Incidental Findings in Small Field of View Cone-beam Computed Tomography Scans.

INTRODUCTION: The use of cone-beam computed tomography (CBCT) in endodontics has increased in recent years. In clinical application of small field of view (FOV) CBCTs, these scans are not reviewed routinely by a radiologist. Studies of large FOV CBCT scans show the prevalence of incidental findings to be greater than 90%. The purpose of this study was to evaluate the prevalence of missed findings by endodontic residents as compared with a radiologist on small FOV CBCT scans. METHODS: Two hundred three small FOV CBCTs obtained for endodontic purposes were analyzed by an endodontic resident and a medical radiologist. The reported findings of each practitioner were compared to evaluate for missed incidental findings by the endodontic resident. RESULTS: The radiologist reported abnormalities in 176 of the 203 subjects (87%), with a total of 310 abnormalities reported. The endodontic resident reported abnormalities in 102 of the 203 subjects (50%), with a total of 126 abnormalities reported. The percentage of scans with any abnormality reported by the radiologist was significantly greater than the endodontic resident (P < .001). There was no significant difference between jaw locations in percentage of missed findings for the 3 most common types of finding-rarefying osteitis, sinusitis/mucosal lining thickening, and excess restorative material in the periapical area. Rarefying osteitis was missed significantly less than the other 2 types of findings (P < .001). CONCLUSIONS: A radiologist is significantly more likely to identify incidental findings in small FOV CBCT scans than an endodontic resident. Scan location had no significant association with the rate of missed findings.

Pregnancy in patients with pre-existing cardiomyopathies.

To varying extents, women with pre-existing cardiomyopathies have a limited cardiovascular reserve. The hemodynamic challenges of pregnancy, labor, and delivery pose unique risks to this group of patients, which can result in clinical decompensation with overt heart failure, arrhythmias, and rarely, maternal death. A multidisciplinary team approach and a controlled delivery are crucial to adequate management of patients with underlying heart disease. Pre-conception planning and risk assessment are essential, and proper counseling should be offered to expectant mothers with regard to both the risks that pregnancy poses and the implications for future offspring. In this article, we will review the hemodynamic stressors that pregnancy places upon women with pre-existing cardiomyopathies and risk assessment and discuss what evidence exists with regard to the management of 2 forms of cardiomyopathy during pregnancy, labor, and delivery: dilated and hypertrophic cardiomyopathy.

Evolution of ventricular myocyte electrophysiology.

The relative importance of regulatory versus structural evolution for the evolution of different biological systems is a subject of controversy. The primacy of regulatory evolution in the diversification of morphological traits has been promoted by many evolutionary developmental biologists. For physiological traits, however, the role of regulatory evolution has received less attention or has been considered to be relatively unimportant. To address this issue for electrophysiological systems, we examined the importance of regulatory and structural evolution in the evolution of the electrophysiological function of cardiac myocytes in mammals. In particular, two related phenomena were studied: the change in action potential morphology in small mammals and the scaling of action potential duration across mammalian phylogeny. In general, the functional properties of the ion channels involved in ventricular action potential repolarization were found to be relatively invariant. In contrast, there were large changes in the expression levels of multiple ion channel and transporter genes. For the Kv2.1 and Kv4.2 potassium channel genes, which are primary determinants of the action potential morphology in small mammals, the functional properties of the proximal promoter regions were found to vary in concordance with species-dependent differences in mRNA expression, suggesting that evolution of cis-regulatory elements is the primary determinant of this trait. Scaling of action potential duration was found to be a complex phenomenon, involving changes in the expression of a large number of channels and transporters. In this case, it is concluded that regulatory evolution is the predominant mechanism by which the scaling is achieved.