Phase-contrast magnetic resonance (MR) imaging is a well-known but undervalued method of obtaining quantitative information on blood flow. Applications of this technique in cardiovascular MR imaging are expanding. According to the sequences available, phase-contrast measurement can be performed in a breath hold or during normal respiration. Prospective as well as retrospective gating techniques can be used. Common errors in phase-contrast imaging include mismatched encoding velocity, deviation of the imaging plane, inadequate temporal resolution, inadequate spatial resolution, accelerated flow and spatial misregistration, and phase offset errors. Flow measurements are most precise if the imaging plane is perpendicular to the vessel of interest and flow encoding is set to through-plane flow. The sequence should be repeated at least once, with a high encoding velocity used initially. If peak velocity has to be estimated, flow measurement is repeated with an adapted encoding velocity. The overall error of a phase-contrast flow measurement comprises errors during prescription as well as errors that occur during image analysis of the flow data. With phase-contrast imaging, the overall error in flow measurement can be reduced to less than 10%, an acceptable level of error for routine clinical use.

A renal resistance-index value of at least 80 reliably identifies patients with renal-artery stenosis in whom angioplasty or surgery will not improve renal function, blood pressure, or kidney survival.

laboratory investigations. Conversely, aortic dissection is not often considered a cause of myocardial malperfusion; thus misdiagnosis, which represents one of the main preoperative risks for these patients, may frequently occur. 1 This was the case for our patient, to whom systemic thrombolytic treatment was given before a diagnosis of acute aortic dissection was made.The subsequent surgical treatment was strongly influenced by this inadvertent treatment, which induced us to avoid any prosthetic material to replace the ascending aorta and imposed a closed technique of anastomosis to avoid hypothermic circulatory arrest. It should be said, however, that the limited longitudinal extension of the dissection was well suited to the repair technique.This procedure does not fulfill the radical criteria advocated by some authors in the settings of acute type A dissection. 6 However, it should be underlined that the resection included the entire dissected portion of the aorta and that the parts left in place exhibited a completely normal aspect.

This study delineates normal intrathoracic aortic diameters for helical computed tomography, including relationships with sex and age. Pathologic dimensions of the aorta should preferably be provided as percentiles or z scores.

Multi-slice (MS) technology increases the efficacy of CT procedures and offers new promising applications. The expanding use of MSCT, however, may result in an increase in both frequency of procedures and levels of patient exposure. It was, therefore, the aim of this study to gain an overview of MSCT examinations conducted in Germany in 2001. All MSCT facilities were requested to provide information about 14 standard examinations with respect to scan parameters and frequency. Based on this data, dosimetric quantities were estimated using an experimentally validated formalism. Results are compared with those of a previous survey for single-slice (SS) spiral CT scanners. According to the data provided for 39 dual- and 73 quad-slice systems, the average annual number of patients examined at MSCT is markedly higher than that examined at SSCT scanners (5500 vs 3500). The average effective dose to patients was changed from 7.4 mSv at single-slice to 5.5 mSv and 8.1 mSv at dual- and quad-slice scanners, respectively. There is a considerable potential for dose reduction at quad-slice systems by an optimisation of scan protocols and better education of the personnel. To avoid an increase in the collective effective dose from CT procedures, a clear medical justification is required in each case.

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. However, treatment options are limited and often inefficient. The aim of this study was to determine current survival rates for patients diagnosed with HCC and to identify prognostic factors, which will help in choosing optimal therapies for individual patients. A retrospective analysis of medical records was performed on 389 patients who were identified through the central tumour registry at our institution from 1998 to 2003. Clinical parameters, treatments received and survival curves from time of diagnosis were analysed. Overall median survival was 11 months. Liver cirrhosis was diagnosed in 80.5% of all patients. A total of 170 patients received transarterial chemoembolisation (TACE) and/or percutaneous ethanol injections (PEI) with a median survival rate of 16 months for patients receiving TACE, 11 months for patients receiving PEI and 24 months for patients receiving TACE followed by PEI. Independent negative prognostic parameters for survival were the presence of portal vein thrombosis, advanced liver cirrhosis (Child -Pugh score B or C) and a score of 42. This study will help to estimate survival rates for patients with HCC according to their clinical status at diagnosis and the treatments received.

No abstract

Beta 2-microglobulin associated amyloidosis (A beta 2m amyloidosis) is considered an inevitable complication of chronic hemodialysis, particularly in hemodialysis with cellulose based membranes. We performed a single center study to assess the prevalence of A beta 2m amyloidosis in 1988 versus 1996. Randomly selected patients, studied in 1988, were matched for time on hemodialysis (mean 71 months, range 3 to 207) and age (mean 51 years, range 22 to 80) with patients of the 1996 population. Compared to 1988 patients, the 1996 patients exhibited a lower prevalence of carpal tunnel syndrome (7 of 43 in 1988 vs. 1 of 43 in 1996; P < 0.001) and radiological evidence of A beta 2m amyloidosis (13 of 34 patients vs. 3 of 34 patients positive; P < 0.001; and 33 of 272 possible sites affected in 1988 vs. 7 of 272 sites in 1996 patients; P < 0.05). Compared to the 1988 population, the 1996 population exhibited significantly lower serum aluminum levels, lower average serum creatinine (but not urea) levels, more frequent therapy with erythropoietin, less home hemodialysis, longer hemodialysis time using high-flux synthetic dialysis membranes (mean of 13% vs. 6% of the total hemodialysis time in the 1988 group), and more frequent usage of reverse osmosis water plus bicarbonate buffer for dialysate preparation. We conclude that the prevalence and severity of A beta 2m amyloidosis unexpectedly decreased by about 80% in our center between 1988 and 1996. Given the relatively short times spent on high flux hemodialysis in both groups, increased beta 2-microglobulin removal is unlikely to account for this phenomenon. Rather, other factors, for example, dialysate composition and purity, may be involved.