[en] The present series consists of 24 patients with brain metastasis smaller than 10 mm in diameter demonstrated on Gd-DTPA enhanced MR imaging (Gd-MRI). All patients underwent contrast-enhanced (CE) CT to be compared with Gd-MRI in size, number and detectability. The primary lesions of the series included 18 patients with lung cancer (9 with adenocarcinoma, 4 with small cell cancer, 3 with squamous cell cancer and 2 with large cell cancer), 4 with breast cancer, and each 1 with parotid cancer and renal cell carcinoma. All 24 patients except one who underwent surgery were treated with radiation therapy. In 13 patients examined by Gd-MRI and CE-CT both before and after the brain irradiation, therapeutic effect was estimated on each diagnostic imaging comparatively. In regard to size of brain metastases of 24 patients, 91 lesions smaller than 5 mm in diameter were detected by Gd-MRI but only 15 by CE-CT. Three of all patients, no brain metastasis was found on CE-CT. In 6 patients estimated as CR (complete remission) by CE-CT after brain irradiation, Gd-MRI evidenced tumor residues in 5 patients to alter the score of therapeutic effect as PR (partial remission). The difference in therapeutic effects confirmed by Gd-MRI was noted according to histological results and size of metastasis. The most radiosensitive tumor was small cell lung cancer, of which brain metastases smaller than 5 mm in diameter completely disappeared after 20∼50 Gy irradiation. Prophylactic whole brain irradiation has been an alternative indication for small cell lung cancer when CT showed no evidence of brain metastasis. However, our data strongly suggest that the small or tiny brain metastases negative on CE-CT will become new subjects of 'radical' radiotherapy. The higher sensitivity of Gd-MRI for detecting brain metastasis may propose new clinical prospects in staging, planning of therapy and estimation of therapeutic effect. (author)

[en] We analyzed the 44 DS-bronchial arteriograms (DSBAG) of lung cancer with an attention to the demonstration of metastasized mediastinal lymph nodes. The stain of lymph node is well demonstrated in the peripheral region, such as station No.7, No.R4 along the course of bronchial arteries. The swollen nodes with stains on DSBAG show the good reduction rates (37.5%) after BAI that is analogous to the primary lesion (38.9%), in contrast to the nodes without stains (24.5%). DSBAG with exellent contrast resolution contributes to the BAI as verifying the infused area. (author)

[en] This paper deals with the diagnostic capability of CT scan for hepatofugal collaterals in 22 patients with portal hypertension. The patients studied were those who underwent percutaneous transhepatic portography (PTP) and CT scan within a short period. Each collateral vein demonstrated by PTP was classified into three grades according to its caliber (d) : (1) Grade I, d<5mm, (2) Grade II, 5mm< d<10mm and (3) Grade III, 10mm< d. Based on the PTP finding, the demonstrability of these collaterals on the CT images was analysed comparatively. Most collaterals in Grade I failed to demonstrate on CT images, while Grade II and III well coincided with CT images, at the rate of 64% and 100% respectively. CT features of these vascular structures showed multiformity: rounded, ovoid comma-shaped, tubular or beaded, etc.. To get an accurate diagnosis, each image must be analysed together with the adjacent upper and lower ones on the fully-performed contrast enhancement technique. Image deterioration of CT was concerned with Partial Volume Phenomenon for small vessels, and motion artifacts produced by intestinal peristalses, cardiac beats and occasionally by difficulty of breath holding. In spite of such diagnostic Iimitation, CT scan provides much qualified images than conventional angiographic procedures in evaluating hepatofugal collaterals. CT scan, which is widely applied to clinical workup for cirrhosis of the liver with special reference to hepatoma, allows incidental diagnostic information about collaterals in size and course. Such simplicity of the procedure contributes to the follow-up and repeat study after sclerotherapy for esophageal varices. (author)

[en] We performed CT-guided needle biopsy for 92 thoracic mass lesions using Rotex-II screw needle. Fast stain technique was performed for an immediate evaluation of the specimen in the last 39 procedures. The overall accuracy of malignancy was 93.2%, and the correct histological typing was obtained in 82.8% of malignancy proven at surgery or autopsy. The method enabled histopathological diagnosis of thoracic lesions, which could not obtained by other diagnostic modalities including fiberoptic bronchoscopy or fluoroscopy-guided biopsy. The true positive rate increased up 10.2% to 91.3% by introducing fast stain technique. A close cooperation between radiologists and cytopathologists was essential for performing this CT-guided biopsy procedure followed by fast stain technique. (author)

[en] The diagnostic potentiality of MR imaging for lung cancer was researched in 17 patients in evaluating local invasions based on surgical-histological evidence. Comparative reviewing with CT was also performed. MR imaging appeared to have an ability unique to portray malignant invasions somewhere such as in the hili or apices. On the other hand, there were also some diagnostic limitations of MR imaging in delineating the localized invasive changes. On the way of working up lung cancer, CT still may stand at the first choice as a radiographic staging procedure which provides the more detailed anatomic-pathologic informations. We consider that MR imaging is mandatory when CT and/or other modalities could not obtain efficient results. (author)

[en] CT scans in 11 cases of chronic eosinophilic pneumonia (CEP) were reviewed. Peripheral dense opacities suggesting air-space consolidation were the most peculiar findings seen in 9 patients on CT, but 7 on chest radiographs. Five patients showed broad plate-like opacities parallel to the pleura, which were the results of resolution from the periphery of the consolidation. Diffuse interstitial opacities suggesting alveolitis were the predominant finding in 3 patients, one of which also had peripheral air-space consolidation. Follow-up CT showed no residual abnormality except one who had DIP concomitant with CEP. CT scans are useful tool for both diagnosis and follow-up of CEP. (author)

[en] Clinical usefulness of ^99mTc-DTPA-HSA was assessed in 26 patients with cerebral diseases using radionuclide angiography (RNA) and single photon emission computed tomography (SPECT). Positron emission tomography (PET) was also done in 11 cases with occlusion of unilateral cerebral major vessel (CMV) and SPECT with N-isopropyl-[¹²³I]p-iodoamphetamine (IMP) was performed in 19 cases. RNA detected abnormality in 13 out of 14 cases with occlusion of unilateral CMV but failed to detect in 4 cases with unilateral stenosis or bilateral occlusion of CMV. Eight cases without occlusion or stenosis of CMV showed normal RNA. All of 3 cases with arteriovenous malformation and venous angioma showed abnormality with SPECT. CBV images obtained with SPECT showed a good agreement with those of PET. In SPECT studies, 3 cases with occlusion of unilateral CMV showed increased cerebral blood volume (CBV) in the affected cerebral hemisphere with decreased cerebral blood flow (CBF). In these 3 cases, PET studies revealed increased oxygen extraction fraction (OEF) in the affected side. Cases with decreased CBF in affected hemisphere demonstrated normal OEF without CBV abnormality. One case with occlusion of CMV showed increased CBV in affected hemisphere without decreased CBF. PET demonstrated the same finding in CBF and CBV with normal OEF. In 2 cases, PET revealed increased OEF in the bilateral cerebral hemisphere which were not detected by SPECT. In cases with occlusion of unilateral CMV, increased OEF was predicted by increased CBV with decreased CBF. The combined use of CBF and CBV SPECT is a valuable tool for assessment of perfusion reserve in cerebrovascular diseases. (author)

[en] To evaluate the usefulness of ^99mTc-d, l-hexamethylpropyleneamine oxime (HMPAO) as a brain-perfusion tracer, 19 cases of neurological disorders were studied with single-photon-emission computerized tomography (SPECT) and the results compared with the cerebral blood flow (CBF) as measured by positronemission tomography (PET) using the oxygen-15 CO₂ inhalation technique. Although HMPAO SPECT and CBF as measured by PET showed a similar distribution pattern, HMPAO SPECT always showed less contrast than did CBF, and a non-linear relationship was suggested between the distribution of HMPAO and CBF. Based on the assumption of a flow-dependent back-diffusion of HMPAO from the brain to the blood stream, we applied a 'linearization' technique to the HMPAO SPECT images to correct the distribution of the tracer. This correction improved the image contrast of HMPAO SPECT as well as the correlation with CBF. The results indicated that HMPAO can be used as a flow tracer with SPECT after proper correction. (author)

[en] We developed and evaluated a simplified double-injection method for iodine-123 N-isopropyl-p-iodoamphetamine (IMP) to quantify regional cerebral blood flow (rCBF) twice in a single SPECT session. The method enabled rapid calculations of rCBF with five 10-minute SPECT scans, a fixed distribution volume (V_d), and one-point arterial blood sampling to calibrate a standard input function (SIF). Sixty neurological patients were examined to measure rCBF twice in a single session of IMP-SPECT. Patients underwent frequent arterial blood sampling with two injections of IMP and acetazolamide challenge. We generated the SIF and determined the optimal V_d and calibration time (t_cal) for the SIF in 30 patients. Validities of the fixed t_cal and V_d were assessed in the remaining 30 patients. Simulation studies were also performed to evaluate the error sensitivity of the method. The optimal t_cal and V_d were 34 min and 30 ml/ml, respectively. The method was robust in rCBF calculation with noisy SPECT data and yielded rCBF with negligible bias and acceptable errors compared with those obtained by the double-injection method previously reported. The method can be applied to measure rCBF twice in a single SPECT session more easily and less invasively. (author)

[en] We report on an adult case of preduodenal portal vein illustrated by computed tomography (CT) and angiography. These diagnostic modalities were initially performed to evaluate a coexisting pancreatic cancer. Constrast-enhanced CT demonstrated unusual positioning of the portal vein ventral to the duodenum. The superior mesenteric-portal vein, which was L-shaped and convexly caudad, strongly suggested this anomalous condition. (author)