Accuracy and repeatability of joint sparsity multi-component estimation in MR Fingerprinting.

MR fingerprinting (MRF) is a promising method for quantitative characterization of tissues. Often, voxel-wise measurements are made, assuming a single tissue-type per voxel. Alternatively, the Sparsity Promoting Iterative Joint Non-negative least squares Multi-Component MRF method (SPIJN-MRF) facilitates tissue parameter estimation for identified components as well as partial volume segmentations. The aim of this paper was to evaluate the accuracy and repeatability of the SPIJN-MRF parameter estimations and partial volume segmentations. This was done (1) through numerical simulations based on the BrainWeb phantoms and (2) using in vivo acquired MRF data from 5 subjects that were scanned on the same week-day for 8 consecutive weeks. The partial volume segmentations of the SPIJN-MRF method were compared to those obtained by two conventional methods: SPM12 and FSL. SPIJN-MRF showed higher accuracy in simulations in comparison to FSL- and SPM12-based segmentations: Fuzzy Tanimoto Coefficients (FTC) comparing these segmentations and Brainweb references were higher than 0.95 for SPIJN-MRF in all the tissues and between 0.6 and 0.7 for SPM12 and FSL in white and gray matter and between 0.5 and 0.6 in CSF. For the in vivo MRF data, the estimated relaxation times were in line with literature and minimal variation was observed. Furthermore, the coefficient of variation (CoV) for estimated tissue volumes with SPIJN-MRF were 10.5% for the myelin water, 6.0% for the white matter, 5.6% for the gray matter, 4.6% for the CSF and 1.1% for the total brain volume. CoVs for CSF and total brain volume measured on the scanned data for SPIJN-MRF were in line with those obtained with SPM12 and FSL. The CoVs for white and gray matter volumes were distinctively higher for SPIJN-MRF than those measured with SPM12 and FSL. In conclusion, the use of SPIJN-MRF provides accurate and precise tissue relaxation parameter estimations taking into account intrinsic partial volume effects. It facilitates obtaining tissue fraction maps of prevalent tissues including myelin water which can be relevant for evaluating diseases affecting the white matter.

[Mycobacteriosis caused by Mycobacterium scrofulaceum. Report of 1 case]. / Micobacteriosis por Mycobacterium scrofulaceum. Reporte de 1 caso.

The case of a 71-year-old patient who had respiratory disorders for more than 11 years is reported. Direct microscopy was negative in 4 sputum samples and finally, on five occasions, the culture gave rise to a strain biochemically labeled as Mycobacterium scrofulaceum. The case corresponded to a mycobacteriosis.

Whole-arm t(X;17) (Xp17q;Xq17p) and gonadal dysgenesis. A further exception to the critical region hypothesis.

A 19-year-old female patient with gonadal dysgenesis and a de novo t(X;17) (Xp17q;Xq17p) is described. Since the critical segment Xq13----q26 was intact, this case is a further exception to the critical region hypothesis.

Double-outlet right atrium with two atrioventricular valves and left atrial outlet atresia.

In double-outlet atrium either the right or the left atrium empties into both ventricles while the other atrium remains disconnected from the ventricular cavities. Cases of double-outlet atrium with a single atrioventricular (AV) valve have been reported but no cases of double-outlet left atrium and only two of double-outlet right atrium (one with three valves) have been reported. A description of the second case of double-outlet right atrium with two AV valves and a review of the other reported case are presented. Common anatomic characteristics were: two AV valves in the right atrium that connected with two normal ventricles; disconnection of the left atrium from the ventricular cavities; an atrial septal defect in a malpositioned atrial septum; and drainage of a left superior vena cava into the left atrium. Mitral incompetence was found in both cases. Clinical findings were similar to those seen in ostium primum atrial septal defect. Two-dimensional echocardiography and angiocardiography are able to accurately demonstrate this entity. Successful surgical correction was performed in both cases. Two morphogenetic hypotheses are proposed: abnormal development of the septum primum or primitive malposition of the common atrioventricular canal.

Subacute left ventricular free wall rupture following acute myocardial infarction: bedside hemodynamics, differential diagnosis, and treatment.

Six patients with subacute left ventricular free wall rupture (anatomically proved) following acute myocardial infarction are presented. Diagnosis of cardiac rupture in every case was suspected several hours before death or surgical intervention, when clinical and hemodynamic data of cardiac tamponade were found. In three patients right atrial pressure decreased with inspiration and in the other three cases it did not show any modification. These latter three patients had associated right ventricular infarction; the abnormal respiratory behavior could be explained by restriction produced by a noncompliant right ventricle. All six patients improved initially with medical treatment (inotropics and fluid infusion) and three of them were operated upon. One of the latter patients died on the eighteenth postoperative day of extracardiac causes and two are long-term survivors.

[Double mitral orifice with a single atrium. Apropos of a case with functionally normal mitral valve]. / Double orifice mitral avec oreillette unique. A propos d'un cas avec valve mitrale fonctionnellement normale

The authors report a case with a double mitral orifice associated with a single auricle; it was operated on successfully. It was unnecessary to carry out any surgical procedure on the mitral valve itself, as it was functioning normally. A review of the literature follows.