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Biomedical subjects

A Wackenheim

Publications and source records attributed to A Wackenheim.

At least 181 records · Page 10Linked to original sources

Magnetic resonance imaging in congenital heart disease of newborns: preliminary results in 23 patients.

Until now little attention has been paid to the potential of MR imaging in congenital heart disease of the newborn. ECG-gated MRI was therefore performed at 0.5 tesla in 23 newborns (mean age 7.5 days) with suspected congenital heart disease. Two newborns were controlled after surgery (switch, Blalock-Taussig procedure). All had undergone prior evaluation by two-dimensional Doppler echocardiography (2-D DE). MR imaging was of a satisfying quality in all but one newborn. The aim of this study was to assess complementary information provided by MRI in comparison to 2-D DE. Pre-operatively MRI missed some abnormalities shown by 2-D DE: one coartaction, one ductus arteriosus and one pulmonary atresia. MRI demonstrated lesions that echocardiography had either failed to visualize or found inconclusive, including double aortic arch (one patient), muscular ventricular septum defect (two patients) and severe ductus arteriosus (one patient). In one of the two patients with a ventricular septum defect, angiography was avoided and in the other patient it merely confirmed the MRI results. Post-operatively, MRI demonstrated information complementary to that obtained from to 2-D DE: (1) clearly visualizing the reinsertion of the coronary arteries in the 'switched' transposition of the great vessels, (2) appreciating the diameter and patency of the palliative shunt in the Blalock-Taussig procedure.

Angiography↗

Spin echo MRI in the evaluation of pericardial disease.

As in other pathological processes of the heart, the contribution of MRI is not limited to optimal anatomical evaluation but also offers functional or etiological information (approach of tissue characterization). In this work we report on our experience in evaluating normal and pathological pericardium with MRI spin echo sequences. The results with 41 patients, including pericardial effusion, thickening, and mass are discussed and confronted with previously reported data. Contrary to classical echocardiographic notions, pericardial effusions are more frequently in the anterior than posterior location (26/30 vs. 19/30 p less than 0.03). Not only does MRI provide a precise and positive diagnosis, but also a rather clear distinction appears in spin echo sequences between hemopericardium with high signal intensity and other effusions with lower signal (high intensity found in 6/6 patients with hemopericardium versus only 8/24 in the remaining group; p less than 0.01). When constriction signs are present, MRI solves the difficult differential diagnosis between pericardial thickening and restrictive cardiomyopathy. In paracardiac primary or metastatic tumors pericardial involvement is clearly demonstrated. Distinction between paracardiac, respectively pericardial cyst or false aneurysm is possible. We conclude that MRI is a new imaging method, complementary to echocardiography and/or computed tomography in the evaluation of pericardial pathology especially when hemopericardium, constrictive pericarditis, or tumoral etiologies are suspected. Important technological improvements are needed to solve the problem of long acquisition time and to improve the possibilities of tissue discrimination.

Aged↗

Detection and quantification of recent myocardial infarction: diagnostic value of multiecho multislice spin echo imaging.

Thirty-four patients with documented transmural MI were studied with gated three echo, multislice MR imaging. In 12 patients MRI MI size was compared with CK release measurement, Tl-201 SPECT defect, and with Tc-99m LVEF. Infarct was visualised in 29/34 patients on 3rd echo images (18/34 on 2nd and 6/34 on 1st echo images). Mean MR infarct size (planimetered from 3rd echo images): 33.1 +/- 9% overestimated the SPECT defect (mean value of 23.8 +/- 15%). However, the overall correlation between MRI and Tl-201 sizing was significant: r = 0.82; p less than 0.001; SEE = 5.5%. The correlation with LVEF also appeared significant: r = -0.61; p less than 0.038.

Adult↗

Fetal shoulder measurements with MRI.

OBJECTIVE: We studied the ability of MRI to predict fetal shoulder width (FSW). MATERIALS AND METHODS: In 30 patients referred for MR pelvimetry, measurement of FSW was performed and compared with caliper measurements at term. We report here the feasibility of a method using axial and coronal MR images oriented to the fetal body axes. RESULTS: Shoulder width by MRI (mean = 12.76 +/- 1.42 cm) correlated significantly with postnatal orthopedic caliper measurements (mean = 12.99 +/- 1.37 cm; r = 0.955, SEE = 4.29 mm, p = 0.00001) and with birth weight (r = 0.63, p = 0.0005). Mean paired differences showed a statistically significant 2.3 +/- 4.2 mm underestimation of FSW by MRI (p = 0.01). This reasonably quick nonionizing technique seems to have the potential for evaluating shoulder dystocia and deserves further evaluation.

Female↗