Spontaneous resolution of prenatally diagnosed dural sinus thrombosis: a case report.

Fetal thrombosis of the dural sinus is an extremely rare congenital cerebrovascular condition that is potentially fatal. We report a case of dural sinus thrombosis diagnosed by prenatal ultrasonography and fetal magnetic resonance imaging (MRI) in the second trimester. The thrombosis showed partial resolution during pregnancy and resolved spontaneously after birth without neurological complications. This is the first report of spontaneous postnatal resolution, and may provide helpful information on the natural history and prenatal counseling of fetal thrombosis of the dural sinus.     

Balancing the bipotential gonad between alternative organ fates: a new perspective on an old problem.

The embryonic gonads give rise to one of two morphologically and functionally different organs, a testis or an ovary. Sex determination is the embryonic process that determines the developmental fate of the gonad. In mammals, sex determination is regulated by a DNA binding protein encoded on the Y chromosome, Sry, and it's downstream mediator, Sox9, which trigger testis determination in the bipotential gonad. However, evidence suggests that the extracellular signals. Fgf9 and Wnt4, are also required to establish divergent organogenesis of the gonad. In this review, we discuss how these extracellular signals interface with cell-autonomous factors to determine the fate of the mammalian gonad, and we derive a model that could provide a molecular explanation for testis determination in vertebrates where Sry is absent.     

Pullout reattachment of tibial avulsion fractures of the anterior cruciate ligament: a firm,effective suture-tying method using a tensioner

We describe a firm, effective suture-tying method using a tensioner for reattaching tibial avulsion fractures of the anterior cruciate ligament. Our simple method achieves strong, firm reattachment of the fracture. In addition, it prevents fixation loosening during suture tying effectively. Since pullout repair using nonabsorbable sutures is commonly used to fix various avulsion fractures, the tensioner helps attain strong, firm reattachment of avulsion fractures simply and effectively.     

Performance measurement of the microPET focus 120 scanner.

The microPET Focus 120 scanner is a third-generation animal PET scanner dedicated to rodent imaging. Here, we report the results of scanner performance testing. METHODS: A (68)Ge point source was used to measure energy resolution, which was determined for each crystal and averaged. Spatial resolution was measured using a (22)Na point source with a nominal size of 0.25 mm at the system center and various off-center positions. Absolute sensitivity without attenuation was determined by extrapolating the data measured using an (18)F line source and multiple layers of absorbers. Scatter fraction and counting rate performance were measured using 2 different cylindric phantoms simulating rat and mouse bodies. Sensitivity, scatter fraction, and noise equivalent counting rate (NECR) experiments were repeated under 4 different conditions (energy window, 250 approximately 750 keV or 350 approximately 650 keV; coincidence window, 6 or 10 ns). A performance phantom with hot-rod inserts of various sizes was scanned, and several animal studies were also performed. RESULTS: Energy resolution at a 511-keV photopeak was 18.3% on average. Radial, tangential, and axial resolution of images reconstructed with the Fourier rebinning (FORE) and filtered backprojection (FBP) algorithms were 1.18 (radial), 1.13 (tangential), and 1.45 mm full width at half maximum (FWHM) (axial) at center and 2.35 (radial), 1.66 (tangential), and 2.00 mm FWHM (axial) at a radial offset of 2 cm. Absolute sensitivities at transaxial and axial centers were 7.0% (250 approximately 750 keV, 10 ns), 6.7% (250 approximately 750 keV, 6 ns), 4.0% (350 approximately 650 keV, 10 ns), and 3.8% (350 approximately 650 keV, 6 ns). Scatter fractions were 15.9% (mouse phantom) and 35.0% (rat phantom) for 250 approximately 750 keV and 6 ns. Peak NECR was 869 kcps at 3,242 kBq/mL (mouse phantom) and 228 kcps at 290 kBq/mL (rat phantom) at 250 approximately 750 keV and 6 ns. Hot-rod inserts of 1.6-mm diameter were clearly identified, and animal studies illustrated the feasibility of this system for studies of whole rodents and mid-sized animal brains. CONCLUSION: The results of this independent field test showed the improved physical characteristics of the F120 scanner over the previous microPET series systems. This system will be useful for imaging studies on small rodents and brains of larger animals.     

American Society of Nuclear Cardiology review of the ACCF/ASNC appropriateness criteria for single-photon emission computed tomograph myocardial perfusion imaging (SPECT MPI)

Conclusion  The ACCF/ASNC AC for SPECT MPI provides recommendations for the appropriate use of SPECT MPI. After the publication of the AC document in 2005, the AC has been used by nuclear cardiology practices with many clinical studies evaluating the list of indications in routine clinical practice. From these data. ASNC recommends minor but important changes to the indication list, suggesting the addition of 6 new indications and the modification of the definitions for “chest pain syndrome” and “CHD high risk.”. An objective review of existing indications focused on only those indications that had significant variability among the reviewers (n=20). These indications were reviewed in the presence of existing and new evidence-based data, and ASNC recommends that the grades for 6 indications be re-evaluated. The AC for SPECT MPI will require periodic review as new evidence becomes available or as clinical practice evolves. ASNC recognizes the importance of these criteria to improve the quality of patient care, and it will continue to play a key role in assembling the information for this ongoing review. From the current summary of evidence, ASNC consensus opinions, and ASNC recommendations in this document, ASNC strongly recommends that the AC guidelines be reviewed Prepared by the American Society of Nuclear Cardiology Quality Assurance Subcommittee for Quality in Imaging Standards. Reviewed by members of the American Society of Nuclear Cardiology Quality Assurance Committee. Approved by the American Society of Nuclear Cardiology Board of Directors, September 6, 20.     

A hypertensive response to exercise is associated with transient ischemic dilation on myocardial perfusion SPECT imaging.

BACKGROUND: A hypertensive response to exercise (HRE) is associated with false-positive stress echocardiograms and myocardial perfusion single photon emission computed tomography (myocardial perfusion imaging [MPI]) defects even in the absence of coronary artery disease (CAD). Transient ischemic dilation (TID) of the left ventricle on stress MPI is a marker of severe CAD and future cardiac events. This study evaluated the association between an HRE and TID. METHODS AND RESULTS: Blinded quantitative TID assessment was performed in 125 patients who had an HRE and a summed stress score (SSS) of less than 4, as well as 125 control patients with an SSS of less than 4 and without an HRE matched for age, gender, and resting systolic blood pressure. Cardiac comorbidities, pretest Framingham risk, and exercise results were recorded. TID was defined as a stress-to-rest volume ratio of 1.22 or greater. An HRE was associated with a high prevalence of TID and significantly more TID than no HRE (25.6% vs 11.2%; odds ratio, 3.00 [95% confidence interval, 1.41-6.38]). TID was more prevalent even in subgroups with a low pretest probability CAD, including those without diabetes mellitus or angina. On conditional logistic regression analysis, an HRE was found to be independently associated with TID after consideration of other clinical and exercise MPI variables (odds ratio, 2.72 [95% confidence interval, 1.01-7.31]). CONCLUSION: An HRE is associated with a high prevalence of TID in patients without other significant perfusion defects, possibly as a result of global subendocardial ischemia induced by the HRE.