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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 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, p0.0001). The MTT obtained with perfusion-weighted MR imaging correlated statistically with cerebral blood flow (r = -0.74, p0.001), vascular reactivity (r = -0.73, p0.001) and oxygen extraction fraction (r = 0.61, p0.01). Similarly, the MTT obtained using PET statistically correlated with cerebral blood flow (r = -0.78, p0.0001), vascular reactivity (r = -0.51, p0.05) and oxygen extraction fraction (r = 0.68, p0.01). The reliability of the MTT obtained using perfusion-weighted MR imaging appears to be approximately equal to that obtained with positron emission tomography.

Rationale and Objectives To evaluate the value of magnetic resonance (MR) perfusion imaging for diagnosis of Alzheimer disease (AD), the authors compared relative cerebral blood flow (CBF) maps obtained with MR perfusion imaging and technetium-99m hexamethyl-propyleneamine oxime (HMPAO) single photon emission computed tomography (SPECT) in patients with AD. Materials and Methods Eight patients with AD were studied with MR perfusion imaging and HMPAO SPECT. The relative CBF maps from the two techniques were spatially coregistered, and relative CBF values in 13 cerebral gray matter regions (total, 26 regions of interest) were compared with regression analysis. To evaluate the degree of deviation of each brain region from the regression line, a P value for the residual was calculated for each region. Results A significant overall correlation was seen between the relative CBF values produced by the two techniques ( r = 68, P P values for the residuals were obtained in the anterior cingulate cortex ( P = 05) and posterior cingulate cortex ( P P Conclusion Despite fairly large discrepancies in the anterior and posterior cingulate cortices, the relative CBF map obtained with MR imaging is generally in close agreement with the HMPAO SPECT map, suggesting that MR perfusion imaging can provide clinically useful information regarding CBF abnormalities in patients with AD.

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.

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 ECATEXACT 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.

Clinicopathological prognostic factors in soft tissue leiomyosarcoma: a multivariate analysis Aims: Prognostic factors affecting survival in cases of leiomyosarcoma of soft parts were investigated in this study. Methods and results: A retrospective study of 267 patients was carried out. This group comprised 142 females (53%) and 125 males (47%), whose ages ranged from 7 to 95 years (median 58 years). One hundred and five cases were superficially situated (arising from the skin or subcutis), while the remaining 162 cases were deeply situated (subfacial). Nineteen were cases of pleomorphic leiomyosarcoma where the diagnosis had been amended from malignant fibrous histiocytoma to leiomyosarcoma whilst under review. Of the 167 patients with follow-up data, 83 died of leiomyosarcoma. In univariate analysis, depth, tumour size (≥50 mm), mitotic rate of >20 per 10 high-power fields (HPF), tumour necrosis of >50% and a high stage according to the most recent American Joint Committee on Cancer (AJCC) staging for soft tissue sarcoma were found to lessen significantly the rate of survival (log rank test; P

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 purpose of this study was to clarify the hemodynamic changes associated with hepatocarcinogenesis using CT angiography.Eighty-six hepatocellular lesions were confirmed at pathology in 49 patients who underwent CT with both hepatic arteriography and arterioportography. These images were compared with lesion-to-liver vascular ratios of cumulative arteries, preexisting hepatic arteries, and portal veins in resected specimens. Lesions were classified in five groups according to intranodular hemodynamics determined by CT hepatic arteriography and CT during arterioportography: group 1, isoattenuating on both procedures; group 2, hypoattenuating on CT hepatic arteriography and isoattenuating on CT during arterioportography; group 3, hypoattenuating on both procedures; group 4, isoattenuating on CT hepatic arteriography and hypoattenuating on CT during arterioportography; and group 5, hyperattenuating on CT hepatic arteriography and hypoattenuating on CT during arterioportography.Among 86 lesions, we identified seven low-grade dysplastic nodules, eight high-grade dysplastic nodules, 14 well-differentiated hepatocellular carcinomas, 45 moderately differentiated hepatocellular carcinomas, and 12 poorly differentiated hepatocellular carcinomas. The lesions were classified as group 1 (n = 5), group 2 (n = 13), group 3 (n = 6), group 4 (n = 2), or group 5 (n = 60). Intranodular hemodynamics was significantly correlated with pathologic grading (p0.001). For correlations between combinations of the groups and pathologic gradings, the order "groups 1-2-3-4-5" was the most significant (p0.001).During hepatocarcinogenesis, most hepatocellular nodules show deterioration of arterial blood flow before loss of portal blood flow. Vascular imaging of hepatic nodules may predict malignant abnormality via the early loss of hepatic arterial flow seen before portal flow changes.

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. Yabuuchi H., et al. (2002). Clinical Radiology57, 205–210.

Background/Aim: To investigate the mode of progression of combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC). Methods: An immunohistochemical study for E-cadherin (ECD) and alpha- and beta-catenins was performed on 29 cases of cHCC-CC. Results: Reduced expression of ECD was significantly correlated with the tumour grade of the hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) components, intrahepatic metastasis (IM) of HCC, IM of CC, and vascular invasion of CC (p

Cerebral blood flow and vasodilatory capacity in anemia secondary to chronic renal failure. Background Our previous study reported that cerebral oxygen extraction fraction (OEF) increased in hemodialysis patients with anemia. The increased OEF suggests that the cerebral vasodilatory capacity might be impaired in these patients. To clarify this issue, we measured the CO 2 response in patients with anemia secondary to chronic renal failure (CRF) using positron emission tomography (PET). Methods Ten anemic patients with CRF (6 females and 4 males) and 6 age-matched normal controls were studied. The underlying diseases of CRF were glomerulonephritis in 8 patients, systemic lupus erythematosus (SLE) in one patient, and hypertension in one patient; in this cohort, 5 patients were on hemodialysis treatment and the remaining 5 patients were in a pre-hemodialysis state. The cerebral blood flow (CBF) was measured by the O-15H 2 O bolus injection method with each patient in a resting state and during 5% CO 2 inhalation. The CO 2 response was estimated as the percentage change of CBF per 1mm Hg change of PaCO 2 . Results The CO 2 response was significantly attenuated in anemic patients with CRF in comparison to the normal controls, and it inversely correlated with the severity of anemia. There was no significant difference in the CO 2 response between the hemodialysis and pre-hemodialysis patients. The CO 2 response significantly correlated with CBF and the cerebral metabolic rate for oxygen (CMRO 2 ) at rest, however, it did not correlate with OEF and cerebral blood volume (CBV). Conclusions The present study revealed the existence of a reduced cerebral vasodilatory capacity in anemic patients with CRF, suggesting that chronic hypoxic brain damage might play a role in the impaired cerebrovascular response to CO 2 .

A 64-year-old male was referred to our hospital for evaluation of a large tumor extending from his left inguinal area to the scrotum. The removed tumor specimen showed that the epidermis was permeated with numerous Paget cells lying singly and in groups, and the dermis was infiltrated with tumor masses of relatively small Paget cells. These tumor cells showed a different immunostaining for CEA: the epidermal cells positive, but the dermal cells negative. He was diagnosed with Paget's carcinoma, suggestive of lung and adrenal metastases. The patient received four courses of combined chemotherapy with low dose FP with effect initially after operation, but he died of multiple metastases of Paget cells one year later. [SkinCancer (Japan) 2002; 17: 189-192]

Background. No effective follow-up strategy for non-Hodgkin's lymphoma (NHL) has been identified to date. The aim of this study was to assess the value of a strict follow-up procedure in patients with NHL after they showed clinical remission. Methods. One hundred and twenty-one patients with localized NHL of the head and neck who had achieved clinical remission after radiation therapy and/or chemotherapy were followed with a strict follow-up strategy (consisting of a schedule of frequent office visits, imaging studies, and blood tests, even if the patient was asymptomatic). Results. Thirty-nine patients relapsed after remission. Twenty-two (56.4%) of the relapses were associated with symptoms. In the 17 patients with asymptomatic relapses (43.6%), an abnormal physical examination result initially indicated relapse in 10 patients. The other tests that initially indicated relapse included scheduled computed tomography scans (3 patients), scheduled gallium scans (2 patients), and serum lactate dehydrogenase levels (2 patients). According to the Ann Arbor stage at relapse, 72.7% of the patients with symptomatic relapses were stage III or IV, while 70.6% of the patients with asymptomatic relapses were stage I or II. Conclusions. These results indicate that a strict follow-up procedure is effective in detecting asymptomatic relapses, which generally involve a smaller tumor load than symptomatic relapses.

Purpose: The goal of this work was to evaluate the diagnostic accuracy of transabdominal ultrasound (US), helical CT, and MRI in the diagnosis of adenomyomatosis (ADM) of the gallbladder. Method: Twenty patients with surgically proven ADM were included, all of whom underwent preoperative US, helical CT with 3 mm collimation, and MRI with half-Fourier rapid acquisition with relaxation enhancement (RARE). All images were retrospectively reviewed by two radiologists, and the presence of ADM was assessed at three compartments (neck, body, and fundus) of the organ. Receiver operating characteristic analysis was performed, and sensitivity, specificity, and accuracy were calculated for each modality. Results: The A z values (area under the curve) for MRI, helical CT, and US were 0.98, 0.85, and 0.72 for the Reader 1, respectively, showing no statistically significant interobserver difference in any of the three modalities. MRI showed a significantly higher A z value than helical CT or US (p < 0.1). The accuracies of MRI, helical CT, and US were 93, 75, and 66%, respectively. Conclusion: Among the three modalities tested, MRI with half-Fourier RARE sequence was the most accurate for diagnosing ADM.

Objective: We retrospectively assessed and compared the usefulness of11C-methionine (MET)-PET with that of18F-FDG-PET for the differentiation between benign lesions and malignant tumors of the lung.Methods: We examined 101 patients with a suspected lung tumor including 79 patients with primary lung cancer and 22 patients with benign lesions. One hundred and forty PET studies (46 studies with MET-PET and 94 studies with FDG-PET) were performed. Both MET-PET and FDG-PET were performed on 39 patients. The MET-PET was performed 15 minutes after the administration of 67–740 MBq of MET, and FDG-PET 45 minutes after the administration of 30–437 MBq of FDG. The results were then evaluated by the standardized uptake value (SUV).Results: The MET uptake in lung cancer was 3.69±1.22 (n=37) which was significantly higher than that in benign lesions 1.81±1.04 (n=9) (p

We report the radiologic findings of sclerosed hemangioma (SH), a rare variant of hepatic hemangioma. Dynamic contrast-enhanced computed tomography showed a hypodense mass in the liver with delayed enhancement. T2-weighted magnetic resonance imaging showed the mass as hypointense in relation to cerebrospinal fluid. The final diagnosis of SH was made pathologically. Although SH is rare, understanding its radiologic appearance is important to avoid unnecessary surgery and should be included in the differential diagnoses of hepatic lesion with delayed enhancement.

Malignant peripheral nerve sheath tumours: high Ki67 labelling index is the significant prognostic indicator Aims: We investigated p53, Ki67, MDM2, and p21WAF1/CIP1 in order to evaluate its relationship with prognosis in malignant peripheral nerve sheath tumours (MPNST). Methods and results: In 49 cases of MPNSTs, the immunohistochemical studies of Ki67, p53, MDM2, p21WAF1/CIP1 and polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) with direct sequencing of p53 were performed with the formalin-fixed paraffin-embedded tissue. In 43 cases with survival data available, an evaluation of the prognostic significance of clinicopathological factors was also carried out. A high Ki67 labelling index (LI) (>25%) was correlated with a reduced survival rate in the 43 cases of MPNST (P=0.0106, log-rank test). Furthermore, there was a significant correlation between the Ki67 LI and the immunohistochemical expression of p53 or MDM2. In 17 MPNST cases, PCR amplification of exons 5 through 8 of the p53 gene was successful. One case showed a base change of codon 240 (AGTAGC), but translated amino acid (Ser) remained unchanged. Multivariate Cox analysis of our series showed that the association of von Recklinghausen’s disease, tumour depth, and the presence of rhabdomyoblasts (malignant triton tumour) each had an independent negative impact on overall survival. Conclusion: High Ki67 LI (>25%) was of significant prognostic value in MPNST.

A boy with Alagille syndrome complicated by hepatic nodular hyperplasia (HNH) is reported. During pre-transplantation evaluation, CT and MRI revealed a large hepatic lesion with multiple small nodular lesions. Angiography demonstrated a large hypervascular lesion and CT arterial portography (CTAP) showed a portal perfusion defect corresponding to the lesion. CTAP also revealed large portal vein branches running through the lesion. Although hepatocellular carcinoma is known to accompany Alagille syndrome, HNH should also be considered when large vessels running through the lesion are demonstrated.

We present a case of adrenal metastasis from clear-cell renal cell carcinoma in which presence of a small amount of fat was shown on chemical shift gradient-echo magnetic resonance imaging. Radiologists should be aware that signal loss of the adrenal tumor on out-of-phase gradient-echo images does not always suggest the diagnosis of benign adenoma, particularly in patients with a history of renal cell carcinoma.

We present two cases of abdominal cystic tumors containing small amounts of fat in their septa. Although the final pathologic diagnoses of these tumors were cystic lymphangioma and angiomatosis, the computed tomographic and magnetic resonance imaging features were almost identical and indistinguishable; a purely cystic mass around the region of the pancreas head associated with little mass effect on the surrounding organs and septa containing a radiologically evident fatty component. Radiologists should be aware of these two entities as differential diagnoses of abdominal cystic masses containing small amounts of septal fat.

Alteration of the p53/mdm2 pathway has been reported in the well-differentiated iiposarcoma (WDLS)/dedifferentiated liposarcoma (DDLS) group. We investigated the immunoreactivity of p53, mdm2, and p21WAF1, along with the MIB-I-labeling index (MIB-1-LI) in 21 WDLS and 21 DDLS cases, to clarify the association of these markers with the morphologic changes and the biological factors responsible for the aggressiveness of DDLS. Within DDLS, p53 and p21WAF1 expression and mdm2 overexpression were significantly more prevalent in the dedifferentiated (DD) components than in the well-differentiated (WD) components. The mdm2 overexpression and p2lWAFl expression was significantly associated with sclerosing liposarcomas in both WDLS and the WD components of DDLS. There was no significant difference in the immunoreactivity of p53, mdm2, or p21WAF1 or MIB-1-LI between WDLS and the WD components of DDLS. An association was found between p53 expression and mdm2 overexpression in the WD group (comprising WDLS and WD components of DDLS) and in the DD group, significantly so in the WD group. Notably, this correlation was found in the subtype of sclerosing liposarcoma but not in that of lipoma-like liposarcoma. Within DDLS, the clinical outcome of the nonaccessible soft tissue (nonAST: comprising retroperitoneum and mediastinum) group was significantly worse than that of the accessible soft tissue (AST: comprising extremities, buttocks, axilla, and scrotum) group; however, the immunophenotypes of p53, mdm2, and p21WAF1 and the MIB-1-LI showed no correlation with survival in the AST group alone, in the non-AST group alone, or in the 2 together. This study suggests that the immunoreactivity of p53, mdm2, and p21WAFl is associated with the morphologic changes, but not with the biological factors responsible for the aggressiveness of DDLS.

A port-catheter system was implanted via femoral artery access for hepatic artery chemotherapy infusion. Implantation was attempted in 90 patients and was successful in 88. Blood flow redistribution was performed using embolization coils. In the first ten patients a soft heparin-coated infusion catheter was used. For the following 78 patients we used a stiffer catheter coated with fluorine-acryl-styrene-urethane-silicone (FASUS) copolymer. The catheter was connected to a port implanted subcutaneously below the level of the inguinal ligament. Complications during the procedure and after placement were observed in 7 of 90 patients and 24 of 88 patients, respectively. These included catheter obstruction (11%), dislocation of the catheter tip (10%), drug toxicity (5.7%), and catheter infection (3.4%). In 6 of 10 patients with catheter obstruction, recanalization of the port system was achieved. In 7 of 9 patients with dislocation of the indwelling catheter tip, replacement of the port system was successful. Our complications appear to be comparable with those encountered with the subclavian/brachial approach when the new catheter coating is used. Notable is the avoidance of cerebral infarcts.

To investigate the etiology of leiomyosarcoma, we examined abnormalities of p53 and its regulation in 13 cases of leiomyosarcoma using fresh tumor specimens. We estimated p53 and MDM2 mRNA level and MDM2 gene amplification using a real-time semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) based on the TaqMan fluorescence method. We also used immunohistochemistry (IHC) for p53 and MDM2 protein overexpression, polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and direct sequencing to detect p53 mutation. Eight of the 13 cases (62%) showed an overexpression of p53 protein on IHC and eight of 13 cases (62%) had p53 gene point mutations. Five of the 13 cases (38%) showed positive staining for MDM2 protein and only one case (7.7%) demonstrated MDM2 gene amplification. The relative p53 mRNA level of the tumors compared with normal tissue ranged from 1.14 to 12.19 arbitrary units (AU), and the MDM2 mRNA level ranged from 1.06 to 17.17 AU. The mRNA level in the p53-positive cases was higher than in the negative cases (positive: 7.70 AU on average; negative: 3.38 AU on average; P=0.0344). However, there was no significant correlation between the MDM2 mRNA level and other factors, such as p53 IHC, p53 mutation status, p53 mRNA level and MDM2 IHC. Our results indicate that p53 abnormalities are major events and that an increasing level of p53 mRNA is associated with an overexpression of p53 protein in leiomyosarcoma and they may play an important role in the tumorigenesis in this tumor.

To compare the diagnostic efficacy of three-dimensional fast imaging with steady precession (3D-FISP) dynamic MR imaging in assessing pancreatic ductal adenocarcinoma with conventional MR imaging and helical CT, 15 patients with surgically proven pancreatic ductal adenocarcinoma were studied. Contrast-to-noise ratio (CNR) of the tumor, tumor detectability, local tumor extension, and vascular involvement were evaluated for all techniques. The results indicate that 3D-FISP dynamic MR imaging may improve the imaging assessment of pancreatic ductal adenocarcinoma.

The purpose of this study is to elucidate the usefulness of dynamic MR study of the whole liver using 3DFISP with double dose gadolinium (Gd) enhancement in detecting enhancing lesions in 20 patients. Twenty patients with hepatocellular carcinoma (HCC) underwent 3DFISP dynamic study with double dose Gd. The demonstration of enhancing hypervascular lesions regardless of etiology was evaluated on a segment-by-segment basis with receiver operating characteristic (ROC) analysis, using findings on CT during hepatic arteriography as a gold standard. Diagnostic accuracy of 3DFISP in the detection of HCC was also evaluated. As to the demonstration of enhancing lesions, the Az value of the ROC curve was 88%. The detection rate of HCC with 3DFISP was 98%. 57% of enhancing pseudolesions were not detected on 3DFISP. We concluded that Dynamic MR study of the whole liver using 3DFISP with double dose Gd enhancement is a useful method to demonstrate hypervascular HCC.

Purpose: To evaluate proliferative response according to c- myc and c- fos gene expression as an early indicator of late radiation damage to the kidney. Methods and Materials: c- myc and c- fos gene expression was measured in the irradiated kidney of C3H/HeSlc mice using reverse transcriptase-polymerase chain reaction (RT-PCR) 24 h after 9, 12, and 15 Gy as well as 2 and 7 days after 15 Gy. In a second experiment, 12 Gy was administered to the right kidney plus the lower half of left kidney. The mice underwent left nephrectomy 24 h after, and the correlation between increased gene expression and elevation of the blood urea nitrogen (BUN) level representing late functional damage was investigated. Results: c- myc and c- fos expression increased in 1 of 10 controls and in 8 of 10 and 7 of 10 mice that received 15 Gy, respectively. Expression increased dose-dependently from 9 to 15 Gy. In mice having an increased BUN level, 7 of 10 and 8 of 10 were positive for c- myc and c- fos , respectively. All 6 mice having an unchanged BUN level were negative for c- fos , while 5 were negative for c- myc . Conclusion: Measurement of c- myc and c- fos gene expression is potentially an early indicator of late radiation damage to the kidney.

Magnetic resonance (MR) cholangiopancreatography (MRCP) is widely used in the evaluation of pancreatobiliary disorders. However, numerous related pitfalls may simulate or mask pancreatobiliary disease. Maximum-intensity-projection (MIP) reconstructed images completely obscure small filling defects and may demonstrate respiratory motion artifacts. T2 weighting may vary with different MR imaging sequences and influence MRCP findings. Incomplete imaging may create confusion regarding ductal anatomy or disease. Furthermore, MRCP yields only static images and thus may fail to depict various anomalies. Limited spatial resolution makes differentiation between benign and malignant strictures with MRCP alone extremely difficult. Susceptibility artifacts may be caused by metallic foreign bodies or gastric-duodenal gas. Fluid accumulation may produce a pseudolesion or pseudostricture, although changing the imaging angle or section thickness may be helpful. Pneumobilia may be misinterpreted as bile duct stones, and true stones may be overlooked. Pulsatile vascular compression can cause pseudo-obstruction of the bile duct. Use of both source and MIP reconstructed images obtained from different angles can help avoid cystic duct-related pitfalls. Repeat MRCP or conventional MR imaging can help avoid pitfalls related to the periampullary region. Segmental collapse of the normal main pancreatic duct may be misinterpreted as stenosis, but administration of secretin is helpful. An awareness of these pitfalls and possible solutions is crucial for avoiding misinterpretation of MRCP images.

Sorptive behaviors of polycyclic aromatic hydrocarbons (PAHs) as well as other classes of hydrophobic pollutants (i.e., n-alkanes and linear alkylbenzenes: LABs) were investigated for street runoff and for particle-size segregated river water samples. PAHs, except for 3-ring aromatics, were mostly transported with particles >1.2μm. In all the environmental samples PAHs were more hydrophobic than expected from their Kow; whereas vigorous mixing of road dust with water for 24 hours resulted in more desorption of PAHs into the aqueous phase. It indicates that although strongly associated with particles, at least some part of the “particle bound” PAHs could be available for active exchange wirh their dissolved counterparts. As opposed to PAHs, n-alkanes and LABs revealed less hydrophobic nature than expected from Kow, although their majorities were in “particulate form”.

The purpose of this study is to investigate the correlation between lactate levels and cerebral vascular reactivity (VR) in regions outside an area of chronic cerebral infarction. Multivoxel proton magnetic resonance spectroscopy ((1)H-MRS) and positron emission tomography (PET) were performed in 11 patients who suffered chronic cerebral infarction. Of these 11 patients, 4 were examined before and after bypass surgery. Two regions-of-interests (ROIs) were placed outside the area of chronic infarction. One ROI was placed within a control region on the contralateral side. A lactate peak area was obtained in all ROIs. An N-acetyl aspartate (NAA) peak area was obtained in the ROI within the control region. The ratio of the lactate peak area and NAA peak area (Lct/NAA) was calculated for normalization of the lactate level, and was found to be 0.13 +/- 0. 10 (range, 0 to 0.43). The VR was recorded at 13.3 +/- 20.7% (range, - 44.3 to 68.9%), utilizing PET and administering acetazolamide. A significant negative correlation was observed between the Lct/NAA ratio and VR (r = - 0.709, p0.0001). These results suggest that lactate levels and VR are closely related in regions outside areas of chronic cerebral infarction.

A case of radiologically identified molar invasion into extensive arteriovenous shunts (AVSs) is described. CT and MRI revealed a large uterine mass, accompanied by multiple AVSs. Dynamic MRI and pelvic angiography demonstrated multiple trophoblastic cysts invading into the AVSs. Resected specimen confirmed the diagnosis of invasive mole. Dynamic MRI was very useful in determining the etiology of AVS.

We analyzed the hemodynamic properties and vascular supply changes in relation to the carcinogenesis of hepatocellular carcinoma (HCC), selecting 18 premalignant and malignant nodules less than 3 cm diameter (from 14 patients) for our study. The computed tomographic (CT) arteriography and CT arterioportography (CTAP) findings for these nodules were correlated with the histopathologic findings. The ratios of all microscopically counted arteries (normal hepatic and abnormal arteries), normal hepatic arteries, and portal veins in each nodule to those in the surrounding liver were calculated. Well differentiated lesions had low attenuation on CT arteriography and isoattenuation on CTAP. Moderately-to-poorly differentiated lesions had high attenuation on CT arteriography and low attenuation on CTAP. In well differentiated lesions, the ratios of all arteries, normal hepatic arteries, and portal veins were 1.17+/-0.10, 0.66+/-0.12, and 0.80+/-0.10, respectively. In moderately-to-poorly differentiated lesions, the ratios were 2.64+/-0.23, 0.09+/-0.03, and 0.07+/-0.03, respectively. We concluded that blood flow does not parallel the actual number of arteries seen on the histological examination of tumors. In well differentiated lesions, the combination of normal hepatic arterial degeneration and preserved portal veins results in low attenuation on CT arteriography and isoattenuation on CTAP. In advanced HCC, the combination of neoplastic (abnormal) arterial development by angiogenesis and obliteration of portal veins results in high attenuation on CTA and low attenuation on CTAP. These findings are characteristic of early and advanced stage HCC, and may reflect a combination of sequential changes in their hemodynamic states.

To evaluate the usefulness of 16alpha-[18F]-fluoro-17beta-estradiol (FES) for the assessment of estrogen receptor (ER), we examined the tissue distribution and kinetics of FES in immature female Sprague-Dawley rats and then examined FES uptake in rat breast tumors induced by 7,12-dimethylbenz(a) anthracene (DMBA). The FES uptake by the uterus, an ER-rich tissue, was highly selective and it was 3.34 +/- 0.79%ID/g at 60 minutes and 1.57 +/- 0.57%ID/g at 120 minutes after injection. The FES uptakes in ER-negative tissues were 0.12 +/- 0.05%ID/g or less and 0.05 +/- 0.03%ID/g or less, respectively. Coadministration of unlabeled beta-estradiol showed marked depression of uterine FES uptake. The FES uptake by rat breast tumors was 0.14 +/- 0.06%ID/g at 60 min and 0.12 +/- 0.09%ID/g at 120 min. The FES uptake by rat breast tumors correlated with the ER concentration (r = 0.45, p0.05). In conclusion, these results suggest that the FES uptake by tissue is mainly ER mediated and FES is thus useful for detecting ER positive breast tumors.

The purpose of this work was to demonstrate the variety of causes of crazy-paving appearance (CPA) on high resolution CT (HRCT).To identify cases exhibiting CPA (ground-glass opacity with superimposed interlobular septal thickening and intralobular interstitial thickening) on HRCT, we prospectively searched for them over a period of 29 months.We identified 10 cases of CPA on HRCT, including 4 Pneumocystis carinii pneumonia, 1 alveolar proteinosis, 1 usual interstitial pneumonia, 1 pulmonary hemorrhage, 1 acute radiation pneumonitis, 1 adult respiratory distress syndrome, and 1 drug-induced pneumonitis.CPA can result from a variety of diseases. When we encounter CPA on HRCT, clinical information is necessary for differentiation of these entities.

In order to clarify the characteristic computed tomographic findings of peripheral small cell lung cancer, the authors investigated 12 patients with surgically resected and histologically proven peripheral small cell lung cancer. Conventional computed tomography was performed on all, and additional high-resolution computed tomographic images were obtained for nine patients. Marginal, internal, and surrounding features of the tumors were analyzed, and these findings were correlated with histologic findings. All 12 tumors appeared as homogenous masses, and eight had well-defined margins. Lobulation was found in seven, marginal ground-glass opacity in three, fine spiculation in two, and both ground-glass opacity and spiculation in one. Cut specimens showed whitish medullary masses without large areas of necrosis, and microscopic specimens showed small areas of necrosis in 11 patients. Marginal ground-glass opacities corresponded to focal edema and hemorrhage in two patients and to intraalveolar invasion in one. Fine spiculation corresponded to vascular/lymphatic invasion in one patient and to irregular intraalveolar spread in another. The authors concluded that a homogenous mass without necrosis is the most characteristic feature of peripheral small cell carcinoma on computed tomography.

Background: A nationwide effort is in progress to establish the actual state of radiotherapy and its quality assurance (QA) in Japan by using the Patterns of Care Study (PCS). In this study, national averages are calculated with a limited number of patients. A calculation program for national averages was prepared and applied to the radiotherapeutic processes used for esophageal cancer patients entered in the PCS. Methods: The calculation program for national averages, which were revised on the basis of differences between individual facilities and institutional strata, was developed in accordance with Sedransk's equation for the original PCS in the USA. National averages for several aspects concerning the sampled patients who had esophageal cancer between 1992 and 1994 were calculated with these procedures. Data for facilities and stratification of institution were simulated from a national structure survey of radiation oncology in 1990. Results: Values of the national average by Sedransk's equation were different from those of the simple sample average. There were significant differences in radiotherapeutic processes among stratification of institutions. For esophageal cancer, national averages were 0.129 for applications of endoscopic ultrasound, 0.599 for 'all fields treated each day' and 0.088 for application of brachytherapy. Conclusion: National averages for radiotherapy could be calculated. The values obtained in this PCS will be a useful measure for future QA in radiation oncology and in other specialties in Japan.

OBJECTIVE: The purpose of this study is to show and analyze the CT appearance of pseudolesions of the liver caused by rib compression and to discuss the possible mechanism on the basis of findings of incremental dynamic CT, CT during arterial portography, and CT hepatic arteriography. CONCLUSION: Focal compression of the liver caused by curved ribs can cause transient focal diminishment of portal venous perfusion without significantly altering hepatic arterial perfusion. Such diminishment may be observed as low-density areas on the early phase of incremental dynamic CT.

In order to develop new imaging markers for brain hypoxia, two lipophilic nitroimidazoles, 1-(3-fluoropropyl)-2-nitroimidazole (FPN) and 1-(8-fluorooctyl)-2-nitroimidazole (FON) were synthesized and labeled with fluorine-18. The octanol/water partition coefficients were measured as an indication of lipophilicity, giving values of logP=0.28 for FPN and logP=2.72 for FON, respectively, which are in the range thought to be optimal for the diffusion of molecules across the blood-brain barrier. It was suggested from a comparative study of in vitro radiosensitization in V79 cells that these lipophilic analogs may have reduction potentials close to those of fluoromisonidazole (FMISO) and misonidazole (MISO), known hypoxic cell radiosensitizers. The preparation of 18F-labeled FON (18FON) and FPN (18FPN) was achieved via two-steps through [18F]fluoride ion displacement of tosylate precursors, in reasonable radiochemical yields. Tissue distribution of 18FPN and 18FON in normal rats and tumor-bearing mice after intravenous injection was investigated and compared to the behavior of 18F-labeled FMISO (18FMISO), a proven hypoxic imaging agent. The high lipophilicity of 18FON and 18FPN resulted in increased initial uptake into normal rat brain, relative to 18FMISO, followed by a rapid washout from brain. Both of these lipophilic analogs had significantly lower tumor uptake and lower tumor-to-blood ratios than 18FMISO, suggestive of a poor trapping mechanism within the tumor tissue. Neither 18FON or 18FPN offers improved biological properties over 18FMISO as a potential agent for use in brain hypoxic imaging.

The aim of this retrospective study was to clarify whether MR cholangiopancreatography (MRCP) is a suitable replacement for ERCP in evaluation of the choledochal cyst.Sixteen patients (six adult and 10 pediatric) with choledochal cysts underwent MRCP using a half-Fourier acquisition single-shot turbo spin-echo sequence. Extent of the cyst, defects within the biliary tree, and presence or absence of the anomalous junction of the pancreaticobiliary duct were evaluated. Findings were compared with those of ERCP.MRCP better defined the proximal biliary tree than did ERCP in two patients. Defects within the biliary tree were diagnosed correctly on MRCP in eight patients; however, two defects within the distal common bile duct were missed in pediatric patients. The presence of the anomalous junction of the pancreaticobiliary duct was revealed accurately by MRCP in all adult patients but was revealed accurately in only four of the 10 pediatric patients.MRCP appears to offer diagnostic information that is equivalent to that of ERCP for assessment of choledochal cysts in adults. In pediatric patients, MRCP should not replace ERCP; however, MRCP can play an important role as a noninvasive examination and should be considered a first-choice imaging technique for evaluation of choledochal cysts.

We report a case of a chronic expanding hematoma caused by an angiomyolipoma of the spleen in a patient diagnosed with tuberous sclerosis in infancy. Computed tomography showed large bilateral renal angiomyolipomas. A splenic mass that increased in size during the follow-up period of 62 months was also noted. A large subcapsular hematoma of the spleen finally developed, and a splenectomy was performed. The splenic mass consisted of a chronic hematoma with prominent granulation tissue, which was considered to be caused by repeated bleeding from a small angiomyolipoma in the spleen.

Thallium-201, carbon-11 methionine (MET) and fluorine-18 fluorodeoxyglucose (FDG) have all been used to assess brain tumours. The aim of this study was to determine which of these tracers are of use for evaluating the histological grade and the extent of astrocytoma. 201Tl single-photon emission tomography (SPET), MET positron emission tomography (PET) and FDG PET were all performed in 23 patients (13 men, 10 women) with newly diagnosed astrocytic tumours [seven with astrocytoma (grade II), ten with anaplastic astrocytoma (grade III) and six with glioblastoma (grade IV)]. The 201Tl uptake of the tumours was evaluated by a lesion-to-normal region count ratio. Both MET and FDG uptake of the tumours was evaluated by a semiquantitative analysis using the standardized uptake value. 201Tl uptake was found to increase in rank order with histological grade and was significantly different among the three groups (grade II: 1.51+/-0.36; grade III: 2.58+/-1.50; grade IV: 7. 65+/-3.84). MET uptake in grade II (1.49+/-0.44) was also significantly lower than that in both grade III (3.29+/-1.44) and grade IV (3.20+/-0.92). FDG uptake was not significantly different among the three groups (grade II: 2.90+/-0.45; grade III: 3.86+/-1. 56; grade IV: 3.57+/-0.83). No significant correlation was observed between 201Tl uptake and either MET uptake or FDG uptake. In most patients, the extent of the increased MET uptake was the largest while that of the increased FDG uptake was the smallest. In patients with positive 201Tl uptake, the extent of the 201Tl uptake was equal to or smaller than that of gadolinium enhancement. For evaluation of histological grade of astrocytic tumours. 201Tl is therefore considered to be useful though the 201Tl uptake in some grade III astrocytomas was not different from that in grade II astrocytomas. MET was found to be highly useful for detecting astrocytomas, for differentiating between benign and malignant astrocytomas, and for evaluating the extent of astrocytomas; however, it was not sufficiently useful permit evaluation of the histological grade. FDG was not found to be useful either for evaluating the histological grade or for differentiating between benign and malignant astrocytomas.

To improve the quality of radiation therapy in Japan, Patterns of Care Study (PCS), a widely known QA program in the USA, was introduced in Japan. The feasibility was tested by collecting nationwide data by extramural audit for esophageal cancer.From July 1996 through February 1997, PCS audits were performed for 29 institutions. Based on the facility survey by Tsunemoto, 13 institutes were classified as A1 (university hospital/cancer center treating300 patients/year), 10 as B1 (other institutes120 patients/year) and six as B2 (other institutes120 patients/year). Medical charts for 455 patients with thoracic esophageal cancer between 1992 and 1994 were reviewed based on the data format of PCS in the USA.Concerning external beam equipment, linear accelerators ofor = 10 MV were used for 73% of patients in A1, whereas in B1-2, 60Co machines were still used for 13% of patients (P0.0001). The median number of full-time equivalent (FTE) radiation oncologists was 2.7 in A1, 0.65 in B1 and 0.2 in B2. Forty-five percent of patients had received surgery in A1 and 34% in B1-2 (P = 0.0068). In the non-surgery group, a higher radiation dose of60 Gy was delivered in A1 than in B1-2 (P = 0.0008). Chemotherapy was administered to 51% of the patients in A1 and to 30% in B1-2 (P0.0001). Brachytherapy was utilized for 17% in A1 and only for 5% in B1-2 (P = 0.0001).Institutional stratification, including equipment and personnel, significantly affected the patterns of care for esophageal cancer. Therefore, to improve the quality of radiation therapy nationwide, improvement of equipment and supply of FTE personnel is extremely important. PCS was found to have great potential for the practical evaluation of how much will be required in Japan.

OBJECTIVE: Our goal was to elucidate the CT and MR imaging characteristics in patients with autoimmune pancreatitis, which is a reversible chronic pancreatitis with an autoimmune cause. CONCLUSION: On CT and MR imaging, a capsulelike rim, which is thought to correspond to an inflammatory process involving peripancreatic tissues, appears to be a characteristic finding of autoimmune pancreatitis. Also, diffuse pancreatic enlargement along with hypointensity on T1-weighted MR images and delayed enhancement on dynamic CT and MR studies are other features of this disorder.

Computed tomography (CT) plays a leading role in the evaluation of nonmalignant disease of the adrenal gland. CT is highly accurate in the localization of adrenal masses in patients with diseases associated with hyperfunctioning adrenal glands such as Cushing syndrome and Cushing disease, Conn syndrome, adrenal tumors leading to virilization or feminization, and pheochromocytomas. CT permits a specific diagnosis of acute or subacute adrenal hematoma and myelolipoma. Hematomas are round to oval and have increased attenuation (50-90 HU) that decreases on follow-up CT scans. Myelolipomas typically manifest as a well-defined suprarenal mass with an attenuation of-30 to -115 HU. Adrenal cysts are usually round to oval and manifest as a hypoattenuating mass with a smooth, thin wall. CT is useful in the evaluation of patients with Addison disease, particularly the subacute form secondary to tuberculosis or disseminated histoplasmosis. Findings typically include bilateral adrenal enlargement with a central necrotic area of hypoattenuation and peripheral enhancement. Thin-section unenhanced CT permits accurate measurement of attenuation and can be used to differentiate adrenal adenoma from metastasis in a cancer patient with an indeterminate mass: Attenuation of 10 HU or less usually indicates adenoma rather than cancer. If the mass is found incidentally at contrast material-enhanced CT, delayed scans obtained as early as 5-15 minutes after intravenous administration of contrast material appear to have comparable accuracy.

Purpose: the aim of this study was to assess the depth of invasion of early esophageal carcinoma (EEC) by means of double-contrast esophagography Material and Methods: the radiological findings of 46 EECs were retrospectively analyzed for the following factors that might be related to the depth of invasion: in depressed lesions (n=30): maximum size, surface appearance, sharpness of contour, and wall rigidity; and in elevated lesions (n=16): maximum size, height, shape, and wall rigidity. All lesions were surgically or endoscopically resected and the radiological findings were compared with the histological appearance Results: in depressed lesions, the size of the surface granules correlated very strongly with the depth of invasion (rs=0.8147). in both depressed and elevated lesions, wall rigidity correlated strongly with the depth of invasion (rs=0.7540 and rs=0.6702 respectively). in depressed lesions, sharpness of contour also correlated strongly with the depth of invasion (rs=0.6731). the other factors did not correlate with the depth of invasion Conclusion: Double-contrast esophagography could provide useful information for assessing the depth of invasion of EECs

We studied the cerebral muscarinic acetylcholinergic receptor (mACh-R) by means of 11C-N-methyl-4-piperidyl benzilate (11C-NMPB) and positron emission tomography (PET) in Alzheimer's disease (AD) cases, and the findings were compared with the cerebral blood flow (CBF) and the glucose metabolism (CMRGlc) to evaluate the relationship between the mACh-R and the CBF or the CMRGlc. The subjects consisted of 18 patients with AD and 18 age and sex matched normal volunteers. The patients were clinically diagnosed according to the criteria of the NINDS-ADRDA as having "probable AD" and were thus classified into two groups (mild and moderate AD) according to the severity of dementia determined by DSM-III-R. The CBF was measured by 99mTc-HMPAO SPECT, and the CMRGlc was measured by 18FDG PET. The 11C-NMPB uptake was evaluated by the graphical method and the ratio method (ROIs/Cerebellum). A significant mACh-R decrease and more severe CMRGlc decrease in the cortical region was seen in mild and moderate AD. The decrease in the CBF was not as obvious as that in the mACh-R and the CMRGlc. Our study thus suggested that the mACh-R decreased in patients with AD, and that the 18FDG PET was the most sensitive method for detecting the degenerative regions in patients with AD.

To determine the appropriate acquisition parameters for magnetic resonance cholangiopancreatography (MRCP) with a half-Fourier rapid acquisition with relaxation enhancement (RARE) sequence; to determine the optimal MRCP technique by comparing half-Fourier RARE, steady-state free precession (SSFP) two-dimensional (2D) fast spin-echo (SE), and three-dimensional (3D) fast SE sequences; and to clarify the usefulness and limitations of MRCP in diagnosing pancreatic abnormalities.Half-Fourier RARE MRCP images with varying parameters were compared by using a phantom. Duct conspicuity and contrast-to-noise ratios (C/Ns) were compared for the four MRCP techniques in a phantom and healthy volunteers. The optimal MRCP technique was used to study healthy volunteers and clinical cases. Receiver operating characteristic (ROC) curves were created for data analysis.A 5-mm-thick section without intersection gap was appropriate for half-Fourier RARE MRCP. Only half-Fourier RARE MRCP could depict a 1-mm duct. C/N was the highest with half-Fourier RARE, followed by 3D fast SE, 2D fast SE, and SSFP sequences. ROC curve analysis revealed no interobserver differences, and the area under the curve for detection of strictures of the main pancreatic duct was as high as 0.89.Half-Fourier RARE MRCP has the highest contrast and spatial resolution among the four techniques studied and may play an important role in diagnosing pancreatic abnormalities.

BACKGROUND Primary non-Hodgkin's lymphoma of the lacrimal sac is extremely rare, with most reported cases representing secondary involvement of a systemic malignancy. METHODS The clinical record of a 70-year-old female who presented with epiphora and swelling of the lacrimal sac area is described. A review of the literature of patients with primary lacrimal sac lymphoma also is presented. RESULTS Computed tomography demonstrated a lacrimal sac mass involving the nasolacrimal canal. Histopathologic examination of a biopsy specimen revealed a diffuse large cell lymphoma. Using immunohistologic staining, the tumor was a B-cell type, similar to those described in the literature. The patient was treated with 50 gray of irradiation and chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone. The patient remained free of lymphoma 26 months after initial treatment. An ocular examination was unremarkable except for epiphora. CONCLUSIONS Radiotherapy and/or chemotherapy can treat localized lymphoma of the lacrimal sac successfully. Cancer 1997; 80:2151-5. © 1997 American Cancer Society.

To describe the endoscopic ultrasound (US) features of benign versus malignant submucosal tumors throughout the gastrointestinal tract.One hundred nine patients aged 24-81 years suspected to have submucosal tumors (11 esophageal, 41 stomach, 24 duodenal, and 33 colorectal tumors) at barium studies or endoscopy underwent endoscopic US. The layer of origin, internal echo pattern, and lesion margin were analyzed by means of consensus and independent interpretation by three radiologists.Endoscopic US findings revealed several distinct patterns among various submucosal tumors. Sixteen (94%) of the 17 homogeneous lesions with histopathologic findings of malignancy were hypoechoic, although 29 (43%) of the 68 homogeneous lesions with histopathologic findings of benignity were similarly hypoechoic. Homogeneous lesions that were anechoic, of intermediate echogenicity, or hyperechoic were almost exclusively benign (39 [98%] of 40). In contrast, 23 (96%) of the 24 malignant lesions were heterogeneous (n = 7) or homogeneously hypoechoic (n = 16). The sizes of benign and malignant lesions were significantly different (P.05). There was no significant difference in the echo pattern (i.e., homogeneous versus heterogeneous), but there was a significant difference in the proportion of hypoechoic versus nonhypoechoic lesions (anechoic, hyperechoic, or of intermediate echogenicity; P.001).The differential diagnosis of gastrointestinal submucosal tumors is assisted with endoscopic US.

We studied the cerebral blood flow (CBF), cerebrovascular response to hypercapnia, oxygen extraction fraction (OEF), metabolic rate for oxygen (CMRO2), blood volume (CBV) and transit time (TT: CBV/CBF) in Moyamoya disease using positron emission tomography (PET). The subjects consisted of 23 patients with Moyamoya disease, including eight pediatric and 15 adult patients. Among them, ten patients were examined both before and after surgery. The pediatric patients showed a marked increase in the CBV and a prolonged TT, especially in the striatum. The adult patients also showed a prolonged TT, but it was less prominent than that observed in pediatric patients, while the CBF remained at the level of the normal controls. The cerebrovascular response to hypercapnia was markedly impaired in both the pediatric and adult patients, which thus indicates a decrease in the hemodynamic reserve capacity. After surgery, the CBV, TT and cerebrovascular response to hypercapnia all improved, mainly in the temporal cortex where extracranial–intracranial (EC–IC) bypass surgery had been performed. In the striatum, the CBV also decreased, while the TT was shortened after surgery. A PET study was thus found to be useful for evaluating the cerebral hemodynamics in Moyamoya disease and monitoring the effect of surgery.