An improved MR imaging technique for the visualization of myocardial infarction.

PURPOSE: To design a segmented inversion-recovery turbo fast low-angle shot (turboFLASH) magnetic resonance (MR) imaging pulse sequence for the visualization of myocardial infarction, compare this technique with other MR imaging approaches in a canine model of ischemic injury, and evaluate its utility in patients with coronary artery disease. MATERIALS AND METHODS: Six dogs and 18 patients were examined. In dogs, infarction was produced and images were acquired by using 10 different pulse sequences. In patients, the segmented turboFLASH technique was used to acquire contrast material-enhanced images 19 days +/- 7 (SD) after myocardial infarction. RESULTS: Myocardial regions of increased signal intensity were observed in all animals and patients at imaging. With the postcontrast segmented turboFLASH sequence, the signal intensity of the infarcted myocardium was 1,080% +/- 214 higher than that of the normal myocardium in dogs-nearly twice that of the next best sequence tested and approximately 10-fold greater than that in previous reports. All 18 patients with myocardial infarction demonstrated high signal intensity at imaging. On average, the signal intensity of the high-signal-intensity regions in patients was 485% +/- 43 higher than that of the normal myocardium. CONCLUSION: The segmented inversion-recovery turboFLASH sequence produced the greatest differences in regional myocardial signal intensity in animals. Application of this technique in patients with infarction substantially improved differentiation between injured and normal regions.

Delineation of normal human left ventricular twist throughout systole by tagged cine magnetic resonance imaging.

Myofibril shortening and the oblique fiber orientation of the left ventricular myocardium results in a twisting motion of the left ventricle. Advances in cardiac magnetic resonance imaging (MRI) have made it possible to label the myocardium noninvasively and track this motion (twist) through the cardiac cycle, but little data exist on its complete systolic time course. The purpose of this study was to delineate the normal human systolic time course of ventricular twist using tagged cine-MRI. Tagged cine-MRI was performed in 10 healthy subjects. The mean systolic twist angle relative to the short axis centroid for the 10 volunteers was calculated. Interstudy and intra- and interobserver variability were assessed. During isovolumic contraction, all ventricular twist was counterclockwise. Later in systole, the basal segments changed direction and rotated in a clockwise direction, whereas the apical segments continued counterclockwise rotation. The midpoint for rotation was 45+/-8% of ventricular length. The mean short axis net ventricular twist (apex-base) at 80% systole was 12.6+/-1.5 degrees. The four wall segments showed heterogeneity in twist (lateral wall, 20.6+/-1.7 degrees; anterior wall, 17.5+/-5.1 degrees; inferior wall, 8.8+/-4.9 degrees; septum, 3.5+/-2.4 degrees). The anterior and lateral walls demonstrated significantly higher twist than the other walls (p < 0.01). Torsion increased steadily throughout systole after isovolumic contraction, whereas twist displayed rate changes. The mean interstudy and intra- and interobserver differences were less than 2.1 degrees. The close similarity in twist between subjects and the low interstudy and inter/intraobserver variation indicates that twist is a robust parameter of myocardial function. Torsion varies smoothly during systole, which may play a role in minimizing oxygen consumption. These data can serve as a baseline from which to compare alterations in regional myocardial function in disease.

Efficacy and tolerability of cefprozil versus amoxicillin/clavulanate for the treatment of adults with severe sinusitis.

Cefprozil is a beta-lactamase-stable oral cephalosporin with an antimicrobial spectrum that includes gram-positive and gram-negative pathogens commonly associated with acute bacterial sinusitis, one of the most common upper respiratory tract infections among adults. We conducted a multicenter, open-label study to compare the efficacy and safety of cefprozil and amoxicillin/clavulanate in the treatment of adults with severe acute bacterial sinusitis diagnosed by clinical and radiographic criteria. A total of 278 patients entered the study, 140 (59 males, 81 females) in the cefprozil group and 138 (69 males, 69 females) in the amoxicillin/clavulanate group. Patients were randomized to 10 days of treatment with either cefprozil 500 mg BID or amoxicillin/clavulanate 500 mg/125 mg TID. Clinical severity was assessed at study entry, and patients were stratified based on symptom grade. Efficacy was evaluated using a 10-point questionnaire administered during, at the end of, and 2 weeks after completing therapy. At the end of treatment, 84.5% (71/84) of patients with severe sinusitis treated with cefprozil had a satisfactory clinical response, which was not significantly different from the 89.9% (80/89) of patients in the amoxicillin/clavulanate group who had a satisfactory clinical response. Two weeks after completing treatment, 80.8% (63/78) of cefprozil-treated patients and 81.0% (64/79) of amoxicillin/clavulanate-treated patients with severe sinusitis had a satisfactory response. Relapse was more common among amoxicillin/clavulanate patients (6/70; 8.6%) than among cefprozil patients (2/65; 3.1%), but the difference was not statistically significant. Significantly more amoxicillin/clavulanate-treated patients experienced adverse events compared with cefprozil-treated patients (P < 0.001), including diarrhea (P < 0.001), nausea (P < 0.042), and rash (P < 0.035). Three times as many amoxicillin/clavulanate patients discontinued treatment because of adverse events. Cefprozil demonstrated comparable clinical efficacy to amoxicillin/clavulanate in the treatment of adults with severe sinusitis; however, cefprozil was associated with a significantly lower incidence of diarrhea, nausea, and rash.

TAGASIST: a post-processing and analysis tools package for tagged Magnetic Resonance Imaging.

The Magnetic Resonance Imaging technique myocardial tagging allows the tracking and measurement of local parameters of heart wall motion. Tagging provides detailed information about regional cardiac function never before available with non-invasive techniques. The growth of this technique has been limited in part by the availability of post-processing tools. We introduce the TAGged cine AnalySIS Tools package (TAGASIST) for the processing of images from this technique. TAGASIST includes a graphical user interface for image segmentation, kinematic analysis, plotting of regional averages as well as multiple subjects (or patient populations) simultaneously, statistical analysis, and a database of all studies processed.

Comparative study of cephalexin hydrochloride and cephalexin monohydrate in the treatment of skin and soft tissue infections.

In two prospective, randomized multicenter double-blind studies with a dosage of either 250 mg given four times a day (study A) or 500 mg given two times a day (study B), the comparative efficacy and safety of cephalexin hydrochloride (LY061188; Keftab) and cephalexin monohydrate (Keflex) for treatment of skin and soft tissue infections were determined. In study A, 97 patients received cephalexin hydrochloride and 101 patients received cephalexin monohydrate. In study B, 75 patients received cephalexin hydrochloride and 70 patients received cephalexin monohydrate. Diagnoses included abscesses, cellulitis, wound infections, and infected dermatitis, and were comparable in the different treatment groups. Pathogens were isolated from 82% of patients enrolled; the majority of isolates were of Staphylococcus aureus, Streptococcus pyogenes, other staphylococcal species, and a few gram-negative bacteria. In study A, 68 of 71 (95.7%) evaluable patients who received cephalexin hydrochloride responded satisfactorily; 73 of 81 (90%) patients who received cephalexin monohydrate also responded satisfactorily. In study B, 56 of 58 (96.5%) evaluable patients who received cephalexin hydrochloride responded satisfactorily; 47 of 50 (94%) patients who received cephalexin monohydrate also responded satisfactorily. An adverse clinical event leading to discontinuation of the treatment drug developed in 17 of 343 (4.95%) patients in both studies. No differences were noted between the two drugs. Skin eruptions, pruritus, and mild gastrointestinal symptoms were the common adverse effects. These data suggest that cephalexin hydrochloride, a new formulation of cephalexin, is a safe and effective antimicrobial agent for treatment of a variety of skin and subcutaneous infections in a dosage of either 250 mg four times a day or 500 mg twice a day.