Pulmonary cryptococcosis in immunocompetent patients: HRCT characteristics.

We analyzed the high-resolution CT (HRCT) findings of cryptococcosis in immunocompetent patients. The predominant manifestations were multiple nodules (n=6) and a single nodule (n=7). Regarding the pattern of multiple nodules, two cases of cavities or necrosis, four cases of surrounding centrilobular micronodules and five cases of "acinar" nodules were seen. No "tree-in-bud" appearance was detected. Five of seven cases of a single nodule were classified as polygonal, and two of them were round. Two cases accompanied micronodules and one case cavitation. Although no "tree-in-bud" appearance was observed, pulmonary cryptococcosis mimics tuberculosis.

The characteristics of patients with atopic dermatitis demonstrating a positive reaction in a scratch test after 48 hours against house dust mite antigen.

The clinical characteristics of patients in whom an IgE-mediated reaction against house dust mite (HDM) antigens that contribute to the pathogenesis of atopic dermatitis (AD) remain unclear. This study attempted to elucidate the characteristics of patients who exhibit a positive reaction 48 hr or later against HDM in scratch tests. The reactions after epi-cutaneous application of the allergen to skin with prior scratching were observed for one week in sixteen AD patients showing positive immediate-type hypersensitivity reactions for HDM. Fifty percent of the patients demonstrated positive reactions at 48 hours after epi-cutaneous application of HDM. Significantly higher values were demonstrated in the group positive for HDM after 48 h in serum total IgE, specific IgE for Der f 1, and lactate dehydrogenase, peripheral eosinophil counts, eruption score, and the area of eruption than in the group negative for HDM after 48 h. Domestic exposure to Der f 1 was also higher in the group positive for HDM after 48 h than in the negative group. These results indicate that the patients in whom the HDM-induced reaction continuing more than 48 h and contributing to their real eczematous eruptions are characterized by considerably increased levels of specific IgE for HDM antigens, high disease activity in AD, and increased exposure to domestic HDM.

Increased levels of serum interleukin-16 in adult type atopic dermatitis.

Interleukin (IL)-16 serves as a natural ligand of CD4 molecules and induces chemotaxis in CD4-expressing cells such as T cells, eosinophils, dendritic cells and monocytes. We examined the serum levels of IL-16 in patients with adult atopic dermatitis when their eruptions were aggravated and in non-atopic healthy controls, and then analysed the possible correlation between these values and the levels of several clinical markers. The serum levels of IL-16 were significantly higher in patients with atopic dermatitis than in the controls--both in exacerbation status and after conventional treatment. Multiple regression analyses showed that serum IL-16 was a predictor of the eosinophil count. Circulating IL-16 levels decreased significantly in patients with atopic dermatitis after topical treatment with corticosteroids or tacrolimus. These findings provide evidence that IL-16 plays a role in the exacerbation of chronic adult atopic dermatitis.

Presacral dermoid cyst with scanty fat component: usefulness of chemical shift and diffusion-weighted MR imaging.

We present a case of a dermoid cyst located at the presacral space. Although CT and conventional MR (T1- and T2-weighted images) demonstrated a non-specific cystic mass with little evidence of calcification or fat, chemical shift and diffusion-weighted MR imaging suggested the presence of small amount of fat and abundant keratinoid substance within the tumor, respectively. Pre-operative diagnosis of dermoid cyst was made. The tumor was surgically resected and the diagnosis was confirmed. Chemical shift and diffusion-weighted MR imaging are useful in the diagnosis of dermoid cyst with little evidence of calcification and fat.

Reliability of mean transit time obtained using perfusion-weighted MR imaging; comparison with positron emission tomography.

The purpose of this project was to assess the reliability of the cerebral mean transit time (MTT) obtained using perfusion-weighted MR imaging by comparing it with the MTT obtained when performing positron emission tomography (PET). Ten patients with chronic occlusive cerebrovascular disease were investigated. They had either unilateral internal carotid artery occlusion or middle cerebral artery occlusion. The regions-of-interest were placed in non-infarcted areas within the territory of the middle cerebral artery on the affected side. Control regions-of-interest were placed in mirrored regions of the contralateral side. Linear regression analyses were performed using the parameters of the MTT obtained with perfusion-weighted MR imaging and the MTT, cerebral blood flow, vascular reactivity, and oxygen extraction fraction obtained with PET. The respective MTTs of the affected and non-affected sides obtained with perfusion-weighted MR imaging versus those with PET were 7.3 +/- 2.2 s and 6.0 +/- 1.2 s versus 8.2 +/- 3.0 s and 6.4 +/- 1.7 s. The MTT obtained using perfusion-weighted MR imaging and PET demonstrated statistically significant correlation (r = 0.87, p < 0.0001). The MTT obtained with perfusion-weighted MR imaging correlated statistically with cerebral blood flow (r = -0.74, p < 0.001), vascular reactivity (r = -0.73, p < 0.001) and oxygen extraction fraction (r = 0.61, p < 0.01). Similarly, the MTT obtained using PET statistically correlated with cerebral blood flow (r = -0.78, p < 0.0001), vascular reactivity (r = -0.51, p < 0.05) and oxygen extraction fraction (r = 0.68, p < 0.01). The reliability of the MTT obtained using perfusion-weighted MR imaging appears to be approximately equal to that obtained with positron emission tomography.

Comparison between the shape of resected femoral sections and femoral prostheses used in total knee arthroplasty in Japanese patients: simulation using three-dimensional computed tomography.

Simulation of the femoral cut for total knee arthroplasty was performed in 44 knees using three-dimensional computed tomography. The three-dimensional images were measured, and the shape of the femur was compared to the provided femoral prosthesis. The ratio between the medial-lateral and anteroposterior dimensions of the three-dimensional images did not always match the prosthesis. The widths of the medial condyles of the three-dimensional images tended to be larger than those of the prosthesis. The lengths of the lateral posterior condyles of the three-dimensional images tended to be shorter than those of the prosthesis. These results suggest that a new prosthesis should be designed to achieve a better anatomical fit.

Diffusion tensor in posterior cingulate gyrus: correlation with cognitive decline in Alzheimer's disease.

To determine whether the diffusion abnormalities in brains with Alzheimer's disease (AD) correlate with disease severity, we studied 34 AD patients using diffusion tensor MRI. Mean diffusivity and fractional anisotropy (FA) as well as three eigenvalues (lambda1, lambda2, and lambda3) of the diffusion tensor of the posterior cingulate white matter correlated with the Mini-Mental State Examination (MMSE) score. The mean diffusivity and the three eigenvalues showed significant correlation with the MMSE score. On the other hand, no significant correlation was seen between the FA and MMSE score. Our results suggested that mean diffusivity and the eigen-values, but not FA, reflect progression of AD-related histopathlogical changes in the posterior cingulate white matter and may be useful biological indices to monitor AD.

MR imaging of ampullary carcinomas.

OBJECTIVE: The purpose of this study was to demonstrate the appearance of ampullary carcinomas on MR images. METHODS: Sixteen patients with ampullary carcinomas underwent MR imaging. Tumor detectability, signal intensity of the tumor, and enhancement pattern on dynamic study were analyzed. MR cholangiopancreatography (MRCP) findings were assessed and were compared with the endoscopic retrograde cholangiopancreatography (ERCP) findings. RESULTS: Signal intensities of the tumor on each image were various. Dynamic study detected all tumors except one, and all detected tumors showed delayed enhancement. MRCP delineated more than half of the tumors as a filling defect within the duodenal fluid and clearly demonstrated pancreaticobiliary ductal. CONCLUSIONS: Dynamic study is mandatory in diagnosing ampullary carcinoma, because it can depict most of the tumors, and delayed enhancement of such tumors is characteristic in case of ampullary carcinoma. MRCP can provide reliable information about pancreaticobiliary duct and it can replace diagnostic ERCP.

Unilateral proximal interruption of the pulmonary artery in adults: CT findings in eight patients.

PURPOSE: The authors retrospectively reviewed CT findings of unilateral proximal interruption of the pulmonary artery in eight adults. METHODS: Patient age ranged from 23 to 65 years (mean, 44 years), and three men and five women (six left-side affected and two right-side affected) comprised the study group. High resolution CT was obtained in five patients. Associated anomalies of great vessels included five cases of right aortic arch and one tetralogy of Fallot. RESULTS: On the affected side, complete defects of pulmonary arteries were seen in all patients. CT revealed serrated pleural thickening in six patients (75%), subpleural parenchymal bands in five (63%), and mosaic attenuation in three (38%) on the affected lung. Dilatation of bronchial arteries in five patients (71%), internal thoracic arteries in four (57%), and intercostal arteries in three (43%) were also seen. As for other parenchymal changes, cystic bronchiectasis and honeycombing were seen in two (25%) respective cases. On the unaffected lung, mosaic attenuation was seen in four (50%) patients. CONCLUSIONS: The main manifestations of unilateral proximal interruption of the pulmonary artery were complete defects of pulmonary arteries, enlarged bronchial arteries, and formed pleural thickening or some parenchymal changes of the lung.

Pulmonary complications after hepatic artery chemoembolization or infusion via the inferior phrenic artery for primary liver cancer.

PURPOSE: The purpose of this study was to determine the frequency, patterns of disease, and risk factors for development of pulmonary complications after liver chemoembolization via the inferior phrenic artery (IPA). MATERIALS AND METHODS: Forty-four selective transcatheter hepatic chemoembolization (THCE) procedures via the IPA were performed in patients with primary liver cancers with use of a mixture of anticancer agents and iodized oil (Lipiodol) with or without transcatheter arterial embolization. The grades of pulmonary complications were assessed on triphasic helical computed tomographic (CT) images after THCE and were correlated with angiographic findings of the IPA, infused dosages of Adriamycin and Lipiodol, and hepatic venous tumor thrombus on triphasic CT images before THCE. RESULTS: THCE via the IPA frequently resulted in lung CT changes: Lipiodol accumulation in the lung field (52%), consolidation (68%), and pleural effusion (41%). Among 44 patients, two (5%) developed respiratory symptoms. An excellent correlation was shown between Lipiodol accumulation and the presence of angiographic abnormalities of the IPA (P <.005). A significant correlation was also shown between the grades of pulmonary complications and the numbers of angiographic abnormalities (P <.01). The grades of pulmonary complications increased according to the infused dosage of Adriamycin and Lipiodol (P <.05). CONCLUSIONS: Angiographic abnormalities such as arteriovenous shunts, dilated anastomotic branches, and dense pleural staining are important risk factors for pulmonary complications of THCE via the IPA. Embolization for shunts may be required to prevent such complications, especially in cases with shunts to pulmonary vessels or hepatic veins.

[A case of advanced esophageal cancer with multiple lymph node metastases successfully treated with induction chemotherapy consisting of nedaplatin and 5-FU followed by chemoradiotherapy].

A 61-year-old male patient had esophageal carcinoma with multiple mediastinal and right supraclavicular lymph node metastases. Chemotherapy consisting of infusion of nedaplatin and continuous infusion of 5-fluorouracil was performed. After three courses of the chemotherapy, the patient was treated with a combination of cisplatin and 5-FU and radiotherapy. However, only radiotherapy was performed after 18 Gy because of grade 3 leukocytonenia during the chemoradiotherapy. The patient achieved a partial response (nearly complete response) for 9 months after the initiation of the treatment. In conclusion, chemotherapy with NDP and 5-FU followed by chemoradiotherapy is effective and safe for patients with esophageal carcinoma with multiple lymph node metastases.

Clinical impact of whole body FDG-PET on the staging and therapeutic decision making for malignant lymphoma.

OBJECTIVES: The aim of this study is to evaluate the clinical impact of whole-body FDG-PET for the pre-therapeutic evaluation of malignant lymphoma and compared to that of 67Ga-scintigraphy when added to non-RI examinations. METHODS: We examined 46 patients with malignant lymphoma including 42 newly diagnosed cases and 4 relapsed cases. Whole-body FDG-PET was started 63 minutes after the administration of FDG with ECAT EXACT HR+. The clinical stage of each patient was determined based on the results of a non-RI examination (consisting of physical examination, CT, gastrointestinal studies and bone marrow aspiration), 67Ga planar images and FDG-PET. Discrepant findings were verified based on the response to treatment and the findings of a follow-up examination more than 6 months after treatment. Finally, 152 nodal regions and 19 extranodal tissues were found to be involved by disease. RESULTS: In the 152 nodal lesions, FDG-PET detected 54 nodal lesions in addition to 98 lesions detected by non-RI examinations, whereas 67Ga-scintigraphy detected 14 additional lesions. The sensitivity of non-RI, non-RI + 67Ga and non-RI + FDG was 64.5%, 73.7% and 100.0%, respectively. In 19 extranodal lesions, FDG-PET detected 5 extranodal lesions in addition to 13 lesions detected by non-RI examinations, whereas 67Ga-scintigraphy detected 1 additional lesion. The sensitivity of non-RI, non-RI + 67Ga and non-RI + FDG was 68.4%, 73.7% and 94.7%, respectively. When combining the FDG-PET findings with the non-RI findings, the improvement of the detectability was much higher than that when 67Ga findings were combined to the non-RI findings. For the staging of lymphoma, the non-RI and non-RI + 67Ga findings accurately diagnosed 76.1% and 80.4%, respectively, whereas the non-RI + FDG findings accurately diagnosed 82.6%. Finally, FDG-PET resulted in changes in the clinical management of 8 patients (17.4%). CONCLUSIONS: FDG-PET offers more information in addition to the findings of conventional diagnostic methods than 67Ga-scintigraphy in order to accurately detect malignant lymphoma. FDG-PET can therefore play an important role in therapeutic decision making on lymphoma.

Patterns of Care Study quantitative evaluation of the quality of radiotherapy in Japan.

BACKGROUND: Quality assurance (QA) of clinical practice is important for any medical specialty. Programs based on the Patterns of Care Study (PCS) have been developed to compare the quality of radiotherapeutic care at individual institutions, with the national average representing the process and outcome of radiotherapy. The feasibility of these programs was analyzed. METHODS: Calculation programs for the national average and standard score were developed to evaluate quantitatively the process and outcome of radiotherapy at individual institutions as well as at the national level. The programs were used to evaluate the quality of radiotherapy for 561 esophageal carcinoma patients surveyed in the Japanese PCS. RESULTS: As a representative example of QA measurement, the national average for the 5-year survival rate for these patients in the nonsurgery group was 5%. The regional averages for those in academic and nonacademic institutions were 9% and 1%, respectively (P = 0.0142), showing a significant difference between these two institutional strata. The standard score compared with the national average for institution No.105, for example, was 16.3 (P < 0.0001), with the positive value indicating that the outcome at this institution was significantly higher than the national average. The corresponding figure compared with the regional average was -0.3 (P = 0.7391), with the negative value indicating the outcome is not superior to the regional average of academic institutions. CONCLUSIONS: These programs make it possible to compare quantitatively the quality of radiation therapy at individual institutions with the national and regional averages. They should also be useful for nationwide QA projects in radiation oncology as well as in other medical specialities.

11C-methionine uptake in cerebrovascular disease: a comparison with 18F-fDG PET and 99mTc-HMPAO SPECT.

OBJECTIVES: Carbon-11-L-methyl-methionine (11C-methionine) has been reported to be useful for evaluating brain tumors, but several other brain disorders have also shown signs of high methionine uptake. We retrospectively evaluated the significance of 11C-methionine uptake in cerebrovascular diseases, and also compared our results with those for 18F-FDG PET and 99mTc-HMPAO SPECT. METHODS: Seven patients, including 3 patients with a cerebral hematoma and 4 patients with a cerebral infarction, were examined. All 7 patients underwent both 11C-methionine PET and 99mTc-HMPAO SPECT, and 6 of them underwent 18F-FDG PET. RESULTS: A high 11C-methionine uptake was observed in all 3 patients with cerebral hematoma. Increased 99mTc-HMPAO uptake was observed in 2 out of 3 patients, and all 3 patients had decreased 18F-FDG uptake. Of 4 patients with a cerebral infarction, high 11C-methionine uptake was observed in 3. Increased 99mTc-HMPAO uptake was also observed in one patient, whereas 3 patients had decreased 18F-FDG uptake. CONCLUSIONS: We should keep in mind that high 11C-methionine uptake is frequently observed in cerebrovascular diseases. CVD should therefore be included in the differential diagnosis when encounting patients with a high 11C-methionine uptake.

Optimal multi-phase three-dimensional fast imaging with steady-state free precession dynamic MRI and its clinical application to the diagnosis of hepatocellular carcinoma.

PURPOSE: To determine the appropriate acquisition parameters for three-dimensional fast imaging with steady-state free precession (3D-FISP), to clarify the superiority of 3D-FISP to two-dimensional fast low-angle shot (2D-FLASH) on phantom study, and to clarify the clinical usefulness of 3D-FISP in diagnosing hepatocellular carcinoma (HCC). MATERIALS AND METHODS: 3D-FISP images with varying flip angles were compared by using a phantom. Signal-to-noise ratios (SNRs) and contrast-enhancement ratios (CERs) were compared for the four two-dimensional fast low-angle shot (2D-FLASH) sequences and 3D-FISP sequences in a phantom. The optimal 3D-FISP dynamic study was compared with plain, postcontrast MR sequences used to study 78 HCC cases and analyzed according to histological grade. The 3D-FISP image obtained 30 sec after gadopentetate dimeglumine (Gd) administration was also compared with CT hepatic angiography (CTHA). RESULTS: A 25 degrees flip angle and double-dose Gd administration were appropriate for 3D-FISP dynamic study. CER was the highest with 3D-FISP, and SNR was higher in 3D-FISP than in 2D-FLASH images in a phantom with high Gd concentration. Among the 105 lesions, 103 (98%) were depicted on 3D-FISP images. The detection rate of HCC on 3D-FISP was higher than 95% for each histological grade. The vascularity of the tumors as determined by CTHA findings was correctly diagnosed on 3D-FISP in 80% of cases. CONCLUSION: In phantom study, 3D-FISP with double-dose Gd injection showed higher contrast than 2D-FLASH as a sequence for liver dynamic study. In clinical study, 3D-FISP is useful in the detection of HCC, regardless of tumor vascularity and histological grade.

Helical CT of the local spread of carcinoma of the gallbladder: evaluation according to the TNM system in patients who underwent surgical resection.

OBJECTIVE: Our aim was to evaluate the performance of helical CT as an aid in the preoperative diagnosis of the spread of carcinomas of the gallbladder. MATERIALS AND METHODS: Two radiologists retrospectively reviewed both hard-copy and soft-copy (on a monitor with multiplanar reconstruction capability) versions of helical CT scans (3-mm collimation and 3-mm reconstruction) of 21 patients who had undergone surgical resection for carcinomas of the gallbladder. The local spread of the disease was evaluated according to the TNM system, and the results were correlated to the pathologic findings. Inter- and intraobserver differences were checked with kappa statistics. Results of the consensus interpretations were used to calculate sensitivity, specificity, and accuracy of helical CT. RESULTS: No significant inter- or intraobserver differences were found in any T category evaluation. The sensitivities of the hard-copy consensus interpretations in the diagnosis of T1, T2, T3, and T4 lesions were 33%, 64%, 80%, and 100%, respectively; specificities of hard-copy interpretations were 94%, 80%, 81%, and 95%, respectively. For soft-copy (monitor) consensus interpretations, the sensitivities for the diagnosis of T1, T2, T3, and T4 lesions were 33%, 73%, 80%, and 100%, respectively; the specificities of soft-copy interpretations were 94%, 80%, 88%, and 95%, respectively. Overall accuracy of the hard-copy interpretation was 83%; the overall accuracy of the soft-copy interpretation was not significantly different-86%. CONCLUSION: Helical CT provided 83-86% accuracy in the diagnosis of the local extent of carcinomas of the gallbladder, showing acceptable sensitivity and specificity for the T2 and more advanced lesions but poor sensitivity for the T1 lesions. Use of a monitor with multiplanar reconstructions of the CT data did not significantly improve the diagnostic accuracy.

Synthesis and evaluation of 4-bromo-1-(3-[18F]fluoropropyl)-2-nitroimidazole with a low energy LUMO orbital designed as brain hypoxia-targeting imaging agent.

In order to develop new imaging markers for brain hypoxia, 4-bromo-1-(3-fluoropropyl)-2-nitroimidazole (4-BrFPN) was designed based on molecular orbital calculations, synthesized and labeled with fluorine-18 as a lipophilic nitroimidazole analog with a lower energy LUMO orbital than those for fluoromisonidazole (FMISO) and 1-(3-fluoropropyl)-2-nitroimidazole (FPN). In an in vitro radiosensitization study, the sensitizer enhancement ratio for 4-BrFPN was found to be 1.65 at a I mM concentration, in comparison to 1.81 for FMISO. The preparation of 18F-labeled 4-BrFPN (4-Br18FPN) was achieved by [18F]fluoride ion displacement reaction of the tosylate precursor, in a reasonable radiochemical yield (33%, not corrected for decay). Metabolites in tumor and muscle extracts from methylcholanthrene-induced fibrosarcoma mice, as well as the tissue distribution of 4-Br18FPN in normal rats, were studied. The initial uptake into rat brain of 4-Br18FPN was significantly higher relative to 18F-labeled FMISO (18FMISO), followed by a rapid washout from the brain. The tumor uptake of 4-Br18FPN was somewhat enhanced compared to those obtained with 18FMISO and 18F-labeled FPN (18FPN), but with lower tumor localization than 18FMISO. Analyses of tumor and muscle extracts showed metabolites remaining base line on the radio-TLC plates, and they were produced to a greater extent in tumor than muscle. The use of two drugs which increase hypoxic cell fraction in tumor, hydralazine or nitro-L-arginine, produced a significant increase in tumor levels of 4-Br18FPN, suggestive of a hypoxic mechanism of accumulation. The results imply that lowering of the LUMO energy of a molecule alone is not sufficient to improve its biodistribution properties for better imaging of regions of hypoxia.

Coexpression of neural cell adhesion molecules and bcl-2 in intrahepatic cholangiocarcinoma originated from viral hepatitis: relationship to atypical reactive bile ductule.

It has been shown that atypical reactive bile ductules (ARBD) display positive immunoreactivity of neural cell adhesion molecules (NCAM) and bcl-2. We investigated the clinicopathological features of intrahepatic cholangiocarcinoma (CC) arising in cases of viral hepatitis B or C (VHBC) and examined their relation to ARBD by means of immunohistochemical analysis. Sixty-eight surgical cases with CC were included in this study. The cause of the background liver disease was hepatitis B surface antigen (HBsAg)(+) in eight cases, antihepatitis C virus antibody (HCVAb)(+) in 13 cases, both HBsAg(+) and HCVAb(+) in one case, and both HBsAg(-) and HCVAb(-) in 46 cases. The average age of patients with CC arising in the HBsAg(+) group was significantly less than that of patients with CC in the HCVAb(+) group (P = 0.0192). Immunohistochemically, CC arising in the HBsAg(+) and HCVAb(+) groups was correlated with coexpression of NCAM/bcl-2 in the tumor cells (P = 0.0068 and P = 0.0382, respectively). Among the 12 cases of CC coexpressing NCAM/bcl-2, 11 were of mass-forming and peripheral type (P = 0.0437), and lymph node metastasis was a rare finding compared with CC showing negative coexpression of NCAM/bcl-2 (P = 0.0213). The tumor cells of CCs arising in VHBC have some characteristics of ARBD. In such tumors, because lymph node metastases were rarely seen and lymph node dissection did not improve patient's survival, lymph node dissection can be limited.

The usefulness of dipyridamole thallium-201 single photon emission computed tomography for predicting perioperative cardiac events in patients undergoing non-cardiac vascular surgery.

UNLABELLED: The aim of this study was to evaluate the usefulness of dipyridamole Tl-201 myocardium single photon emission computed tomography (201Tl-SPECT) for predicting perioperative cardiac events in patients with arteriosclerosis obliterans (ASO) and abdominal aortic aneurysm (AAA) undergoing non-cardiac vascular surgery. METHODS: Preoperative dipyridamole 201Tl-SPECT imaging in association with clinical risk assessment was performed in 224 consecutive patients (97 ASO and 127 AAA). RESULTS: The patients were classified into three groups, including low-risk (n = 173, 77%), intermediate-risk (n = 39, 18%), and high-risk (n = 12, 5%) groups according to the clinical risk stratification. The prevalence of reversible Tl-201 defect was significantly higher in the high-risk group than that in the low-risk group (83% vs. 14%, p < 0.001). In 180 patients who underwent vascular surgery, 9 patients (5.0%) had perioperative cardiac events, including heart failure (n = 1), unstable angina (n = 2), and other cardiac events such as arrhythmias (n = 6). The clinical variables including the clinical risk stratification did not significantly correlate with the perioperative cardiac events. In contrast, the reversible defect on 201Tl-SPECT was the only variable to predict perioperative cardiac events by a stepwise logistic regression analysis (odds ratio 7.0, 95% confidence interval 1.7-28.0, p = 0.007). It was also a significant predictor of perioperative cardiac events in a subgroup of low risk patients (odds ratio 11.6, 95% confidence interval 2.3-57.4, p = 0.004). The sensitivity and specificity of the reversible defect for predicting perioperative cardiac events were 55.6% and 84.8% in all operated patients, and 57.1% and 89.7% in low risk patients, respectively. CONCLUSIONS: The preoperative dipyridamole 201Tl-SPECT was useful for predicting perioperative cardiac events in patients with vascular diseases, even in patients identified as having a low risk based on the clinical risk assessment.

CT and MR features of nasopharyngeal carcinoma in children and young adults.

AIM: To clarify CT and MR features of nasopharyngeal carcinoma (NPC) in children and young adults. METHOD: CT and MR findings of 13 patients (30 years old or younger) with a histopathologic diagnosis of NPC were reviewed. RESULTS: Skull base invasion (12/13), lymphadenopathy (10/13), and infiltrative growth (8/8) were common findings. The signal intensity of tumours was slightly higher than that of muscles in six cases and isointense to that of muscles in two cases on T1-weighted images; it was higher than that of muscle and lower than that of cerebellar grey matter on T2-weighted images in all cases. Internal signals were homogeneous in both pre- and post-Gd-enhanced MR images in all cases. CONCLUSIONS: Despite its rarity in this age group, NPC should be included in a differential diagnosis when CT and MR imaging reveal these features.