Cardiac magnetic resonance for assessment of cardiac involvement in Takotsubo syndrome: Do we still need contrast administration?

BACKGROUND: This study evaluated the ability of T1 and T2 mapping cardiovascular magnetic resonance to assess myocardial involvement in Takotsubo syndrome (TTS). We hypothesized that non-contrast mapping techniques can be accurate and sufficient. METHODS: We prospectively analysed 30 patients with TTS and 34 controls. CMR was performed a mean 5 days after the onset of symptoms and after a mean 3 month follow-up. RESULTS: On admission, compared to controls, TTS patients had significantly higher global T2 values (59 ± 8 ms vs 51 ± 4 ms, p < 0.001), native T1 (1053 ± 75 ms vs 960 ± 61 ms, p < 0.001) and extracellular volume (ECV) fraction (29% ± 5 vs 23% ±3, p < 0.001). The sensitivity and specificity for T2 (cut off: 56 ms) were 62% and 97% respectively; for native T1: (cut off 1011 ms) were 72% and 91% respectively; and for ECV (cut off: 27%) were 72% and 97% respectively. Combining T2 and native T1 provided the best sensitivity (91.7%) with a good specificity (88.2%). No patients had late gadolinium enhancement. Segmental analysis showed that T2, native T1 and ECV values were significantly higher in regions with wall motion abnormalities (WMA) compared to normokinetic segments (62 ± 9 ms vs 55 ± 5 ms, p < 0.001; 1060 ± 65 ms vs 1025 ± 56 ms, p = 0.02; and 34% ± 5 vs 29% ± 1, p = 0.02). At follow up, native T1 and ECV values did not normalized. CONCLUSION: In TTS patients, a non-contrast mapping technique provides a high diagnostic accuracy allowing identification of acute and persistent myocardial injury. Segmental analysis showed that myocardial injury is preferably detected in segments with WMA.

Contribution of magnetic resonance imaging of the wrist and hand to forensic age assessment.

Forensic age estimation of living individuals is a controversial subject because of the imprecision of the available methods which leads to errors. Moreover, young persons are exposed to radiation, without diagnostic or therapeutic advantage. Recently, non-invasive imaging techniques such as magnetic resonance imaging (MRI) have been studied in this context. The aim of this work was to study if the analysis of wrist/hand MRI enabled determination of whether a subject was 18 years old. Two observers retrospectively analyzed metaphyseal-epiphyseal fusion of the distal epiphysis of the radius and the ulna and the base of the first metacarpus in wrist/hand MRI of living people between 9 and 25 years of age. A three-stage scoring system was applied to all epiphyses. Intra- and inter-observer variability was excellent. Staging of the distal radial epiphysis allowed the subjects to be correctly evaluated with regard to the 18-year-old threshold in more than 85 % of cases. Analysis of the radius alone was as good as the analysis of the three epiphyses together. Evaluation of the metaphyseal-epiphyseal fusion of the distal radius in wrist MRI gave good results in forensic age estimation. Wrist MRI could meet ethical expectations with regard to the link between the benefit and risk of practicing radiologic examination on individuals in this context.

Accuracy of a new method for semi-quantitative assessment of right ventricular ejection fraction by cardiovascular magnetic resonance: right ventricular fractional diameter changes.

OBJECTIVE: Longitudinal shortening is traditionally considered the predominant part of global right ventricular (RV) systolic function. Less attention has been paid to transverse contraction. The aim of this study was to evaluate RV transverse motion by cardiovascular magnetic resonance (CMR) in a large cohort of patients and to assess its relationship with RV ejection fraction (RVEF). STUDY DESIGN: We retrospectively analyzed the CMR scans of 300 patients referred to our center in 2010. RVEF was determined from short axis sequences using the volumetric method. Transverse parameters called RV fractional diameter changes were calculated after measuring RV diastolic and systolic diameters at basal and mid-level in short axis view (respectively FBDC and FMDC). We also measured the tricuspid annular plane systolic excursion (TAPSE) as a longitudinal reference. RESULTS: Our population was divided into 2 groups according to RVEF. 250 patients had a preserved RVEF (>40%) and 50 had a RV dysfunction (RVEF ≤ 40%). Transverse and longitudinal motions were significantly reduced in the group with RV dysfunction (p<.0001). After ROC analysis, areas under the curve for FBDC, FMDC and TAPSE, were respectively 0.79, 0.82 and 0.72, with the highest specificity and sensitivity respectively of 88% and 68% for FMDC (threshold at 20%) for predicting RV dysfunction. FMDC had an excellent negative predictive value of 93%. CONCLUSION: RV fractional diameter changes, especially at the mid-level, appear to be accurate for semi-quantitative assessment of RV function by CMR. A cut-off of 20% for FMDC differentiates patients with a low (EF≤40%) or a preserved RVEF.