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Introduction: To determine the best imaging modality for preoperative detection, characterization and measurement of colorectal liver metastases (CRLM) after neoadjuvant chemotherapy (NAC). Methods: A total of 79 lesions in 15 patients with CRLM were included. Following NAC, all patients received multislice liver CT (MSCT) and magnetic resonance imaging (MRI) that were scored by two observers for lesion number, type, diameter (mm) and segmental location. Intraoperative findings, histopathology and follow-up imaging were used as reference standard for surgically treated patients; non-surgical candidates underwent follow-up imaging. Results: Lesion detection rate was similar for MSCT and MRI (76 and 80%, respectively, p = 0.648). Lesion characterization was significantly superior (p = 0.021) at MRI (89%, κ 0.747, p = 0.001) compared to MSCT (77%, κ 0.235, p = 0.005). Interobserver variability for diameter measurement was not significant at MRI (p = 0.909 [95% CI -1.245 to 1.395]), but significant at MSCT (p = 0.028 [95% CI -3.349 to -2.007]). Differences in diameter measurement were independent of observer (p = 0.131), and no statistical effect from imaging modality on diameter measurement was observed (p = 0.095). Conclusion: MRI is superior to MSCT in preoperative characterization and measurement of CRLM after NAC. Lesion detection rates for both modalities are comparable. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: In patients with carotid artery stenosis, ipsilateral hemodynamic compromise is associated with an increased risk of stroke. It is unclear which factors determine cerebral perfusion. We studied the effect of both the degree of the stenosis and the collateral circulation via the circle of Willis (CoW) on cerebral perfusion in patients with symptomatic carotid artery stenosis. Methods: In 88 patients with unilateral symptomatic carotid artery stenosis of ≥50%, CT perfusion was used to measure the relative cerebral blood volume (rCBV), the difference in mean transit time (ΔMTT) and the relative cerebral blood flow (rCBF). CT angiography was used to measure the degree of carotid stenosis and to assess the configuration of the CoW. Differences in mean rCBF, rCBV and ΔMTT between patients with a carotid stenosis of ≤69, 70–79, 80–89 and 90–99%, and between patients with a complete and those with an incomplete CoW were determined by analysis of covariance. Results: The ipsilateral rCBF showed a gradual decrease with increasing severity of carotid stenosis (1.09 ± 0.06, 0.93 ± 0.06, 0.90 ± 0.04 and 0.83 ± 0.04 ml/100 g/min, respectively; p = 0.005), and the ΔMTT showed a gradual increase (–0.02 ± 0.33, 0.16 ± 0.34, 1.08 ± 0.22 and 1.47 ± 0.20 s, respectively; p < 0.001). The rCBV was not related to the severity of stenosis. No relation was found between the configuration of the CoW and the cerebral perfusion parameters. Conclusions: Cerebral perfusion is inversely related to the degree of stenosis in patients with symptomatic carotid artery stenosis. A relation between the configuration of the CoW and cerebral perfusion was not detected, suggesting that other collateral pathways play an important role. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background/Aims: It has been hypothesized that cerebral hypoperfusion may contribute to cognitive deterioration. Patients with white matter lesions (WML) may be more vulnerable to a decrease in cerebral blood flow (CBF) due to an impaired autoregulation. We investigated the association between CBF and cognitive performance and whether WML modified this relation. Methods: Within the SMART-MR study, a cohort study among patients with manifest arterial disease, cross-sectional analyses were performed in 472 patients (mean age 57 ± 10 years, 77% male). Total CBF was measured with magnetic resonance angiography in the internal carotid arteries and basilar artery, and was expressed per 100 ml brain volume. Neuropsychological tests assessing executive functioning and memory were performed and composite scores were calculated. We used linear regression analyses, adjusted for age, sex, education and intelligence, to investigate the association between CBF and cognitive performance. Results: We found that WML modified the association between CBF and executive functioning (p for interaction <0.001); the association between lower CBF and worse performance on executive functioning became stronger and significant with increasing volumes of WML. Lower CBF was not associated with worse memory. Conclusion: Our results suggest that a combination of lower CBF and WML may impair executive functioning but not memory. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background and Purpose: A reliable scoring method for ischemic cerebral white matter hyperintensities (WMH) will help to clarify the causes and consequences of these brain lesions. We compared an automated and two visual WMH scoring methods in their relations with age and cognitive function. Methods: MRI of the brain was performed on 154 participants of the Utrecht Diabetic Encephalopathy Study. WMH volumes were obtained with an automated segmentation method. Visual rating of deep and periventricular WMH (DWMH and PWMH) was performed with the Scheltens scale and the Rotterdam Scan Study (RSS) scale, respectively. Cognition was assessed with a battery of 11 tests. Results: Within the whole study group, the association with age was most evident for the automated measured WMH volume (β = 0.43, 95% CI = 0.29–0.57). With regard to cognition, automated measured WMH volume and Scheltens DWMH were significantly associated with information processing speed (β = –0.22, 95% CI = –0.40 to –0.06; β = –0.26, 95% CI = –0.42 to –0.10), whereas RSS PWMH were associated with attention and executive function (β = –0.19, 95% CI = –0.36 to –0.02). Conclusion: Measurements of WMH with an automated quantitative segmentation method are comparable with visual rating scales and highly suitable for use in future studies to assess the relationship between WMH and subtle impairments in cognitive function. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Purpose: To assess the presence of anterior and posterior collateral pathways in the circle of Willis in patients with symptomatic carotid artery stenosis (SCAS) and to compare this to patients without carotid artery stenosis. Materials and Methods: Multislice CT angiography was performed in 91 patients and 91 control subjects. Using consensus reading, 2 observers evaluated the presence and diameter of the anterior communicating artery (AcomA), the A1 segments of the anterior cerebral arteries, the posterior communicating arteries (PcomA) and the P1 segments of the posterior cerebral arteries. Anterior or posterior pathways were assumed to be present if the diameter of continuous arterial segments was >1 mm; both A1 segments and AcomA anterior, and ipsilateral P1 segment and PcomA posterior. Comparison between patients and controls was performed using the χ2 test. Results: In the patients we found significantly more hypoplastic (<1 mm) or invisible A1 segments (16 and 14 vs. 4 and 1, respectively, p < 0.01). The AcomA was invisible in 4 patients versus 1 control. An isolated compromised anterior pathway and a combined compromised anterior and posterior pathway occurred more frequently in the patients as compared to the controls; 9 versus 1% (p < 0.01) and 26 versus 4% (p < 0.01). Conclusion: A compromised anterior collateral pathway, usually combined with a compromised posterior pathway, occurs more frequently in patients with SCAS as compared to controls, which suggests a relation between symptomatic carotid stenosis and an incomplete circle of Willis. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: The standard care in patients with a painful osteoporotic vertebral compression fracture (VCF) is conservative therapy. Percutaneous vertebroplasty (PV), a minimally invasive technique, is gaining popularity as a new treatment option. Many prospective and retrospective studies have reported on the effectiveness and safety of PV, but no large randomized controlled trial (RCT) has been published. Objective: To estimate cost-effectiveness of PV compared to conservative therapy in terms of: pain reduction, quality of life, complications, secondary fractures and mortality. Materials and methods: The VERTOS II study is designed as a prospective, multicenter RCT. Patients with a painful VCF with bone edema on MR imaging, local back pain for 6 weeks or less, osteopenia and aged 50 years or older, after obtaining informed consent are included and randomized for PV or conservative therapy. In total 200 patients will be enrolled. Follow-up is at regular intervals during a 1-year period with standard questionnaires, addressing: clinical symptoms, pain medication, Visual Analogue Scale (VAS) score, quality of life and cost-effectiveness. Secondary fractures, necessary additional therapies and complications are recorded. Conclusion: The VERTOS II study is the first methodologically sound RCT designed to assess the cost-effectiveness of PV compared to conservative therapy in patients with an acute osteoporotic VCF. Trial registration: http://www.clinicaltrials.gov, NCT00232466 [ABSTRACT FROM AUTHOR]

Purpose: To assess the value of MR angiography (MRA) with automatic table movement in a consecutive series of patients with peripheral arterial disease. Methods: Seventy-two patients underwent both conventional angiography (CA) and MRA for peripheral arterial ccclusive disease. Both techniques were scored in a masked way. Consensus scoring for CA was compared with MRA scoring per observer. If there was a discrepancy in scoring of a segment on MRA and CA, the images were reviewed and a consensus arrived at. Results: Observer A found 7.4% and observer B found 6.5% of the segments could not be analyzed on MRA. Observer A scored 11.4% dissimilar on MRA and CA, observer B 15.2%. In the aortoiliac arteries, this was mainly caused by stents and overestimation of stenoses; in the crural arteries it resulted from underestimation of the stenoses on MRA. Overall sensitivity and specificity for the aortoiliac, femoro-pepliteal and crural vessels were respectively 90% and 91%, 90% and 96%, 59% and 96% for observer A, and 85% and 91%, 84% and 89%, 68% and 85% for observer B. Conclusion: Although MRA of the lower extremities is a promising technique, improvements still need to be made. In particular, MRA below the knee is suboptimal for clinical use. [ABSTRACT FROM AUTHOR]

Purpose: To assess, in a multicenter setting, safety, technical results, and restenosis rate of the Palmaz stent for treatment of atherosclerotic ostial renal artery stenosis.Methods: Ten centers enrolled 106 patients (120 treated renal artery stenoses) in the study. Patient selection was based on unsuccessful percutaneous transluminal renal angioplasty (residual stenosis >/= 20%) performed for treatment of ostial stenosis >/= 50%, in patients with hypertension and/or impaired renal function. Safety was assessed by means of the complication rate, and technical results by the number of successful stent placements and occurrence of restenosis (>50%) at intraarterial angiographic follow-up.Results: Stent placement was successful (n = 112) or partially successful (n = 5) in 117 (98%) arteries. Complications occurred in 19 procedures; seven were of serious clinical significance. Angiographic follow-up was performed in 89 of 117 (76%) cases, at a mean of 8 months (range 2. 5-18 months). Fifteen stents (16.9%) showed restenosis (at a mean of 8.5 months), of which 10 were successfully redilated.Conclusion: Renal artery stenting has a high technical success rate, a complication rate comparable to percutaneous transluminal renal angioplasty, and a low rate of restenosis at 8 months angiographic follow-up. [ABSTRACT FROM AUTHOR]

Purpose: To assess the accuracy of intraarterial measurement of transstenotic pressure gradients for the detection of hemodynamically suboptimal iliac angioplasty.Methods: In 14 patients, referred for diagnostic angiography, mean pressure gradients in the aorta and iliac artery were obtained twice, using a double-sensor pressure catheter. Additional iliac measurements were performed during pharmacologically induced flow augmentation. Repeatability was assessed by calculation of the mean difference plus standard deviation (MD +/- SD) and repeatability coefficient (2 x SD). These results were extrapolated to 137 iliac angioplasty procedures with secondary stenting where there was a residual pressure gradient > 10 mmHg.Results: MD +/- SD for repeated measurements at rest and during flow augmentation were 0 +/- 2 mmHg and 1 +/- 3 mmHg, respectively. Repeatability coefficients were 3 and 6 mmHg. Mean pressure gradients after hemodynamically insufficient angioplasty were 8 +/- 7 mmHg at rest and 17 +/- 5 mmHg following vasodilatation. Inaccurate pressure recordings may have led to inappropriate stent placement in less than 2.5%, and inappropriate denial of stent placement in less than 5% of the lesions.Conclusion: Variability of intraarterial pressure measurements has little consequence in the detection of hemodynamically significant stenosis after angioplasty. [ABSTRACT FROM AUTHOR]

Purpose: To describe short-term complications during stent placement for atherosclerotic renal artery ostial stenosis.Methods: Sixty-one arteries in 50 patients were treated with Palmaz stents. Nineteen patients had a single functioning kidney, 23 had a bilateral stenosis, which was stented bilaterally in 11, and 8 had a unilateral stenosis. The complications were grouped as those related to the catheterization procedure, those related to stent placement, and those possibly related to either category. The complications were divided into those with severe clinical significance (SCS), those with minor clinical significance (MCS), and radiological-technical complications (RTC). The stent placement procedures were ordered chronologically according to examination date and the complications were tabulated per group of 10 patients.Results: Five (10%) SCS, 5 (10%) MCS, and 8 (16%) RTC occurred in 50 patients. The catheterization procedure led to 2 SCS, 3 MCS, and 1 RTC. Stent placement gave rise to 7 RTC. Three SCS and 2 MCS could have been related to either catheterization or stent placement. More SCS occurred in the first group of 10 patients than in the following groups.Conclusion: Renal artery stent placement for atherosclerotic ostial stenosis has a considerable complication rate and a learning curve is present. The complications related to the actual stent placement were without clinical consequences. [ABSTRACT FROM AUTHOR]

Purpose: To assess the predictive value of immediate angiographic results after percutaneous transluminal angioplasty (PTA) for stenoses in femoral bypass grafts using duplex ultrasound (DUS) criteria. Methods: A 1-year follow-up with DUS was performed in 38 patients with 50 stenoses in 41 grafts, treated with PTA for a graft stenosis. The indication for PTA according to DUS criteria was a severe stenosis in 43 lesions, and a moderate stenosis in 7 lesions. In the moderate stenosis group 3 patients showed claudication and 1 patient had a nonhealing ulcer. For the purposes of statistical evaluation, primary patency was considered present if the graft was not occluded. The graft was considered to have failed when it was found to be occluded on DUS, or when secondary interventions (surgery, repeat PTA) were performed. Results: After 1 year the cumulative primary patency rate was 44% [95% confidence interval (CI) 27.8-59.8]. Stenoses with initially good angiographic results after PTA (< 30% residual stenosis) were 2.9 times more likely to be patent at 1 year than stenoses with initially poor or moderate angiographic results (hazard ratio 2.9, 95% CI 1.3-6.4, p = 0.007). Conclusion: A poor or moderate angiographic result immediately following PTA was prognostic for poor long-term results and may indicate a requirement for earlier surgical intervention. [ABSTRACT FROM AUTHOR]

Purpose: To determine initial technical results of percutaneous transluminal angioplasty (PTA) and stent procedures in the iliac artery, mean intraarterial pressure gradients were recorded before and after each procedure.Methods: We randomly assigned 213 patients with typical intermittent claudication to primary stent placement (n = 107) or primary PTA (n = 106), with subsequent stenting in the case of a residual mean pressure gradient of > 10 mmHg (n = 45). Eligibility criteria included angiographic iliac artery stenosis (> 50% diameter reduction) and/or a peak systolic velocity ratio > 2.5 on duplex examination. Mean intraarterial pressures were simultaneously recorded above and below the lesion, at rest and also during vasodilatation in the case of a resting gradient < or = 10 mmHg.Results: Pressure gradients in the primary stent group were 14.9 +/- 10.4 mmHg before and 2.9 +/- 3.5 mmHg after stenting. Pressure gradients in the primary PTA group were 17.3 +/- 11.3 mmHg pre-PTA, 4.2 +/- 5.4 mmHg post-PTA, and 2.5 +/- 2.8 mmHg after selective stenting. Compared with primary stent placement, PTA plus selective stent placement avoided application of a stent in 63% (86/137) of cases, resulting in a considerable cost saving.Conclusion: Technical results of primary stenting and PTA plus selective stenting are similar in terms of residual pressure gradients. [ABSTRACT FROM AUTHOR]

Purpose: To exploit the potential benefits of percutaneous transluminal angioplasty (PTA) in patients with short obstructive lesions in the lower extremity, it is preferable to select patients suitable for PTA before proceeding to hospital admission and angiography. The aim of this prospective study was to evaluate the role of color-coded duplex scanning in the correct selection of patients for PTA and its influence on planning the approach to the lesion.Methods: On the basis of clinical history, physical examination, pressure indices, and ultrasound duplex scanning, 109 patients were scheduled for PTA.Results: The indication for PTA was correct in 103 patients (94%), while the procedure was performed successfully in 98 patients (90%). The approach to the lesion was planned successfully in the majority of patients.Conclusion: This study shows that it is justifiable to plan PTA on the basis of information obtained by duplex scanning. Results of the duplex scan may guide the catheterization route. [ABSTRACT FROM AUTHOR]

Twenty-six children who underwent an arterial switch operation for transposition of the great arteries were examined with MRI and Doppler ultrasound (US). The aim was to determine the capability of MRI for detecting a possible stenosis of the pulmonary arteries. In 10 children angiocardiography (ACG) was done after the MRI examination. Using ACG as the gold standard, MRI was sensitive in the detection of pulmonary artery stenosis. MRI was more precise in the localization of a stenosis than was Doppler US. Right ventricular hypertrophy was a sensitive indicator of pulmonary artery stenosis. These results suggest that MRI could serve as a screening examination for pulmonary artery stenosis after an arterial switch operation. [ABSTRACT FROM AUTHOR]

In a fifty-one-year-old female patient, bilateral fibromuscular dysplasia of the internal carotid artery was treated during surgery with intraluminal dilatation. The backflow excludes the occurrence of cerebral embolism. The method and its possibilities are discussed. [ABSTRACT FROM AUTHOR]