Dataset Information

256-slice CT angiographic evaluation of coronary artery bypass grafts: effect of heart rate, heart rate variability and Z-axis location on image quality.

ABSTRACT: The objective of this study is to assess the effect of heart rate, heart rate variability and z-axis location on coronary artery bypass graft (CABG) image quality using a 256-slice computed tomography (CT) scanner.A total of 78 patients with 254 CABG (762 graft segments) were recruited to undergo CABG assessment with 256-slice CT and prospective ECG-gating. Two observers rated graft segments for image quality on a 5-point scale. Quantitative measurements were also made. Logistic and cumulative link mixed models were used to assess the predictors of graft image quality.Graft image quality was judged as diagnostic (scores 5 (excellent), 4 (good) and 3 (moderate)) in 96.6% of the 762 segments. Interobserver agreement was excellent (kappa ?0.90). Graft image quality was not affected by heart rate level. However, high heart rate variability was associated with an important and significant image quality deterioration (odds ratio 4.31; p ?=? 0.036). Distal graft segments had significantly lower image quality scores than proximal segments (p ? 0.02). Significantly higher noise was noted at the origin of the mammary grafts (p ?=? 0.001), owing to streak artifacts from the shoulders.CABG imaging with 270-msec rotation 256-slice CT and prospective ECG-gating showed an adequate image quality in 96.6% of graft segments, and an excellent interobserver agreement. Graft image quality was not influenced by heart rate level. Image quality scores were however significantly decreased in patients with high heart rate variability, as well as in distal graft segments, which are closer to the heart.

SUBMITTER: Gramer BM

PROVIDER: S-EPMC3956757 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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256-slice CT angiographic evaluation of coronary artery bypass grafts: effect of heart rate, heart rate variability and Z-axis location on image quality.

Gramer Bettina M BM Diez Martinez Patricia P Chin Anne S AS Sylvestre Marie-Pierre MP Larrivée Sandra S Stevens Louis-Mathieu LM Noiseux Nicolas N Soulez Gilles G Rummeny Ernst J EJ Chartrand-Lefebvre Carl C

PloS one 20140317 3

<h4>Purpose</h4>The objective of this study is to assess the effect of heart rate, heart rate variability and z-axis location on coronary artery bypass graft (CABG) image quality using a 256-slice computed tomography (CT) scanner.<h4>Methods</h4>A total of 78 patients with 254 CABG (762 graft segments) were recruited to undergo CABG assessment with 256-slice CT and prospective ECG-gating. Two observers rated graft segments for image quality on a 5-point scale. Quantitative measurements were also ...[more]

PMID: 24637891

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Project description:Purpose: Discovery of curative therapies for renal cell carcinoma (RCC) is hampered by lack of authentic preclinical models. Tumorgrafts, generated by direct implantation of patient-derived tissues into mice, have demonstrated superior ability to predict therapeutic response. We evaluated âtissue slice graftsâ (TSGs) as an improved tumorgraft model of RCC. Experimental Design: Cores of fresh RCC were precision-cut at 300-Î¼m and implanted under the renal capsule of RAG2-/-Î³C-/- mice. Engraftment rate, histology, biomarker expression, genetic fidelity and metastatic potential were evaluated. Magnetic resonance imaging (MRI) was tested as a non-invasive method to measure tumor volume, and response to a targeted therapy was determined. Results: All 13 cases of RCC engrafted and displayed characteristic histology and biomarkers. TSG volume quantified non-invasively by MRI highly correlated with graft weights, providing a unique tool for monitoring orthotopic growth. Moreover, in 2 cases, cancer cells from TSGs metastasized to clinically relevant sites, including bone. Microarray analysis and DNA sequencing demonstrated a high degree of correlation of global gene expression and VHL status between TSGs and parental tumors. Treatment of TSGs with sunitinib significantly decreased graft weight and mean vessel density compared to controls. Conclusions: The TSG model of RCC faithfully recapitulates tumor pathology, gene expression, genetic mutation and drug response. The high engraftment rate and metastatic potential of this authentic model, in conjunction with the ability to generate large first-generation animal cohorts and to quantitate tumor volume at the orthotopic site by MRI, proffer significant advantages compared to other preclinical platforms. Three pairs of tissue slice graftes and parent tumors were included in the study. Tissue slice grafts and parent tumors were preserved in Allprotect tissue reagent (Qiagen, Valencia, CA) at -20Â°C prior to RNA extraction using an AllPrep DNA/RNA/Protein Mini Kit (Qiagen, Valencia, CA). The quality of RNA was determined using an Agilent 2100 Bioanalyzer (Agilent Biotechnologies, Santa Clara, CA). Microarray hybridization was performed using Illumina Human HT-12 v4 Beadchips (Illumina Inc., San Diego, CA) according to the manufacturerâs directions. Expression data was rank invariant normalized using BeadStudio software (Illumina Inc.).

Project description:Reduced heart rate variability (HRV) is an autonomic nervous system (ANS) response that may indicate dysfunction in the human body. Consistent evidence shows cancer patients elicit lower HRV; however, only select cancer locations were previously evaluated. Thus, the aim of the current study was to explore HRV patterns in patients diagnosed with and in varying stages of the most prevalent cancers. At a single tertiary academic medical center, 798 patients were recruited. HRV was measured via an armband monitor (Warfighter MonitorTM, Tiger Tech Solutions, Inc., Miami, FL, USA) equipped with electrocardiographic capabilities and was recorded for 5 to 7 min with patients seated in an upright position. Three time-domain metrics were calculated: SDNN (standard deviation of the NN interval), rMSSD (the root mean square of successive differences of NN intervals), and the percentage of time in which the change in successive NN intervals exceeds 50ms within a measurement (pNN50). Of the 798 patients, 399 were diagnosed with cancer. Cancer diagnoses were obtained via medical records one week following the measurement. Analysis of variance models were performed comparing the HRV patterns between different cancers, cancer stages (I-IV), and demographic strata. A total of 85% of the cancer patients had breast, gastrointestinal, genitourinary, or respiratory cancer. The cancer patients were compared to a control non-cancer patient population with similar patient size and distributions for sex, age, body mass index, and co-morbidities. For all HRV metrics, non-cancer patients exhibited significantly higher rMSSDs (11.1 to 13.9 ms, p < 0.0001), SDNNs (22.8 to 27.7 ms, p < 0.0001), and pNN50s (6.2 to 8.1%, p < 0.0001) compared to stage I or II cancer patients. This significant trend was consistently observed across each cancer location. Similarly, compared to patients with stage III or IV cancer, non-cancer patients possessed lower HRs (-11.8 to -14.0 bpm, p < 0.0001) and higher rMSSDs (+31.7 to +32.8 ms, p < 0.0001), SDNNs (+45.2 to +45.8 ms), p < 0.0001, and pNN50s (19.2 to 21.6%, p < 0.0001). The HR and HRV patterns observed did not significantly differ between cancer locations (p = 0.96 to 1.00). The depressed HRVs observed uniformly across the most prevalent cancer locations and stages appeared to occur independent of patients' co-morbidities. This finding highlights the potentially effective use of HRV as a non-invasive tool for determining common cancer locations and their respective stages. More studies are needed to delineate the HRV patterns across different ages, between sexes and race/ethnic groups.

Dataset Information

256-slice CT angiographic evaluation of coronary artery bypass grafts: effect of heart rate, heart rate variability and Z-axis location on image quality.

Publications

256-slice CT angiographic evaluation of coronary artery bypass grafts: effect of heart rate, heart rate variability and Z-axis location on image quality.

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