The cost of screening esophageal varices: traditional endoscopy versus computed tomography.

OBJECTIVE: Under current guidelines, patients diagnosed with cirrhosis are to undergo initial and continued screening endoscopy for esophageal varices throughout the course of disease. Recent literature suggests that computed tomography (CT) of the abdomen is adequately sensitive for detecting grade 3 varices, those in need of immediate intervention. This study presents a cost comparison of traditional endoscopy versus CT of the abdomen. METHODS: Using TreeAge Pro software, a budget impact cost model was created for a hypothetical managed care organization covering 1 million lives over a 10-year period. Incidence figures for cirrhosis and the progression of esophageal varices were applied to the patient population. National Medicare reimbursement costs were used to compare screening with traditional endoscopy versus CT. Costs utilizing screening with combined endoscopy and CT were also examined. RESULTS: The results of comparing screening paradigms under a budget impact cost model results in an outcome measure termed "per-member, per-month" (PMPM) cost of implementing a new strategy. Computed tomography was the least expensive modality with an average 10-year cost per screened patient of $1097.30 and PMPM of $0.03. Endoscopy was the most expensive modality with an average 10-year cost per screened patient of $1464.89 and PMPM of $0.04. CONCLUSION: Computed tomography has been shown to be sensitive in detecting esophageal varices and now less costly to implement in screening. The cost of esophageal rupture in endoscopy and the less costly risk of contrast reaction as well as radiation exposure in CT of the abdomen should be considered when developing a screening paradigm.

High resolution magnetic susceptibility mapping of the substantia nigra in Parkinson's disease.

PURPOSE: To determine if tissue magnetic susceptibility is a more direct marker of tissue iron content than other MR markers of iron. This study presents the first quantitative, in vivo measurements of the susceptibility of the substantia nigra in patients with Parkinson's disease. MATERIALS AND METHODS: Nine patients and 11 controls were studied at 7 Tesla. Susceptibility maps were created by inverting the filtered phase maps associated with T2* weighted images. RESULTS: On average, patients showed an increase in susceptibility of the pars compacta compared with controls, which correlates with the predicted increase in brain iron in Parkinson's disease. A rostral-caudal gradient in susceptibility was also observed in controls and patients. CONCLUSION: Susceptibility mapping may provide a new tool for studying the development of Parkinson's disease.

Structural properties of the corticospinal tract in the human brain: a magnetic resonance imaging study at 7 Tesla.

Several fibre tracts can be accurately located using conventional Magnetic Resonance Images (MRI) of the human brain, including the corticospinal tract (CST), which appears as a T (1)-weighted hypointense/T (2)-weighted hyperintense patch in the posterior part of the posterior-limb of the internal capsule (PLIC). Here we use high-field MRI (7T) to assess the quantitative MRI properties of the CST at the PLIC level in 22 healthy young male participants. We used three different imaging modalities: the T (1) and T (2) relaxation times (T (1) and T (2)) and the Magnetization Transfer Ratio (MTR). These measurements obtained in the CST were compared with those in the anterior two-thirds of the PLIC. We observed longer T (1) and T (2) and lower MTR in the CST region compared with the adjacent (control) PLIC region. This effect is consistent with the presence of sparsely distributed, large-diameter fibres described in previous histological studies and, as such, might reflect lower myelin density and/or different morphology of fibres in the CST.