We compute explicitly the bialgebra cohomology of the duals of the generalized Taft algebras, which are noncommutative, noncocommutative finite-dimensional Hopf algebras. In order to do this, we use an identification of this cohomology with an Ext algebra (Taillefer, 2004a) and a result describing the Drinfeld double of the dual of a generalized Taft algebra up to Morita equivalence (Erdmann et al., 2006).

We investigate the Drinfeld doubles D(Λn,d) of a certain family of Hopf algebras. We determine their simple modules and their indecomposable projective modules, and we obtain a presentation by quiver and relations of these Drinfeld doubles, from which we deduce properties of their representations, including the Auslander–Reiten quivers of the D(Λn,d). We then determine decompositions of the tensor products of most of the representations described, and in particular give a complete description of the tensor product of two simple modules. This study also leads to explicit examples of Hopf bimodules over the original Hopf algebras.

Objective: The aim of this multicenter study was to evaluate the diagnostic performance of a hybrid SPECT/CT attenuation correction system for the detection of angiographic coronary artery disease (CAD).

A radionuclide technique was developed to obtain reproducible measurements of cerebrospinal fluid flow in Rickham-Holter type shunt systems. In attempting to reproduce previously described radionuclide procedures, we found that different flow rate measurements can be obtained simply by chaning the radiotracer injection technique or the method of analysis of the time activity curves which are generated. The importance of these technical pitfalls cannot be over-emphasized, since there is no gold standard to evaluate cerebrospinal fluid flow in vivo. An experimental model with a calibrated Harvard pump and a shunt system filled with normal saline was constructed. Aliquots of 500 μCi of pertechnetate in 0.05 ml of saline were injected serially into the center of the Rickham reservoir using a size 28 needle. Time-activity curves were obtained after waiting five min to reach equilibrium, and standard curves of radiotracer clearance vs actual flow for each system used clinically in our institution were generated. In addition, a technique to quantify and thus correct for the small but significant leak of radiotracer which occurs at the site of injection in the reservoir is described. Excellent correlation was obtained between our results and the clinical and radiological findings in a preliminary clinical evaluation.

Objective: To assess the distribution of ischemia and infarct observed across a heterogeneous population of patients enrolled in a study of utilization and outcomes after PS SPECT Imaging. Methods Patients from 8 countries were enrolled, clinically assessed and assigned to an ACC / AHA Pretest Likelihood (LK) for CAD cohort, or the Known CAD cohort. Patients completed a PS-SPECT or Low-Level exercise PS (LEPS) SPECT MPI study. Site investigators assigned summed stress (SSS) rest (SRS), and difference scores (SDS), using the 17-segment (0–4 perfusion scale) model. SPECT MPI studies were classified as Normal (SDS < 2 and SSS < 3), Abn-No Ischemia (SDS < 2 and SSS ≥3: i.e., fixed defect only), or Abn-Ischemia (SDS ≥2 and SSS ≥3: i.e., any reversible defect). 5174 patients were enrolled (89 centers) and 4855 (94%) had imaging results scored.

PURPOSE:To evaluate the accuracy of scintimammography as an adjunct to physical examination and mammography in the detection of breast cancer in women with dense and fatty breasts.MATERIALS AND METHODS:A total of 558 women were prospectively enrolled from 42 centers in North America. Images were interpreted by readers blinded to the subjects' clinical history, mammographic findings, and other test results. The Breast Imaging Reporting and Data System classification was used to describe breast density. Parenchymal patterns of "heterogeneously dense" and "extremely dense" were used to classify breasts as dense, whereas "almost entirely fat" and "numerous vague densities" defined fatty breasts. Between-group differences were evaluated with the 2 test for categorical variables and Student t test for continuous variables. Accuracy of scintimammography was assessed against the core laboratory histopathologic evaluation, the standard. The 95% CIs around point estimates of sensitivity, specificity, and positive and negative predictive values were calculated with the normal approximation to the binomial distribution.RESULTS:The analyses were based on 580 breasts with an abnormality; 276 (48%) breasts were dense and 228 had a malignant lesion. Diagnostic properties for scintimammography of fatty versus dense breasts were, respectively, sensitivity, 72% versus 70%; specificity, 80% versus 78%; positive predictive value, 72% versus 67%; negative predictive value, 81% versus 81%; and accuracy, 77% versus 75% (all not significant). Scintimammography led to similar and significant changes in the posttest likelihood of cancer for both dense and fatty breasts.CONCLUSION:The diagnostic accuracy of scintimammography is not affected by breast density.

Controversy persists in the surgical approach to treat esophageal achalasia. This investigation reports the long-term effects of esophageal myotomy and partial fundoplication in treating this disorder. From 1984 to 1998, 32 patients with achalasia underwent myotomy and partial fundoplication (Belsey Mark IV) using a left thoracotomy. The median follow up is 7.2 years. Assessments include clinical evaluation, esophagogram, radionuclide transit, manometry, 24-h pH, and endoscopy. There is no complication and no mortality. Preoperative assessment was compared with that in 0-3, 3-7, and 7-16 postoperative years. Clinically, the prevalence of dysphagia was decreased from 100% to 6%, 12%, and 13%, respectively (P < 0.001). Heartburn remains unchanged (P > 0.25). On radiology, the prevalence of barium stasis was decreased from 97% to 44%, 48%, and 47%, respectively (P=0.001), whereas a pseudo-diverticulum was observed in two-thirds of patients after operation (P=0.001). Percent radionuclide stasis at 2 min was measured as 70%, 17%, 20%, and 20%, respectively (P=0.001). Manometrically, lower esophageal sphincter (LES) gradient was decreased from 29 to 10, 9, and 9 mmHg, respectively (P=0.001). LES relaxation was improved from 41% preoperatively to 100% postoperatively at each postoperative period (P < 0.001). An abnormal acid exposure was observed in four patients after the operation. Endoscopy documented mucosal damage in three patients (P > 0.25). In conclusion, on long-term follow up, myotomy and partial fundoplication for achalasia relieve obstructive symptoms and improve esophageal emptying, and reduce LES gradient and improve LES relaxation. Acid reflux is recorded in 13% of patients and esophageal mucosal damage is identified in 11% of the patient population. A longer myotomy not covered by the fundoplication results in pseudodiverticulum formation and increased esophageal retention.

Venous thrombosis and pulmonary embolism are major clinical problems that result in significant morbidity and mortality. It is estimated that 600,000 cases of pulmonary embolism occur each year in the United States, resulting in the death of approximately 100,000 patients. Most of these pulmonary emboli arise from deep venous thrombosis (DVT). The clinical diagnosis of DVT is unreliable. Only a third of patients with a clinical suspicion of DVT have objective evidence of the disease, and half of patients with proven DVT do not have any clinical symptoms. Although ascending contrast venography is the present standard for the diagnosis of DVT, duplex ultrasonography, which is increasingly used in combination with color Doppler flow imaging, is accepted as a useful clinical afternative to contrast venography. Both contrast venography and ultrasonography are imaging procedures that detect changes in venous anatomy that are caused by the presence of an intraluminal thrombus that is sufficiently formed either to reduce vascular filling with contrast medium or to resist compression. However, these imaging procedures do not reflect the metabolic activity of the clot, and therefore, they may overestimate the presence of active clots. The sensitivity of ultrasonography is also limited by various disease-related and technical factors. An alternative approach to the diagnosis of acute DVT is to detect a molecular marker of acute DVT that is not present in old, organized DVT. Recent advances in biotechnology permit the use of highly specific synthetic peptide or small molecular markers, which are involved in the acute stages of DVT formation and can be labeled efficiently with 99mTc. 99mTc-apcitide, a glycoprotein (GP IIb/IIIa) receptor antagonist previously known as 99mTc-P280, has been approved recently by the Food and Drug Administration for the clinical detection of acute DVT. Two other agents are currently under clinical investigation: 99mTc-DMP 444, which is another GP IIb/IIIa receptor antagonist, and 99mTc-Fibrin-Binding Domain (FBD), a radio-labeled fibrin-binding domain of fibronectin. Different clinical studies have shown a high diagnostic accuracy with these synthetic 99mTc-labeled peptides in the detection of acute DVT. Although further studies are needed to fully appreciate all of the diagnostic potential of these radiopharmaceuticals, the clinical introduction of 99mTcapcitide scintigraphy will certainly be helpful in expanding the use of nuclear medicine in a specific field in which it used to play a relatively marginal role.