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Maximilian F Reiser

Publications and source records attributed to Maximilian F Reiser.

At least 55 records · Page 3Linked to original sources
PubMed2006

Renal artery stenosis: functional assessment with dynamic MR perfusion measurements--feasibility study.

PURPOSE: To prospectively assess feasibility of renal magnetic resonance (MR) perfusion measurement method based on turbo fast low-angle shot sequences for grading effect of renal artery stenosis (RAS) on parenchymal perfusion. MATERIALS AND METHODS: Institutional review board approved this study, and patients gave written consent. Seventy-three patients (34 male, 39 female; age range, 17-84 years) who were clinically suspected of having RAS underwent contrast material-enhanced (gadodiamide) saturation-recovery turbo fast low-angle shot imaging for measurement of renal perfusion and high-spatial-resolution MR angiography for RAS detection and grading. Degree of stenosis was evaluated as high grade (>/=75% stenosis), low to intermediate grade (>0% to <75% stenosis), or absent. High temporal resolution of the turbo fast low-angle shot sequence allowed acquisition of an exact first-pass tracing of the contrast agent bolus from which a signal intensity (SI)-time curve was derived. On the basis of this curve, mean transit time (MTT) of the contrast agent bolus, maximal upslope (MUS) of the curve, maximum SI, and time to SI peak (TTP) were calculated with a gamma variate fit. Wilcoxon rank sum test, Pearson product moment correlation, and paired t test were used for statistical analysis. RESULTS: Twenty-four renal arteries had high-grade RAS, 12 renal arteries had low- to intermediate-grade RAS, and 104 renal arteries had no RAS. Significant differences between patients without stenoses or with low- to intermediate-grade stenoses and patients with high-grade stenoses were found for MTT, MUS, and TTP (P < .001). Perfusion parameters were correlated with patients' serum creatinine levels, and significant correlations were found for MTT (r = 0.41), MUS (r = 0.48), and TTP (r = 0.4), with P < .001. CONCLUSION: MR perfusion parameters can be used to assess effect of RAS on parenchymal perfusion. Perfusion measurements reflect renal function as measured with serum creatinine levels.

Adolescent↗
PubMed2006

Single-shot inversion recovery TrueFISP for assessment of myocardial infarction.

OBJECTIVE: The aim of the study was to assess the diagnostic accuracy of imaging the myocardium with a fast multislice inversion recovery 2D single-shot true fast imaging with steady-state precession (trueFISP) sequence during a single breath-hold in comparison with an established segmented inversion recovery turbo fast low-angle shot (turboFLASH) sequence. SUBJECTS AND METHODS: Forty-three patients with myocardial infarction were examined on a 1.5-T MR system 10 min after administration of contrast material (gadodiamide, 0.2 mmol/kg) with a single-shot 2D multislice technique (single-shot inversion recovery trueFISP) that allows one to image the entire short axis during one breath-hold (18 heartbeats) and with a segmented 2D single-slice technique (inversion recovery turboFLASH) that requires one breath-hold per slice (12 heartbeats). Signal intensity was determined in normal myocardium, in infarcted myocardium, and in the left ventricle. The contrast-to-noise ratio (CNR) of normal and infarcted myocardium was determined. The areas of hyperintense infarctions on selected slices and the entire volumes were compared for both sequence techniques. RESULTS: The inversion recovery trueFISP sequence has a lower CNR than the inversion recovery turboFLASH sequence (mean values, 10.0 vs 12.9, respectively; p = 0.005) for differentiation of viable from nonviable myocardium. The CNR of injured myocardium and blood in the left ventricular cavity also has a lower value for the multislice technique compared with the single-slice technique (0.6 vs 1.2, respectively; p = 0.045). Assessment of the area of infarction within one slice (r = 0.97, p < 0.002) and of the volume of the entire infarction (r = 0.96, p < 0.003) is possible with excellent correlation of both techniques. CONCLUSION: Despite having a lower CNR, the inversion recovery 2D single-shot trueFISP sequence allows fast and accurate identification of the area and volume of infarction with high spatial resolution within a single breath-hold.

Adult↗
PubMed2006

Clinical value of MDCT in the diagnosis of coronary artery disease in patients with a low pretest likelihood of significant disease.

OBJECTIVE: The aim of this study was to evaluate the clinical value of MDCT in the diagnosis of coronary artery disease in a population having a low pretest likelihood of significant disease. SUBJECTS AND METHODS: Sixty-four patients with suspected coronary artery disease and a low pretest likelihood of significant disease according to the criteria of the American Heart Association underwent both MDCT of the heart and quantitative conventional coronary angiography (QCA). MDCT examinations were performed on a 16-MDCT scanner. CT data sets were evaluated on a per-patient basis and a per-segment basis and were classified as indicating no disease, nonsignificant disease (stenoses </= 50%), or significant disease (stenoses > 50%). Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of 16-MDCT in the detection or exclusion of significant and nonsignificant coronary artery disease were evaluated on both per-patient and per-segment bases. RESULTS: Regarding the success rate of 16-MDCT, 94% (60/64) of patients and 92% (388/420) of vessel segments were of sufficient quality for diagnosis. In the remaining 60 patients evaluated, QCA revealed significant coronary artery disease, nonsignificant disease, and no disease in 8.3% (5/60), 75.0% (45/60), and 16.7% (10/60) of cases, respectively, on a per-patient basis, and in 1.3% (5/388), 23.2% (90/388), and 75.5% (293/388) of cases, respectively, on a per-segment basis. The sensitivity, specificity, NPV, and PPV of 16-MDCT for the detection of significant coronary artery disease were 80.0%, 94.5%, 98.1%, and 57.1%, respectively, on a per-patient basis, and 80.0%, 99.2%, 99.7%, and 57.1% on a per-segment basis. CONCLUSION: In a population having a low pretest likelihood of significant coronary artery disease, 16-MDCT shows a moderate to high sensitivity and high NPV for the detection or exclusion of significant disease, but has a somewhat reduced PPV compared with QCA.

Adult↗
PubMed2006

Accuracy of 64-MDCT in the diagnosis of ischemic heart disease.

OBJECTIVE: The aim of this study was to evaluate the potential clinical value of a new generation of 64-MDCT systems with that of invasive coronary angiography in the diagnosis of coronary artery disease (CAD). SUBJECTS AND METHODS: Seventy-two consecutive patients with known or suspected CAD underwent both 64-MDCT and quantitative coronary angiography (QCA). A CT system with acquisition of 64 slices per gantry rotation was used with a spatial resolution of 0.4 x 0.4 x 0.4 mm and a gantry rotation time of 330 milliseconds. Sensitivity, specificity, and diagnostic accuracy of 64-MDCT in the detection or exclusion of CAD were evaluated on both a per patient and a per segment basis. RESULTS: Sixty-eight of 72 coronary CT angiograms (CTAs) (94%) were of diagnostic image quality. QCA showed significant CAD (i.e., one or more stenoses in > 50%) in 57% (39/68) and nonsignificant disease or healthy CTAs in 43% (29/68) of the patients. Sensitivity, specificity, and the negative predictive value (NPV) of 64-MDCT per patient were 97%, 79%, and 96%, respectively. Per segment, 923 of 1,020 coronary artery segments were assessable (90%). For the detection of stenoses of more than 50% and more than 75% per segment, 64-MDCT showed a sensitivity of 82% and 86%, respectively. Per segment, specificity and NPV were as high as 95% and 97%, respectively. CONCLUSION: In clinical routine, coronary CTA will primarily be used for risk stratification on a per patient basis. In the present study, coronary 64-MDCT showed a high diagnostic accuracy on both per patient and per segment analyses.

Adult↗
PubMed2005

Measurement of basal forebrain atrophy in Alzheimer's disease using MRI.

Alzheimer's disease is characterized by the degeneration and loss of cholinergic neurones in the nucleus basalis Meynert, located within the substantia innominata at the ventral surface of the basal forebrain. An in vivo measure of morphological changes in the nucleus basalis Meynert would be of high relevance to better understand the structural correlate of cholinergic dysfunction in Alzheimer's disease. In this study, we applied a newly developed automated technique of image regression analysis, implemented through code written in Matlab 5.3 (MathWorks, Natick, MA), to the analysis of proton density weighted structural MRI of the basal forebrain from 13 patients with Alzheimer's disease (mean age = 77.5 years, SD = 4.4 years, 8 women) and 12 healthy elderly subjects (mean age = 62.3 years, SD = 5.6 years, 6 women). This technique allows searching a large portion of the substantia innominata for signal changes. We used corresponding MRI and histological sections of a post mortem brain to map the locations of basal forebrain cholinergic nuclei into the MRI standard space. Additionally, we used voxel-based morphometry, implemented in SPM2 (Wellcome Department of Imaging Neuroscience, London, UK) to determine correlations between signal changes in the substantia innominata and cortical grey matter atrophy in the patients with Alzheimer's disease. When matching the locations of signal reductions in the in vivo MRI to the template of basal nuclei based on the postmortem brain, signal intensity was decreased in areas corresponding to anterior lateral and anterior medial nucleus basalis Meynert and increased in the third ventricle, the transverse fissure and the optic tract in patients with Alzheimer's disease compared with controls. The reduction of the signal intensity in an area corresponding to the anterior lateral nucleus basalis Meynert was significantly correlated with reduced grey matter concentration in the bilateral prefrontal cortex, inferior parietal lobule and cingulate gyrus. Our findings suggest that signal changes occur in patients with Alzheimer's disease in the substantia innominata which may be related to the loss or degeneration of cholinergic neurones and correspond to regional cortical grey matter atrophy. If replicated in an independent sample, our technique may be useful to detect degeneration of basal forebrain cholinergic neurones in vivo.

Aged↗
PubMed2005

Pulmonary arterial hypertension: diagnosis with fast perfusion MR imaging and high-spatial-resolution MR angiography--preliminary experience.

PURPOSE: To determine prospectively the accuracy of a magnetic resonance (MR) perfusion imaging and MR angiography protocol for differentiation of chronic thromboembolic pulmonary arterial hypertension (CTEPH) and primary pulmonary hypertension (PPH) by using parallel acquisition techniques. MATERIALS AND METHODS: The study was approved by the institution's internal review board, and all patients gave written consent prior to participation. A total of 29 patients (16 women; mean age, 54 years +/- 17 [+/- standard deviation]; 13 men; mean age, 57 years +/- 15) with known pulmonary hypertension were examined with a 1.5-T MR imager. MR perfusion imaging (temporal resolution, 1.1 seconds per phase) and MR angiography (matrix, 512; voxel size, 1.0 x 0.7 x 1.6 mm) were performed with parallel acquisition techniques. Dynamic perfusion images and reformatted three-dimensional MR angiograms were analyzed for occlusive and nonocclusive changes of the pulmonary arteries, including perfusion defects, caliber irregularities, and intravascular thrombi. MR perfusion imaging results were compared with those of radionuclide perfusion scintigraphy, and MR angiography results were compared with those of digital subtraction angiography (DSA) and/or contrast material-enhanced multi-detector row computed tomography (CT). Sensitivity, specificity, and diagnostic accuracy of MR perfusion imaging and MR angiography were calculated. Receiver operator characteristic analyses were performed to compare the diagnostic value of MR angiography, MR perfusion imaging, and both modalities combined. For MR angiography and MR perfusion imaging, kappa values were used to assess interobserver agreement. RESULTS: A correct diagnosis was made in 26 (90%) of 29 patients by using this comprehensive MR imaging protocol. Results of MR perfusion imaging demonstrated 79% agreement (ie, identical diagnosis on a per-patient basis) with those of perfusion scintigraphy, and results of MR angiography demonstrated 86% agreement with those of DSA and/or CT angiography. Interobserver agreement was good for both MR perfusion imaging and MR angiography (kappa = 0.63 and 0.70, respectively). CONCLUSION: The combination of fast MR perfusion imaging and high-spatial-resolution MR angiography with parallel acquisition techniques enables the differentiation of PPH from CTEPH with high accuracy.

Diagnosis, Differential↗
PubMed2005

Diagnosis of osteoporosis: visual assessment on conventional versus digital radiographs.

In many radiological departments conventional radiography has been replaced by digital radiography. Therefore, the purpose of this study was to analyze the visual detection of osteopenia/osteoporosis with both digital and conventional radiographs. In 286 patients we retrospectively evaluated radiographs of the lumbar spine in two planes. One hundred twenty-eight patients had conventional and 158 patients had digital radiographs. Patients with pre-existing vertebral fractures were excluded. Four experienced musculoskeletal radiologists blinded to the values of DXA and to the patients' ages assessed independently from each other whether the bone density of the lumbar spines was normal or decreased. The results of dual X-ray absorptiometry served as the standard of reference. The threshold value for the diagnosis of osteopenia was a T-score less than -1 SD according to the WHO classification of osteoporosis. Sensitivity/specificity was 86%/36% for conventional and 72%/47% for digital radiographs. The overall diagnostic accuracy was 68% for conventional and 64% for digital radiographs. Eighty percent of the patients with osteopenia and 96% of the patients with osteoporosis were correctly assessed as true positive on conventional radiographs and 65% (osteopenia) and 82% (osteoporosis) on digital radiographs. Interobserver agreement was markedly lower for digital (35%) than for conventional radiographs (73%). However, the differences were not statistically significant. There is no major difference in diagnostic accuracy in the assessment of osteopenia/osteoporosis using digital and conventional radiographs, respectively. However, the high interobserver variance on digital radiographs indicates that visual assessment of osteoporosis/osteopenia is problematic, which may be due to image processing and postprocessing algorithms that manipulate the visual aspect of bone density.

Absorptiometry, Photon↗
PubMed2005

Prospective, multireader evaluation of image quality and vascular delineation of multislice CT angiography of the brain.

The aim of this prospective, multireader trial was to investigate image quality and vascular delineation of cranial multislice CT angiography (MSCTA) to identify strengths and weaknesses of the method. Sixty consecutive patients underwent standardized cranial MSCTA. The mean estimated effective dose was 0.96+/-0.11 mSv. Three masked readers independently graded image quality parameters and vascular delineation on a 5-point scale. Vascular attenuation values and dose-length products were assessed quantitatively. Quantitative parameters were evaluated with a proportional odds regression model with bootstrapped standard errors to adjust the relevant standard errors for correlation within subjects and across readers. The non-parametric Wilcoxon sign-rank test was applied for quantitative measurements. Good to excellent ratings were observed regarding image quality parameters and vascular delineation. The delineation of veins was rated higher than that of arteries (OR 2.00). Smaller arterial segments were rated significantly less favorably than larger segments (OR up to 26.98). Moreover, the cavernous sinus, the C2 segment of the ICA and the communicating arteries demonstrated lower scores. Attenuation values were >240 HU and vessel-to-parenchyma ratios >7 in all vessels. Cranial MSCTA achieved high ratings regarding image quality and vascular delineation. Relative weaknesses were found in small arterial subsegments and in vessels in close topographical proximity to bone.

Adolescent↗
PubMed2005

Assessment of myocardial perfusion and viability from routine contrast-enhanced 16-detector-row computed tomography of the heart: preliminary results.

To assess the diagnostic accuracy of 16-detector-row computed tomography (16DCT) of the heart in the assessment of myocardial perfusion and viability in comparison to stress perfusion magnetic resonance imaging (SP-MRI) and delayed-enhancement magnetic resonance imaging (DE-MRI). A number of 30 patients underwent both 16DCT and MRI of the heart. Contrast-enhanced 16DCT data sets were reviewed for areas of myocardium with reduced attenuation. Both CT and MRI data were examined by independent reviewers for the presence of myocardial perfusion defects or myocardial infarctions (MI). Volumetric analysis of the hypoperfusion areas in CT and the infarct sizes in DE-MRI were performed. According to MRI, myocardial infarctions were detected in 11 of 30 cases, and perfusion defects not corresponding to an MI were detected in six of 30 patients. CTA was able to detect ten of 11 MI correctly (sensitivity 91%, specificity 79%, accuracy 83%), and detected three of six hypoperfusions correctly (sensitivity 50%, specificity 92%, accuracy 79%). Assessing the volume of perfusion defects correlating to history of MI on the CT images, a systematic underestimation of the true infarct size as compared to the results of DE-MRI was found (P<0.01). Routine, contrast-enhanced 16-detector row CT of the heart can detect chronic myocardial infarctions in the majority of cases, but ischemic perfusion defects are not reliably detected under resting conditions.

Adult↗
PubMed2005

High-spatial-resolution MR angiography of renal arteries with integrated parallel acquisitions: comparison with digital subtraction angiography and US.

PURPOSE: To retrospectively compare three-dimensional gadolinium-enhanced magnetic resonance (MR) angiography, performed with an integrated parallel acquisition technique for high isotropic spatial resolution, with selective digital subtraction angiography (DSA) and intravascular ultrasonography (US) for accuracy of diameter and area measurements in renal artery stenosis. MATERIALS AND METHODS: The study was approved by the institutional review board, and consent was obtained from all patients. Forty-five patients (17 women, 28 men; mean age, 62.2 years) were evaluated for suspected renal artery stenosis. Three-dimensional gadolinium-enhanced MR angiograms were acquired with isotropic spatial resolution of 0.8 x 0.8 x 0.9 mm in 23-second breath-hold with an integrated parallel acquisition technique. In-plane diameter of stenosis was measured along vessel axis, and perpendicular diameter and area of stenosis were assessed in cross sections orthogonal to vessel axis, on multiplanar reformations. Interobserver agreement between two radiologists in measurements of in-plane and perpendicular diameters of stenosis and perpendicular area of stenosis was assessed with mean percentage of difference. In a subset of patients, degree of stenosis at MR angiography was compared with that at DSA (n = 20) and intravascular US (n = 11) by using Bland-Altman plots and correlation analyses. RESULTS: Mean percentage of difference in stenosis measurement was reduced from 39.3% +/- 78.4 (standard deviation) with use of in-plane views to 12.6% +/- 9.5 with use of cross-sectional views (P < .05). Interobserver agreement for stenosis grading based on perpendicular area of stenosis was significantly better than that for stenosis grading based on in-plane diameter of stenosis (mean percentage of difference, 15.2% +/- 24.2 vs 54.9% +/- 186.9; P < .001). Measurements of perpendicular area of stenosis on MR angiograms correlated well with those on intravascular US images (r(2) = 0.90). CONCLUSION: Evaluation of cross-sectional images reconstructed from high-spatial-resolution three-dimensional gadolinium-enhanced MR renal angiographic data increases the accuracy of the technique and decreases interobserver variability.

Adult↗
PubMed2005

Critical limb ischemia: hybrid MR angiography compared with DSA.

PURPOSE: To compare a hybrid magnetic resonance (MR) angiography protocol with selective digital subtraction angiography (DSA) in patients with critical limb ischemia. MATERIALS AND METHODS: The study was approved by the institutional review board, and written consent was obtained from all patients. Pretreatment DSA and hybrid MR angiography were performed in 19 consecutive patients (15 men, four women; mean age, 69.8 years; range, 44-86 years). Hybrid MR angiography included submillimeter dual-phase three-dimensional gadolinium-enhanced MR angiography in lower calf and foot, and four-station bolus-chase MR angiography in pelvis, thigh, and upper calf. Three readers identified the target lesion and inflow and outflow segments and determined treatment (bypass graft placement, percutaneous transluminal angioplasty, conservative management, amputation). Results of interobserver and intermethod comparisons were expressed as percentage of agreement and 95% confidence interval (CI). RESULTS: On hybrid MR angiograms, no substantial venous overlay was present and image quality was excellent or adequate in 18 (95%) of 19 limbs. Readers 1, 2, and 3 selected the identical target lesion on the DSA image and the MR angiogram in 18, 17, and 18 of 18 comparable limbs, respectively. Mean percentage of agreement for readers 1 and 3 was 100% (95% CI: 81%, 100%) and for reader 2 was 94% (95% CI: 73%, 100%). Agreement of all three readers was superior with use of MR angiography for determination of inflow segments (13 [72%] of 18 limbs) and outflow segments (17 [94%] of 18 limbs), compared with agreement with use of DSA (13 [68%] of 19 inflow segments, 10 [53%] of 19 outflow segments). Agreement in therapy decisions was higher with DSA (15 [79%] of 19) than with MR angiography (11 [61%] of 18). CONCLUSION: Preliminary data strongly support the combination of submillimeter dual-phase MR angiography in lower calf and foot with four-station bolus-chase MR angiography to extend the utility of MR angiography to patients with critical limb ischemia.

Adult↗
PubMed2005

Fast oxygen-enhanced multislice imaging of the lung using parallel acquisition techniques.

The purpose of this study was to evaluate an optimized multislice acquisition technique for oxygen-enhanced MRI of the lung using slice-selective inversion and refocusing pulses in combination with parallel imaging. An inversion recovery HASTE sequence was implemented with respiratory triggering to perform imaging in end-expiration and with ECG triggering to avoid image acquisition during the systolic phase. Inversion pulses and the readout of echo trains could be interleaved to decrease acquisition time. The sequence was evaluated in 15 healthy volunteers, comparing three acquisition schemes: (1) acquisition of four slices without parallel imaging; (2) acquisition of four slices with parallel imaging; (3) acquisition of six slices with parallel imaging. These multislice acquisitions were repeated 80 times with alternating inhalation of room air and oxygen. The oxygen-induced signal increase showed no significant difference with and without parallel imaging. However, only with parallel imaging did the interleaved acquisition of six or more slices become possible, thus enabling a more complete anatomic coverage of the lung. The average required end-expiration time per repetition to acquire six slices could be significantly reduced from 4112 ms without to 2727 ms with parallel imaging. Total acquisition time varied between 8 and 13 min depending on the respiratory frequency.

Adult↗
PubMed2005

Practical approaches to the evaluation of signal-to-noise ratio performance with parallel imaging: application with cardiac imaging and a 32-channel cardiac coil.

In this work, two practical methods for the measurement of signal-to-noise-ratio (SNR) performance in parallel imaging are described. Phantoms and human studies were performed with a 32-channel cardiac coil in the context of ultrafast cardiac CINE imaging at 1.5 T using steady-state free precession (SSFP) and TSENSE. SNR and g-factor phantom measurements using a "multiple acquisition" method were compared to measurements from a "difference method". Excellent agreement was seen between the two methods, and the g-factor shows qualitative agreement with theoretical predictions from the literature. Examples of high temporal (42.6 ms) and spatial (2.1x2.1x8 mm3) resolution cardiac CINE SSFP images acquired from human volunteers using TSENSE are shown for acceleration factors up to 7. Image quality agrees qualitatively with phantom SNR measurements, suggesting an optimum acceleration of 4. With this acceleration, a cardiac function study consisting of 6 image planes (3 short-axis views, 3 long-axis views) was obtained in an 18-heartbeat breath-hold.

Female↗
PubMed2005

Comprehensive magnetic resonance imaging of the small and large bowel using intraluminal dual contrast technique with iron oxide solution and water in magnetic resonance enteroclysis.

OBJECTIVE: The objective of this study was to improve delineation of small and large bowel (SB, LB) anatomy and pathology with postoperative or complex multisegmental inflammatory changes using dual-contrast-technique (DCT) for magnetic resonance enteroclysis (MRE) with luminal contrast media of opposed signal characteristics. MATERIALS AND METHODS: Sixty patients underwent MRE with iron oxide-based negative contrast in the SB. Thirty patients received additional rectal instillation of water for positive contrast (DCT). Two observers evaluated the degree of distention and the ease of identification of bowel anatomy and pathologies (none n=22, stenosis n=16, abscess n=4, fistulae n=5, postoperative changes and adhesions n=13) using a 4-point scale. Mann-Whitney U-test and kappa statistics were applied. RESULTS: LB and the terminal ileum were significantly better distended and identified with DCT (P<or=0.0001; P=0.034). Interobserver agreement improved with DCT for all pathologies except for "prestenotic dilatation." CONCLUSIONS: Comprehensive MR imaging of SB and LB with DCT improves the identification of modified anatomy and most pathologies in inflammatory and postsurgical bowel.

Adolescent↗
PubMed2005

Use of iso-osmolar nonionic dimeric contrast media in multidetector row computed tomography angiography for patients with renal impairment.

OBJECTIVES: We wanted to determine the rate of contrast-induced nephropathy (CIN) caused in patients with renal impairment undergoing multidetector row computed tomography (MDCT) angiography with intravenous administration of iso-osmolar dimeric contrast media (iodixanol). MATERIALS AND METHODS: The first consecutive 100 patients referred to CT with a serum creatinine level (SCr) between 1.5 and 6 mg/dL were enrolled in the study. Serum creatinine also was determined on days 3 and 7 after the intravenous administration of 100 mL of iodixanol 270 with 5 mL/s. A CIN was considered if variation of SCr on day 3 was >0.5 mg/dl above baseline. RESULTS: Nine patients developed a CIN after MDCT angiography; 7 of them recovered completely by day 7, and the remaining 2 showed elevated SCr on day 7 but did not develop renal failure during their hospital stay. CONCLUSIONS: MDCT angiography performed in patients with impaired renal function with iodixanol may result in CIN but complete recovery is probable.

Aged↗
PubMed2005

Assessment of large bowel motility by cine magnetic resonance imaging using two different prokinetic agents: a feasibility study.

OBJECTIVES: We sought to assess large bowel motility, induced by 2 prokinetic agents, senna tea and erythromycin, using functional cine magnetic resonance imaging (MRI). MATERIALS AND METHODS: Twelve volunteers underwent functional cine MRI before and after the administration of senna tea or erythromycin. The protocol consisted of 2 sets of repeated measurements using coronal T2-weighted HASTE sequences, adjusted to the course of the colon. For the assessment of large bowel motility, the changes of the luminal diameter were measured at 5 defined locations in the ascending, transverse, and descending colon. RESULTS: In all examined volunteers after senna tea, the mean number of significant changes in the ascending colon was 8.6 and after erythromycin, 7.2. In the transverse colon, 9.6 diameters changed significantly for senna tea and 7.2 for erythromycin. In the descending colon, 6.6 diameters changed after senna tea and 7.2 after erythromycin. CONCLUSION: Senna tea and erythromycin proved to induce large bowel motility; senna tea was more effective. Functional cine MRI is a reliable, noninvasive method for the assessment of colonic motility.

Administration, Oral↗