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Computed tomographic coronary artery calcium scanning enables cardiovascular risk stratification; however, exposing patients to high radiation levels is an ongoing concern. New-generation computed tomographic systems use lower radiation doses than older systems do. To quantify comparative doses of radiation exposure, we prospectively acquired images from 220 patients with use of a 64-slice GE LightSpeed VCT scanner (control group, n=110) and a 256-slice GE Revolution scanner (study group, n=110). The groups were matched for age, sex, and body mass index; statistical analysis included t tests and linear regression. The mean dose-length product was 21% lower in the study group than in the control group (60.2 ± 27 vs 75.9 ± 22.6 mGy·cm; P Our study group was exposed to radiation doses lower than the previously determined standard of 1 mSv, even after adjustment for body mass index and waist circumference. In 256-slice scanning for coronary artery calcium, radiation doses are now similar to those in lung cancer screening and mammography.

Introduction Coronary CT Angiography (CCTA) is a rapidly increasing technique for coronary imaging; however, it exposes patients to ionising radiation. We examined the impact of dose reduction techniques using ECG‐triggering, kVp/mAs reduction and high‐pitch modes on radiation exposure in a large Australian tertiary CCTA service. Methods Data on acquisition modes and dose exposure were prospectively collected on all CCTA scans from November 2009 to March 2014 at an Australian tertiary care centre. A dose reduction algorithm was developed using published techniques and implemented with education of medical staff, radiographers and referrers. Associations of CCTA acquisition to radiation over time were analysed with multivariate regression. Specificity in positive CCTA was assessed by correlation with invasive coronary angiography. Results 3333 CCTAs were analysed. Mean radiation dose decreased from 8.4 mSv to 5.3, 4.4, 3.7, 2.9 and 2.8 mSv (P, Cardiac CT angiography dosing was reviewed after implementation of dose reduction strategies. 3333 CCTAs were analyzed. Implementation of evidence‐based dose reduction strategies and a decision‐support algorithm accounted for 91% of dose reduction, with 9% attributable to hardware. Significant reductions in radiation exposure are feasible in real‐world clinical practice and can be successfully applied through better education and training.

Background: It was hypothesized that the accuracy of coronary CT angiography would be affected by case volume of the referring sites. Methods: The positive predictive value (PPV) of CTCA performed at a tertiary hospital specialising in cardiothoracic medicine and services with lower case-volumes were calculated. The tertiary hospital used as the high case-volume reference centre was The Prince Charles Hospital, which performed >1500 CTCA scans per annum over the study period. The low case-volume services used in the study were suburban radiology services, each with

Pulmonary artery pseudoaneurysm is a dangerous pathology often missed as a differential and on imaging. With a 50% mortality rate early detection and intervention are critical to patient outcome, rendering diagnosis based on clinical grounds to be of paramount importance. A high index of suspicion should be placed on patients presenting with unprovoked hemoptysis, hemorrhage or hemothorax. Knowledge of the common causes of pulmonary artery pseudoaneurysms is also important; however, it is integral to note spontaneous occurrences in patients with no known risk factors. Herein, we report a case of an unprovoked pulmonary artery pseudoaneurysm in a 72-year-old male with no known risk factors or causes for the pathology. Additionally, we review the pathophysiology behind the potential association of polyarthritic gout as a cause of pulmonary artery pseudoaneurysms. To the best of our knowledge this is the first reported link between the two diseases, providing grounds to widen literature and increase diagnoses of pulmonary artery pseudoaneurysms. J Clin Med Res. 2018;10(10):781-785 doi: https://doi.org/10.14740/jocmr3513w

Rationale: The NLST (National Lung Screening Trial) reported a 20% reduction in lung cancer mortality with low-dose computed tomography screening; however, important questions on how to optimize screening remain, including which selection criteria are most accurate at detecting lung cancers and what nodule management protocol is most efficient. The PLCOm2012 (Prostate, Lung, Colorectal and Ovarian) Cancer Screening Trial 6-year and PanCan (Pan-Canadian Early Detection of Lung Cancer) nodule malignancy risk models are two of the better validated risk prediction models for screenee selection and nodule management, respectively. Combined use of these models for participant selection and nodule management could significantly improve screening efficiency. Objectives: The ILST (International Lung Screening Trial) is a prospective cohort study with two primary aims: 1) Compare the accuracy of the PLCOm2012 model against U.S. Preventive Services Task Force (USPSTF) criteria for detecting lung cancers and 2) evaluate nodule management efficiency using the PanCan nodule probability calculator-based protocol versus Lung-RADS. Methods: ILST will recruit 4,500 participants who meet USPSTF and/or PLCOm2012 risk ≥1.51%/6-year selection criteria. Participants will undergo baseline and 2-year low-dose computed tomography screening. Baseline nodules are managed according to PanCan probability score. Participants will be followed up for a minimum of 5 years. Primary outcomes for aim 1 are the proportion of individuals selected for screening, proportion of lung cancers detected, and positive predictive values of either selection criteria, and outcomes for aim 2 include comparing distributions of individuals and the proportion of lung cancers in each of three management groups: next surveillance scan, early recall scan, or diagnostic evaluation recommended. Statistical powers to detect differences in the four components of primary study aims were ≥82%. Conclusions: ILST will prospectively evaluate the comparative accuracy and effectiveness of two promising multivariable risk models for screenee selection and nodule management in lung cancer screening. Clinical trial registered with www.clinicaltrials.gov (NCT02871856).

Coronary artery disease is the leading cause of morbidity and mortality. Tools have been developed to accurately diagnose and evaluate coronary artery disease. Coronary CT angiography (CCTA) provides detailed imaging to deliver precise analysis and prognostic information. We sought to compare the radiation dose from a 256-detector-row CT scanner with that from a 64-detector-row CT scanner across a similar profile of patients. Methods: Consecutive patients were screened for the Converge Registry study and, after consenting to be included, were enrolled in accordance with an Institutional Review Board-approved protocol. A control group who underwent 64-row CCTA were matched by age, sex, and body mass index (BMI) with a group who underwent 256-row CCTA. Results: We compared 110 patients in each group. We found that mean dose-length product (DLP) was significantly lower in the 256-row group than in the 64-row group (P < 0.05). The radiation dose was reduced by 32% with use of the 256-row scanner for BMIs of 18.5-24.9 (DLP, 111.2 vs. 76.1 mGy-cm [1.56 vs. 1.07 mSv]; P < 0.05). For each BMI subgroup, there was a significant decrease in dose. Regression analysis found that with increasing BMIs, DLP significantly increased for both scanners. Conclusion: The 256-row scanner provided CCTA scans at significantly lower radiation doses than the 64-row scanner in different BMI groups, with all other variables accounted for. Lower radiation exposure along with lower contrast requirements can provide images with high diagnostic accuracy and less risk to the patient.

Intro: Coronary artery disease is the leading cause for morbidity and mortality. Tools have been developed to accurately diagnose and evaluate coronary artery disease. Coronary computed tomographic angiography (CCTA) scans provide detailed imaging along with analysis to in order to deliver precise analysis and prognostic information. We sought to evaluate the radiation doses of the 256 detector CT scanner to a 64 slice scanner across a similar profile of patients. Methods: Consecutive patients were screened, enrolled, and consented for the Converge Registry study, in accordance with the Institutional Review Board (IRB) approved protocol. 110 patients underwent CCTA using the GE Revolution 256 detector CT scanner. We matched patients by age, gender and body mass index (BMI) who underwent 64 slice CT scanning. Results: We compared 110 patients in each group. We found that mean dose length product (DLP, presented also in the tables below in millisieverts (mSv)) was significantly lower in the Revolution 256 detector group compared to the 64 slice control group (p

Rationale and Objectives: Novel technology in coronary computed tomographic angiography allows assessment of coronary artery disease with high image quality (IQ). There are currently two wide detector “whole heart” coverage scanners available, which avoid misregistration artifacts. However, there are no data directly comparing IQ between the two scanners. The aim of the current study is to investigate if IQ is different between the most current scanners of GE and Toshiba broad detector scanners. Materials and Methods: Prospective, observational, multicenter international cohort study comparing 236 consecutive patients who underwent coronary computed tomographic angiography using whole-heart scanners; 126 patients on scanner S1 (Aquilion ONE, Toshiba), and 110 patients on scanner S2 (Revolution CT, GE Healthcare). Hounsfield units were measured using regions of interest in the descending aorta at 6 points (cranial slice, level of the visualized first, second, third, and fourth spines, and the caudal slice). We also compared the coverage length (z-axis) of the full width field of view between a single rotation of the two scanners. Results: Evaluating mean CT attenuation values Hounsfield units through the scan range, are progressively reduced across the descending aorta in the S1 group, resulting in the larger difference of contrast brightness between the cranial and caudal slices compared to the S2 group (absolute difference: S2 13.0 ± 4.4 vs S1 141.9 ± 16.4, p < 0.0001; Percent difference: 19.3 ± 2.1 vs −3.4 ± 1.2

Chest digital tomosynthesis (DT) has potential advantages compared to computed tomography (CT) such as radiation dose reduction. However, the role of DT in pulmonary nodule management remains investigative. We compared DT against CT for pulmonary nodule detection and size measurement. A clinical population comprising 54 nodules from 30 patients and a screening population comprising 42 nodules from 52 patients were included. Scans were independently read by two radiologists. Agreement in nodule measurements between readers and between modalities was assessed by Bland-Altman analysis using a 95% level of significance. The DT true positive fraction for the two readers was 0.44 and 0.39 in the clinical population, and 0.10 and 0.05 in the screening population. No significant inter-modality bias was observed between DT and CT measurements of nodule size, but the range of variation between modalities was approximately 30%. Inter-reader DT measurements also showed no significant bias, with a range of variation of approximately 15%. We conclude that DT has poor nodule detection sensitivity compared to CT. However, DT showed good measurement reproducibility and may be useful for monitoring growth of existing pulmonary nodules.

It was hypothesized that the accuracy of coronary CT angiography would be affected by case volume of the referring sites.The positive predictive value (PPV) of CTCA performed at a tertiary hospital specialising in cardiothoracic medicine and services with lower case-volumes were calculated. The tertiary hospital used as the high case-volume reference centre was The Prince Charles Hospital, which performed1500 CTCA scansThe positive predictive value (PPV) of the high case-volume group (n = 199) wasThere was no significant difference in PPV between the two groups. This suggests that high-volume and lower-volume sites both have high PPV in Australia, above the published pooled PPV of four large prospective diagnostic accuracy studies (Miller et al., 2008; Budoff et al., 2008; Meijboom et al., 2008; Achenbach, 2007).

In well-compensated PAH, early RV maladaptation is best captured by changes in SV/ESV at exercise by cardiac MRI http://ow.ly/MyEi302UUeL