Cardiovascular magnetic resonance demonstration of the spectrum of morphological phenotypes and patterns of myocardial scarring in Anderson-Fabry disease.

BACKGROUND: Although it is known that Anderson-Fabry Disease (AFD) can mimic the morphologic manifestations of hypertrophic cardiomyopathy (HCM) on echocardiography, there is a lack of cardiovascular magnetic resonance (CMR) literature on this. There is limited information in the published literature on the distribution of myocardial fibrosis in patients with AFD, with scar reported principally in the basal inferolateral midwall. METHODS: All patients with confirmed AFD undergoing CMR at our center were included. Left ventricular (LV) volumes, wall thicknesses and scar were analyzed offline. Patients were categorized into 4 groups: (1) no wall thickening; (2) concentric hypertrophy; (3) asymmetric septal hypertrophy (ASH); and (4) apical hypertrophy. Charts were reviewed for clinical information. RESULTS: Thirty-nine patients were included (20 males [51%], median age 45.2 years [range 22.3-64.4]). Almost half (17/39) had concentric wall thickening. Almost half (17/39) had pathologic LV scar; three quarters of these (13/17) had typical inferolateral midwall scar. A quarter (9/39) had both concentric wall thickening and typical inferolateral scar. A subgroup with ASH and apical hypertrophy (n = 5) had greater maximum wall thickness, total LV scar, apical scar and mid-ventricular scar than those with concentric hypertrophy (n = 17, p < 0.05). Patients with elevated LVMI had more overall arrhythmia (p = 0.007) more ventricular arrhythmia (p = 0.007) and sustained ventricular tachycardia (p = 0.008). CONCLUSIONS: Concentric thickening and inferolateral mid-myocardial scar are the most common manifestations of AFD, but the spectrum includes cases morphologically identical to apical and ASH subtypes of HCM and these have more apical and mid-ventricular LV scar. Significant LVH is associated with ventricular arrhythmia.

Deep basal inferoseptal crypts occur more commonly in patients with hypertrophic cardiomyopathy due to disease-causing myofilament mutations.

PURPOSE: To determine the relationship between deep basal inferoseptal crypts and disease-causing gene mutations in hypertrophic cardiomyopathy (HCM). MATERIALS AND METHODS: Institutional research and ethics board approval was obtained for this retrospective study, and the requirement to obtain informed consent was waived. Two readers, who were blinded to genetic status, independently assessed cardiac magnetic resonance (MR) images obtained in 300 consecutive unrelated genetically tested patients with HCM. Readers documented the morphologic phenotype, the presence of deep basal inferoseptal crypts, and the imaging plane in which crypts were first convincingly visualized. The Student t test, the Fisher exact test, and multivariate logistic regression were used for comparisons and to evaluate the relationship between these crypts and the detection of disease-causing mutations. RESULTS: The frequency of deep basal inferoseptal crypts was significantly higher in patients with disease-causing mutations than in those without disease-causing mutations (36% and 4%, respectively; P < .001). The presence of crypts was a stronger predictor of disease-causing mutations than was reverse septal curvature (P = .025). Patients with these crypts had a higher likelihood of having disease-causing mutations than non-disease-causing mutations (P < .001). Thirty-one of the 34 patients with both deep basal inferoseptal crypts and reverse septal curvature (91%) had disease-causing mutations (sensitivity, 26%; specificity, 98%). The presence of deep basal inferoseptal crypts (odds ratio: 6.64; 95% confidence interval: 2.631, 16.755; P < .001) and reverse septal curvature (odds ratio: 4.8; 95% confidence interval: 2.552, 9.083; P < .001) were predictive of disease-causing mutations. Both observers required additional imaging planes to identify approximately half of all crypts. CONCLUSION: Deep basal inferoseptal crypts occur more commonly in patients with HCM with disease-causing mutations than in those with genotype-negative HCM.

Tracking and Resolving CT Dose Metric Outliers Using Root-Cause Analysis.

PURPOSE: The aim of this study was to examine the frequency and type of outlier dose metrics for three common CT examination types on the basis of a root-cause analysis (RCA) approach. METHODS: Institutional review board approval was obtained for this retrospective observational study. The requirement to obtain informed consent was waived. Between January 2010 and December 2013, radiation dose metric data from 34,615 CT examinations, including 26,878 routine noncontrast CT head, 2,992 CT pulmonary angiographic (CTPA), and 4,745 renal colic examinations, were extracted from a radiation dose index monitoring database and manually cleaned. Dose outliers were identified on the basis of the statistical distribution of volumetric CT dose index and dose-length product for each examination type; values higher than the 99th percentile and less than the 1st percentile were flagged for RCA. RESULTS: There were 397 noncontrast CT head, 52 CTPA, and 80 renal colic outliers. Root causes for high-outlier examinations included repeat examinations due to patient motion (n = 122 [31%]), modified protocols mislabeled as "routine" (n = 69 [18%]), higher dose examinations for patients with large body habitus (n = 27 [7%]), repeat examinations due to technical artifacts (n = 20 [5%]), and repeat examinations due to suboptimal contrast timing (CTPA examinations) (n = 18 [5%]). Root causes for low-outlier examinations included low-dose protocols (n = 112 [29%]) and aborted examinations (n = 8 [2%]). On the basis of examination frequency over a 3-month period, the 90th and 10th percentile values were set in the radiation dose index monitoring database as thresholds for sending notifications to staff members responsible for outlier investigations. CONCLUSIONS: Systematic RCA of dose outliers identifies sources of variation and dose excess and pinpoints specific protocol and technical shortcomings for corrective action.

Bilateral mobile thoracolithiasis.

Thoracolithiasis is the presence of one or more freely mobile pleural stones (with or without calcification) in the pleural space. They occur with a reported incidence of less than 0.1% and are benign and do not require intervention. Historically, they have led to unnecessary interventions - something unlikely in the era of multidetector computed tomography (CT). Thoracolithiasis should be included in the differential diagnosis of a single or multiple, mobile peripheral pulmonary nodules. Here, we review the imaging characteristics of a rare case of bilateral mobile thoracolithiasis.

Left-sided patent ductus arteriosus in a right-sided aortic arch.

We present a 31-year-old female with repaired tetralogy of Fallot (TOF) and right-sided aortic arch (RAA) with left-sided patent ductus arteriosus (PDA) originating from the left brachiocephalic artery. This is a rare finding but most common site for a PDA in TOF and a RAA. To the best of our knowledge, this is the first demonstration of this rare finding on MRI in the literature.