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

We report a case of iatrogenic pseudoaneurysm of the right pulmonary artery induced by a Swan-Ganz (SG) catheter. An SG catheter was inserted to the pulmonary artery before the esophageal surgery. Chest radiograph after the surgery showed a nodule in the right lower lung field. Based on the retrospective review of serial chest radiographies after SG catheter placement, we suspected iatrogenic pseudoaneurysm of the pulmonary artery caused by over-insertion of the catheter tip. Contrast-enhanced CT showed the nodular shadow with eccentric and marked enhancement continuing right A4b. We diagnosed a pseudoaneurysm of the pulmonary artery. The nodular shadow resolved spontaneously over a 2-month period.

Purpose: ECG-gated cardiac MDCT offers many cardiac clinical applications. The goals of this report are 1) to introduce a new concept of effective reliability (ER) from effective temporal resolution for the evaluation of ejection fraction (EF) and evaluation of image quality (IQ) of coronary arteries, and 2) to show the correlation of ER and the accuracy of EF with different cardiac reconstruction algorithms and different rotation speeds.

Methods and materials: To assess the accuracy of EF, helical scanning was performed with a gated cardiac MDCT (GE LightSpeed, 8/16 slice) on pulsating cardiac coronary phantoms (0.5 and 0.6 sec rotation speed for each 50-110 bpm, 5-bpm step). We define effective reliability (ER) from effective temporal resolution (%) as follows: ER= (1-TR/HC) x 100; TR: Effective temporal resolution, HC: time of heart cycle in each bpm.

Results: From the results of the EF measurement and calculated ER, high accuracy was obtained by using optimal scan conditions (optimal rotation speed and cardiac reconstruction algorithm) in a wide range of heart rates (heart rate<90: EF & ER>81%; heart rate<110 bpm: EF & ER>73%). Results showed that the calculated ER is closely correlated with the measurement results of EF based on the phantom experiment (R2=0.901+/-0.075; Max: 0.994, Min: 0.738). Optimal reconstruction thickness can reduce total image number for the evaluation of EF.

Conclusion: We concluded that the ER is useful to evaluate EF accuracy and the IQ of images of coronary arteries.

Brachytherapy has long been used because its therapeutic gain factor is high. The high-dose-rate remote after loading system (RALS) that enables therapists to treat patients without any radiation exposure recently has become the mainstream method and has been used in preference to low-dose-rate brachytherapy. 192Ir fine seeds were developed to expand the number of diseases treated and to increase the precision of treatment through computerization. However, because of new adaptations of brachytherapy and its use with external irradiation and other techniques, new issues have been generated as a result of the technological advances in external beam radiotherapy. The current status of brachytherapy is summarized, and information on the cautions and future views for developments and problems in brachytherapy are given in this report.

We have reported the cytoprotective effects of HSP 70 on various stress damage induced by mild heating. In this study, we examined the cytoprotective effects of HSP 70 induced by the local preheating of the oral cavity of mice at 42 degrees C for 30 min, and the following results (1-4) were obtained. We also examined the cytoprotective effects against radiation injury by whole-body preheating at 41.3-41.6 degrees C for 30 min (5-6). 1) The concentration of HSP 70 in lymphocytes was increased 2 days after preheating, but not significantly. 2) The concentration of HSP 70 in masseter muscle was significantly increased 2 days after preheating. 3) Under non-heat stress (control), tongue muscle was strongly stained with immunoblotting of HSP 72 antibody, an antibody of induced-type HSP 70. 4) Tongue damage and weight loss of the mice in the preheating group, whose tongues were burned, were less than in the control group. These results showed that HSP 70 induced by local preheating of the oral cavity protected against tongue damage from burning. 5) Radiation injury of the small intestine on HE stain of whole-body radiated mice was obviously reduced by whole-body preheating. 6) Decrease of the ratio of the villus length to the crypt of whole body-irradiated mice was significantly improved by whole-body preheating. From these results, it was concluded that local and whole-body preheating were useful for cytoprotection from stressful damage.

Synovial sarcomas are a less common cervical tumor in young patients. We report a 23-year-old man with synovial sarcoma in the submandibular region. T2-weighted MR images demonstrated a mixed-intensity tumor attached to the submandibular gland. T1-weighted MR images revealed a focal area with mildly increased signal intensity, indicating intratumoral hemorrhage. MR images were also useful for visualization of tumor extension. Synovial sarcoma should be considered in the differential diagnosis of well-defined inhomogeneous tumors adjacent to the submandibular gland in young adults.

Purpose: To investigate the appropriate time of arterial phase for the detection of hypervascular hepatocellular carcinoma (HCC).

Materials and methods: Fifty-two hypervascular HCCs of 36 patients were evaluated on double arterial-phase images of the liver. The first and second arterial-phase images were obtained 10 sec after aortic peak enhancement time as determined by test bolus injection. Patients received a low or high concentration of contrast medium, according to their body weight, that was administered intravenously at a rate of 4 mL/sec and injection duration of 23 sec. Three radiologists evaluated the images separately.

Results: Sensitivity in detecting hypervascular HCCs was higher in the first arterial phase than in the second arterial phase (p = 0.039). HCCs were not detected as hypervascular nodules in one of 20 cases during 31 or fewer sec, or in 8 of 19 cases during 48 or more sec after the initiation of contrast medium injection. All nodules were detected as hypervascular lesions between 32 and 47 sec after the initiation of contrast medium injection.

Conclusion: When a single arterial phase is obtained to detect hypervascular HCCs with a 23-sec injection time and an injection rate of 4 mL/sec, a protocol is recommended in which scanning is started at 35 sec and ended within 47 sec after initiating the injection of contrast medium.

Congenital diaphragmatic hernia (CDH) is a developmental defect of the diaphragm with herniation of abdominal viscera into the thorax. The morbidity and mortality in cases is caused primarily by pulmonary hypoplasia. A prenatal diagnosis of CDH can be established by ultrasound, but ultrasound cannot detect pulmonary hypoplasia with certainty. We evaluated pulmonary hypoplasia by the simple method of lung intensity. The subjects were eight fetuses. In four fetuses, the lungs showed low intensity, and these fetuses all had pulmonary hypoplasia. Two of the four fetuses with high intensity showed a good prognosis, however, the other two fetuses did not. One of the two cases with poor prognosis had complex congenital heart disease, and the other died of sepsis and pulmonary hypertension. A high signal did not always promise a favorable prognosis, probably because accompanying abnormalities dominated the prognosis. MR assessment of lung intensity in fetuses with CDH may be useful in evaluating the severity of pulmonary hypoplasia. Low signal of the lung may reflect pulmonary hypoplasia and suggests a poor prognosis.