Expansive arterial remodeling of the carotid arteries and its effect on atherosclerotic plaque composition and vulnerability: an in-vivo black-blood 3T CMR study in symptomatic stroke patients

Background: Based on intravascular ultrasound of the coronary arteries expansive arterial remodeling is supposed to be a feature of the vulnerable atheroslerotic plaque. However, till now little is known regarding the clinical impact of expansive remodeling of carotid lesions. Therefore, we sought to evaluate the correlation of expansive arterial remodeling of the carotid arteries with atherosclerotic plaque composition and vulnerability using in-vivo Cardiovascular Magnetic Resonance (CMR). Methods: One hundred eleven symptomatic patients (74 male/71.8 +/- 10.3y) with acute unilateral ischemic stroke and carotid plaques of at least 2 mm thickness were included. All patients received a dedicated multi-sequence black-blood carotid CMR (3Tesla) of the proximal internal carotid arteries (ICA). Measurements of lumen, wall, outer wall, hemorrhage, calcification and necrotic core were determined. Each vessel-segment was classified according to American Heart Association (AHA) criteria for vulnerable plaque. A modified remodeling index (mRI) was established by dividing the average outer vessel area of the ICA segments by the lumen area measured on TOF images in a not affected reference segment at the distal ipsilateral ICA. Correlations of mRI and clinical symptoms as well as plaque morphology/vessel dimensions were evaluated. Results: Seventy-eight percent (157/202) of all internal carotid arteries showed atherosclerotic disease with AHA Lesion-Type (LT) III or higher. The mRI of the ICA was significantly different in normal artery segments (AHA LT I;mRI 1.9) compared to atherosclerotic segments (AHA LT III-VII;mRI 2.5;p < 0.0001). Between AHA LT III-VII there was no significant difference of mRI. Significant correlations (p < 0.05) of the mRI with lumen-area (LA), wall-area (WA), vessel-area (VA) and wall-thickness (WT), necrotic-core area (NC), and ulcer-area were observed. With respect to clinical presentation (symptomatic/asymptomatic side) and luminal narrowing (stenotic/non-stenotic) no relevant correlations or significant differences regarding the mRI were found. Conclusion: Expansive arterial remodeling exists in the ICA. However, no significant association between expansive arterial remodeling, stroke symptoms, complicated AHA VI plaque, and luminal stenosis could be established. Hence, results of our study suggest that expansive arterial remodeling is not a very practical marker for plaque vulnerability in the carotid arteries

Penumbra Pattern Assessment in Acute Stroke Patients: Comparison of Quantitative and Non-Quantitative Methods in Whole Brain CT Perfusion

Background and Purpose: While penumbra assessment has become an important part of the clinical decision making for acute stroke patients, there is a lack of studies measuring the reliability and reproducibility of defined assessment techniques in the clinical setting. Our aim was to determine reliability and reproducibility of different types of three-dimensional penumbra assessment methods in stroke patients who underwent whole brain CT perfusion imaging (WB-CTP). Materials and Methods: We included 29 patients with a confirmed MCA infarction who underwent initial WB-CTP with a scan coverage of 100 mm in the z-axis. Two blinded and experienced readers assessed the flow-volume-mismatch twice and in two quantitative ways: Performing a volumetric mismatch analysis using OsiriX imaging software (MMVOL) and visual estimation of mismatch (MMEST). Complementarily, the semiquantitative Alberta Stroke Programme Early CT Score for CT perfusion was used to define mismatch (MMASPECTS). A favorable penumbral pattern was defined by a mismatch of >= 30% in combination with a cerebral blood flow deficit of = 1, respectively. Inter-and intrareader agreement was determined by Kappa-values and ICCs. Results: Overall, MMVOL showed considerably higher inter-/intrareader agreement (ICCs: 0.751/0.843) compared to MMEST (0.292/0.749). In the subgroup of large (>= 50 mL) perfusion deficits, inter-and intrareader agreement of MMVOL was excellent (ICCs: 0.961/0.942), while MMEST interreader agreement was poor (0.415) and intrareader agreement was good (0.919). With respect to penumbra classification, MMVOL showed the highest agreement (interreader agreement: 25 agreements/4 non-agreements/kappa: 0.595;intrareader agreement 27/2/0.833), followed by MMEST (22/7/0.471;23/6/0.577), and MMASPECTS (18/11/0.133;21/8/0.340). Conclusion: The evaluated approach of volumetric mismatch assessment is superior to pure visual and ASPECTS penumbra pattern assessment in WB-CTP and helps to precisely judge the extent of 3-dimensional mismatch in acute stroke patients

Assessing Pulmonary Perfusion in Emphysema Automated Quantification of Perfused Blood Volume in Dual-Energy CTPA

Objectives: The objective of this study was to determine whether automated quantification of lung perfused blood volume (PBV) in dual-energy computed tomographic pulmonary angiography (DE-CTPA) can be used to assess the severity and regional distribution of pulmonary hypoperfusion in emphysema. Materials and Methods: We retrospectively analyzed 40 consecutive patients (mean age, 67 13] years) with pulmonary emphysema, who have no cardiopulmonary comorbidities, and a DE-CTPA negative for pulmonary embolism. Automated quantification of global and regional pulmonary PBV was performed using the syngo Dual Energy application (Siemens Healthcare). Similarly, the global and regional degrees of parenchymal hypodensity were assessed automatically as the percentage of voxels with a computed tomographic density less than -900 Hounsfield unit. Emphysema severity was rated visually, and pulmonary function tests were obtained by chart review, if available. Results: Global PBV generated by automated quantification of pulmonary PBV in the DE-CTPA data sets showed a moderately strong but highly significant negative correlation with residual volume in percentage of the predicted residual volume (r = -0.62; P = 0.002; n = 23) and a positive correlation with forced expiratory volume in 1 second in percentage of the predicted forced expiratory volume in 1 second (r = 0.67; P < 0.001; n = 23). Global PBV values strongly correlated with diffusing lung capacity for carbon monoxide (r = 0.80; P < 0.001; n = 15). Pulmonary PBV values decreased with visual emphysema severity (r = -0.46, P = 0.003, n = 40). Moderate negative correlations were found between global PBV values and parenchymal hypodensity both in a per-patient (r = -0.63; P G 0.001; n = 40) and per-region analyses (r = -0.62; P < 0.001; n = 40). Conclusions: Dual-energy computed tomographic pulmonary angiography allows simultaneous assessment of lung morphology, parenchymal density, and pulmonary PBV. In patients with pulmonary emphysema, automated quantification of pulmonary PBV in DE-CTPA can be used for a quick, reader-independent estimation of global and regional pulmonary perfusion, which correlates with several lung function parameters

Technical outcome, clinical success, and complications of low-milliampere computed tomography fluoroscopy-guided drainage of lymphoceles following radical prostatectomy with pelvic lymph node dissection

To evaluate the technical outcome, clinical success, and safety of low-milliampere CT fluoroscopy (CTF)-guided percutaneous drain (PD) placement in patients with lymphoceles following radical prostatectomy (RP) with pelvic lymph node dissection (LND). This retrospective analysis comprised 65 patients with PD placement in lymphoceles following RP under low-milliampere CTF guidance. Technical and clinical success were evaluated. Complications within a 30-day time interval associated with CTF-guided PD placement were classified according to SIR. Patient radiation exposure was quantified using dose-length products (DLP) of the pre-interventional planning CT scan (DLPpre), of the sum of intra-interventional CT fluoroscopic acquisitions (DLPintra) and of the post-interventional control CT scan (DLPpost). Eighty-nine lymphoceles were detected. Seventy-seven CT-guided interventions were performed, with a total of 92 inserted drains. CTF-guided lymphocele drainage was technically successful in 100% of cases. For all symptomatic patients, improvement in symptoms was reported within 48 h after intervention. Time course of C-reactive protein and Leucocytes within 30 days revealed a statistically significant (p < 0.0001) decrease. Median DLPpre, DLPintra and DLPpost were 431 mGy*cm, 45 mGy*cm and 303 mGy*cm, respectively. Only one minor complication (self-resolving haematoma over the bladder dome; SIR Grade 2) was observed. Low-milliampere CTF-guided drainage is a safe treatment option in patients with lymphoceles following RP with pelvic LND characterized by high technical and good clinical success rates, which provides rapid symptom relief and serves as definite treatment or as a bridging therapy prior to laparoscopic marsupialisation.peer-reviewe

Renal and renal sinus fat volumes as quantified by magnetic resonance imaging in subjects with prediabetes, diabetes, and normal glucose tolerance.

PURPOSE:We hypothesize that MRI-based renal compartment volumes, particularly renal sinus fat as locally and potentially independently acting perivascular fat tissue, increase with glucose intolerance. We therefore analyze the distribution of renal volumes in individuals with normal glucose levels and prediabetic and diabetic individuals and investigate potential associations with other typical cardiometabolic biomarkers. MATERIAL AND METHODS:The sample comprised N = 366 participants who were either normoglycemic (N = 230), had prediabetes (N = 87) or diabetes (N = 49), as determined by Oral Glucose Tolerance Test. Other covariates were obtained by standardized measurements and interviews. Whole-body MR measurements were performed on a 3 Tesla scanner. For assessment of the kidneys, a coronal T1w dual-echo Dixon and a coronal T2w single shot fast spin echo sequence were employed. Stepwise semi-automated segmentation of the kidneys on the Dixon-sequences was based on thresholding and geometric assumptions generating volumes for the kidneys and sinus fat. Inter- and intra-reader variability were determined on a subset of 40 subjects. Associations between glycemic status and renal volumes were evaluated by linear regression models, adjusted for other potential confounding variables. Furthermore, the association of renal volumes with visceral adipose tissue was assessed by linear regression models and Pearson's correlation coefficient. RESULTS:Renal volume, renal sinus volume and renal sinus fat increased gradually from normoglycemic controls to individuals with prediabetes to individuals with diabetes (renal volume: 280.3±64.7 ml vs 303.7±67.4 ml vs 320.6±77.7ml, respectively, p < 0.001). After adjustment for age and sex, prediabetes and diabetes were significantly associated to increased renal volume, sinus volume (e.g. βPrediabetes = 10.1, 95% CI: [6.5, 13.7]; p<0.01, βDiabetes = 11.86, 95% CI: [7.2, 16.5]; p<0.01) and sinus fat (e.g. βPrediabetes = 7.13, 95% CI: [4.5, 9.8]; p<0.001, βDiabetes = 7.34, 95% CI: [4.0, 10.7]; p<0.001). Associations attenuated after adjustment for additional confounders were only significant for prediabetes and sinus volume (ß = 4.0 95% CI [0.4, 7.6]; p<0.05). Hypertension was significantly associated with increased sinus volume (β = 3.7, 95% CI: [0.4, 7.0; p<0.05]) and absolute sinus fat volume (β = 3.0, 95% CI: [0.7, 5.3]; p<0.05). GFR and all renal volumes were significantly associated as well as urine creatinine levels and renal sinus volume (β = 1.6, 95% CI: [0.1, 2.9]; p<0.05). CONCLUSION:Renal volume and particularly renal sinus fat volume already increases significantly in prediabetic subjects and is significantly associated with VAT. This shows, that renal sinus fat is a perivascular adipose tissue, which early undergoes changes in the development of metabolic disease. Our findings underpin that renal sinus fat is a link between metabolic disease and associated chronic kidney disease, making it a potential imaging biomarker when assessing perivascular adipose tissue

Penumbra Pattern Assessment in Acute Stroke Patients: Comparison of Quantitative and Non-Quantitative Methods in Whole Brain CT Perfusion - Table 2

<p>* CBF perfusion deficit ≥50 mL, N = 14.</p>†<p>CBF perfusion deficit <50 mL, N = 15.</p><p>** statistically significant.</p><p>ICC: intraclass correlation coefficient.</p><p>doi:10.1371/journal.pone.0105413.t002</p><p>Inter- and intrareader agreement for quantitative methods of mismatch assessment, depending on perfusion deficit volume of the patient, N = 29.</p