Search

It is important to differentiate human herpesvirus 6 (HHV-6)-associated encephalopathy from herpes simplex encephalitis (HSE). Although these conditions are similar with regard to involvement of the mesial temporal lobe, HSE is sensitive to acyclovir but HHV-6 encephalopathy is not. We compared the imaging findings of the two conditions.We encountered eight cases of HHV-6 encephalopathy and nine cases of HSE. We divided an observation time into early, middle, and late periods defined as 0-2, 3-30, and more than 30 days from the onset of neurologic symptoms. Differences between HHV-6 encephalopathy and HSE on CT scans in the early period and in distribution and temporal changes in the affected regions on MR images in the three periods were analyzed.At MRI in the early and middle periods, all eight patients with HHV-6 encephalopathy had exclusive involvement of the mesial temporal lobes, and all nine patients with HSE had involvement of both the mesial temporal lobes and the extratemporal regions (p0.01). Among patients who underwent head MRI, six of six with HHV-6 encephalopathy but none of six with HSE had resolution of high signal intensity on T2-weighted and FLAIR images (p0.01). Among patients who underwent head CT in the early period, none of the four with HHV-6 encephalopathy and six of the seven with HSE had abnormal findings, including parenchymal swelling, decreased attenuation of affected regions, and abnormal gyral enhancement (p0.05).Serial MRI showed transient abnormal signal intensity in the mesial temporal lobes in patients with HHV-6 encephalopathy but persistent abnormal signal intensity in both the mesial temporal lobes and the extratemporal regions in patients with HSE. CT in the early period showed no abnormality in patients with HHV-6 encephalopathy but definite abnormal findings in patients with HSE. These differences may be useful in the differential diagnosis of the two conditions.

Purpose To investigate the correlation between MR findings and the histological diagnosis of incidentally detected lesions in candidates for breast-conserving therapy. Materials and Methods MR images of 299 patients with breast cancer were reviewed. Incidentally detected lesions were noted in 59 of 299 (20%) patients, and a histological diagnosis was obtained in 48 of 59 (81%) patients. There were 25 benign and 23 malignant lesions. The number, size, location, morphologic character, and kinetic curve assessment of the MR findings were analyzed. Statistical analyses were performed to determine whether any differences could be observed between benign and malignant lesions. Results Lesions of over 10 mm tended to be malignant (11/16; 69%), whereas those equal or less than 5 mm tended to be benign (12/17; 71%; P < 0.05). Lesions in the same quadrant as the main lesion tended to be malignant (20/27.5; 73%), whereas those in a different quadrant tended to be benign (17.5/20.5; 85%; P < 0.001). Lesions with early peak of enhancement tended to be malignant (20/25; 80%), whereas those with persistent enhancement tended to be benign (20/23; 87%; P < 0.001). Conclusion Incidentally detected lesions that are found in a different quadrant from the main lesion, are smaller than 10 mm in diameter, and show persistent enhancement on MR imaging suggest benign lesions. Therefore, patients with such lesions should avoid unnecessary surgical procedures unless lesions are proved to be malignant by cytology or biopsy. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc.

Purpose: A great synergy has been reported in a number of preclinical studies when 5-fluorouracil (5-FU) precedes cisplatin (CDDP). The objective of this study was to determine the feasibility of ambulatory continuous infusion of 5-FU followed by CDDP through hepatic artery for metastatic colorectal cancer. Patients and methods: Seventeen patients with unresectable liver metastases, who underwent primary tumor resection, were treated with 5-FU (450 mg/m2/day) for seven consecutive days followed by CDDP (100 mg/body/week) for seven consecutive days, each administered continuously by using a balloon pump via Infuse-A-Port catheter inserted into common hepatic artery. The doses of drugs were reduced 20% in patients older than 70 years. The treatment was repeated every 4–6 weeks until disease progression. Results: Of 17 assessable patients, nine patients showed PR (53%; 95% CI, 29.3–76.7%) and eight patients had SD (47%; 95% CI, 23.3–70.7%), with disease control rate of 100%. The median overall survival was 26 months (95% CI: 17.5–41 months) and TTP 14 months (95% CI: 11–20.3 months). Two patients (11.8%), who showed progression due to collateral feeding arteries, responded to HAI again after occlusion. Grade 3 toxicity included leukopenia (12%) and anemia (24%). Grade 4 toxicity was absent. Four patients (23.5%) progressed at extrahepatic sites. Conclusions: This sequential combination of 5-FU followed by CDDP through hepatic artery is active and safe in an outpatient setting, and warrants further multi-institutional study, although prevention of micrometastasis would be mandatory to further prolong overall survival.

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.

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.

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.

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.

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.

Purpose: The purpose of this study was to evaluate the performance of helical CT in preoperative T-staging in patients with gastric cancer. Method: A total of 71 patients with an established diagnosis of gastric cancer [75 lesions, 46 early (T1) and 29 advanced (T2 or more) cancers] were evaluated with helical CT. Helical CT was performed with 5-mm slice thickness at 5-mm/s table incrementation. Using the volumetric data by helical scanning, axial CT images (5-mm slice thickness at 5-mm intervals) and multiplanar reconstruction (MPR) images were obtained. CT findings were compared with histopathologic studies of the resected specimen. Results: Sensitivity of helical CT for gastric cancer was 26% (12 of 46) for early and 100% (29 of 29) for advanced cancer. Three lesions were misdiagnosed as gastric cancer by helical CT. Histopathologically, all early gastric cancers detected by helical CT were either polypoid or elevated types or showed massive invasion of the submucosal layer. The differentiation between T1 cancer with massive submucosal invasion and advanced cancer was difficult. The differentiation between T2 and T3 cancer was possible in 73% (19 of 26) and between T1/T2 and T3/T4 (extraserosal invasion) in 83% (34 of 41). Overall T-staging was correct in 66% (27 of 41). MPR images improved the detection rate (three lesions) or increased confidence in T-staging (eight lesions) over axial CT images. Conclusion: When helical CT detected gastric cancer that was not a polypoid or elevated type with underlying normal-appearing gastric wall, it was either T1 cancer with massive invasion of the cancer cells into the submucosal layer or advanced cancer. However, differentiation between these two stages was difficult on CT. Diagnosis of serosal invasion was not markedly improved by helical CT. MPR images increased confidence in the staging of certain gastric cancers, such as those in locations where CT images are susceptible to partial volume averaging effects.

上腸間膜静脈, 卵巣静脈を介しての門脈-大循環短絡により高アンモニア血症を生じた慢性血液透析患者を経験した. 症例は43歳, 女性. 主訴は意識障害, せん妄. 1983年に末期腎不全で血液透析に導入. 1993年に原因不明の汎発性腹膜炎のため人工肛門の造設および腹壁ヘルニア根治術を行った. 1995年1月頃より傾眠傾向, 家族の名前を忘れる, 理由もなく興奮するなどの症状が出現し増悪するため3月14日当科に入院した. 神経学的検査では, 意識レベルはJapan Coma Scaleで1点であり, 羽ばたき振戦を認めた. 血液生化学検査ではGOT, GPT, 総ビリルビン値は正常であったが, 血中アンモニア値は424μg/dlと上昇していた. 肝炎ウイルスマーカーは陰性で, 肝生検組織にも肝障害の所見は認められなかった. 脳波では両側性の徐波を認めた. 頭部MRIでは, T1強調画像で, 淡蒼球に対称性に高信号域を認めた. 上腸間膜動脈造影で上腸間膜静脈より下大静脈への短絡路を認め, 同部へ塞栓術を施行した. 塞栓術後, 血中アンモニアは正常化し, 意識障害も改善した.

Purpose: We evaluate the usefulness of neoadjuvant chemotherapy for bladder cancer.Materials and Methods: The usefulness of neoadjuvant, modified methotrexate, vinblastine, doxorubicin and cisplatin chemotherapy was evaluated in 36 patients with locally advanced bladder cancer.Results: Of 36 patients 12 achieved a clinical complete response and 17 had a partial response. Of the 12 patients who achieved a clinical complete response the bladder was preserved in 11 and all patients were disease-free at a median of 33 months. No significant toxicity was observed.Conclusions: This chemotherapy is useful for locally advanced bladder cancer and the feasibility of bladder preservation in patients with a clinical complete response was suggested.

A phase II study of a new combination therapy was performed using intraarterial (i.a.) cisplatin and Adriamycin in combination with i.v. methotrexate and vincristine for 27 patients with invasive urinary bladder carcinoma of stages T2-3NOMO, and the therapeutic effects were assessed. Methotrexate (20 mg/m2) was given i.v. on days 1,15, and 22, and vincristine (0.7 mg/m2) was injected i.v. on day 2 before i.a. infusion therapy and on days 15 and 22. The i.a. chemotherapy was performed after both superior gluteal arteries had been embolized using 3- or 5-mm stainless-steel coils. A mixture of cisplatin (50-70 mg/m2) and Adriamycin (20 mg/m2) was infused i.a. via both internal iliac arteries over a period of 20-30 min. Angiotensin II (mean dose, 21 micrograms) was simultaneously infused i.a. in 15 of 27 patients. In 24 of the 27 patients, at least 2 cycles of full-dose chemotherapy were completed. The dose was decreased in the remaining 3 patients because of their poor health status and advanced age. Among the 27 patients, 9 and 14 had complete (CR) and partial responses (PR), respectively; 3 manifested no change (NC), and 1 had progressive disease (PD). The objective response rate (CR+PR) was 85.2%. Among the 27 patients staged T2-3 NOMO, 6 (CR, 1; PR, 5) underwent total cystectomies and 18 (CR, 8; PR, 8; NC, 2) had transurethral resection of a bladder tumor (TUR-Bt) or partial resections following chemotherapy. The remaining 3 diminished-dose patients had no surgery. Of the 27 patients, 22 were alive after a median follow-up period of 21+ (range, 7-48+) months. No significant side effect was observed except for lower extremity paresthesias in 5 patients (18.5%). These results point to the effectiveness of this therapy and to the possibility of urinary bladder preservation in patients with invasive, advanced urinary bladder cancers.

We aimed to evaluate the application of apparent diffusion coefficient (ADC) values calculated from diffusion-weighted imaging (DWI) (b value = 1500 s/mm2) in the breast imaging reporting and data system (BI-RADS). For 104 cases of breast lesions with definitive histology diagnosis (45 benign cases, 59 malignant cases) in which breast magnetic resonance imaging was performed, ADC values were compared between benign and malignant cases, between ductal carcinoma in situ (DCIS) and fibrocystic changes, and between DCIS and ductal hyperplasia (one type of fibrocystic change). Diagnostic accuracy was compared for a total of 101 images and for 34 images including only nine DCIS and 25 fibrocystic changes between BI-RADS alone (with categories 4a, 4b, and 5 defined as malignancies) and BI-RADS plus ADC. There were significant differences in mean ADC values between malignant and benign cases (p

We studied the growth of 89 patients who were long-term survivors of childhood leukemia and lymphoma. Eight patients with CNS relapse had a greater decrease in height standard deviation score (SDS) after the relapse than 81 patients without CNS relapse (p less than 0.0001). Two patients who received cranial irradiation when they were younger than 2 years of age demonstrated a marked decrease in height SDS more than 3.0 SD. Five patients appeared to have a decline in height SDS before their CNS relapse. There were no apparent changes in the weight of patients with or without CNS relapse. In endocrine studies, all eight patients with CNS relapse failed to show the normal growth hormone (GH) response to arginine, GH-releasing factor, and glucagon-propranolol tests, while spontaneous GH secretion during sleep was normal. Magnetic resonance imaging (MRI) revealed small pituitary glands in seven patients with CNS relapse. These findings suggest that in leukemia and lymphoma patients with CNS relapse, GH secretion is impaired at the hypothalamic level, resulting in a secondary atrophy of the pituitary gland. The MRI together with selected endocrinologic tests may help to clarify the mechanism of growth impairment in such patients. A decline in height SDS in each patient may be a useful marker for predicting a CNS relapse in a child with leukemia or lymphoma.

Percutaneous transcatheter embolization of the testicular vein was performed on 28 patients with angiographically proven varicocele testis. In 2 patients bilateral and in 26 only the left vein was embolized using 3-, 5-, or 8-mm stainless steel coils. All patients had clinically palpable varicoceles and male infertility. The grade of varicoceles improved after embolization in 23 of 28 cases (82%). Effective sperm count increased significantly from 34.5 ± 44.6 to 65.1 ± 71.0 following embolization. However, pregnancy was achieved only in one of 28 cases. Technically, the basilic vein approach was felt to be superior to the femoral vein or jugular vein approach for this procedure.

Magnetic resonance (MR) imaging performed in 13 patients with moyamoya disease was reviewed and compared with computed tomography (CT) and angiography. The MR findings consisted of occlusion of arteries, collateral vessels and parenchymal changes. Narrowing or occlusion of the middle cerebral artery and the supraclinoid portion of the internal carotid artery were seen in all hemispheres but one. Collateral vessels, cerebral infarcts and atrophy with dilatation of the ventricles were observed on MR imaging. In general, the MR findings correlated well with angiography regarding occlusive changes and moyamoya vessels but was less sensitive in a few cases. Because of its higher sensitivity in detecting occlusive changes and collateral vessels, MR imaging was superior to CT in the diagnosis of this disease.

A 43-year-old non-cirrhotic woman suffered from encephalopathy caused by an extrahepatic portosystemic shunt between the ileal vein and inferior vena cava via the right gonadal vein. Percutaneous transcatheter embolization with stainless steel coils was performed by the retrograde systemic venous approach. Encephalopathy improved dramatically.

To retrospectively evaluate the ultrasonographic (US), computed tomographic (CT), and magnetic resonance (MR) imaging features that differentiate traumatic neuroma from recurrent lymphadenopathy after neck dissection.Imaging findings of 10 patients with a traumatic neuroma and 17 with recurrent lymphadenopathy were reviewed. US and CT were performed in all patients; MR imaging was performed in 16 patients. Findings analyzed at US included the diameter of the long and short axes, the short-axis-to-long-axis ratio, and the presence of a central hyperechoic area. Findings analyzed at CT were contiguity with common or internal carotid artery, lesion location in correlation with carotid artery, and the presence of a hyperattenuating rim. Findings analyzed at MR imaging included signal intensity on T1- and T2-weighted images, the presence of ring enhancement, and the presence of a hypointense rim on T2-weighted images.Statistically significant differences were found between traumatic neuroma and recurrent lymphadenopathy in the short-axis-to-long-axis ratio (mean, 0.47 vs 0.72; P.001), the short-axis diameter (mean, 5.7 vs 12.2 mm; P.001), the presence of a central hyperechoic area (five of 10 patients [50%] vs one of 17 patients [6%]; P.05), the frequency of contact with carotid artery (two of 10 patients [20%] vs 13 of 17 patients [76%]; P.01), and the presence of a hypointense rim on T2-weighted MR images (three of six patients [50%] vs zero of 10 patients [0%]; P.05). Findings in other parameters were not statistically significant.Several imaging findings can differentiate traumatic neuroma from recurrent lymphadenopathy after neck dissection.

A malignant peripheral nerve sheath tumour (MPNST) generally occurs in adults and often in patients with neurofibromatosis-1 (NF-1). We present a rare case of a huge thoracic MPNST arising from the intercostal nerve in a 12-year-old girl without NF-1. In addition to the unusual occurrence in a child without NF-1, MRI demonstrated a unique pedunculated appearance mimicking a pleural tumour. In this report, we present the CT and MRI findings of our case, together with the histopathological findings, and review previous reports.

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.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.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%.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.

BACKGROUND The current study evaluated whether the sites of liver metastasis from gallbladder carcinoma are correlated with areas of cholecystic venous drainage (CVD) utilizing helical computed tomography (CT) during the injection of contrast medium into the cholecystic artery (cholecystic artery CT). METHODS Cholecystic artery CT scans were performed in 26 patients with gallbladder carcinoma. Liver metastases were examined retrospectively in these patients on CT, and the sites of liver metastasis and CVD were compared closely. The patients were divided into concurrent (those who had metastasis at the time of cholecystic artery CT), early postoperative metastasis (those who developed metastasis within 6 months after surgery), and late postoperative metastasis (those who developed metastasis more than 6 months after surgery) groups. The frequency of metastasis related to CVD was compared between the three groups. RESULTS A total of 32 metastases were identified in 11 patients, 21 of which were related to CVD. Six patients were included in the concurrent metastasis group; 18 of 20 tumors were found to be related closely to CVD. There were two patients in the early postoperative metastasis group; all three of the tumors detected were found to be closely related to CVD. Three patients were subclassified as being in the late postoperative metastasis group; none of the nine tumors detected appeared to be in areas associated with CVD. CONCLUSIONS The sites of liver metastases were found to be well correlated with the areas with CVD, particularly in the concurrent and early postoperative metastasis groups. CVD may be a useful marker of potential areas of liver metastasis from gallbladder carcinoma, particularly in patients with early stage metastasis. Cancer 2001;92:340–8. © 2001 American Cancer Society.

We report a rare case of iatrogenic arterial dissection of the superior mesenteric artery (SMA) during diagnostic angiography. A conventional superior mesenteric arteriogram obtained using an automated power injector revealed an arterial dissection 2 s after the initiation of contrast-medium injection. This case indicates that although careful catheter manipulations during angiography are essential, certain unavoidable complications may occur.

The purpose of this study was to establish MR cholangiopancreatographic criteria for discriminating benign from malignant intraductal mucin-producing tumors of the pancreas.Thirty-one patients with 34 intraductal mucin-producing tumors underwent MR cholangiopancreatography. Tumors were classified as either main duct type (n = 10) or branch duct type (n = 24). In patients with the main duct type, the maximum diameter and the location of the main pancreatic duct, the extent of main pancreatic duct dilatation, and the presence of a filling defect were evaluated. For branch duct type, the location and maximum diameter of the cystic lesion, the presence of a filling defect, and the presence of associated main pancreatic duct dilatation were evaluated.In patients with the main duct type, the main pancreatic duct was significantly narrower when associated with benign rather than malignant tumors. All malignant tumors showed diffuse main pancreatic duct dilatation, whereas all benign tumors showed segmental dilatation. Among patients with branch duct type, the cyst was smaller when it was a benign rather than malignant tumor. All but one malignant tumor showed mild associated main pancreatic duct dilatation, whereas benign tumors were not associated with main pancreatic duct dilatation. Filling defects suggested malignancy, although half of the malignant tumors had no filling defects.In patients with intraductal mucin-producing tumors of the pancreas, filling defects are indicative of malignancy. Diffuse main pancreatic duct dilatation greater than 15 mm (main duct type), or any main pancreatic duct dilatation (branch duct type), is strongly associated with malignancy.

Our objective was to analyze the hemodynamic properties and vascular supply changes in the carcinogenesis of hepatocellular carcinoma.Ten nodules (nine patients) (one early, three early-advanced, and six advanced cases of hepatocellular carcinoma) less than 3 cm in diameter were selected from 45 patients (50 nodules) who underwent CT arteriography and CT during arterial portography. These images were correlated with histopathologic findings. Ratios of all microscopically counted (normal hepatic and abnormal) arteries, normal hepatic arteries, and portal veins in each nodule to those in the surrounding liver were calculated.Early hepatocellular carcinoma (one early case and early areas in three early-advanced cases) had low attenuation on CT arteriography and isoattenuation on CT during arterial portography. Advanced hepatocellular carcinoma (six advanced cases and advanced areas in three early-advanced cases) had high attenuation on CT arteriography and low attenuation on CT during arterial portography. In early hepatocellular carcinoma, the ratios of all arteries, normal hepatic arteries, and portal veins were 1.21 +/- 0.07, 0.60 +/- 0.07, and 0.73 +/- 0.06, respectively. In advanced hepatocellular carcinoma, the ratios were 2.66 +/- 0.26, 0.08 +/- 0.04, and 0.07 +/- 0.03, respectively.In early hepatocellular carcinoma, the combination of normal hepatic artery degeneration and preserved portal veins results in low attenuation on CT arteriography and isoattenuation on CT during arterial portography. In advanced hepatocellular carcinoma, the combination of neoplastic (abnormal) arterial development by angiogenesis and obliteration of portal veins results in high attenuation on CT arteriography and low attenuation on CT during arterial portography. These findings are a characteristic difference between early and advanced hepatocellular carcinoma.

A 51-year-old man suffered from bleeding esophageal varices. He had undergone partial gastrectomy for gastric cancer 1 year before. An extrahepatic arterioportal fistula and resultant portal hypertension were found. We successfully performed transarterial embolization of the fistula using stainless steel coils. Portal hypertension improved dramatically.

We evaluated the MR imaging features of adenomyomatosis of the gallbladder with particular emphasis on Rokitansky-Aschoff sinuses.MR images of 17 patients with histologically proven adenomyomatosis were retrospectively reviewed. The presence of Rokitansky-Aschoff sinuses was evaluated and analyzed; four T2-weighted (fast spin-echo with a surface coil, with or without breath-holding, fast spin-echo with a phased-array coil with breath-holding, and half-Fourier rapid acquisition with relaxation enhancement with breath-holding) and two contrast-enhanced dynamic pulse sequences were studied. These six pulse sequences were separately rated on a 5-point scale by two radiologists for comparison. Interobserver differences were evaluated. Other MR findings were also analyzed.Among the six pulse sequences studied, three T2-weighted with breath-holding sequences were found to be superior to the other three sequences in showing Rokitansky-Aschoff sinuses. In particular, the half-Fourier rapid acquisition with relaxation enhancement was scored the highest by the two observers and received the highest kappa coefficient in our statistical analysis of the scoring. Diffuse-type adenomyomatosis typically showed early mucosal and subsequent serosal enhancement. Localized adenomyomatosis exhibited homogeneous enhancement, showing smooth continuity with the surrounding gallbladder epithelium.MR imaging may be able to provide important information in the diagnosis of adenomyomatosis.

We attempted to determine whether cytoplasmic fat in clear cell renal cell carcinoma (RCC) can be identified by chemical shift gradient-echo magnetic resonance imaging (CSI). CSI was performed for 22 clear cell RCCs and 30 other renal tumors (including 16 non-clear cell RCCs), all of which were surgically proven. Signal reduction in out-of-phase images of these tumors was retrospectively evaluated and compared. The signal loss ratio (SLR) was defined and calculated. Fat staining of specimens from 16 tumors was performed and correlated with SLR. SLR was significantly higher in clear cell RCCs than in non-clear cell RCCs (P < 0.001). There was a significant correlation between degree of fat staining positivity of the specimens and SLR (P < 0.01). When signal reduction in out-of-phase images suggested the diagnosis of clear cell RCC, correct diagnosis of this entity was made in resected renal tumors with sensitivity, specificity, and accuracy of 82%, 90%, and 87%, respectively. CSI can demonstrate cytoplasmic fat in clear cell RCCs, which helps to differentiate this entity from other RCCs.

Purpose: The purpose of this work is to describe the findings on MRI in patients with groove pancreatitis, a specific form of chronic pancreatitis affecting the groove between the pancreatic head, the duodenum, and the common bile duct. Method: MR images, including MR cholangiopancreatography, of five patients with groove pancreatitis were reviewed. Three patients underwent pancreatoduodenectomy due to severe duodenal stenosis, and the MR findings were compared to the histologic findings. Results: A sheet-like mass was demonstrated between the pancreatic head and the duodenum in all patients. The masses were hypointense relative to pancreatic parenchyma on T1-weighted images and iso- to slightly hyperintense on T2-weighted images. After administration of Gd-DTPA, the masses showed delayed enhancement. Histologically. fibrous scar tissue was detected in the groove. Conclusion: MR images can clearly demonstrate the fibrous tissue in the groove in groove pancreatitis, and MR cholangiopancreatography can also provide useful information.

The purpose of this study was to use helical CT to elucidate the anatomy and clinical importance of cholecystic venous drainage.We performed helical CT of the upper abdomen during injection of contrast medium through a superselectively catheterized cholecystic artery (cholecystic artery CT) in 28 patients, all of whom were surgical candidates for suspected hepatobiliary abnormality. In nine of these patients, CT during arterial portography (CTAP) was also performed.Cholecystic venous blood most frequently entered peripheral portal branches of hepatic segment V (27 of 28 patients, 96%) and segment IV (26 of 28, 93%). In order of decreasing frequency, cholecystic venous blood also drained to segments I, VI, VIII, III, and VII. Cholecystic venous blood subsequently drained into the middle hepatic vein (21 of 28, 75%) or right hepatic vein (20 of 28, 71%). In two patients with adenocarcinoma involving the gallbladder associated with multiple liver metastases, cholecystic venous drainage was seen around each metastatic focus. In the nine patients in whom both cholecystic artery CT and CTAP were performed, nontumorous portal perfusion defects were attributable to cholecystic venous drainage.Recognition of cholecystic venous drainage as a possible pathway for spread of disease from the gallbladder to the liver and also as one of the causes of non-tumorous portal perfusion defects seen on CTAP is important.

To analyze CT findings of Bellini duct carcinoma, a rare variant of renal cell carcinoma. The CT findings of five cases of Bellini duct carcinoma were reviewed and the findings were recorded. In all cases the affected kidneys maintained the normal outer contours. In four cases the renal masses protruded into the central sinuses. Contrast enhancement was minimal in four cases. Bellini duct carcinoma should be suspected in cases with these CT findings. 17 refs., 5 figs., 1 tab.

Objective Our goal was to elucidate the CT and MRI findings of inflammatory pseudotumors of the spleen. Methods The CT and MRI findings of three patients with inflammatory pseudotumors of the spleen were reviewed and compared with the pathologic findings. Results On the early phase of CT, the masses were hypodense to the normal spleen, and on the delayed phase, they demonstrated delayed enhancement. On T1-weighted MR images, the masses were isointense to the normal spleen, and on T2-weighted images, the masses had heterogeneous low signal intensities. After administration of Gd-DTPA, the masses showed delayed enhancement. Conclusion Inflammatory pseudotumors of the spleen were characterized by low signal intensity on T2-weighted MR images and delayed enhancement after contrast material administration on CT and MRI. The fibrous stroma may contribute to these unusual findings.

Purpose : To evaluate the initial changes within the nidus of arteriovenous malformations (AVMs) and to assess the reaction of the brain tissue surrounding AVMs after radiosurgery by serial magnetic resonance (MR) imaging. Methods and Materials : Twenty-one patients, treated using 60Co gamma knife unit with cerebral AVMs, were retrospectively evaluated. Forty-seven follow-up MR images of the 21 patients were performed including 10 patients with two or more serial gadolinium enhanced studies (Gd-MR). Two or more sequential MR angiographies (MRA) were obtained in 13 patients. Three-dimensional (3D) time-of-flight MRA and two-dimensional (2D) phase contrast MRA were used in 13 patients for evaluating the flow changes of AVMs. The follow-up period after radiosurgery ranged from 3 to 30 months (average 10.8 months) and the interval time of MRI ranged from 34 days to 13 months (average 4.9 months). Results : Reduction of nidus size was observed in 14 of the 21 patients (67%) between 4 to 13 months on spin echo (SE) images. Complete obliteration was observed on SE images in 4 of these 14 patients; three were confirmed by conventional angiography. New hyperintense areas surrounding the nidus on T2-weighted images (T2WI) developed in 9 of the 14 patients who showed nidus reduction between 5 to 17 months after radiosurgery; in three patients, size of the hyperintense area started to decrease between 6 to 7 months after its appearance. Probable radiation necrosis of pons developed in one patient 26 months after radiosurgery. The irradiated area within the AVM nidus was significantly enhanced in 8 of the 10 patients who underwent Gd-MR. The degrees of enhancement within the nidus increased with time in 7 of the 10 patients. Overall, total enhancement of irradiated areas was observed in four of the 10 patients; in three of the four, the enhancement decreased in size and degree, indicating nidus reduction. In three patients who had a partial volume irradiation within the nidus, the enhancing areas corresponded with the exact portions of irradiated volume. The nidus reduction was observed in 7 of the 13 patients on MRA during 5 to 13 months after radiosurgery. MRA was more useful compared to SE images in four of the seven patients in evaluating the size change of AVM nidus, feeding arteries, and draining veins. Conclusion : Magnetic resonance imaging and MRA were useful in assessing the progress of nidus reduction. T2-weighted imaging was sensitive to radiation-induced reaction in and around the AVM nidus. The enhancement within the AVM nidus on Gd-MR may represent the initial sign of nidus reduction and demonstrates the exact location of irradiation in the nidus. The changes of the enhancement pattern are presumed to represent the processes of nidus reduction and irradiated reaction within the AVM nidus.

OBJECTIVE We report MR findings in three patients with dysembryoplastic neuroepithelial tumor (DNT), which is a recently described benign tumor in childhood or young adolescents. MATERIALS AND METHODS The MR studies of three patients with surgically proven DNT were reviewed. All cases presented with partial complex seizures. Axial and coronal T1- and T2-weighted MR imaging of the head was performed using a 1.5 T MR unit. T1-weighted imaging after Gd-DTPA was also performed. RESULTS The tumors were located mainly in the cortical to subcortical area with very little perifocal mass effects on MR imaging. They were essentially hypointense on T1-weighted imaging and hyperintense well-demarcated mass on T2-weighted imaging and retained a thick gyrus-like configuration within the lesions. None of them exhibited contrast enhancement after administration of Gd-DTPA. CONCLUSION Differentiation of DNT from gangliogliomas or other low grade gliomas is possible using these MR features and is important because DNT does not recur after epilepsy surgery, therefore postoperative radiation and chemotherapy are not needed.

We report a case of primary CNS B-cell lymphoma indistinguishable from multiple sclerosis (MS). MRI of the head showed the spontaneous disappearance of the white matter lesions and the progressive cerebral atrophy. The brain biopsy failed to make a diagnosis of CNS lymphoma but rather suggested MS. Although the primary CNS lymphoma was suspected at autopsy, the immunohistochemical study showed the CNS-infiltrating lymphoid cells comprising both T-cells and B-cells. Analysis of the immunoglobulin and T-cell receptor gene rearrangements first provided evidence of primary CNS B-cell lymphoma.

We present a case of pituitary hypertrophy due to juvenile primary hypothyroidism with subsequent return to normal size after therapy. This clinical entity is well known, but there are few reports on its magnetic resonance (MR) findings. We stress the usefulness of Gadolinium-DTPA-enhanced (Gd-DTPA-nhanced) MRI in the differential diagnosis of pituitary hypertrophy and pituitary adenoma.

Ultrasonography is of proven value in the diagnosis of the acute abdomen in children, notably intussusception and acute appendicitis. This report describes an unusual case of acute, primary, multiple gastric ulcers in a child. Ultrasonography was used in the establishment of the correct diagnosis and in subsequent follow-up. An 11-year-old boy was admitted to our hospital because of sudden onset of severe, epigastric pain preceded by 2 days of diarrhoea and vomiting. On admission, the abdomen was soft, but tender in the upper part. Laboratory tests showed 7100/mm3 leucocytes and haemoglobin 11.6 g/dl with haematocrit 49.3%.

This is a report of a 10-year-old girl with congenital hemihypertrophy (CH) associated with medullary sponge kidney (MSK) and adrenocortical adenoma. Computed tomography (CT) and ultrasonography demonstrated a small, non-functional, adrenocortical adenoma. A search of the literature failed to reveal any previously reported case having all three conditions. A 10-year-old Japanese girl was admitted with fever, headache and vomiting of 2 days duration. She was born without complications after full-term pregnancy with a birth weight of 3750 g. Slight asymmetry of her legs was noted at birth. Her development was normal and there was no family history of renal disease. On admission, slight hypertrophy of the left lower extremity was noted and the left thigh was 3.0 cm greater in girth than the right.

A 8-year-old Japanese girl had congenital bile duct dilatation, associated with both choledocholithiasis and acute pancreatitis. Ultrasonography (US) was used to demonstrate a stone within a dilated common bile duct, and US provides the most useful preoperative information to proceed to surgery.