Cardiovascular magnetic resonance in heart transplant patients: diagnostic value of quantitative tissue markers: T2 mapping and extracellular volume fraction, for acute rejection diagnosis.

BACKGROUND: The diagnosis of acute rejection in cardiac transplant recipients requires invasive technique with endomyocardial biopsy (EMB) which has risks and limitations. Cardiovascular magnetic resonance imaging (CMR) with T2 and T1 mapping is a promising technique for characterizing myocardial tissue. The purpose of the study was to evaluate T2, T1 and extracellular volume fraction (ECV) quantification as novel tissue markers to diagnose acute rejection. METHODS: CMR was prospectively performed in 20 heart transplant patients providing 31 comparisons EMB-CMR. CMR was performed close to EMB. Images were acquired on a 1.5 Tesla scanner including T2 mapping (T2 prepared balanced steady state free precession) and T1 mapping (modified Look-Locker inversion recovery sequences: MOLLI) at basal, mid and apical level in short axis view. Global and segmental T2 and T1 values were measured before and 15 min (for T1 mapping) after contrast administration. RESULTS: Acute rejection was diagnosed in seven patients: six cellular rejections (4 grade IR, 2 grade 2R) and one antibody mediated rejection. Patients with acute rejection had significantly higher global T2 values at 3 levels: 58.5 ms [55.0-60.3] vs 51.3 ms [49.5-55.2] (p = 0.007) at basal; 55.7 ms [54.0-59.7] vs 51.8 ms [50.1-53.6] (p = 0.002) at median and 58.2 ms [54.0-63.7] vs 53.6 ms [50.8-57.4] (p = 0.026) at apical level. The area under the curve (AUC) for each level was 0.83, 0.79 and 0.78 respectively. Patients with acute rejection had significantly higher ECV at basal level: 34.2% [32.8-37.4] vs 27.4% [24.6-30.6] (p = 0.006). The AUC for basal level was 0.84. The sensitivity, specificity and diagnosis accuracy for basal T2 (cut off: 57.7 ms) were 71, 96 and 90% respectively; and for basal ECV: (cut off 32%) were 86, 85 and 85% respectively. Combining basal T2 and basal ECV allowed diagnosing all acute rejection and avoiding 63% of EMB. CONCLUSIONS: In heart transplant patients, a combined CMR approach using T2 mapping and ECV quantification provides a high diagnostic accuracy for acute rejection diagnosis and could potentially decrease the number of routine EMB.

[Acute pancreatitis related to hemobilia complicating hepatocarcinoma]. / Pancréatite aiguë liée à une hémobilie compliquant un carcinome hépatocellulaire.

Hemobilia is an rare cause of acute pancreatitis. The most frequent causes are iatrogenic trauma (percutaneous liver biopsy) and hepatic artery aneurysm. To our knowledge, this is the second published case of acute pancreatitis related to hemobilia secondary to hepatocarcinoma complicated cirrhosis in a patient treated with anticoagulants for a mechanical valvular aortic prosthesis. The clinical picture included acute epigastric pain, fever and jaundice. Increased amylase and lipase serum activities, and abdominal CT data confirmed the diagnosis of acute pancreatitis. Gallstone induced acute pancreatitis was suspected and thus, a cholecystectomy was performed. No bile duct stones were found but a clot was extracted from the extrahepatic bile duct during surgery. Arterial embolization was then performed and repeated 1 and 3 months later for recurrence. The patient was asymptomatic eight months later. Hepatic arterial embolization is an effective haemostatic treatment for hemobilia, even though, in this case treatment had to be repeated because of an anticoagulant therapy.

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.