Tadayuki Maehara

Management of branch duct-type intraductal papillary mucinous tumor of the pancreas based on magnetic resonance imaging

Background: We assessed the usefulness of magnetic resonance imaging (MRI) in identifying nonmalignant intraductal papillary mucinous tumors (IPMTs) of the pancreas.Methods: Thirty-three patients with branch duct-type IPMT diagnosed by endoscopic retrograde cholangiopancreatography were prospectively examined with magnetic resonance cholangiopancreatography followed by dynamic gadolinium-enhanced MRI examinations, and patients with no findings suggestive of malignancy, including a solid mass, mural nodules, a main pancreatic duct wider than 5 mm in diameter, and stenosis of the main pancreatic duct, were prospectively followed up with sequential MRI examinations once or twice a year.Results: Twenty-six (79%) patients showed no findings suggestive of malignancy in the initial MRI examination. The diameter (mean ± standard error) of the main pancreatic duct was 3.9 ± 0.7 mm and that of the ectatic branch pancreatic duct was 36.0 ± 9.1 mm. Twenty-three patients were prospectively followed for more than 36 months and 22 of them showed no findings suggestive of malignancy during follow-up periods ranging from 39 to 77 months (mean = 55 months).Conclusion: MRI was useful to identify nonmalignant IPMTs of the branch duct type, and close follow-up observation with serial MRI examinations may be appropriate in the management of such patients.

Early detection of extrahepatic bile-duct carcinomas in the nonicteric stage by using MRCP followed by EUS

BACKGROUND Most extrahepatic bile-duct carcinomas are usually diagnosed when they are already in an advanced stage, which is the main reason for the poor prognosis of this tumor. OBJECTIVE To examine the usefulness of MRCP followed by EUS in the early diagnosis of extrahepatic bile-duct carcinoma in the nonicteric stage. PATIENTS This study included patients who were nonicteric, who had abnormal serum concentrations of alkaline phosphatase and gamma glutamyl transpeptidase, and whose common hepatic duct was more than 8 mm in diameter on abdominal US because of unknown reasons. DESIGN A single-center, prospective study. SETTING An academic medical center. MAIN OUTCOME MEASUREMENTS The sensitivity and specificity of MRCP followed by EUS for the early diagnosis of extrahepatic bile duct carcinoma in the nonicteric stage. RESULTS A total of 142 patients who were nonicteric underwent prospective MRCP, and 26 of them underwent EUS. Ten patients (5 with stricture, 4 with filling defect, and 1 with no stricture or filling defect) had extrahepatic bile-duct carcinoma, including 5 patients with an incidentally diagnosed T1 stage tumor. The sensitivity and specificity of MRCP followed by EUS were 90% and 98%, respectively. LIMITATIONS A single center and small number of patients. CONCLUSIONS MRCP followed by EUS was highly sensitive and specific for the early diagnosis of extrahepatic bile-duct carcinoma in the nonicteric stage, including T1 stage tumors. Filling defects, as well as stenosis in the bile duct, are important MRCP findings of T1 stage carcinoma.

Computed tomography of intracranial chondroma with emphasis on delayed contrast enhancement.

Intracranial chondroma is an unusual cartilaginous tumor originating from the base of the skull. We report on two cases of intracranial chondroma that showed delayed contrast enhancement on CT after high-dose administration of contrast medium. This CT feature may be useful to differentiate chondromas from other tumors of the skull base such as meningiomas and neurinomas.

Successful transarterial glue embolisation by wedged technique for a tentorial dural arteriovenous fistula presenting with a conjunctival injection

Abstract Many tentorial dural arteriovenous fistulae (TDAVF) present with intracranial haemorrhage. We report a patient who presented with conjunctival injection. Transarterial embolisation of the TDAVF was undertaken with a wedged injection of a low concentration of N-butyl cyanoacrylate, arresting the flow next to the proximal segment of the venous outlet. After three sessions, a complete cure was achieved. We present a useful method which has not been reported previously.

Neurinoma of the oculomotor nerve: CT and MR features.

The authors present a case of neurinoma of the oculomotor nerve without evidence of von Recklinghausen disease. The literature is reviewed and CT and magnetic resonance findings are discussed.

Pancreatic-duct–lavage cytology in candidates for surgical resection of branch-duct intraductal papillary mucinous neoplasm of the pancreas: should the International Consensus Guidelines be revised?

BACKGROUND The International Consensus Guidelines are helpful for the management of branch-duct intraductal papillary mucinous neoplasms (IPMNs), because they allow us to exclude malignancy. However, it is not possible to predict malignancy with certainty, and further preoperative differentiation between benign and malignant IPMNs is required to avoid the false-positive results. OBJECTIVE To examine the usefulness of pancreatic-duct-lavage cytology by using an originally designed double-lumen catheter for discriminating benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines. PATIENTS Pancreatic-duct-lavage cytology was investigated in 24 patients with branch-duct IPMNs who underwent surgical resection based on the International Consensus Guidelines, namely, they either had intramural nodules or the ectatic branch duct was >30 mm in diameter. DESIGN Single-center retrospective study. SETTING Academic medical center. MAIN OUTCOME MEASUREMENTS The sensitivity and specificity of pancreatic-duct-lavage cytology for discriminating benign from malignant IPMNs. RESULTS More than 30 mL of pancreatic-duct-lavage fluid was obtained from each patient, and there were no patients with noninformative results. The sensitivity, specificity, positive predictive value, and negative predictive value of the cytologic diagnosis were 78%, 93%, 88%, and 88%, respectively. LIMITATIONS Single-center and small number of patients. CONCLUSIONS Pancreatic-duct-lavage cytology can improve differentiation between benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines.

Successful surgical treatment of a dural arteriovenous fistula at the craniocervical junction with reference to pre- and postoperative MRI

Abstract We report a 62-year-old woman who presented with a myelopathy at the lower thoracic level. Left vertebral angiography revealed a dural arteriovenous fistula (DAVF) at the craniocervical junction, draining into an anterior spinal vein. Below the T 7 level, the spinal cord gave high signal on T 2-weighted images and enhanced with Gd-DTPA. The patient was successfully treated by simple clipping of vein draining the DAVF. The abnormal signal intensity and contrast enhancement rapidly regressed, except in the conus medullaris. Regression of the parenchymal abnormality on serial MRI following treatment corresponded closely with postoperative improvement of neurological function.

Medically treated steroid-induced epidural lipomatosis.

A 26-year-old male with nephrotic syndrome, who had been on prednisone, 20~80 nag per day (average daily dose 50 rag) for the last 44 months, was admitted to our hospital on December 6, 1983 after two weeks of progressive low-back pain, numbness of right thigh and leg weakness. His medication on admission consisted of prednisone, 40 mg per day and cyclophosphamide, 100 mg per day. He had right femoral paresthesia, flaccid paraparesis, bilateral lower extremity weakness and T8 radicular pain. There was hyperreflexia of the knees and ankles with positive Babinskls sign. CT showed a large amount of fatty tissue (attenuation -126HU) in the posterior part of the spinal canal from T-5 to T-10 with anterior compression of the dural sac and cord (Fig. 1). A diagnosis of epidural lipomatosis secondary to prolonged corticosteroid therapy was established and conservative medical treatment was chosen because the patient rejected the surgical procedure. The steroid dose was tapered down to 20 mg prednisone every other day over the next 4 months. CT on August 27, 1985 showed marked regression of the fatty tissue in the spinal epidural space and almost normal configuration of the thoracic thecal sac (Fig.2). Proteinuria was kept below 0.2 mg per day and definite improvement of the neurological symptoms was observed.

Anomalous origin of the posterior meningeal artery from the lateral medullary segment of the posterior inferior cerebellar artery

SummaryThe authors present two cases of angiographically-confirmed anomalous origin of the posterior meningeal artery (PMA) from the lateral segment of the posterior inferior cerebellar artery (PICA) and describe briefly the probable embryogenesis of this anomaly.

Diffusion-weighted MR imaging in multiple sclerosis : comparison with contrast-enhanced study

OBJECTIVE To assess the utility of cerebral diffusion-weighted MR imaging in the diagnosis of multiple sclerosis (MS) in comparison with contrast-enhanced T1-weighted imaging. METHODS AND MATERIALS We reviewed T2-weighted spin-echo (SE), fluid-attenuated inversion-recovery (FLAIR), contrast-enhanced T1-weighted SE and echo-planar diffusion-weighted images (DWIs) obtained in seven patients with definite MS on nine occasions. RESULTS In total, 94 plaques were demonstrated on T2-weighted SE and/or FLAIR images. A total of 13 of these plaques showed enhancement on contrast-enhanced T1-weighted images and hyperintensity on DWIs, and five non-enhancing plaques showed hyperintensity on DWIs. CONCLUSION Diffusion-weighted imaging, which provides information based on pathophysiology different from contrast-enhanced imaging, is a potential supplementary technique for characterizing MS plaques.