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Objective: Fluoroscopically guided interventional procedures are performed in cardiology, and complex interventions are performed in cerebral as well as peripheral circulation. These procedures sometimes deliver a high radiation dose to the patient's skin and can cause serious skin injuries., Conclusion: Interventionalists are often unaware of the high radiation doses to which a patient's skin may be subjected. Most are unaware that such injuries can occur even with the use of modern equipment. Therefore, they and other physicians, including dermatologists, often do not recognize such skin injuries as being related to an interventional procedure.

Mediastinal lung herniation is a rare condition characterized by protrusion of 1 lower lung through behind the heart into the opposite side of the chest, usually from right to left. We present a case of mediastinal lung herniation associated with pulmonary sequestration, which was confirmed both surgically and pathologically in a 13-year-old girl initially admitted with a diagnosis of pneumonia. Contrast-enhanced computed tomographic images using a multidetector-row computed tomography clearly demonstrated the right lung herniation toward the left and 2 aberrant systemic arteries supplying the sequestered lung mass. These arteries run through the herniated lung from right to left. Additionally, on the basis of pleural anatomy, we discuss herein the difference between a mediastinal lung herniation and horseshoe lung.

Pulmonary adenocarcinoma complicated with a pulmonary infarction presenting as an intrapulmonary metastasis is relatively rare. We present a case of pulmonary infarction manifesting as intrapulmonary metastases of lung cancer. A previously healthy 59-year-old woman was admitted to our hospital on May 16, 2002 for evaluation of multiple abnormal radiographic shadows in the right lower lung field. Laboratory tests showed no abnormalities except for a slight elevation of carcinoembryonic antigens. Computed tomography of the chest revealed a hilar mass lesion with parenchymal lesions in the periphery of the right lower lobe, highly suspected to be a pulmonary adenocarcinoma with intrapulmonary metastases. A diagnosis of pulmonary adenocarcinoma was confirmed by a transbronchial brushing examination. A right middle and lower bilobectomy with mediastinal lymph node dissection was needed by hilum lymphadenopathy and a lower lobe invasion of the main tumor. Histopathological findings of the resected specimens revealed poorly differentiated adenocarcinoma of the lung with N1 (#11i) disease and multiple pulmonary infarctions with coagulation necrosis and recanalization. Pulmonary infarctions are demonstrated on chest x-rays as round or polygonal in shape, and located at the periphery of the same lobe as the primary tumor. Computed tomography is more sensitive than conventional radiography in the detection of pulmonary infarction. Our case suggests that pulmonary infarction associated with lung cancer should be considered as one important cause of peripheral pulmonary nodules.

Purpose: This study evaluated the usefulness of combined polyethylene glycol solution plus contrast medium bowel preparation (PEG-C preparation) followed by dual-contrast computed tomography enema (DCCTE) and conventional colonoscopy. The main purpose of these examinations is the preoperative staging of already known tumors., Materials and Methods: One hundred patients with colorectal tumors were alternately allocated to either a polyethylene glycol solution preparation (PEG preparation) group (n=50) or a PEG-C preparation group (n=50) before undergoing conventional colonoscopy and computed tomographic (CT) colonography. After conventional colonoscopy, multidetector row CT scans were performed. Air images were reconstructed for both groups; contrast medium images were additionally reconstructed for the PEG-C preparation group. DCCTE images were a composite of air images and contrast medium images without use of dedicated electronic cleansing software. Quality scores (the presence or absence of blind spots of the colon) were compared between the two groups., Results: Complete tumor images were obtained by DCCTE for all 50 (100%) lesions in the PEG-C preparation group, as compared with only nine of the 50 lesions (18%) in the PEG preparation group (air-contrast CT enema). The overall quality score in the PEG-C preparation group was significantly better than that in the PEG preparation group (P<0.0001)., Conclusions: DCCTE showed the entire colon without blind spots in nearly all patients in the PEG-C preparation group because the areas under residual fluid were reconstructed as contrast medium images. DCCTE and conventional colonoscopy after PEG-C preparation are feasible and safe procedures that can be used for preoperative evaluation in patients with colorectal cancer.

Creutzfeldt-Jakob disease causes progressive dementia and, eventually, death. The infectious agent is thought to be proteinaceous scrapie particles. Prompt diagnosis is essential to prevent human-to-human transmission. Progressive brain atrophy and areas of high signal intensity in the cerebral cortex and basal ganglia are well-known features of Creutzfeldt-Jakob disease depicted on T2-weighted magnetic resonance (MR) images. However, in the early stage of disease, the appearance of the brain on T2-weighted MR images often is normal, and it may be impossible on that basis to reach a diagnosis. Diffusion-weighted imaging therefore has gained attention as a useful modality for the early diagnosis of Creutzfeldt-Jakob disease. Even before the appearance of the characteristic periodic synchronous discharges on the electroencephalogram, diffusion-weighted images in most cases of Creutzfeldt-Jakob disease depict areas of abnormal signal hyperintensity in the cortex and in the basal ganglia or thalamus. These imaging abnormalities are accompanied by decreased apparent diffusion coefficient values suggestive of restricted diffusion within the tissue. However, if diffusion-weighted imaging findings of abnormal high signal intensity are restricted to the cerebral cortex, it may be necessary to differentiate between Creutzfeldt-Jakob disease and other conditions that may produce progressive dementia (eg, venous hypertensive en-cephalopathy; chronic herpes encephalitis; and the syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes)., ((c) RSNA, 2006.)

Pulmonary adenocarcinoma complicated with a pulmonary infarction presenting as an intrapulmonary metastasis is relatively rare. We present a case of pulmonary infarction manifesting as intrapulmonary metastases of lung cancer. A previously healthy 59-year-old woman was admitted to our hospital for evaluation of abnormal shadows in the right lower lung field. Laboratory tests showed no abnormalities except for a slight elevation of carcinoembryonic antigens (CEAs). Computed tomography (CT) of the chest revealed a hilar mass lesion with parenchymal lesions in the periphery of the right lower lobe, highly suspected to be a pulmonary adenocarcinoma with intrapulmonary metastases. A diagnosis of pulmonary adenocarcinoma was confirmed by a transbronchial brushing examination. A right middle and lower bilobectomy with mediastinal lymph node dissection was due to hilar lymphadenopathy and a lower lobe invasion of the main tumor. Histopathological findings of the resected specimens revealed poorly differentiated adenocarcinoma of the lung with N1 (number 11i and 12 l) disease and multiple pulmonary infarctions with coagulation necrosis and recanalization. Our case suggests that pulmonary infarction associated with lung cancer should be considered as one important cause of peripheral pulmonary nodules.

Completion pneumonectomy (CP) is a difficult operation in which the surgeon must use techniques such as intrapericardial ligation of the pulmonary vessels. We report herein a case of CP for a patient with recurrent lung cancer. A 63-year-old man was admitted to our hospital for evaluation of abnormal shadows in the right lung field in October 2002. Right middle lobectomy with mediastinal lymph node dissection had been performed in February 1993. Computed tomography (CT) revealed a hilar mass in the right upper lobe the day after admission. Bronchofiberscopic cytology revealed squamous cell carcinoma. Right completion pneumonectomy was performed on suspicion of metachronous multiple lung cancers 4 days later. Histopathologically, resected specimens represented adenosquamous carcinoma similar to the prior lesion from the middle lobe, and examination revealed that the tumor represented a recurrence following middle lobectomy. The patient remains well as of 19 months postoperatively.

Objective: The objective of our study was to evaluate the clinical usefulness of MRI findings, including diffusion-weighted imaging, in relation to the clinical signs and symptoms of Creutzfeldt-Jakob disease (CJD)., Materials and Methods: We reviewed nine cases of CJD in which MRI was performed from the early to terminal phase of the disease. MRI findings were correlated before (early phase) and after (intermediate phase) the onset of the characteristic clinical findings of myoclonus and periodic synchronous discharges on electroencephalograms. The chronologic changes in imaging findings were followed from the akinetic mutism to the terminal phase of the disease (terminal phase). T2-weighted images had been obtained in all the patients, and diffusion-weighted images and FLAIR images had been obtained in six patients. We evaluated the images for the presence and location of abnormal signal intensities., Results: During the early phase, the T2-weighted images showed no abnormal findings. The diffusion-weighted images, however, revealed abnormal high signal intensities in the cortex in all patients and in the basal ganglia in five patients. In two cases, there were abnormal signals on FLAIR images that corresponded to diffusion-weighted imaging abnormalities. During the intermediate phase, the area of the high signal intensities on the diffusion-weighted images had expanded and progressive cerebral atrophy had become apparent. During the terminal phase, abnormal high signal intensities in the cerebral cortex and basal ganglia on the diffusion-weighted images in one patient disappeared., Conclusion: Diffusion-weighted imaging is extremely useful in detecting CJD during the very early phase-even before the onset of characteristic clinical findings.

We experienced with a relatively rare case of an aneurysmal bone cyst (ABC) arising in the left rib. A 34-year-old female, had experienced chest discomfort on the left anterior side and pain for 1 year. A chest X-ray suggested a left chest wall tumor involving the ribs. Computed tomography (CT), magnetic resonance imaging (MRI) and a bone scintigram revealed an expansive tumor of the anterior portion of the left 4th rib involving the 3rd and 5th rib with "blow out appearance" and "fluid-fluid level". Wide excision of the tumor and adjacent muscle tissue was performed with an antero-axillary incision. Chest wall reconstruction was performed with prolene mesh (140 x 90 mm). The resected specimen showed an encapsulated bony mass (75 x 60 x 35 mm) with multiple blood-filled spaces. Histopathological diagnosis was an ABC originating in the left 4th rib. She has been doing well with no evidence of recurrence 12 months postoperatively.

Background/aims: We conducted a study on three-dimensional computed tomography (CT) images, in particular CT air-contrast enema (CT enema), using multidetector-row CT (MDCT), to see whether CT enema is useful as a preoperative examination for colorectal cancer. We aimed to evaluate the detectability of lesions and the depth of cancer invasion using CT enema., Methods: 292 patients (328 lesions) with colorectal cancer were enrolled. After an adequate insufflation of the large intestine, MDCT scans were performed. With the data obtained by MDCT, we reconstructed CT enema images. CT enema images were assessed for the detectability of lesions. The depth of invasion was evaluated by the deformity of the lesion on profile images. The deformities were divided into five groups: no deformity, slight deformity, mild deformity, moderate deformity and severe deformity., Results: The detectability of lesions was 97.3%. The reasons for undetectability were due to residual fluid in 8 cases and insufficient colonic distention in 1 case. As the depth of invasion increased, the grade of the deformity became severer (p < 0.0001)., Conclusions: CT enema proved to be an excellent examination tool to detect lesions. The deformity demonstrated by CT enema could be an additional source of information to predict the depth of invasion., (Copyright 2004 S. Karger AG, Basel.)

A 72-year-old man with a history of brain infarction presented with left sided anterior chest pain secondary to a thymic carcinoma. He received induction radiotherapy, 45 Gy. Preoperative computed tomography showed the tumor was adherent to a thoracic aortic aneurysm (TAA) which had extensive mural thrombus and calcification. To obtain adequate exposure without exerting tension on the fragile aneurysmal wall, ribs were resected to allow us to separate the tumor from the TAA, after which median sternotomy was performed uneventfully, creating generous exposure. The tumor had invaded the sternum, ribs, innominate vein, phrenic and recurrent laryngeal nerves, and lung. The tumor was removed en bloc, and the chest wall was reconstructed. Intra- and post-operative brain infarction and rupture of the TAA were avoided. The patient is alive and well without recurrence 10 months after surgery.

A 59-year-old man who underwent radiation therapy (41 Gy) to the mediastinum through the anterior chest for Hodgkin's disease presented with a painful anterior chest wall tumor 18 years later. The tumor originated from the left parasternal region and was excised with the sternum. Chest wall reconstruction was performed. The tumor measured 45 x 45 mm and invaded the sternum. The pathologic diagnosis was malignant fibrous histiocytoma. Early and complete excision of the tumor is indicated.

Purpose: The purpose of this work was to assess CT demonstration of the enlarged gonadal vein as a portosystemic shunt of mesenteric varices., Method: The clinical records and CT images of eight patients with angiographically confirmed mesenteric varices were studied retrospectively. We measured the size of the right gonadal vein of these eight patients and also measured the size of the right gonadal vein in 60 patients without mesenteric varices., Results: In all eight patients, CT demonstrated that the mesenteric varices drained into the inferior vena cava through the dilated right gonadal vein (diameter 6-10 mm) in all and that the left gonadal vein was not dilated (diameter 2-3 mm). In 60 patients without mesenteric varices, the diameter of the right gonadal vein was 1-5 mm., Conclusion: CT demonstrates the dilated gonadal vein as a portosystemic shunt of the mesenteric varices. Awareness of a dilated gonadal vein in patients with portal hypertension may be helpful to consider the possibility of mesenteric varices.

A superior outcome is observed for cases of complete resection compared with that of incomplete resection. The reason and the countermeasure of the incomplete resection for lung cancer were analyzed. During 12 years, 274 patients with primary non-small cell lung cancer were surgically treated. Two hundred and forty-eight patients underwent complete resection and 26 incomplete resection. Three-year survival was 62% for patients with complete resection and 17% for patients with incomplete resection. Survival rates were not different between the paroative reduction surgery and the exploratory thoracotomy. Tiny but multiple pleural dissemination or small amount of the malignant pleurfal effusion was not able to detect preoperatively. In these cases, preoperative thoracoscopic observation may useful for avoiding the meaningless thoracotomy. Postoperative radiochemotherapy may improve the prognosis if the therapy is effective. Chemotherapy on the basis of the sensitivity assay is warranted.

This article describes the fast MRI of fetal abnormalities and placental anomalies in evaluation of the usefulness of fast MRI in obstetric diagnoses. Fast MRI provides excellent resolution for imaging fetal and maternal anatomies without the need for sedation. Fast MRI is therefore useful to clarify diagnoses suggested by equivocal ultrasonographic findings and to obtain additional information for prenatal counseling and management.

A 44-year-old female was admitted to our hospital because of the left cervical tumor. Radiologic examination showed that the tumor was 5 cm in diameter and was inhomogeneous. The tumor was spread to the upper mediastinum. Esophagoscopy showed that the tumor was covered by the normal mucosa. Percutaneous fine needle biopsy did not appear the histopathological diagnosis. The patient underwent surgical resection through the cervical approach and the tumor was located between the mucosal and muscular layers of the esophagus. The tumor was enucleated without any complication. Histopathological diagnosis was leiomyoma. Postoperative course was uneventful. Expecting diagnosis and positive complete resection is recommended for leiomyoma of the esophagus.

Purpose: The purpose of this work was to demonstrate the appearance of the right inferior phrenic artery (RIPA) on CT in patients with hepatocellular carcinoma (HCC)., Method: We assessed the biphasic helical CT scans using 10 mm collimation in 16 patients with arteriographically proven HCCs supplied by the RIPAs. Size of the right and left inferior phrenic arteries and origin of the RIPA were evaluated and correlated with arteriographic images., Results: Helical CT showed dilated RIPAs on the right diaphragmatic crus as foci of high attenuation on arterial-phase images in all patients. Diameter of the RIPA (average 3.3 mm) was larger than that of the left inferior phrenic artery (average 1.5 mm). The origin of the RIPAs was correctly predicted in 13 of 16 (celiac artery 6, abdominal aorta 5, right renal artery 2) patients., Conclusion: Asymmetric dilatation of the RIPA as an indicator of extrahepatic collateral of HCC can be demonstrated on the right diaphragmatic crus with arteriographic images of biphasic helical CT.

A 32-year-old man who underwent evaluation for dyspnea and left chest pain proved to have a left pneumothorax and a right giant bulla. After surgery for the left pneumothorax, drug induced liver injury was observed. Seventeen days after surgery, left giant bulla was infected and niveau formation was seen with high fever. After administration of antibiotics, the niveau was disappeared and the body temperature was down, however, drug induced liver injury was caused. After that, again, the niveau formation was noticed in the right bulla. We speculated that adequate drug therapy could not used because of liver injury if the right bulla would be infected one more time. Bullectomy of the right lung was performed. One year after surgery, there were no signs of infection. We usually administer the adequate antibiotics against the infectious giant bulla without surgical therapy because the bulla will be reduced with the infection. However, there is a situation like this case that surgical treatment is required because of the drug induced liver injury.

Diffusion-weighted imaging (DWI) provides unique information about various pathological changes of the brain. DWI is sensitive for the detection of hyperacute infarcts, and useful in distinguishing acute or subacute infarcts from chronic infarcts. DWI is useful in differentiating cytotoxic edema from vasogenic or interstitial edema, which may help to determine prognosis. DWI is useful in differentiating cystic or necrotic tumors from abscesses or epidermoids. DWI can discriminate nonenhanced tumor infiltration from vasogenic edema, and differentiate dysmyelination from demyelination.

The thoracic cage after a lung resection is filled by the remaining lobes, the elevated diaphragm, the diminished thoracic cage, and by mediastinal shifting. The changes in the thorax after a lung resection were quantified using magnetic resonance imaging. The study group consisted of 39 patients who had undergone a lobectomy, four who had undergone a pneumonectomy, and 14 controls. The left ventricular angle, ascending aortic angle, mediastinal shift, longitudinal length of the thoracic cage, the distance between the thoracic apex and the level of the aortic valve, and diaphragmatic elevation were all measured. After a right lower lobectomy, the mediastinum shifted more rightward than after a right upper lobectomy. The diaphragm became more greatly elevated after a right upper lobectomy than after a right lower lobectomy. When a chest wall resection was added to a right upper lobectomy, the mediastinal anatomical changes decreased. After a left upper lobectomy, the degree of mediastinal shifting was greater than after a left lower lobectomy. A left upper lobectomy shifted the mediastinum at the level of the right atrium. This method is easily reproducible and was found to be effective for quantifying the changes in the thorax after a lung resection.

Purpose: The appearance of localized lymphatic spread of lung cancer as evaluated by computed tomography (CT) was correlated with the pathologic specimens in 178 patients. Clinical significance was also studied, with emphasis on nodal staging (N factor)., Materials and Methods: Eighteen of 178 patients histopathologically demonstrated severe lymphatic spread of lung cancer along the bronchovascular bundles. CT findings of localized lymphatic spread of lung cancer and nodal staging of 18 patients were retrospectively reviewed and compared with 160 patients with no severe localized lymphatic spread of lung cancer., Results: All 18 patients with severe lymphatic spread showed linear opacities extending from the tumor to the pulmonary hilum or peripheral pleura depending on the location of lung cancer. Ten of the 18 patients also showed regional thickening of bronchovascular bundles. The nodal staging of these 18 patients was more aggressive than that of other patients without severe lymphatic spread., Conclusion: If linear opacities and regional thickening of bronchovascular bundles extending from the tumor to pulmonary hilum or peripheral pleura are demonstrated on CT, severe lymphatic spread of lung cancer can be strongly suspected, and lung cancer staging should be done carefully.

Objective: This study was carried out to determine whether asthma affects the development of emphysema., Methods: We studied 62 patients with reversible airway obstruction during remission, and evaluated the presence and severity of emphysema using high-resolution CT. The emphysema score (ES) was evaluated with the visual scoring method on CT scans., Results: Of the 62 patients, 14 were judged to have emphysema. Patients with emphysema were significantly older and more likely to be male than those without emphysema. All patients with emphysema were smokers. There was no significant difference in the duration or severity of asthma between patients with and without emphysema. The 62 patients were divided into three groups according to the ES: 48 patients without emphysema (ES = 0%), 8 patients with mild emphysema (0% < ES < 15%), and 6 patients with more severe emphysema (ES > or = 15%). Highly significant differences between patients without emphysema and those with more severe emphysema were found in FEV1 (p<0.01), FEV1/FVC (p<0.001), diffusing capacity for carbon monoxide (DCO) (p<0.01), and DCO/alveolar volume (p<0.0001)., Conclusion: Neither the duration nor the severity of asthma was correlated with the presence of emphysema, while smoking history, sex, and age were strongly correlated. No patients with emphysema were found among the nonsmokers, including those with severe asthma or asthma of long duration. These results suggest that asthma does not lead to emphysema.

The authors review their experience with magnetic resonance imaging (MRI) of the thymus and discuss the appearance of thymic epithelial tumors where MRI is clinically useful. Detailed descriptions of MRI findings in benign thymomas, invasive thymomas, and thymic carcinomas are provided. Most benign (noninvasive) thymomas appear with a slightly higher signal intensity than that of muscle on T1-weighted images. On T2-weighted images, thymomas have an increase in signal intensity on both T1- and T2-weighted images. Neither fibrous septa nor lobulated internal architecture can be detected on MRI. Gd-DTPA-enhanced MR images show homogeneous enhancement. On the other hand, invasive thymomas show the same signal intensity as benign thymomas, both on T1- and T2-weighted images. However, invasive thymomas appear inhomogeneous in signal intensity on T2-weighted images. T2-weighted images also show a lobulated border, fibrous septa, and lobulated internal architecture, characteristic of most invasive thymomas. Irregularity of tumor margins indicating invasion into surrounding structures is noted in some cases of invasive thymomas. Exceptionally minute thymomas (< 1 cm in diameter) show a different signal intensity on MRI as compared to those of usual thymomas: both T1- and T2-weighted MR images show a low signal intensity mass with irregular or unclear borders. Histopathologically, these minute thymomas contain numerous tiny cysts and/or abundant collagenous tissues. Generally, thymic carcinomas, except carcinoid tumors, appear with a relatively low signal intensity on T1- and T2-weighted MR images in comparison to those of thymomas. In particular, well-differentiated squamous cell carcinomas appear with a low signal intensity on both T1- and T2-weighted images. Abundant collagenous tissue may be a causative factor for the low signal intensity on T2-weighted MR images. Thymic carcinomas appear slightly inhomogeneous on both T1- and T2-weighted images. Neither fibrous septa nor lobulated internal architecture can be detected in any thymic carcinoma. If MRI is performed on a patient with anterior mediastinal tumors, thymic carcinoma may be precisely diagnosed when characteristic MR findings are demonstrated.

The effects of dipyridamole on radiation damage in the mouse were investigated. Dipyridamole (i.p. 2 mg/mouse) administered 1 h before exposure, protected against gamma-irradiation. Pretreatment significantly decreased the death rate at 30 days from 89 to 33% (p<0.001) after 9 Gy whole-body irradiation. LD50 at 30 days was increased from 6.67 to 7.65 Gy in the dipyridamole pretreated group. The level of thiobarbituric acid reactive substances (TBARS) in the liver and spleen, a measure of free radical initiated liver peroxidation, increased 155, 193, 195, and 236% of control (without irradiation) in liver, and 132, 146, 168, and 276% of control (without irradiation) in spleen on days 2, 4, 7, and 10 after 9 Gy of whole-body irradiation respectively. The TBARS levels in both liver and spleen 2 days after irradiation were reduced to 73 +/- 7 and 60 +/- 19% respectively after dipyridamole treatment (2 mg/mouse, i.p. injection 1 h before exposure). In electron microscopic studies, mitochondria and endoplasmic reticulum in the irradiated mouse liver were swollen, but otherwise appeared normal after dipyridamole treatment. These results suggest that dipyridamole has a protective effect on animal survival 30 days after 60Co gamma-irradiation and inhibits lipid peroxidation - which is thought to play a part in the radiation injury in mouse liver and spleen.

Four patients with coexistent lung cancer and acute pulmonary tuberculosis were operated during recent 5 years. All were males and cigarette smokers (B.I. > 600). Adenocarcinoma were recovered from 3 patients, while the remaining 1 had squamous cell carcinoma. Only 1 curative resection was performed for lung cancer. In most cases, late stage of the disease was alleged to be a factor contributing to the poor prognosis.

Objective: Tuberculous mediastinitis, a rare complication of pulmonary tuberculosis, may simulate a mediastinal tumor on chest radiography. For evaluation and follow-up of the disease, CT and MRI are needed., Materials and Methods: Two cases of tuberculous mediastinitis are presented with emphasis on the importance of MRI. In both cases, MRI was performed because the CT appearance was unusual for a mediastinal tumor., Results: The areas of low signal intensity within the anterior mediastinal mass on both T1- and T2-weighted imaging were due to the reactive fibrous tissue and were suggestive of an inflammatory mass., Conclusion: When a mediastinal mass would be unusual on CT, MRI should be performed. If there are areas of low signal intensity within the mass on both T1- and T2-weighted imaging, an inflammatory mass such as tuberculous mediastinitis, is one of the possibilities.

Mucinous carcinomas of the gallbladder are relatively uncommon. Their radiological findings have not been described previously. We describe the CT and US findings of mucinous carcinoma of the gallbladder in 3 cases. Tumors (thickened wall and/or intraluminal polypoid mass) showed hyperechogeneity or isoechogeneity on US and water density on CT. US clearly detected large polypoid lesions, but CT was unable to detect these lesions in 2 cases. Therefore, we stressed the discrepancy between the findings of US and CT. These features can be explained by the fact that a tumor containing a large amount of mucin produces a mass of near-water density in the gallbladder on CT. It is of value to know the radiological findings of these tumors because the diagnosis is easily missed by CT study alone.

A 56-year-old female, who suffered a subarachnoid hemorrhage (SAH) due to spontaneous dissection of the right vertebral artery 7 years previously, was admitted to our hospital with headache and vertigo. She hadn't had any attacks of SAH for 7 years. A magnetic resonance imaging (MRI) showed a high signal intensity mass and a low signal intensity due to calcification on the right ventrolateral surface of the medulla on both T1 and T2 weighted images. Vertebral angiography showed complete occlusion of the cervical segment of the right vertebral artery (VA). Left vertebral angiography didn't reveal any retrograde filling of the intracranial segment of the right VA through VA union. Thus, the spontaneous entrapment by dissection of the vertebral artery was demonstrated 7 years after SAH with MRI and serial angiography.

We reviewed the CT findings of four cases of Wegener's granulomatosis that presented as inflammatory masses in the sinonasal cavity or orbit. In the present study, an infiltrative nature and homogeneous texture with contrast enhancement were typical of the masses. In addition, the masses were frequently accompanied by infiltration of the pterygopalatine fossa or destruction of adjacent bone. However, no pathognomonic findings were observed.

Pulmonary inflammatory pseudotumor (plasma cell granuloma) is not a true neoplastic lesion, but is composed of a variety of inflammatory cells, predominantly plasma cells. The chest X-ray features resemble those of malignant lung tumors; therefore, CT is often necessary for further evaluation. We report the CT features of five cases with histologically proved pulmonary inflammatory pseudotumor, which can be summarized as follows: a solitary round or oval parenchymal mass with regular or irregular margin, and with or without calcifications. The calcifications are useful for differential diagnosis if present, but they are usually non-specific in shape and configuration. The mean CT attenuation value of the major portion of the mass was increased from 41 HU to 78 HU by the injection of contrast material. In one case, a linear extension of the lesion was seen from the mass to the lung hilum. In three cases, satellite lung nodules were seen. One of these nodules was also proved histopathologically to be inflammatory pseudotumor. The biopsy specimens obtained by using a 20 gauge cutting-needle and an automated biopsy gun were satisfactory for histopathological diagnosis.

We investigated the effects of dimethyl sulfoxide (DMSO) on radiation damage in the mouse. DMSO (i.p. 0.11 g/mouse) administered 30 min before exposure protected the mice from the gamma-whole body irradiation: the 30 days lethality was significantly decreased from 44% to 16% (P < 0.05). The contents of thiobarbituric acid reactive substances(TBA-RS) in the mouse liver increased linearly between days 2 and 10 after 9 Gy gamma ray irradiation. The TBA-RS contents in the liver on days 2 to 10 after irradiation were reduced by DMSO pretreatment. The irradiation decreased superoxide dismutase (SOD) activity in the liver on day 10. Decrease in SOD activity was prevented by DMSO pretreatment. In the electron microscopic study, the mitochondria in the irradiated mouse liver were swollen, but we could observe no change after DMSO pretreatment. The results suggest that DMSO has radioprotective effects, probably due to inhibition of lipid peroxidation.

As desmoid tumors invade locally and postoperative recurrence is common, accurate diagnosis of the extent of the tumor is needed prior to surgery. CT and/or MRI evaluation of tumor extension was retrospectively studied in eight patients with desmoid tumors, and the results were correlated with the histopathological findings. All tumors were completely resected even in patients who were evaluated by CT alone. However, the delineation of tumor and local invasion were not clearly demonstrated by CT. On the other hand, the delineation of tumor and local invasion were well visualized on MRI. The MRI picture of desmoid tumors was mainly composed of two different areas of signal intensity. The area of hypointensity in both T 1- and T 2-weighted images was found to have abundant collagen fibers, while the area of isointensity or slight hyperintensity in T 1-weighted images and hyperintensity in T 2-weighted images was found to have fibroblasts. In conclusion, MRI is better suited to the evaluation of patients with desmoid tumors than CT.

CT findings were reviewed in four adult patients with chronic maxillary osteomyelitis (CMO) that was histologically proved. The CT features of CMO included bone destruction and soft tissue mass, predominantly in the inferior portion of the maxillary antrum (all 4 cases), thickening of the antral wall (3 cases) and abnormal soft tissue around the antrum associated with or without bony wall destruction (3 cases). CMO could not be distinguished from cancer of the maxillary antrum on CT because of the similar findings. However, abnormal soft tissue around the antrum together with an undestructed bony antral wall may be useful for differentiating the two diseases.

Mucin-producing pancreatic cancers (MPPC), which include mucinous adenocarcinoma, papillary adenocarcinoma and cystadenocarcinoma, are radiographically characterized by diffuse or localized dilatation of the main pancreatic duct due to excessive mucin production. Therefore, MPPC are occasionally difficult to distinguish from chronic pancreatitis on CT unless the primary pancreatic lesion is visualized. We compared five cases of MPPC with five cases of chronic pancreatitis with marked duct dilatation to determine differences in CT images between the two diseases. There was no significant difference between the two diseases in the nature of duct dilatation (size, extent, contour) or parenchymal changes (atrophy, enlargement, calcification, cystic lesion). However, dilatation of the intramural duct was characteristically observed in MPPC but not in chronic pancreatitis. Papillary masses in the pancreatic duct, when observed, were another finding specific to MPPC.

Twenty-five percutaneous lung biopsies using a 20-gauge cutting needle and automated biopsy gun (ABG) were performed under CT guidance in 25 patients with thoracic lesions. This procedure was compared with that using a 21-gauge manual aspiration needle in 36 patients (40 examinations, 37 lesions) in terms of success rate, rate of correct diagnosis, mean examination time and rate of complications. Specimens obtained from lung biopsy were graded by a histopathologist according to quality and quantity from 0 to 4 (pathological score). There were no statistically significant differences between the two procedures in terms of success rate, rate of correct diagnosis and rate of complications; only the time required was significantly different. However, sufficient biopsy material and a mean pathological score of G-II 2.8 (that of G-I was 1.9, p less than 0.05) could be obtained by the biopsy procedure using the cutting needle. The above results indicated that aspiration needle biopsy was adequate for lung biopsy, but that a cutting needle and ABG should be used when a good biopsy specimen is needed for tissue diagnosis.

In order to seek for the factors to suggest a risk of rupture of abdominal aortic aneurysms (AAA), we measured the largest diameter of AAA and the thickness of intra-luminal thrombus on CT in 72 patients. The mean aneurysmal size was 64 mm in diameter in 9 patients with ruptured aneurysm and 61 mm in diameter in 63 patients with non-ruptured aneurysm respectively (p less than 0.90). The rupture of AAA was seen in 3 of 30 patients with AAA of the small size (less than 50 mm in diameter), in 3 of 16 patients with AAA of the intermediate size (51-66 mm in diameter) and in 3 of 26 patients with AAA of the large size (more than 70 mm in diameter), respectively. The mean intra-luminal thrombus was 9 mm in 9 patients with ruptured aneurysm and 19 mm in thickness in 63 patients with non-ruptured aneurysm respectively (p = 0.05). We concluded from the above results that the aneurysmal size was not important, but the thickness of intra-luminal thrombus was useful for suggestion of a risk of rupture of AAA.

A case of renal cell carcinoma with unusual extension is reported, in which the radiographic findings have a close resemblance to those of transitional cell carcinoma of the renal pelvis. We emphasize that it is occasionally difficult to draw a distinction between transitional cell carcinoma with renal invasion and renal cell carcinoma with renal pelvic extension even by computed tomography (CT) and angiography.

The possibility that hypotension associated with protamine or heparin might be related to changes in levels of serum ionized calcium values was determined by in vitro and in vivo studies in dogs. In vitro protamine did not decrease serum calcium levels, but heparin did in a dose-dependent fashion. The reduction ranged from 7% with 10 units/ml of heparin to 20% with 100 units/ml of heparin. Ionized calcium concentrations initially decreased by heparin were restored toward control levels by our increasing the dose of protamine, indicating that the electrostatic attraction between protamine and heparin molecules is stronger than that between heparin and ionized calcium. Despite significant reductions in blood pressure and heart rate, clinical doses of protamine did not decrease ionized calcium in vivo. Although the results of the in vitro study suggested that heparin-induced hypocalcemia might occur in vivo, in vivo heparin caused neither a decrease in ionized calcium nor hypotension. The reduction of ionized calcium by heparin might have been rapidly compensated for in vivo. The results indicate that hypotension due to protamine or heparin is unlikely to be related to changes in serum ionized calcium levels.

The radiographic findings and the hypotension patterns were reviewed in 19 patients having hypotensive reactions in routine excretory urography using ionic contrast medium. The lowest systolic blood pressure was above 80 mmHg in 10 patients while below 80 mmHg in remaining 9 patients. The urogram was unremarkable as long as the systolic blood pressure was preserved above 80 mmHg. In 2 patients, whose systolic blood pressure decreased quickly beyond 80 mmHg immediately after injection of contrast medium, the pyelogram was faint or non-visualized. On the other hand, in 4 patients, whose systolic blood pressure decreased beyond 80 mmHg in several minutes after injection of contrast medium and remained under 80 mmHg for more than 20 minutes, the nephrogram was dense and the pyelogram was faint or non-visualized. Although systolic blood pressure decreased beyond 80 mmHg, the urogram was unremarkable in 3 patients. This was due to the delayed hypotension or the short duration of hypotension.

The CT features of retroperitoneal lymphangiomas are unilocular or multilocular cysts in the retroperitoneum and slightly and uniformly thickened wall that enhances following contrast medium administration. Three cases are reported.