Pharmacological considerations in antipsychotic drug selection for prevention of drug-induced dysphagia.

Antipsychotic drugs have the ability to induce dysphagia. The aim of this study was to determine the association between the receptor affinity of antipsychotic drugs and the time-to-onset of dysphagia, and to identify factors that prevent antipsychotic drug-induced dysphagia. We used the receptor affinity of 13 antipsychotic drugs for which data were reported in an in vitro test using human receptors, extracted time-to-onset dysphagia from the Japan Adverse Drug Event Report database, and used data from 46 patients to evaluate the correlation between receptor affinity and time-to-onset of dysphagia. We found a negative correlation between D2 receptor affinity and time-to-onset of dysphagia (r = -0.4572, p = 0.0016), and a positive correlation between H1, M1, and M3 receptor affinity and time-to-onset of dysphagia (r = 0.5006, p = 0.0006; r = 0.4130, p = 0.0059; and r = 0.4149, p = 0.0057, respectively). Antipsychotic drugs with a strong D2 receptor-blocking action may accelerate the onset of dysphagia, whereas a strong H1, M1, and M3 receptor-blocking action may delay the onset of dysphagia. The current study revealed the relationship between the receptor affinity of antipsychotic drugs and the time-to-onset of dysphagia, which should aid in the selection of antipsychotic drugs, while preventing dysphagia.

Accuracy of pre- and postcontrast 3D time-of-flight MR angiography in patients with acute ischemic stroke: correlation with catheter angiography.

BACKGROUND AND PURPOSE: 3D time-of-flight (TOF) MR angiography (MRA) is insensitive to slow flow; however, the use of MR imaging contrast agents helps to visualize slow-flow vessels and avoids overestimation of vascular occlusion. The purpose of this study was to correlate pre- and postcontrast 3D TOF MRA with the results of conventional angiography during endovascular reperfusion therapy and to determine the accuracy of postcontrast 3D TOF MRA. MATERIALS AND METHODS: Thirteen patients who underwent endovascular reperfusion therapy for acute ischemic stroke were retrospectively analyzed. MR imaging techniques included single-slab 3D TOF MRA with and without contrast, as well as perfusion-weighted imaging. Angiography during reperfusion therapy was used as a standard of reference. Affected arteries were divided into segments either proximal or distal to the lesion, and pre- and postcontrast MRA signals were graded as absent, diminished or narrowed, or normal. RESULTS: In 2 of 5 patients with arterial stenosis and 6 of 8 patients with complete occlusion, MRA signal intensity proximal to each lesion was absent, indicating a proximal pseudo-occlusion on precontrast MRA. Postcontrast MRA demonstrated an arterial signal intensity proximal to the stenotic or occlusive lesions in all 13 patients. Arterial signal intensity distal to the occlusion was identified on postcontrast MRA in 7 of 8 patients having complete occlusion, and the extent of occlusion on postcontrast MRA was similar to results of conventional angiography. CONCLUSION: In this small series, postcontrast 3D TOF MRA more accurately delineated the extent of stenotic or occlusive arterial lesions than precontrast MRA.

Successful treatment of bleeding due to ileal varices in a patient with hepatocellular carcinoma.

This case report concerns a 62-year-old female who was known to have cirrhosis. An endoscopic examination showed no evidence of haemorrhaging due to either oesophageal or gastric varices. Angiographic studies demonstrated extravasation from the ileal varices. There was a prominent arterio-portal shunt in the liver, and the shunt was considered to be a contributing factor to induce portal hypertension and variceal bleeding in the ileum. Therefore, transcatheter arterial embolization was performed, but was unsuccessful. As a result, the patient underwent a laparotomy, and a dilatating ileocaecal vein and a communicating ovarian vein were selectively ligated. Following the procedure, the haemorrhaging stopped and she then recovered. The patient is doing well 21 months after surgery at the time of writing.

[Gradually enhancing breast cancer on dynamic MRI].

PURPOSE: The aim of our study was to evaluate the frequency and the radiologic and pathologic features of gradually enhancing breast cancers on contrast enhanced dynamic MRI. MATERIAL AND METHODS: 83 patients with pathologically proven breast cancer underwent contrast enhanced dynamic MRI. Breast cancers that showed a gradually enhancing pattern were selected, and their pathological features and the findings in other imaging modalities were retrospectively analyzed. RESULTS: Of 83 lesions, 8 lesions (10%) showed a gradually enhancing pattern on dynamic MRI. The lesions included 3 papillotubular carcinomas, 3 scirrhous carcinomas, one solid-tubular carcinoma, and one mucinous carcinoma. All of them had imaging features suggesting malignancy on mammography and ultrasonography. Histopathologically, all 7 invasive ductal carcinomas showed prominent fibrosis in the stroma, and one showed many dilated ducts. One mucinous carcinoma showed large mucinous pools. CONCLUSION: Some breast cancers may show a gradually enhancing pattern on dynamic MRI. Other imaging features should be taken into account in the differential diagnosis of breast tumors.

[Diagnosis of common bile duct stones by MR imaging, mainly MR cholangiopancreatography].

We evaluated the accuracy of MR imaging (MRI), mainly MR cholangiopancreatography (MRCP), in the diagnosis of choledocholithiasis in comparison with ultrasound (US), computed tomography (CT), direct cholangiography, and intravenous cholangiography (DIC). Thirty-seven patients with biliary disease diagnosed by surgery and direct cholangiography underwent MRI with T1-weighted images (T1-WI), T2-weighted images (T2-WI), and MRCP (source images and projection images). The rate of stone detection was evaluated for each MRI image and modality. Fifteen of 37 patients were found to have common bile duct stones at surgery. The depiction rate of T1-WI, T2-WI, source images, and projection images were 7%, 67%, 93%, and 53%, respectively. The depiction rate of MR, US, CT, direct cholangiography, and DIC were 100% (15/15), 25% (3/12), 64% (9/14), 71% (5/7), and 57% (4/7), respectively. In addition, there were two false-positive cases, one of duodenal diverticulum (Lemmel's syndrome) and the other of hemobilia. MRI had a sensitivity of 100%, specificity of 91%, and accuracy of 94% in the diagnosis of common bile duct stones. In conclusion, MRI is useful for evaluating suspected choledocholithiasis. In spite of the high depiction rate of the source images, other images should also be taken into consideration in the diagnosis of choledocholithiasis.

[Differentiation between benign and malignant breast lesions using fat-suppressed dynamic MR imaging].

PURPOSE: To assess the value and problems of fat-suppressed dynamic MR imaging in differentiating between benign and malignant lesions. MATERIALS AND METHODS: In twenty-nine patients who underwent excisional biopsy or surgical resection, fat-suppressed dynamic MR imaging was performed with a 0.5 T superconducting magnet. Pre-and postcontrast 3D-spoiled gradient echo sequences were employed with fat suppression. We calculated and evaluated the contrast-to-noise ratio (CNR) and contrast enhancement ratio (CER) at each contrast determination time (CDT), which is the intermediate time in the scan. RESULTS: Time intensity curves of CNR showed no statistically significant difference between cancers and other benign lesions. The difference in CER between malignant and benign disease was highly significant (P = .006) at CDT 45 sec., but there was great overlap in the time intensity curve of CER after CDT 45 sec. CONCLUSION: When we attempt to differentiate malignant from benign breast lesions by dynamic MR imaging, comparison of CNR is impertinent, and we should evaluate the differential diagnosis of cancer versus benign lesions by means of CER at CDT points of about 45 sec.

[Efficacy of respiratory-triggered fast spin-echo 3 dimensional-MR cholangiopancreatography on middle magnetic field MR imaging].

We compared the image quality of three-dimensional (3D) MR cholangiopancreatography (MRCP) and two-dimensional (2D) MRCP on middle magnetic field MR imaging, using a respiratory-triggered fast spin-echo technique in 10 volunteers and 69 patients suspected of having biliary and pancreatic diseases. The bile ducts (BDs) and main pancreatic ducts (MPDs) are, if dilatated, are almost always depicted by 3D-MRCP and 2D-MRCP. The depiction rates by 3D-MRCP of non-dilatated intrahepatic ducts (IHDs), hepatic ducts (HDs), common hepatic ducts, common BDs, cystic ducts (CDs) and MPDs were 57%, 90%, 95%, 95%, 100% and 77%, respectively. The respective rates for 2D-MRCP were 26%, 95%, 100%, 95%, 74% and 38%. Non-dilatated IHDs, CDs, and MPDs were better visualized on 3D-MRCP than on 2D-MRCP, because of the high contrast to-noise ratio and high spatial resolution in the slice-section direction of 3D-MRCP. In conclusion, respiratory triggered fast spin-echo 3D-MRCP on middle magnetic field MR imaging is useful in the evaluation of biliary and pancreatic diseases.

[Efficacy of respiratory-triggered fast spin echo MR cholangiopancreatography on intermediate MR imaging].

MR cholangiopancreatography (MRCP) using a respiratory-triggered fast spin-echo technique was performed on intermediate MR imaging in 26 patients with suspected biliary disease. In almost all of 12 patients without dilated biliary tract, the hilum of the liver and extrahepatic bile duct were clearly visualized. All of 11 cases of cholelithiasis were demonstrated. In all 4 cases of obstructive jaundice, dilatation and obstruction of the bile ducts were clearly demonstrated. Respiratory-triggered fast spin-echo MRCP is a non-invasive technique for visualization of the biliary tract and biliary disease on intermediate MR imaging.