Search

BACKGROUND: Analysis of regional wall motion of the right ventricle (RV) is primarily qualitative with large interobserver variation in clinical practice. Thus, the purpose of this study was to use feature tracking to analyze regional wall motion abnormalities in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). METHODS: We enrolled 110 subjects (39 overt ARVC [mutation+/phenotype+] (35.5%), 40 preclinical ARVC [mutation+/phenotype-] (36.3%), and 31 control subjects (28.2%)). Cine steady state free precession cardiac MR was performed with temporal resolution ≤40 ms in the horizontal long axis (HLA), axial, and short axis directions. Regional strain was analyzed using feature tracking software and reproducibility was assessed by means of intraclass correlation coefficient. Dunnett's test was used in univariate analysis for comparisons to control subjects; cumulative odds logistic regression was used for minimally and fully adjusted multivariate models. RESULTS: Strain was significantly impaired in overt ARVC compared with control subjects both globally (P < 0.01) and regionally (all segments of HLA view, P < 0.01). In the HLA view, regional reproducibility was excellent within (intraclass correlation coefficient [ICC] = 0.81) and moderate between (ICC = 0.62) observers. Using a threshold of -31% subtricuspid strain in the HLA view, the sensitivity and specificity for overt ARVC were 75.0% and 78.2%, respectively. In multivariable analysis involving all three groups, subtricuspid strain less than -31% (beta = 1.38; P = 0.014) and RV end diastolic volume index (beta = 0.06; P = 0.001) were significant predictors of disease presence. CONCLUSION: RV strain can be reproducibly assessed with MR feature tracking, and regional strain is abnormal in overt ARVC compared with control subjects.

We tested the hypothesis that bidimensional measurements of right ventricular (RV) function obtained by cardiac magnetic resonance imaging (CMR) in patients with pulmonary arterial hypertension (PAH) are faster than volumetric measures and highly reproducible, with comparable ability to predict patient survival. CMR-derived tricuspid annular plane systolic excursion (TAPSE), RV fractional shortening (RVFS), RV fractional area change (RVFAC), standard functional and volumetric measures, and ventricular mass index (VMI) were compared with right heart catheterization data. CMR analysis time was recorded. Receiver operating characteristic curves, Kaplan-Meier, Cox proportional hazard (CPH), and Bland-Altman test were used for analysis. Forty-nine subjects with PAH and 18 control subjects were included. TAPSE, RVFS, RVFAC, RV ejection fraction, and VMI correlated significantly with pulmonary vascular resistance and mean pulmonary artery pressure (all P < 0.05). Patients were followed up for a mean (± standard deviation) of 2.5 ± 1.6 years. Kaplan-Meier curves showed that death was strongly associated with TAPSE

ARVD/C: The Triangle of Dysplasia Displaced Introduction The traditional description of the Triangle of Dysplasia in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C) predates genetic testing and excludes biventricular phenotypes. Methods and Results We analyzed Cardiac Magnetic Resonance (CMR) studies of 74 mutation-positive ARVD/C patients for regional abnormalities on a 5-segment RV and 17-segment LV model. The location of electroanatomic endo- and epicardial scar and site of successful VT ablation was recorded in 11 ARVD/C subjects. Among 54/74 (73%) subjects with abnormal CMR, the RV was abnormal in almost all (96%), and 52% had biventricular involvement. Isolated LV abnormalities were uncommon (4%). Dyskinetic basal inferior wall (94%) was the most prevalent RV abnormality, followed by basal anterior wall (87%) dyskinesis. Subepicardial fat infiltration in the posterolateral LV (80%) was the most frequent LV abnormality. Similar to CMR data, voltage maps revealed scar (

PURPOSE: Computed tomography(CT) technology has rapidly evolved. Phantom studies show higher radiation doses with increasing detector rows. However scanner‐based dose‐reduction techniques have also evolved. Given these opposing trends that impact patient dose it is unclear whether doses increased have or decreased over time. Using an automated dose information extraction tool we analyzed trends in radiation doses over time for abdominal and pelvic examinations at our institution. METHOD AND MATERIALS: Radiation dose (total DLP) from 1716 abdominal and pelvic CT examinations performed between 2003 and 2010 were analyzed. Examinations were performed on 6 MDCT scanners ranging from 4 to 64 detectors. Dose data from protocol sheets was extracted using a novel extraction system. RESULTS: Average DLP for CT examinations of the abdomen and pelvis performed in 2003 was 728.9 +/−278 mGy‐cm. Average DLP for examinations performed in 2010 was 1034 +/− 458 mGy‐cm a 41.8% increase. For a 16 slice scanner in constant use since 2003 average DLP increased from 728.9 +/− 278 mGy‐cm in 2003 to 1004 +/− 421 mGy‐cm in 2010 a 37.7% increase. For abdominal and pelvic examinations from the year 2010 average DLP for exams performed on 16‐slice scanners (2 total) was 1094 +/− 478 mGy‐cm. The average DLP for examinations performed on 64‐slice scanners (3 total) was 1245 +/− 598 mGy‐cm which is an average 13.8% higher dose. CONCLUSIONS: Average CT radiation dose has increased over time. Scanners with greater numbers of detector rows delivered a higher radiation dose. Patient radiation doses for abdominal and pelvic examinations performed on a given scanner also increased over time. The upward trend in dose is likely due to a combination of hardware factors protocol changes and potentially changes in the patient population. Knowledge of these trends is important for effective implementation of dose reduction protocols and quality assurance.

PURPOSE: Exposure to radiation as a result of medical imaging is currently in the spotlight receiving attention from Congress as well as the lay press. While scanner manufacturers are moving towards including effective doseinformation in the DICOM headers of imaging studies there is a vast repository of retrospective CT data at every imaging center which stores doseinformation in a patient protocol image. As such it is difficult for imaging centers to participate in the American College of Radiology (ACR) Dose Registry. METHOD AND MATERIALS: We have designed an automated extraction system to query our PACS archive and parse our CT examinations to extract doseinformation stored in each patient protocol image. First an open‐source optical character recognition (OCR) program processes each protocol image and converts the information to ASCII text. We parse each ASCII file and extract radiationdoseinformation which is stored in a database and queried using an existing pathology and radiology enterprise search tool at our institution. We conducted a validation study to compare the extracted text information with the original patient protocol image. 2108 CT examinations performed at our institution between 2003 and 2010 were randomly selected and processed. Two board‐certified radiologists reviewed the extracted radiationdoseinformation and compared it with the patient protocol image of each study. RESULTS: The pipeline extracts and calculates total DLP with an accuracy of 100%. CONCLUSION: Using this automated extraction pipeline we are able to perform dose analysis on the more than 869000 CT examinations in our PACS archive and generate dose report cards for every patient scanned at our institution. The automated extraction pipeline allows us to be compliant with the ACR reporting guidelines and be more cognizant of radiationdose to our patients thus resulting in improved patient care and management. CONFLICT OF INTEREST: None.