Elevated Native T1 Values in the Remote Myocardium Supplied by Obstructive Non-Infarct Related Coronary Arteries in Post-STEMI Cardiac Magnetic Resonance.

INTRODUCTION: Native T1 mapping values are elevated in acutely injured myocardium. We sought to study whether native T1 values, in the non-infarct related myocardial territories, might differ when supplied by obstructive or nonobstructive coronary arteries. METHODS: Consecutive patients (N = 60, mean age 59 years) with the first STEMI following primary percutaneous coronary intervention, underwent cardiac magnetic resonance within 5 ± 2 days. A retrospective review of coronary angiography reports classified coronary arteries as infarct-related coronary artery (IRA) and non-IRA. Obstructive coronary artery disease (CAD) was defined as stenosis ≥50%. Native T1 values were presented using a 16-segment AHA model according to the three main coronary territories: left anterior descending (LAD), left circumflex (LCX), and right coronary artery (RCA). RESULTS: The cutoff native T1 value for predicting obstructive non-IRA LAD was 1,309 msec with a sensitivity and specificity of 67% and 82%, respectively (AUC 0.76, 95% CI: 0.57-0.95, p = 0.04). The cutoff native T1 value for predicting obstructive non-IRA RCA was 1,302 msec with a sensitivity and specificity of 83% and 55%, respectively (AUC 0.7, 95% CI: 0.52-0.87, p = 0.05). Logistic regression model adjusted for age and infarct size demonstrated that native T1 was an independent predictor for the obstructive non-IRA LAD (OR 4.65; 1.32-26.96, p = 0.05) and RCA (OR 3.70; 1.44-16.35, p = 0.03). CONCLUSION: Elevated native T1 values are independent predictors of obstructive non-IRA in STEMI patients. These results suggest the presence of concomitant remote myocardial impairment in the non-infarct territories with obstructive CAD.

Magnetic Resonance Imaging for the Follow-up of Treated Thymic Epithelial Malignancies.

PURPOSE: The purpose of this article was to compare magnetic resonance imaging (MRI) depiction of thymic malignancy progression/recurrence with that of computed tomography (CT). METHODS: We retrospectively reviewed all surgically treated thymic epithelial malignancy (TEM) patients between 2011 and 2018 who were followed-up with chest CT and MRI. We compared the detection of recurrence and metastatic disease between the CT and MRI scans in each of these patients. RESULTS: Of 187 patients treated in our institution for TEM, 22 were followed-up with both CT and MRI. TNM stage at diagnosis was as follows: I (n=14), II (n=1), IIIa (n=4), IIIb (n=2), IVa (n=1), and IVb (n=0). Patients were followed-up for a mean of 6.2 years, range 0.7 to 17.7 years. The mean interval between CT and MRI was 5.4 (range, 1 to 15) months. Most patients had no recurrence (n=16), 4 had recurrence after R0 or R1 resection, 1 had stable disease, and 1 had progression of disease after R2 resection. CT and MRI performed equally in the identification of pleural spread (n=5), lymphadenopathy (n=4), and pulmonary metastases (n=1). Retrosternal recurrence (n=1) was identified by MRI despite sternotomy wire artifacts. MRI identified bone involvement and extension of disease into the thecal sac earlier and more readily. Three patients had an indeterminate mediastinal finding on CT that was correctly identified as a benign cyst or pericardial fluid collection by MRI. CONCLUSION: MRI is an alternative option to follow-up patients after treatment for TEM. However, for those with metallic sternotomy wires, we recommend alternating the follow-up with CT as well.

Overuse of Head CT Examinations for the Investigation of Minor Head Trauma: Analysis of Contributing Factors.

PURPOSE: The aim of this study was to estimate the amount of CT studies performed in the emergency department of a tertiary hospital that are not indicated by Canadian CT Head Rule (CCHR) guidelines and to analyze factors that contribute to unnecessary examinations. METHODS: A total of 955 brain CT examinations performed for minor head injuries were randomly retrospectively selected. Medical records were assessed for the following parameters: demographics, cause of head trauma, and referring physician's seniority and specialty. For each CT scan, it was determined whether the CT referral met the CCHR criteria. The CT interpretations of patients under 65 years of age were evaluated to assess the sensitivity and negative predictive value of the CCHR criteria. RESULTS: A total of 104 examinations (10.9%) were not indicated according to the CCHR, but in patients younger than 65 years, 104 of 279 examinations (37.3%) were not indicated. Neurologists conducted more unwarranted CT studies (odds ratio [OR], 3.5; P = .011), whereas surgeons tended to order fewer studies (OR, 0.676; P = .126). There was no statistically significant difference between the seniority of the referring physician and over-referral (P = .181). Four-wheel motor vehicle accidents (OR, 2.789; P = .001) and a hit on the head by an object (OR, 2.843; P = .006) were associated with a higher rate of nonindicated CT examinations. The CCHR had sensitivity and negative predictive value of 100% for either brain hemorrhage or fractures. CONCLUSIONS: Overuse of CT examinations for minor head injuries was demonstrated, especially in young patients, with an excess of 37.3%. Contributing factors are referring physician specialty and injury mechanism. Analysis of overuse causes can be implemented for education programs and for computerized referring protocols.

Magnetic resonance enterography versus capsule endoscopy activity indices for quantification of small bowel inflammation in Crohn's disease.

BACKGROUND: Video capsule endoscopy (VCE) and magnetic resonance enterography (MRE) are the prime modalities for the evaluation of small bowel (SB) Crohn's disease (CD). Mucosal inflammation on VCE is quantified using the Lewis score (LS). Diffusion-weighted (DW) magnetic resonance imaging (MRI) allows for accurate assessment of SB inflammation without administration of intravenous contrast material. The Magnetic Resonance Index of Activity (MaRiA) and the Clermont index are quantitative activity indices validated for contrast-enhanced MRE and DW-MRE, respectively. The aim of this study was to compare the quantification of distal SB inflammation by VCE and MR-related activity indices. METHODS: Patients with known quiescent SB CD were prospectively recruited and underwent MRE and VCE. LS, MaRIA and Clermont scores were calculated for the distal SB. RESULTS: Both MRI-based indices significantly correlated with the LS and the Clermont index (r = 0.50, p = 0.001 and r = 0.53, p = 0.001, respectively). Both MaRIA and Clermont scores were significantly lower in patients with mucosal healing (LS < 135). The area under the curve (AUC) with both MR scores was moderate for prediction of any mucosal inflammation (LS ⩾ 135) and excellent for prediction of moderate-to-severe inflammation (LS ⩾ 790) (0.71 and 0.74 versus 0.93 and 0.91 for MaRIA and Clermont score, respectively). CONCLUSIONS: Modest correlation between VCE- and MRE-based quantitative indices of inflammation in patients with quiescent SB CD was observed. Between-modality correlation was higher in patients with endoscopically severe disease. DW-MRE gauged by Clermont score was at least as accurate as contrast-enhanced MRE for quantification of SB inflammation.