Background-CT Colonography (CTC) is a non-invasive option for colorectal cancer (CRC) screening. The accuracy of CTC as a screening tool among asymptomatic adults has not been well defined.

The purpose of this paper is to develop a method of eliminating CT image artifacts generated by objects extending outside the scan field of view, such as obese or inadequately positioned patients. CT projection data are measured only within the scan field of view and thus are abruptly discontinuous at the projection boundaries if the scanned object extends outside the scan field of view. This data discontinuity causes an artifact that consists of a bright peripheral band that obscures objects near the boundary of the scan field of view. An adaptive mathematical extrapolation scheme with low computational expense was applied to reduce the data discontinuity prior to convolution in a filtered backprojection reconstruction. Despite extended projection length, the convolution length was not increased and thus the reconstruction time was not affected. Raw projection data from ten patients whose bodies extended beyond the scan field of view were reconstructed using a conventional method and our extended reconstruction method. Limitations of the algorithm are investigated and extensions for further improvement are discussed. The images reconstructed by conventional filtered backprojection demonstrated peripheral bright-band artifacts near the boundary of the scan field of view. Images reconstructed with our technique were free of such artifacts and clearly showed the anatomy at the periphery of the scan field of view with correct attenuation values. We conclude that bright-band artifacts generated by obese patients whose bodies extend beyond the scan field of view were eliminated with our reconstruction method, which reduces boundary data discontinuity. The algorithm can be generalized to objects with inhomogeneous peripheral density and to true "Region of Interest Reconstruction" from truncated projections.

For a patient of known weight, one can calculate the iodine dose needed to provide a desired level of hepatic enhancement. Use of a contrast material with a concentration of 240 mg L/mL is not recommended for dynamic incremental hepatic CT, except in small patients (eg, those weighing less than 73 kg).

As cardiac output decreases, the times to the arrival of the contrast medium bolus in the aorta and to peak aortic and hepatic enhancement increase. Reduction in cardiac output results in a substantial increase in peak aortic enhancement but not in peak hepatic enhancement.

Use of injection rates above 2 mL/sec did not substantially increase hepatic peak enhancement but helped increase the magnitude of arterial enhancement and temporal separation of arterial and venous phases of enhancement for dual-phase spiral CT.

A computer-based, physiologic model that may help predict organ-specific CT contrast medium enhancement for different injection protocols was developed. Such a physiologic model may have many clinical applications.

Febrile morbidity is the most commonly reported adverse event after hysterectomy. Its incidence ranges from 9.1 to 37.4%. Risk factors reported in the literature include prolonged operative time, history of previous surgery, higher parity, greater blood loss, abdominal approach, and no antibiotic prophylaxis.Antibiotic prophylaxis in abdominal hysterectomy may provide protection against febrile morbidity and reduce its incidence, but does not eliminate it. Limited data are available evaluating risk factors for febrile morbidity after hysterectomy. This historical cohort study assessed the incidence of febrile morbidity and associated risk factors in 1980 Thai women, who had an abdominal hysterectomy between 1998 and 2005.Of the 1980 women, febrile morbidity occurred in 517. This represents an overall incidence of 26.1%. Univariate analysis of potential risk factors showed that the incidence of febrile morbidity was higher in patients with lower preoperative hematocrit, more extensive surgery, longer operative time, greater intraoperative blood loss and malignant disease. Median intraoperative blood loss was lower in the nonfebrile group than the febrile group (400 versus 500 ml, P Յ .0005) and median operative time was shorter (135 versus 150 minute, P Յ .0005).When both pre and postoperative variables were included in the logistic regression model, the only two risk factors independently associated with febrile morbidity were intraoperative blood loss of Ն750 ml (odds ratio [OR],1.52; 95% confidence interval [CI], 1.08-2.13; P ϭ .036) and a diagnosis of malignant disease (OR 1.86; 95% CI 1.45-2.13, P Ͻ .0005). GYNECOLOGY Volume 64, Number 1 OBSTETRICAL AND GYNECOLOGICAL SURVEY ABSTRACTAlternatives to hysterectomy such as medical treatment, uterine artery embolization (UAE), and ablative therapy have become available and widely used in the last 10 years. It is unclear if these alternatives are replacing hysterectomy or delaying it. To determine the effect of patient clinical factors on the utilization of hysterectomy and alternatives of hysterectomy, the investigators examined all claims relating to a hysterectomy procedure or a hysterectomy-associated diagnosis in the database of a large insurance provider for 48 consecutive months from 2001 to 2005. A total of 295,148 claim lines were abstracted and analyzed by CPT and diagnostic grouping codes.Of the 7049 procedures represented in the claim lines, 1972 were hysterectomies and 5077 were hysterectomy alternatives. The mean age of patients filing claims was 39.1 years. Patients submitting claims for a hysterectomy were older than those having an alternative procedure (mean age, 49.7 v 46.0 years, P Ͻ .0001). The diagnostic group associated with the majority of all claims was abnormal bleeding (33%); the inflammation/mass/pain/endometriosis group accounted for 32%. The most common diagnostic groups associated with a hysterectomy were fibroids (39.4%), the inflammation/mass/pain/endometriosis category (14.7%), and cancer (13.0%). Bleeding represented the majority o...

Fat-containing tumors of the liver are a heterogeneous group of tumors with characteristic histologic features, variable biologic profiles, and variable imaging findings. Benign liver lesions that contain fat include focal or geographic fatty change (steatosis), pseudolesions due to postoperative packing material (omentum), adenoma, focal nodular hyperplasia, lipoma, angiomyolipoma, cystic teratoma, hepatic adrenal rest tumor, pseudolipoma of the Glisson capsule, and xanthomatous lesions in Langerhans cell histiocytosis. Malignant liver lesions that can contain fat include hepatocellular carcinoma, primary and metastatic liposarcoma, and hepatic metastases. Identification of fat within a liver lesion can be critical in characterization of the lesion. The imaging characteristics of a lesion coupled with the pattern of intratumoral fatty change are helpful in narrowing the differential diagnosis. Although the presence of fat can be demonstrated with computed tomography or ultrasound, magnetic resonance imaging is the most specific imaging technique for demonstration of both microscopic and macroscopic fat.