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

Purpose: To evaluate the feasibility of selective thrombolytic therapy for deep venous thrombosis (DVT)by using a small caliber catheter passed through a temporary vena cava filter.

Materials and methods: During a 3-year period, 14 consecutive symptomatic patients (7 men, 7 women, age range, 35-80 years; mean, 62 years) were referred for treatment. Ten had acute DVT, and four were chronic. At first, a temporary filter catheter was introduced from the right subclavian vein, through which an infusion microcatheter(2.2F, 150 cm) was inserted. A pulse spray system (3F, 135 cm) was also employed. Urokinase (UK) was introduced locally into the thrombus by the pulse method (3,000 U/30 sec)and by continuous infusion (120,000-240,000 U/day). After complete clot dissolution, residual left common iliac vein narrowing in two patients (May-Thurner syndrome) was treated by means of PTA and placement of a Wallstent endoprosthesis. All patients continued to receive oral Warfarin.

Results: Dramatic improvement of symptoms was noted in all patients after treatment. Complete thrombolysis was achieved in 11 patients (11/14: 79% success rate). Each of three incomplete cases had chronic DVT. The duration of filter insertion was a mean 16 days (range, 8-37 days)after administration of a mean 2.58 million U of UK (range, 0.24-5.04 million U). No major or minor complications occurred. At present, no patients show recurrent symptoms.

Conclusion: Selective thrombolytic therapy performed by using a small-caliber catheter passed through a temporary vena cava filter is safe and effective.

One year has passed since we started brachytherapy with radioactive iodine-125 seeds for carcinoma of the prostate. During the follow-up of patients, we have relatively frequently found migrated seeds in the lungs. Migrated seeds are reported to reach mainly the pulmonary artery and cause embolization without clinical symptoms. We counted the embolized seeds and determined the proportion of migrating seeds on chest X-ray exam. We found 47 cases of pulmonary embolization in our initial 100 cases. Less than half of the embolization were found in the chest X-ray exam performed on the next day after the implantation. We found more migrated seeds in the lower lung fields than in the upper and middle lung fields. Pulmonary embolization of implanted iodine-125 seeds is not unusual, and cases of prostate brachytherapy are likely to increase in Japan. We will have increased opportunities to observe chest X-ray films with migrated seeds in the future.

We performed chemoradiotherapy for two patients (aged 6 and 33 years)with neurohypophyseal immature teratoma. The patients received total doses of 40 to 50.6 Gy with concurrent carboplatin and etoposide. In both cases, neurological symptoms improved. Both patients are still alive and remain free from local recurrence and distant metastasis 92 months and 62 months, respectively, after the completion of chemoradiotherapy. No late complications were observed. Chemoradiotherapy is extremely effective in the treatment of neurohypophyseal immature teratoma.

This review aims to provide an overview of prostate brachytherapy and disseminate consensus guidelines formed by the American Brachytherapy Society. In Japan, permanent transperineal prostate brachytherapy with I-125 started in September 2003. Patients with high probability of organ-confined disease are appropriately treated with brachytherapy. Brachytherapy candidates with a significant risk of extraprostatic extension should be treated with supplemental external beam radiation therapy. The recommended prescription doses for monotherapy are 145 Gy. The corresponding boost doses after 40-50 Gy of external beam are 100-110 Gy. Dosimetric planning of the implant should be carried out for all patients before seed insertion. Post-implant dosimetry and evaluation must be performed on all patients. A dose-volume histogram of the prostate should be performed. The dose that covers 90% of the prostate volume, the percentage of prostate volume receiving 100%, 150%, and 200% of the prescribed dose, and the rectal dose and urethral dose should be reported. ABS recommends standardization of the reporting of brachytherapy-related prostate morbidity, including urinary, rectal, and sexual function. These morbidities should be correlated with the doses to normal tissues. High-dose-rate (HDR) brachytherapy with Ir- 192 has preceded seed implants in Japan. HDR has some theoretical advantages. We should develop techniques of both types of brachytherapy in Japan.

Purpose: To examine the ability of radiological technologists (RT) to detect pulmonary nodules with low-dose CT (LCT).

Materials and methods: LCT (20 mAs) and normal-dose CT (NCT; 160 mAs) were performed in 60 patients. We used an RT to detect pulmonary nodules with LCT. The results were compared with those of a radiologist who detected nodules with NCT. The diameter and density of the nodules in NCT were compared between the group of nodules detected (DN) by the RT and the group of nodules not detected (NN).

Results: 60 nodules were detected with LCT out of 74 nodules detected with NCT (81.1%). Eleven patients had NN as well as DN. The mean diameter of NN was smaller than that of DN, and the density of NN was lower than that of DN.

Conclusion: The detection of pulmonary nodules with LCT by radiological technologists was acceptable.

This study aimed to evaluate the efficacy of breath-hold three-dimensional (3D)delayed-enhancement MRI using parallel imaging in terms of the effect of parallel imaging on the image quality and visualization of myocardial infarction. Twenty-two patients (17 men and 5 women) with suspected myocardial infarction underwent breath-hold 3D late-enhanced viability examination at least 30 days after occurrence. All patients underwent a Tl-scintigraphy examination. First, 10 patients were examined without applying parallel imaging, then the next 12 patients were studied using parallel imaging. All 3D late-enhanced images at the short axis were acquired 10, 15, and 20 min after an injection of contrast agent, and both the long axis and the four-chamber views were acquired after 15 min. In quantitative analysis, the late-enhanced myocardial images at 10, 15, and 20 min showed higher contrast-to-noise ratios (CNR) in parallel imaging than those with no parallel imaging. During the time-intensity curve of the myocardium, no significant change was observed at 10 or 15 min; however, marked signal reduction was observed at 20 min. In diagnostic evaluation, images obtained with parallel imaging were superior to those without parallel imaging. In general, the application of parallel imaging reduces acquisition time with an expense of reduction in SNR. However, the breath-hold 3D late-enhanced images with parallel imaging showed no apparent SNR reduction. Furthermore, parallel imaging provided clear edge definition between the infarction and the normal region. The reduction of acquisition time with parallel imaging may be less susceptible to fast cardiac motion. In conclusion, breath-hold 3D delayed-enhancement MRI using parallel imaging was highly evaluated in our study and may show promise in clinical application.

We devised low-output radiofrequency ablation (RFA)combined with transcatheter arterial chemoembolization using iodized oil mixed with anticancer drugs (TACE) for hepatocellular carcinoma (HCC), to reduce the cooling effect of tumoral arterial blood flow, to prevent intraportal disseminations and intrahepatic metastases by sudden ebullition (bumping), and to obtain an adequate margin of safety. We performed low-output RFA on 10 HCC patients. We performed RFA with a lower output of 90W or less within two weeks after TACE. After the ablation, portal venous-phase CT images showed a low-density margin of 5 mm or larger around the site of iodized-oil accumulation, indicating that the necrotic area completely included the tumor. No intrahepatic metastasis or severe complication occurred. Low-output RFA combined with TACE is a safe, effective therapy for HCC.

Purpose: To evaluate histological changes in normal renal tissue induced by the injection of a hypertonic liquid.

Materials and methods: Transarterial injection was performed in 17 healthy rabbits at various rates of infusion and amounts of isotonic and hypertonic (7%) sodium chloride solutions. In group 1, 10 cc of isotonic sodium chloride solution was injected. In groups 2 and 3, 1-10 cc of hypertonic solution was injected at rates of 1.0 cc/sec and 0.05 cc/sec, respectively. After 20 minutes of hemostasis, renal weight measurements and histological examinations were performed. In three rabbits that received 10 cc of 7% sodium chloride, lung samples were also obtained, and histological changes were reviewed.

Results: There was no tissue injury in group 1, and in groups 2 and 3 the histological changes for infusions of 4-10 cc were greater than those of 1-3 cc. There was no vascular endothelial cell damage in any case. None of the histological changes were dose dependent, and the lungs showed no clear histological alterations.

Conclusion: Higher doses of a hypertonic sodium chloride solution cause irreversible histological changes in the rabbit kidney.

Recognition of which interlobar fissure in the right lung is major or minor is important in chest radiography. Based on assessment of the interlobar fissure, the location of diseases or the degree of expansion of the lobes is comprehensible. As a general rule, the major fissure is not seen in normal cases. However, the major fissure is visualized in the presence of volume loss of the lower lobe. Although the medial end of the minor fissure is at the intermediate artery between the upper and lower lobe bronchi, that of the major fissure is continuous to the central portion of the mediastinum. The following cases will be presented: post-pleuritis, atelectasis of the superior segment of the lower lobe (S6), obstructive pneumonia in the middle and lower lobes due to stenosis of the intermediate bronchus, pneumonia of the upper lobe, and superior accessory fissure with atelectasis of the upper lobe.