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Marco Essig

Publications and source records attributed to Marco Essig.

At least 37 records · Page 2Linked to original sources
PubMed2004

Radiation-induced changes of brain tissue after radiosurgery in patients with arteriovenous malformations: correlation with dose distribution parameters.

PURPOSE: To investigate the correlation of radiation-induced changes of brain tissue after radiosurgery in patients with cerebral arteriovenous malformations (AVMs) with treatment planning and dose distribution parameters. METHODS AND MATERIALS: The data from 73 AVM patients with complete follow-up information who underwent stereotactic linear accelerator radiosurgery at our institution between 1993 and 1998 were analyzed. Patients were treated with 11-14 noncoplanar fields shaped by a micromultileaf collimator. A median dose of 19 Gy (range, 13.3-22 Gy) was prescribed to the 80% isodose, which completely encompassed the target. Patients were followed at 3-month intervals the first year and then every 6 months with MRI and neurologic examinations. No patient developed radiation necrosis. The end point of radiation-induced tissue changes on follow-up neuroimaging (i.e., edema, blood-brain barrier breakdown [BBBB], and edema and/or BBBB combined) was evaluated. Each end point was further differentiated into four levels with respect to the extent of the image change (i.e., small, intermediate, large, and very large). The correlation of each end point was investigated for several treatment planning parameters, including prescribed dose and the absolute size of the AVM target volume. In addition, a number of dose-volume variables were calculated from each patient's dose distribution in the brain, including the mean dose to a specified volume of 16 and 20 cm(3) that was given the highest dose (Dmean16 and Dmean20, respectively), and the absolute and percentage of brain volume (including the AVM target) receiving a dose of at least 8, 10, and 12 Gy (V8-V12, and V8(rel)-V12(rel), respectively). These parameters were also determined excluding the AVM target volume from the considered volume (subscript "excl"). The correlation of all treatment planning and dose-volume parameters with outcome was assessed in univariate Cox proportional hazards models. The results were assessed by p values (statistical significance for p < or =0.05), residual deviance (ResDev) of the fits, and odds ratios. RESULTS: The prescribed dose was not predictive of outcome (p >0.05 for all end points). The AVM target volume correlated significantly with large edema, as well as large edema and/or BBBB. V12 and Dmean20 were significantly associated with all end points, except very large edema and large BBBB. Patients with V12 of 27.6 cm(3) (Dmean20 of 18.9 Gy) had a 2.8-fold (fourfold) higher risk of developing edema and/or BBBB with large extent than those with V12 of 4.2 cm(3) (Dmean20 of 8.4 Gy). For all end points, V12(rel) correlated worse with outcome compared with V12 (e.g., end point of large edema and/or BBBB: ResDev = 85.8 and 86.5 for V12 and V12(rel), respectively). Excluding the AVM target volume from the considered irradiated volume led to only small changes in the resulting correlations (e.g., end point of small edema and/or BBBB: ResDev = 99.0 and 98.7 for V12 and V12(excl), respectively, and ResDev = 96.1 and 96.1 for Dmean20 and Dmean20(excl), respectively). Throughout the analysis, V8-V12, Dmean20, and Dmean16 yielded similar results and none of these parameters could be favored over the others. CONCLUSION: Radiation-induced changes of brain tissue after AVM radiosurgery can be well predicted by single dose distribution parameters that are a function of both dose and volume. These can be used to quantify dose-volume response relations. Studies of this nature will eventually help to improve our current understanding of the mechanisms leading to radiation-induced tissue changes after AVM radiosurgery and to optimize radiosurgery treatment planning.

Adolescent↗
PubMed2004

Distribution of cerebral atrophy assessed by magnetic resonance imaging reflects patterns of neuropsychological deficits in Alzheimer's dementia.

Neuropsychological deficits were investigated with respect to regional distribution of cerebral atrophy as assessed by volumetric magnetic resonance imaging (MRI) in 50 patients with Alzheimer's dementia (AD; NINCDS-ADRDA criteria) and 20 healthy volunteers. When compared between groups, test performance of all investigated neuropsychological domains including declarative memory, language, praxia, psychomotor speed, as well as attention and concentration was significantly impaired. These deficits were differentially correlated with regional atrophic changes. In particular, volumes of the right amygdala-hippocampus complex correlated with declarative memory performance, whereas volumes of the left temporo-parietal regions correlated with performance in naming and praxia. Furthermore, left frontal lobe atrophy was associated with verbal fluency. Our data confirm the central role that medial temporal atrophy plays for declarative memory deficits in AD and indicate that additional changes in the parietal, temporal and frontal lobes are responsible for further neuropsychological deficits characteristic of this disorder.

Aged↗
PubMed2004

Neutralization of CD95 ligand promotes regeneration and functional recovery after spinal cord injury.

The clinical outcome of spinal cord injury (SCI) depends in part on the extent of secondary damage, to which apoptosis contributes. The CD95 and tumor necrosis factor (TNF) ligand/receptor systems play an essential role in various apoptotic mechanisms. To determine the involvement of these ligands in SCI-induced damage, we neutralized the activity of CD95 ligand (CD95L) and/or TNF in spinal cord-injured mice. Therapeutic neutralization of CD95L, but not of TNF, significantly decreased apoptotic cell death after SCI. Mice treated with CD95L-specific antibodies were capable of initiating active hind-limb movements several weeks after injury. The improvement in locomotor performance was mirrored by an increase in regenerating fibers and upregulation of growth-associated protein-43 (GAP-43). Thus, neutralization of CD95L promoted axonal regeneration and functional improvement in injured adult animals. This therapeutic strategy may constitute a potent future treatment for human spinal injury.

Animals↗
PubMed2004

Radiation-induced changes of brain tissue after radiosurgery in patients with arteriovenous malformations: dose/volume-response relations.

PURPOSE: . To evaluate late radiation effects in the brain after radiosurgery of patients with cerebral arteriovenous malformations (AVMs) and to quantify dose/volume-response relations for radiation-induced changes of brain tissue identified on follow-up neuroimaging. PATIENTS AND METHODS: . Data from 73 AVM patients who had stereotactic Linac radiosurgery at DKFZ (German Cancer Research Center), Heidelberg, Germany, were retrospectively analyzed. The endpoint of radiation-induced changes of brain tissue on follow-up magnetic resonance (MR) neuroimaging (i.e., edema and blood-brain-barrier breakdown [BBBB]) was evaluated. Each endpoint was further differentiated into three levels with respect to the extent of the image change (small, intermediate, and large). A previous analysis of the data found correlation of the endpoints with several dose/volume variables (DV) derived from each patient's dose distribution in the brain, including the mean dose in a volume of 20 cm(3) (Dmean20) and the absolute brain volume (including the AVM target) receiving a dose of at least 12 Gy (V12). To quantify dose/volume-response relations, patients were ranked according to DV (i.e., Dmean20 and V12) and classified into four groups of equal size. For each group, the actuarial rates of developing the considered endpoints within 2.5 years after radiosurgery were determined from Kaplan-Meier estimates. The dose/volume-response curves were fitted with a sigmoid-shape logistic function and characterized by DV(50), the dose for a 50% incidence, and the slope parameter k. RESULTS: . Dose/volume-response relations, based on two alternative, but correlated, dose distribution variables that are a function of both dose and volume, were observed for radiation-induced changes of brain tissue. DV(50) values of fitted dose/volume-response curves for tissue changes of large extent (e.g., V12(50) = 22.0 +/- 2.6 cm(3) and Dmean20(50) = 17.8 +/- 2.0 Gy for the combined endpoint of edema and/or BBBB) were significantly higher than those for small tissue changes (V12(50) = 4.0 +/- 0.3 cm(3) and Dmean20(50) = 7.6 +/- 0.3 Gy). CONCLUSION: . The derived dose/volume-response relations allow to quantitatively assess the risk of radiation-induced changes of brain tissue after radiosurgery in AVM patients. However, further understanding of the mechanism leading to brain tissue changes and their correlation with the desired obliteration is required. This knowledge will eventually help to optimize radiosurgical treatments in AVM patients.

Brain↗
PubMed2004

Quantification of perfusion of liver tissue and metastases using a multivessel model for replenishment kinetics of ultrasound contrast agents.

Low-MI (mechanical index) ultrasound allows real-time observation of replenishment kinetics after destruction ("flash") of ultrasound contrast agents (USCA). We developed an examination protocol and a mathematical model to quantify perfusion of liver tissue and hepatic metastases. Using a modified multivessel model, we attempted a consistent, physiological description of microbubble replenishment in liver tissue. Perfusion parameters were calculated, separately for the arterial and portal venous phase of liver perfusion, using an i.v. bolus injection of 2 x 2.4 mL SonoVue. The model was evaluated for 10 examinations of liver metastases using flash/low-MI imaging. In contrast to the established, exponential model, the new model consistently describes the sigmoid replenishment of USCA measured in vivo, using flash/low-MI imaging. Parameters for blood volume, blood velocity and blood flow in liver tissue and metastases can be calculated during the arterial and the portal venous phase after a CA bolus injection. The median arterial perfusion in the examined liver metastases was more than 2.5 times higher than in normal liver tissue, whereas the median perfusion during the portal venous phase was more than five times higher in the liver tissue than that in metastases. Microbubble replenishment measured with flash/low-MI US techniques can be consistently analyzed using the multivessel model, even after a bolus injection of USCA. This allows for the quantification of perfusion of liver tissue and hepatic metastases and provides promising parameters of tissue viability and tumor characterization.

Arteries↗
PubMed2004

Low mechanical index contrast-enhanced ultrasound better reflects high arterial perfusion of liver metastases than arterial phase computed tomography.

RATIONALE AND OBJECTIVES: We investigated whether observing the arterial vascularization of liver metastases by contrast-enhanced ultrasound with low mechanical index (low-MI) imaging offers additional diagnostic information for the characterization of the liver lesions. METHODS: Twenty nine patients with untreated liver metastases of different primaries were examined. Measurements were performed using a low frame rate, low-MI pulse inversion technique after injection of 2.4 mL SonoVue. The relative maximum signal intensity of the liver lesions related to the normal liver tissue was quantified. Ultrasound findings were compared with contrast-enhanced, dual-phase computed tomography (CT) using a pattern-based classification scheme. RESULTS: Compared with contrast-enhanced CT, this modality better detects arterial perfusion. Metastases, even those usually considered hypovascularized, often showed homogeneous enhancement (66%) and higher arterial vascularization than normal liver tissue. CT did not show a comparable vascularization pattern (P < 0.001) or any similarly early signal intensity (P < 0.001). CONCLUSIONS: Contrast-enhanced CT may not be able to visualize short-lasting but large differences of the arterial perfusion of liver metastases, as does contrast-enhanced low-MI ultrasound. This offers new methods for their characterization and for monitoring of therapeutic effects.

Contrast Media↗
PubMed2004

Assessment of irradiated brain metastases by means of arterial spin-labeling and dynamic susceptibility-weighted contrast-enhanced perfusion MRI: initial results.

RATIONALE AND OBJECTIVES: To assess if preradiation and early follow-up measurements of relative regional cerebral blood flow (rrCBF) can predict treatment outcome in patients with cerebral metastases and to evaluate rrCBF changes in tumor and normal tissue after stereotactic radiosurgery using arterial spin-labeling (ASL) and first-pass dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion MRI. METHODS: In 25 patients with a total of 28 brain metastases, DSC MRI and ASL perfusion MRI using the Q2TIPS sequence were performed with a 1.5-T unit. Measurements were performed prior to and at 6 weeks, 12 weeks, and 24 weeks after stereotactic radiosurgery. Follow-up examinations were completely available in 25 patients for Q2TIPS and 17 patients with 18 metastases for DSC MRI. The rrCBF of the metastases and the normal brain tissue was determined by a region-of-interest analysis. rrCBF values were correlated with the treatment outcome that was classified according to tumor volume changes at 6 months. RESULTS: The alteration of the rrCBF at the 6-week follow-up was highly predictive for treatment outcome. A decrease of the rrCBF value predicted tumor response correctly in all metastases for Q2TIPS and in 13 of 16 metastases for DSC MRI. The pretherapeutic rrCBF was not able to predict treatment outcome. The rrCBF values in normal brain tissue affected by radiation doses less than 0.5 Gy remained unchanged after therapy. CONCLUSION: These preliminary results suggest that ASL and DSC MRI techniques determining rrCBF changes in brain metastases after stereotactic radiosurgery allow the prediction of treatment outcome.

Adult↗
PubMed2004

Primary and secondary brain tumors at MR imaging: bicentric intraindividual crossover comparison of gadobenate dimeglumine and gadopentetate dimeglumine.

PURPOSE: To evaluate the safety of and compare the enhancement characteristics of gadobenate dimeglumine (MultiHance; Bracco Imaging, Milan, Italy) with those of a standard gadolinium chelate (gadopentetate dimeglumine, Magnevist; Schering, Berlin, Germany) in primary and secondary brain tumors on the basis of qualitative and quantitative parameters, on an intraindiviual basis. MATERIALS AND METHODS: Twenty-seven patients with either high-grade glioma or metastases were enrolled in a bicentric intraindividual crossover study to compare lesion enhancement with doses of 0.1 mmol per kilogram of body weight of 0.5 mol/L gadopentetate dimeglumine and 0.5 mol/L gadobenate dimeglumine. MR imaging was performed before injection (T1-weighted spin-echo [SE] and T2-weighted fast SE acquisitions) and at 1, 3, 5, 7, 9, and 16 minutes after injection (T1-weighted SE acquisitions). Qualitative assessment was performed by blinded off-site readers (for 22 patients) and on-site investigators (for 24 patients) in terms of global contrast enhancement, lesion-to-brain contrast, lesion delineation, internal lesion morphology and structure, tumor vascularization, and global image preference. Additional quantitative assessment with region-of-interest analysis was performed by off-site readers alone. Statistical analysis of qualitative data was performed with the Wilcoxon signed rank test, whereas a nonparametric approach was adopted for analysis of quantitative data. RESULTS: Significant (P <.05) preference for gadobenate dimeglumine over gadopentetate dimeglumine was noted both off-site and on-site for the global assessment of contrast enhancement. For off-site readers 1 and 2 and the on-site investigators, respectively, gadobenate dimeglumine was preferred in 13, 17, and 16 patients; gadopentetate dimeglumine was preferred in four, four, and four patients; and equality was found in five, one, and four patients). Similar preference for gadobenate dimeglumine was noted by off-site readers and on-site investigators for lesion-to-brain contrast and all other qualitative parameters. Off-site quantitative evaluation revealed significantly (P <.05) superior enhancement for gadobenate dimeglumine compared with that for gadopentetate dimeglumine at all time points from 3 minutes after injection. CONCLUSION: Significantly superior contrast enhancement of intraaxial enhancing brain tumors was achieved with 0.1 mmol/kg gadobenate dimeglumine compared with that with 0.1 mmol/kg gadopentetate dimeglumine.

Adult↗
PubMed2004

Plasticity of cortical activation related to working memory during training.

OBJECTIVE: Although it is well established that cerebral activation increases with higher task load, the potential effects of training have been investigated over brief periods only. Training is of potential clinical relevance since training programs are an essential part of psychiatric therapy. METHOD: Cerebral activation during a visual spatial working memory task was examined before, during, and after 4 weeks of daily training in nine healthy subjects using functional magnetic resonance imaging. RESULTS: All subjects showed a pronounced activation mainly involving the right inferior frontal gyrus and the right intraparietal sulcus. While the respective regions showed activation increases with improved performance after 2 weeks of training, the activation values decreased at the time of consolidation of performance gains after 4 weeks. CONCLUSIONS: Our results suggest that training-related cerebral activation changes follow an inverse U-shaped quadratic function and raise the prospect of investigating cerebral mechanisms underlying training effects.

Adult↗
PubMed2003

Cerebrospinal fluid tau levels in Alzheimer's disease are elevated when compared with vascular dementia but do not correlate with measures of cerebral atrophy.

Increased tau levels are a well-established finding in Alzheimer's disease (AD). In contrast, the potential value of tau levels in the differential diagnosis of AD, vascular dementia (VD) and major depression warrants further investigation. The potential impact of psychotropic medication also needs to be established. We investigated cerebrospinal fluid (CSF) tau protein concentrations in 88 patients with AD, 23 patients with VD, 25 patients with major depression and 17 age-paralleled controls without cognitive impairment with respect to important clinical variables, type and dosage of psychotropic medication and cerebral changes as assessed by magnetic resonance imaging (MRI). The AD patients showed significantly elevated tau levels compared with patients with VD or major depression and controls. Tau levels obtained in the VD group were intermediate, with significant differences from both AD patients and patients with major depression and controls. Within the AD group, no significant correlation between tau levels, severity of dementia, age, duration of disease, type and dosage of psychotropic medication or MRI volumetric changes arose. A subgroup of AD patients without increased tau levels was characterized by a significantly larger percentage of patients with presenile onset.

Aged↗
PubMed2003

The use of the multislice CT for the determination of respiratory lung tumor movement in stereotactic single-dose irradiation.

BACKGROUND: In three-dimensional (3-D) precision high-dose radiation therapy of lung tumors, the exact definition of the planning target volume (PTV) is indispensable. Therefore, the feasibility of a 3-D determination of respiratory lung tumor movements by the use of a multislice CT scanner was investigated. PATIENTS AND METHODS: The respiratory motion of 21 lung tumors in 20 consecutively treated patients was examined. An abdominal pressure device for the reduction of respiratory movement was used in 14 patients. Two regions of the tumor were each scanned repeatedly at the same table position, showing four simultaneously acquired slices for each cycle. Stereotactic coordinates were determined for one anatomic reference point in each tumor region (Figure 1). The 3-D differences of these coordinates between the sequentially obtained cycles were assessed (Figure 2), and a correlation with the tumor localization was performed. RESULTS: In the craniocaudal (Z-) direction the mean tumor movement was 5.1 mm (standard deviation [SD] 2.4 mm, maximum 10 mm), in the ventrodorsal (Y-) direction 3.1 mm (SD 1.5 mm, maximum 6.7 mm), and in the lateral (X-) direction 2.6 mm (SD 1.4 mm, maximum 5.8 mm; Figures 3 to 5). Inter- and intraindividual differences were present in each direction. With an abdominal pressure device no clinically significant difference between tumors in different location was seen. CONCLUSION: The 3-D assessment of lung tumor movements due to breathing is possible by the use of multislice CT. The determination, indispensable to the PTV definition, should be performed individually for several regions, because of the inter- and intraindividual deviations detected.

Adult↗
PubMed2003

Comparison of arterial spin-labeling techniques and dynamic susceptibility-weighted contrast-enhanced MRI in perfusion imaging of normal brain tissue.

OBJECTIVES: To evaluate relative cerebral blood flow (rCBF) in normal brain tissue using arterial spin-labeling (ASL) methods and first-pass dynamic susceptibility-weighted contrast-enhanced (DSC) magnetic resonance imaging (MRI). METHODS: Sixty-two patients with brain metastases were examined on a 1.5 T-system up to 6 times during routine follow-up after stereotactic radiosurgery. Perfusion values in normal gray and white matter were measured using the ASL techniques ITS-FAIR in 38 patients, Q2TIPS in 62 patients, and the first-pass DSC echo-planar (EPI) MRI after bolus administration of gadopentetate dimeglumine in 42 patients. Precision of the ASL sequences was tested in follow-up examinations in 10 healthy volunteers. RESULTS: Perfusion values in normal brain tissue obtained by all sequences correlated well by calculating Pearson's correlation coefficients (P < 0.0001) and remained unchanged after stereotactic radiosurgery as shown by analysis of variance (P > 0.05). CONCLUSION: Both ASL and DSC EPI MRI yield highly comparable perfusion values in normal brain tissue.

Adult↗
PubMed2003

Assessment of brain metastases with dynamic susceptibility-weighted contrast-enhanced MR imaging: initial results.

PURPOSE: To assess if preradiation and early follow-up regional cerebral blood volume (CBV) measurements can help predict treatment outcome in patients with cerebral metastases and to evaluate regional CBV changes in tumor and normal tissue after radiosurgery. MATERIALS AND METHODS: In 18 patients, dynamic susceptibility-weighted contrast material-enhanced magnetic resonance (MR) imaging was performed with a 1.5-T unit, which allowed an absolute quantification of the regional CBV. Measurements were performed prior to and at 6 weeks and 3 months after therapy. Treatment outcome was classified according to tumor volume changes at 6 months. The regional CBV of the metastases and the normal adjacent brain tissue were determined with a region-of-interest analysis. Regional CBV values were correlated with the patient outcome to assess the sensitivity and specificity of dynamic susceptibility-weighted contrast-enhanced MR imaging. RESULTS: The pretherapeutic regional CBV was not able to help predict a treatment outcome; however, the method proved to be highly sensitive and specific for treatment outcome prediction at the 6-week follow-up. A decrease of the regional CBV value helped predict the treatment outcome with a sensitivity of more than 90%. The tumor volume change alone had a sensitivity of only 64%. The measured regional CBV values of normal brain tissue and their ratio were comparable to physiologic data and remained unchanged with therapy. CONCLUSION: The results suggest that dynamic susceptibility-weighted contrast-enhanced MR imaging is a useful method for the assessment of radiosurgically treated brain metastases. The implemented technique with determination of the arterial input function enables an absolute quantification of the regional CBV and prediction of tumor response.

Adult↗
PubMed2003

Parahippocampal volume deficits in subjects with aging-associated cognitive decline.

OBJECTIVE: Neuropathological evidence suggests that the earliest changes in Alzheimer's disease selectively affect the parahippocampal regions of the brain. This study was conducted to determine if otherwise healthy elderly subjects with mild cognitive impairment had structural volume deficits affecting the parahippocampal gyrus. METHOD: Magnetic resonance imaging (MRI) was used to compare global and regional brain volumes in 21 subjects with mild cognitive deficits defined according to the criteria for aging-associated cognitive decline, 22 cognitively intact comparison subjects, and 12 patients with Alzheimer's disease. RESULTS: Compared with the cognitively intact subjects, the subjects with aging-associated cognitive decline had a significantly smaller mean volume of the right parahippocampal gyrus. The subjects with aging-associated cognitive decline had a mean parahippocampal volume that was intermediate between that of the Alzheimer's disease patients and that of the cognitively intact subjects. CONCLUSIONS: Parahippocampal atrophy underlies the observed cognitive deficits in aging-associated cognitive decline. These findings support the hypothesis that aging-associated cognitive decline represents a preclinical stage of Alzheimer's disease.

Age Factors↗
PubMed2002

Cognitive function in patients with cerebral arteriovenous malformations after radiosurgery: prospective long-term follow-up.

PURPOSE: To evaluate the long-term cognitive function of patients with cerebral arteriovenous malformations (AVMs) after radiosurgery. METHODS AND MATERIALS: The data of 95 AVM patients were prospectively assessed up to 3 years after radiosurgery. Of these patients, 39 had a follow-up of at least 2 years. Radiosurgery was performed using a modified linear accelerator (minimal doses to the target volume 15-22 Gy, median dose 20). The neuropsychological evaluation included testing of intelligence, attention, and memory. The effect of a preexisting intracranial hemorrhage, as well as AVM occlusion, on cognitive functions was analyzed after 1 and 2 years. RESULTS: No cognitive declines were observed during follow-up. Instead significant improvements occurred in intelligence (1 year, +6.1 IQ points; 2 years, +5.1 IQ points), memory (1 year, +18.3 percentile score; 2 years, +12.2 percentile score), and attention (1 year, +19 percentile score; 2 years, +18 percentile score). Patients without previous intracranial hemorrhage improved more than patients with intracranial hemorrhage, although this difference was not statistically significant. The role of AVM occlusion on cognitive function is not clear at present. CONCLUSION: Radiosurgery does not induce measurable deterioration of cognitive function in patients with cerebral AVMs.

Adult↗
PubMed2002

Multiphase magnetic resonance angiography of the abdominal and pelvic arteries: results of a bicenter multireader analysis.

RATIONALE AND OBJECTIVES: The objective is to assess the diagnostic accuracy and interobserver variability of multiphase 3D gadolinium-enhanced magnetic resonance angiography (3D-Gd-MRA) for assessment of abdominal and pelvic vascular disease. METHODS: In 41 patients from two different institutions multiphase 3D-Gd-MRA of the aorta and pelvis was performed using an identical scanning protocol. In a single breath-hold three to four consecutive phases were acquired. Stenoses in the renal arteries, and aorta and pelvic arteries were independently evaluated by three readers and compared with digital subtraction angiography. Interobserver variability was compared by means of a kappa statistic. RESULTS: Accuracy for stenosis grading consistently ranged between 80% and 90% for all three readers in all vessel segments studied. Good interobserver agreement was found with kappa values exceeding 0.75. Vessel segments with delayed fill-in could be reliably detected on the multiple successive MRA phases. Overall, MRA was rated slightly superior to Digital Subtraction Angiography in terms of interobserver variability, diagnostic confidence and image quality. CONCLUSIONS: Multiphase MRA is a highly robust technique with reproducible accuracy for different observers and different institutions. It can therefore be recommended for screening of atherosclerotic abdominal and pelvic disease.

Aged↗