Evaluation of the supraaortic arteries using non-contrast-enhanced Velocity MR Angiography “Inhance”

Introduction

The aim of this study was to compare the recently developed phase contrast-based Inhance 3D Velocity magnetic resonance angiography technique (Inhance) to the contrast-enhanced standard method (CE-MRA) in the evaluation of the supraaortic arteries.

Methods

Inhance and CE-MRA were performed in ten consecutive patients with a suspected pathology of the supraaortic arteries on a 3-T MR scanner. Two neuroradiologists evaluated in consensus both sequences regarding the visualisation of the supraaortic arteries and their segments on a five-point score. Diagnostic certainty regarding the overall presence of a vascular pathology was rated on the same five-point score.

Results

On CE-MRA as well as on Inhance, a vascular pathology of the supraaortic arteries was detected in seven patients. There was no statistically significant difference in the overall diagnostic certainty regarding the presence or absence of pathologic findings for CE-MRA compared to Inhance. Furthermore, no statistically significant difference was found with regard to visualisation of the distal cervical and intracranial arterial segments, while CE-MRA was superior to Inhance in the visualisation of the origins of the cervical vessels from the aortic arch.

Conclusion

Non-contrast Inhance proved useful in the evaluation of the supraaortic arteries with limited assessment of the proximal supraaortic branches. Hence, this technique features a valuable alternative to CE-MRA in the visualisation of the supraaortic arteries, particularly in patients with renal insufficiency.     

Iodine removal in intravenous dual-energy CT-cholangiography: Is virtual non-enhanced imaging effective to replace true non-enhanced imaging?

Purpose

To evaluate whether virtual non-enhanced imaging (VNI) is effective to replace true non-enhanced imaging (TNI) applying iodine removal in intravenous dual-energy CT-cholangiography.

Materials and Methods

From April 2009 until February 2010, fifteen potential donors for living-related liver transplantation (mean age 37.6 ± 10.8 years) were included. Potential donors underwent a two-phase CT-examination of the liver. The first phase consisted of a single-energy non-enhanced CT-acquisition that provided TNI. After administration of hepatobiliary contrast agent, the second phase was performed as a dual-energy cholangiographic CT-acquisition. This provided VNI. Objective image quality (attenuation values [bile ducts and liver parenchyma] and contrast-to-noise ratio) and subjective overall image quality (1 – excellent; 5 – non diagnostic) were evaluated. Effective radiation dose was compared.

Results

For TNI and VNI, attenuation values for bile ducts were 16.8 ± 11.2 HU and 5.5 ± 17.0 HU (p < 0.05) and for liver parenchyma 55.3 ± 8.4 HU and 58.1 ± 10.6 HU (n.s.). For TNI and VNI, contrast-to-noise ratio was 2.6 ± 0.6 HU and 6.9 ± 2.1 HU (p < 0.001). For VNI, subjective overall image quality was 1 in ten datasets, 2 in four datasets and 3 in one dataset. Effective radiation dose for the dual-energy cholangiographic CT-acquisition was 3.6 ± 0.9mSv and for two-phase single-energy CT-cholangiography 5.1 ± 1.3mSv (p < 0.001).

Conclusion

In this study on iodine removal in intravenous dual-energy CT-cholangiography, subjective image quality is equivalent, contrast-to-noise ratio is improved and effective radiation dose is reduced when VNI is performed. The differences between TNI and VNI with respect to attenuation values seem to have limited clinical relevance and therefore we consider VNI as effective to replace TNI.     

Combined laparoscopic-colonoscopic approach for the removal of a migrated intrauterine contraceptive device penetrating the sigmoid colon

Uterine perforation is a rare but potentially life-threatening complication associated with the use of intrauterine contraceptive devices (IUDs). Following perforation, the IUD can migrate to the peritoneal cavity or even perforate several adjacent organs. Migration to the sigmoid colon is extremely rare. We present the case of a 28-year-old woman who had an IUD inserted soon after delivery. The patient again became pregnant, but no IUD could be detected in routine examinations. After an asymptomatic interval of 3 years, the patient suffered acute abdominal pain. Initial laparoscopy elsewhere revealed the IUD attached to the sigmoid colon, but extraction was not possible. The patient was referred to us for further treatment. Under general anesthesia, laparoscopic exploration of the abdomen was performed. The IUD had perforated the sigmoid colon and was firmly fixed. In order not to injure the sigmoid colon, laparoscopic mobilization of the IUD was assisted with a “rendez-vous” sigmoidoscopy. The IUD was removed transanally with laparoscopic and sigmoidoscopic assistance, and the patient was discharged within 24 h after the operation. Insertion of an IUD necessitates regular checks to confirm the device’s correct position. Migration of an IUD warrants prompt laparoscopic removal, even in asymptomatic patients.     

Tolerability and Absorption Enhancement of Intranasally Administered Octreotide by Sodium Taurodihydrofusidate in Healthy Subjects

Nasal sprays containing different concentrations of the somatostatin analogue octreotide and sodium tauro-24,25-dihydrofusidate (STDHF) as an absorption promoter were evaluated in two consecutive pharmacokinetic studies in healthy volunteers to characterize their bioavailability and local tolerability. The concentrations of STDHF were selected on the basis of a phase diagram generated by a dynamic laser light-scattering technique to ensure that the mixture was above the critical micellar concentrations. Compared to a 50-µg subcutaneous injection, the nasal spray formulation without STDHF had a mean relative bioavailability of 17.9%. For nasal formulations containing 3 and 1.65% (w/v) of STDHF, the bioavailability increased to 29.0 and 25.7%, respectively. The enhancement of nasal absorption was dependent on the STDHF concentrations as shown by decreasing the amounts to 1.2 and 0.8% (w/v) for tolerability reasons; the bioavailability was reduced to 15.3 and 20.5% in these cases, respectively. The local tolerability of all STDHF-containing sprays was poor, leading to stinging sensations and lacrimation. The poor local tolerability of the octreotide nasal spray containing different concentrations of STDHF required for effective nasal absorption enhancement appears to be impractical for further clinical development. These findings clearly stress the necessity to investigate tolerability and safety issues of new drug delivery systems in early developmental phases.     

Myocyte degeneration and cell death in hibernating human myocardium

Objectives. The aim of this study was to analyze the morphologic characteristics of myocyte degeneration leading to replacement fibrosis in hibernating myocardium by use of electron microscopy and immunohistochemical techniques.

Background. Data on the ultrastructure and the cytoskeleton of cardiomyocytes in myocardial hibernation are scare. Incomplete or delayed functional recovery might be due to a variable degree of cardiomyocyte degeneration in hibernating myocardium.

Methods. In 24 patients, regional wall motion abnormalities were analyzed by use of the centerline method before and 6 ± 1 months after coronary artery bypass surgery. Preoperative technetium-99m sestamibi uptake was measured by single-photon emission computed tomography for assessing regional perfusion. Fluorine-18 fluorodeoxyglucose uptake was measured by positron emission tomograph to assess glucose metabolism. Transmural biopsy specimens were taken during coronary artery bypass surgery from the center of the hypocontractile area of the anterior wall.

Results. The myocytes showed varying signs of mild-to-severe degenerative changes and an increased degree of fibrosis. Immunohistochemical analysis demonstrated disruption of the cytoskeletal proteins titin and alpha-actinin. Electron microscopy of the cell organelles and immunohistochemical analysis of the cytoskeleton showed a similarity in the degree of degenerative alterations. Group 1 (n = 11) represented patients with only minor structural alterations, whereas group 2 (n = 13) showed severe morphologic degenerative improvements, and nuclear imaging revealed a perfusion-metabolism mismatch without significant differences between the groups.

Conclusions. Long-term hypoperfusion causes different degrees of morphologic alterations leading to degeneration. Preoperative analysis of regional contractility and perfusion-metabolism imaging does not distingush the severity of morphologic alterations nor the functional outcome after revascularization. The insufficient act of self-preservation in hibernating myocardium may lead to a progressive structural degeneration with an incomplete and delayed recovery of function after restoration of blood flow.     

Comparative study of C5a plasma levels with different hemodialysis membranes using an enzyme-linked immunosorbent assay

Using a specific and sensitive ELISA for C5a, the present study shows that predialysis levels of C5a in end-stage renal disease patients are not elevated and that all membranes studied (Cuprophan, Hemophan, Gambrane and hydrophilic polysulfone) cause significant increases of C5a plasma levels albeit to different degrees. Higher increases of C5a were accompanied by larger decreases of circulating granulocytes and monocytes. Dialyzers with a newly introduced modified regenerated cellulose membrane, Hemophan, showed lower C5a plasma levels during hemodialysis than Cuprophan. With Hemophan C5a plasma levels were comparable to those with polysulfone membranes.     

钛合金网架髋臼重建术

目的 观察自全植骨，钛合多架重症内隐性内陷性髋白的临床效果。方法 １９９３年１月～１９９５年８月，２５例内陷性髋臼应用局部自体植骨，钛合金网架重建术。男１１髋，女１４髋年龄４５～７６岁，平均６９岁。术前诊断类风湿性关节炎１１髋，骨关节炎８髋，股骨头缺血性坏死４颗，髋臼发充膛良２髋。平均随访４．５年（３～５年）。结果 ２５髋平均随访４．５年（３～５年）。结果 ２５髋按Ｍｅｒｌｅ ｄ’Ａｕｂｉｇｎｅ标