fibrous, cystic, cartilaginous, fatty components, hematomas, other benign tumors, and other malignant tumors). MR examinations were performed with a 1.5-Tesla system. Diffusion-weighted single-shot EPI images were obtained in all patients. Apparent diffusion coefficients (ADCs) were calculated by using b factors of 0 and 1,000 sec/mm2.

Results: ADC values of myxomatous, cystic, and cartilaginous components were significantly higher than those of other tumors. In cartilaginous tumors, malignant tumor ADC values (2.33 +/- 0.44) were higher than those of benign tumors (2.13 +/- 0.13). However, there was no significant difference between benign and malignant tumors. Except for high-intensity components on T1-weighted imaging and low or homogeneously very high intensity components on T2-weighted imaging, there was a significant difference in ADC between malignant (1.35 +/- 0.40) and benign (1.97 +/- 0.50) tumors.

Conclusion: Within the limited number of cases, there was a significant difference in ADC between malignant and benign tumors.

Purpose: The purpose of this study was to assess the benefits of stereotactic vacuum-assisted breast biopsy in patients with non-palpable microcalcification detected on mammography.

Methods: Between October 2001 and November 2003, stereotactic Mammotome biopsies were performed for 150 microcalcified lesions on mammography using the prone-type stereotactic vacuum-assisted breast biopsy system (Mammotest and Mammovision, Fischer, Denver, USA) . The mammography findings were classified according to the guidelines of The Japan Radiological Society/The Japan Association of Radiological Technologists. Ninety-eight cases were category 3, 38 were category 4, and 14 were category 5.

Results: All cases were determined to be cases of microcalcification by specimen radiography or histology. Complications were negligible. One hundred twenty of the cases were mastopathy, and 30 of them were breast cancer (14 were ductal carcinoma in situ, 7 were ductal carcinoma in situ with microinvasion, and 9 were invasive ductal carcinoma). Twenty-seven breast cancers were diagnosed as category 4 or 5 (51.9%) on mammography. The operative stages of 27 cases were as follows: 7 were stage 0, 17 were stage 1, and 3 were stage 2A. Twenty-four of 27 (88.9%) were early breast cancers.

Conclusion: Mammotome biopsy is a safe and useful modality for the histological diagnosis of non-palpable microcalcifications.

Purpose: To evaluate the efficacy of the saline flush technique for abdominal multidetector-row computed tomography (CT).

Methods: As a clinical study, 147 patients with chronic hepatic disease were divided into two groups: group A, given 100 cc of contrast material flushed with 50 cc of saline; and group B, given 100 cc of contrast material only. The difference in attenuation values between groups A and B, and cirrhotic liver and non-cirrhotic liver were evaluated. As an in-vitro experimental study, time vs. peak pressure curve was obtained changing injection devices.

Results: Group B showed a greater contrast enhancement effect in the early arterial equilibrium phase of the aorta and late arterial phase of the liver. In cirrhotic liver, the aorta showed greater contrast enhancement in the early arterial phase in group A. Attenuation values of hypervascular hepatic nodules showed no statistically significant difference between groups A and B. Time to reach peak pressure was prolonged when using saline flush devices in vitro. Flow of contrast material from the contrast material cylinder to the saline cylinder was also discovered.

Conclusion: Saline flush causes peak arterial contrast to be strong for a short duration. Abdominal organ attenuation values are not necessarily increased in the saline flush method. It is important to know that contrast enhancement is dependent on the injection device.

We developed a system for teleradiology using exclusive fiber optics for transferring images formatted in uncompressed DICOM. This system was built up with commercially available machines and software provided from various companies. We are now operating the system with five remote hospitals and have had one year of experience. The current system took advantage of the security and transfer efficiency of exclusive fiber optics. Uncompressed DICOM images were useful for the identification of cases and user-friendly for viewing. The reading room is located in our university hospital, and the location is convenient for consultation and discussion of cases.

Coronary revascularization with PTCA or by means of CABG surgery is frequently used in the care of patients with ischemic heart disease. Before revascularization is performed, stress myocardial perfusion imaging may assist in management decisions by demonstrating the presence of myocardial ischemia and viability, and delineating the severity and extent of coronary artery disease. The presence of myocardial ischemia may provide an indication for revascularization, even in asymptomatic persons. The significance of equivocal lesions may be determined and the culprit vessel may be successfully defined by this radionuclide technique. Recently, the quantitative estimation of myocardial flow reserve with N-13 ammonia PET and the precise detection of myocardial viability with F-18 FDG PET have been introduced to support the limitations of conventional SPECT imaging. After revascularization, these radionuclide techniques are useful to demonstrate improvement of myocardial perfusion or flow reserve, and are also very important to determine restenosis after PCI and graft disease after CABG surgery.

Purpose: The purpose of this study was to determine the findings of MR arthrography of the shoulder and to assess the role of MR arthrography in the diagnosis of superior labrum anterior to posterior (SLAP) lesion type V.

Methods and materials: Two radiologists retrospectively reviewed fat-suppressed T1-weighted MR arthrography images of six patients who were diagnosed with SLAP lesion type V by arthroscopy. Each imaging plane, including the transverse, oblique coronal, oblique sagittal, and oblique transverse in abductor external rotation (ABER) position were evaluated for the following three findings: tear of the superior labrum at biceps tendon insertion, Bankart lesion, and continuity of the two former findings.

Results: Tear of the superior labrum was shown in all patients on oblique coronal images. Bankart lesion was noted in five patients on the transverse images and in four on the oblique sagittal images. On the oblique transverse images in ABER position, Bankart lesion was shown in all patients. The continuity of the two former findings was noted in three patients on the ABER positioned images. Therefore, three patients could be diagnosed as having SLAP lesion type V by MR arthrography in our series.

Conclusion: It is difficult to detect all three findings of SLAP lesion type V in one imaging plane, however, a combination of multi-directional images may increase the feasibility of MR arthrography in diagnosing SLAP lesion type V.

Purpose: To evaluate the survival of glottic carcinoma patients treated with radiation therapy (RT). The predictive value of the new sixth edition of the UICC staging system was also evaluated.

Methods and materials: 193 patients with T1-2N0 glottic squamous cell carcinoma, classified according to the fifth edition of the UICC staging system, were treated with definitive RT. Of them, 130 patients evaluated with pretreatment radiological examinations (CT and/or MR) were retrospectively classified according to the UICC sixth edition.

Results: According to the UICC fifth edition, 132 lesions were staged as T1 and 61 as T2. Thirty lesions were categorized as stage T3 according to the UICC sixth edition. Of all patients, 13 died of glottic carcinoma, 25 of second malignancy, and 20 of intercurrent disease. Second primary sites included lung (n=8), esophagus (n=4), liver (n=4), pancreas (n=3), and others (n=6). The 10-year overall survival rate was 66%, and cause-specific survival rates of glottic carcinoma and second malignancy were 91% and 86%, respectively. Multivariate analysis confirmed T-stage in the UICC sixth edition as an independent predictor for death from glottic carcinoma. Although there were no significant factors for second malignancy, there was no death from second malignancy in non-smoking patients.

Conclusion: Second malignancy was the most frequent cause of death, and an association with smoking was suggested. The UICC sixth edition appears to correctly identify patients with T3 lesions as a high-risk group not only for local failure but also for survival.

We describe the CT and MRI findings of gynecologic emergency diseases: pelvic inflammatory disease, ectopic pregnancy, ovarian hemorrhage, ovarian torsion, rupture of ovarian tumor, eclampsia, and HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome. Diagnostic keys to these diseases are presented in this review. CT and MRI play a complementary role to sonography in accurately diagnosing these diseases. In situations that require an exact, immediate diagnosis, radiologists should be familiar with the key imaging findings.

Purpose: To evaluate contrast-enhanced patterns using three-dimensional (3D) dynamic MR imaging in 209 cases of breast cancer.

Materials and methods: Three-dimensional dynamic imaging of the breast (1.5-T scanner) was performed in 755 cases. Of 227 breast carcinomas, 209 cases that were histologically confirmed were enrolled in this study. The histological diagnoses included ductal carcinoma in situ (DCIS) (n=12), invasive ductal carcinoma (n=176), mucinous carcinoma (n=10), medullary carcinoma (n=4), invasive lobular carcinoma (n=6), and other (n=1). Tumor size was a mean 24.6 mm in diameter (range, 7-110 mm), including 110 cases of small breast carcinomas (< or = 2 cm). The contrast-enhancement pattern was analyzed from the early phase of 3D-MRI and the post-contrast T1-weighted SE image acquired before the delayed phase of 3D-MRI. The type of peripheral enhancement (PE) was evaluated on the early and delayed phases of 3D-MRI. These enhancement patterns were also compared with the histological findings of small breast carcinomas.

Results: The sensitivity of the 209 cases of breast carcinoma was 99% (207/209) on 3D dynamic MRI. Two hundred six cases (98.6%), including all DCIS, showed strong enhancement on the early phase of 3D MRI. An increased washout pattern showing signal intensity lower than that of fat on post-contrast T1-weighted imaging was noted in 201 cases (96.1%), of which 179 cases (85.6%) showed washout patterns. PE was identified in 63 cases (30.4%) and in 35 of 110 cases of small breast carcinoma (31.8%). Delayed PE following central washout was noted in 65% of 63 cases and 71.4% of 35 cases of small breast carcinoma. Delayed PE was well correlated with marginal fibrosis.

Conclusion: Three-dimensional dynamic MRI of the breast was highly sensitive for breast carcinoma. Delayed PE following central washout was considered a specific finding of breast carcinoma. It is important to understand the enhancement patterns of 3D dynamic MRI for excellent specificity of breast carcinomas.