Congenital anomalies of coronary artery origin in adults: 64-MDCT appearance

OBJECTIVE: The purpose of this pictorial essay is to review the 64-MDCT appearance of congenital anomalies of the origins of the coronary arteries in adults. CONCLUSION: Increasing use of MDCT for cardiac imaging of adults requires familiarity with the cross-sectional appearance of congenital coronary artery anomalies visualized with noninvasive imaging techniques. Many of these anomalies are benign, but a small number are associated with myocardial ischemia and sudden death. Increasing use of MDCT in cardiac imaging may yield diagnostic information not obtained with coronary angiography. Axial, multiplanar, and 3D volume-rendered reconstructions should aid in detection and improve interpretation of such anomalies.     

Radiation Dose Reduction in Pediatric Cardiac Computed Tomography: Experience from a Tertiary Medical Center

Cardiac CT angiography (cCTA) has become an established method for the assessment of congenital heart disease. However, the potential harmful effects of ionizing radiation must be considered, particularly in younger, more radiosensitive patients. In this study, we sought to assess the temporal change in radiation doses from pediatric cCTA during an 8-year period at a tertiary medical center. This retrospective study included all patients ≤18 years old who were referred to electrocardiography (ECG)-gated cCTA for the assessment of congenital heart disease or inflammatory disease (Kawasaki disease) from November 2004 to September 2012. During the study period, 95 patients were scanned using 3 different scanner models—64-slice multidetector CT (64-MDCT) and first- (64-DSCT) and second-generation (128-DSCT) dual-source CT—and 3 scan protocols—retrospective ECG-gated helical scanning (RG), prospective ECG-triggered axial scanning (PT), or prospective ECG-triggered high-pitch helical scanning (HPH). Effective dose (ED) was calculated with the dose length product method with a conversion factor (k) adjusted for age. ED was then compared among scan protocols. Image quality was extracted from clinical cCTA reports when available. Overall, 94 % of scans were diagnostic (80 % for 64-slice MDCT, 93 % for 64-slice DSCT, and 97 % for 128-slice DSCT).With 128-DSCT, median ED (1.0 [range 0.6–2.0] mSv) decreased by 85.8 % and 66.8 % compared with 64-MDCT (6.8 [range 2.9–13.6] mSv) and 64-DSCT (2.9 [range 0.9–4.1] mSv), respectively. With HPH, median ED (0.9 [range 0.6–1.8] mSv) decreased by 59.4 % and 85.4 % compared with PT (2.2 [range 0.9–3.4] mSv) and RG (6.1 [range 2.5–10.6] mSv). cCTA can now be obtained at very low radiation doses in pediatric patients using the latest dual-source CT technology in combination with prospective ECG-triggered HPH acquisition.     

Significance of Cardiac Computed Tomography Incidental Findings in Acute Chest Pain

Background

Coronary computed tomography angiography might improve the management of patients presenting to the emergency department with acute chest pain; however, noncoronary incidental findings are frequently detected. The prevalence and clinical significance of these findings have not been well described.

Methods

Consecutive patients presenting to the emergency department with acute chest pain and inconclusive initial evaluation between May 2005 and May 2007 underwent 64-slice coronary computed tomography angiography before hospital admission with noncoronary incidental findings immediately reported. An expert panel adjudicated which incidental findings changed in-hospital patient management, and projections for additional testing were based on standard medical practice.

Results

Among 395 patients (37.0% were female, mean age 53 ± 12 years), incidental findings were detected in 44.8% (n = 177): noncalcified pulmonary nodules (n = 94, 23.8%), simple liver cysts (n = 26, 6.6%), calcified pulmonary nodules (n = 16, 4.1%), and contrast-enhancing liver lesions (n = 9, 2.3%). In-hospital management was changed because of incidental finding reporting in 5 patients (1.3%), and a potential alternative diagnosis was offered in another 16 patients (4.1%). Subsequent diagnostic imaging tests were recommended in 81 patients (20.5%), including 74 chest computed tomography scans. After 6 months, biopsy was performed in 3 patients, revealing cancer in 2 (0.5%) who underwent successful tumor resection.

Conclusion

Clinically important findings are detected in up to 5% of patients with a lead symptom of acute chest pain and low to intermediate likelihood of acute coronary syndrome, but only few directly change patient management; 21% are recommended for further imaging tests, resulting in invasive procedures and detection of cancer in few patients.     

Assessment of image quality and radiation dose of prospectively ECG-triggered adaptive dual-source coronary computed tomography angiography (cCTA) with arrhythmia rejection algorithm in systole versus diastole: a retrospective cohort study

In this study, we sought to evaluate the image quality and effective radiation dose of prospectively ECG-triggered adaptive systolic (PTA-systolic) dual-source CTA versus prospectively triggered adaptive diastolic (PTA-diastolic) dual-source CTA in patients of unselected heart rate and rhythm. This retrospective cohort study consisted of 41 PTA-systolic and 41 matched PTA-diastolic CTA patients whom underwent clinically indicated 128-slice dual source CTA between December 2010 to June 2012. Image quality and motion artifact score (both on a Likert scale 1–4 with 4 being the best), effective dose, and CTDI_vol were compared. The effect of heart rate (HR) and heart rate variability [HRV] on image motion artifact score and CTDI_vol was analyzed with Pearson’s correlation coefficient. All 82 exams were considered diagnostic with 0 non-diagnostic segments. PTA-systolic CTA patients had a higher maximum HR, wider HRV, were less likely to be in sinus rhythm, and received less beta-blocker vs. PTA-diastolic CTA patients. No difference in effective dose was observed (PTA-systolic vs. PTA-diastolic CTA: 2.9 vs. 2.2 mSv, p = 0.26). Image quality score (3.3 vs. 3.5, p < 0.05) and motion artifact score (3.5 vs. 3.8, p < 0.05) were lower in PTA-systolic CTAs than in PTA-diastolic CTAs. For PTA-systolic CTAs, an increase in HR was not associated with a negative impact on motion artifact score nor CTDI_vol. For PTA-diastolic CTA, an increase in HR was associated with increased motion artifacts and CTDI_vol. HRV demonstrated no correlation with motion artifact and CTDI_vol for both PTA-systolic and PTA-diastolic CTAs. In conclusion, both PTA-diastolic CTA and PTA-systolic CTA yielded diagnostic examinations at unselected heart rates and rhythms with similar effective radiation, but PTA-systolic CTA resulted in more consistent radiation exposure and image quality across a wide range of rates and rhythms.     

Comparison of the Diamond-Forrester method and Duke Clinical Score to predict obstructive coronary artery disease by computed tomographic angiography

We sought to evaluate the ability of the Diamond and Forrester method (DFM) and the Duke Clinical Score (DCS) to predict obstructive coronary artery disease (CAD) on coronary computed tomographic angiography (CCTA) and the effect of these different risk scores on the appropriateness level using the 2010 Appropriate Use Criteria. Consecutive symptomatic patients who underwent CCTA for evaluation of CAD (n = 114) were classified as having a low, intermediate, or high pretest probability using the DFM and DCS. Using the Appropriate Use Criteria, the indications for CCTA were classified according to the pretest probability and previous testing. The CCTA results were classified as revealing obstructive (≥70% stenosis), nonobstructive (<70%), or no CAD. When the patients' risk was classified using the DFM, 18% were low, 65% intermediate, and 17% high risk. When using the DCS, 53% of patients had a reclassification of their risk, most of whom changed from intermediate to either low or high risk (50% low, 19% intermediate, 35% high risk). The net reclassification improvement for the prediction of obstructive CAD was 51% (p = 0.01). Of the 37 patients who were reclassified as low risk, 36 (97%) lacked obstructive CAD. Appropriateness for CCTA was reclassified for 13% of patients when using the DCS instead of the DFM, and the number of appropriate examinations was significantly fewer (68% vs 55%, p <0.001). In conclusion, reclassification of risk using the DCS instead of the DFM resulted in improved prediction of obstructive CAD on CCTA, especially in low-risk patients. More patients were categorized as having a high pretest probability of CAD, resulting in reclassification of their examination indications as uncertain or inappropriate. These results identify the need for improved pretest risk scores for noninvasive tests such as CCTA and suggest that the method of risk assessment could have important implications for patient selection and quality assurance programs.     

Kisspeptin-54 triggers egg maturation in women undergoing in vitro fertilization

BACKGROUND. Patients with mutations that inactivate kisspeptin signaling are infertile. Kisspeptin-54, the major circulating isoform of kisspeptin in humans, potently stimulates reproductive hormone secretion in humans. Animal studies suggest that kisspeptin is involved in generation of the luteinizing hormone surge, which is required for ovulation; therefore, we hypothesized that kisspeptin-54 could be used to trigger egg maturation in women undergoing in vitro fertilization therapy.METHODS. Following superovulation with recombinant follicle-stimulating hormone and administration of gonadotropin-releasing hormone antagonist to prevent premature ovulation, 53 women were administered a single subcutaneous injection of kisspeptin-54 (1.6 nmol/kg, n = 2; 3.2 nmol/kg, n = 3; 6.4 nmol/kg, n = 24; 12.8 nmol/kg, n = 24) to induce a luteinizing hormone surge and egg maturation. Eggs were retrieved transvaginally 36 hours after kisspeptin injection, assessed for maturation (primary outcome), and fertilized by intracytoplasmic sperm injection with subsequent transfer of one or two embryos.RESULTS. Egg maturation was observed in response to each tested dose of kisspeptin-54, and the mean number of mature eggs per patient generally increased in a dose-dependent manner. Fertilization of eggs and transfer of embryos to the uterus occurred in 92% (49/53) of kisspeptin-54–treated patients. Biochemical and clinical pregnancy rates were 40% (21/53) and 23% (12/53), respectively.CONCLUSION. This study demonstrates that a single injection of kisspeptin-54 can induce egg maturation in women with subfertility undergoing in vitro fertilization therapy. Subsequent fertilization of eggs matured following kisspeptin-54 administration and transfer of resulting embryos can lead to successful human pregnancy.TRIAL REGISTRATION. ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01667406","term_id":"NCT01667406"}}NCT01667406.FUNDING. Medical Research Council, Wellcome Trust, and National Institute for Health Research.     

Where Does It Lead? Imaging Features of Cardiovascular Implantable Electronic Devices on Chest Radiograph and CT

Pacemakers and implantable cardioverter defibrillators (ICDs) are being increasingly employed in patients suffering from cardiac rhythm disturbances. The principal objective of this article is to familiarize radiologists with pacemakers and ICDs on chest radiographs and CT scans. Therefore, the preferred lead positions according to pacemaker types and anatomic variants are introduced in this study. Additionally, the imaging features of incorrect lead positions and defects, as well as complications subsequent to pacemaker implantation are demonstrated herein.