Current opinions on medical radiation: a survey of oncologists regarding radiation exposure and dose reduction in oncology patients.

Purpose: The aim of this study was to evaluate oncologists' opinions about the use of ionizing radiation in medical imaging of oncology patients.

Methods: An electronic survey was e-mailed to 2,725 oncologists at the top 50 National Cancer Institute-funded cancer centers. The survey focused on opinions on CT dose reduction in oncology patients and current philosophies behind long-term imaging in these patients.

Obesity triples the radiation dose of stone protocol computerized tomography.

Purpose: Patients with recurrent nephrolithiasis are often evaluated and followed with computerized tomography. Obesity is a risk factor for nephrolithiasis. We evaluated the radiation dose of computerized tomography in obese and nonobese adults.

Characterization of adrenal nodules with dual-energy CT: can virtual unenhanced attenuation values replace true unenhanced attenuation values?

Objective: The purpose of our study was to investigate whether virtual unenhanced adrenal nodule attenuation values can replace true noncontrast attenuation values.

Materials And Methods: Twenty-three incidentally discovered adrenal nodules (19 adenomas and four metastases) were identified in 19 patients (11 men and eight women; mean age, 65 years; age range, 38-84 years) who underwent unenhanced single-energy CT followed by contrast-enhanced dual-energy CT on the same scanner. A virtual unenhanced imaging dataset was generated from each dual-energy CT dataset.

Histogram analysis of small solid renal masses: differentiating minimal fat angiomyolipoma from renal cell carcinoma.

Objective: The objective of our study was to retrospectively determine whether minimal fat renal angiomyolipoma can be differentiated from clear cell or papillary renal cell carcinoma (RCC) in small renal masses using attenuation measurement histogram analysis on unenhanced CT.

Materials And Methods: Twenty minimal fat renal angiomyolipomas were compared with 22 clear cell RCCs and 23 papillary RCCs using an institutional database. All masses were histologically confirmed and all minimal fat renal angiomyolipomas lacked radiographic evidence of macroscopic fat.

Can the localization of primary colonic tumors be improved by staging CT without specific bowel preparation compared to optical colonoscopy?

Objectives: To investigate the ability of staging computed tomography (CT) without bowel preparation to accurately localize colonic tumors compared to optical colonoscopy.

Methods: The local institutional review board approved this retrospective and HIPAA-compliant study. Forty-six patients with colonic adenocarcinoma, preoperative colonoscopy, and staging CT within 60 days of resection were included.

Rate of contrast material extravasations and allergic-like reactions: effect of extrinsic warming of low-osmolality iodinated CT contrast material to 37 degrees C.

Purpose: To retrospectively determine whether extrinsic warming of the low-osmolality contrast material iopamidol to 37°C prior to intravenous administration at computed tomography (CT) affects extravasation and allergic-like reaction rates.

Materials And Methods: The need to obtain informed patient consent was waived for this HIPAA-compliant and institutional review board-approved analysis. All adverse events related to the intravenous administration of iopamidol during CT examinations occurring 200 days before (period 1) and 200 days after (period 2) the cessation of extrinsic contrast material warming (37°C) for intravenous injections of less than 6 mL/sec at Duke University Medical Center (Durham, NC) were retrospectively reviewed.

Diagnosis of renal angiomyolipoma with hounsfield unit thresholds: effect of size of region of interest and nephrographic phase imaging.

Purpose: To retrospectively determine the optimal Hounsfield unit threshold and region of interest (ROI) size required to accurately diagnose renal angiomyolipoma (AML) and differentiate it from renal cell carcinoma (RCC).

Materials And Methods: This retrospective study was institutional review board approved and HIPAA compliant, and the requirement for written informed patient consent was waived. The radiologic reports on 4502 dual-phase abdominal computed tomography (CT) examinations (nonenhanced and nephrographic phases, 5-mm collimation, 120-140 kVp, variable milliampere-second settings) performed in 2872 patients from June 2002 through October 2007 were reviewed.

Effect of organ enhancement and habitus on estimation of unenhanced attenuation at contrast-enhanced dual-energy MDCT: concepts for individualized and organ-specific spectral iodine subtraction strategies.

Objective: The purpose of this study was to assess whether habitus and organ enhancement influence iodine subtraction and should be incorporated into spectral subtraction algorithms.

Subjects And Methods: This study included 171 patients. In the unenhanced phase, MDCT was performed with single-energy acquisition (120 kVp, 250 mAs) and in the parenchymal phase with dual-energy acquisitions (80 kVp, 499 mAs; 140 kVp, 126 mAs).

Detection of renal lesion enhancement with dual-energy multidetector CT.

Purpose: To determine whether dual-energy multidetector CT enables detection of renal lesion enhancement by using calculated nonenhanced images with spectral-based extraction in a non-body weight-restricted patient population.

Materials And Methods: Between January 2008 and December 2009, 139 patients were enrolled in this prospective HIPAA-compliant, institutional review board-approved study. Written informed consent was obtained from all patients.

Effect of gadolinium chelate contrast agents on diffusion weighted MR imaging of the liver, spleen, pancreas and kidney at 3 T.

Purpose: To retrospectively test the null hypotheses that the qualitative appearance of DWI and the signal intensity values in DWI and corresponding ADC values of the liver, spleen, pancreas and kidneys are identical before and after the administration of gadolinium.

Materials And Methods: Following IRB approval, DWI was acquired in 50 patients (25 male; mean age 54.9 years) prior to and after contrast administration, using single-shot echo planar imaging with b-values of 50 s/mm2 and 800 s/mm2 at 3 T.

Dual-energy multidetector CT: how does it work, what can it tell us, and when can we use it in abdominopelvic imaging?

Dual-energy CT provides information about how substances behave at different energies, the ability to generate virtual unenhanced datasets, and improved detection of iodine-containing substances on low-energy images. Knowing how a substance behaves at two different energies can provide information about tissue composition beyond that obtainable with single-energy techniques. The term K edge refers to the spike in attenuation that occurs at energy levels just greater than that of the K-shell binding because of the increased photoelectric absorption at these energy levels.

MRI of the pelvis in women: 3D versus 2D T2-weighted technique.

Objective: The purpose of this study was to compare triplanar 2D T2-weighted turbo spin-echo MR images with reformatted images from a 3D T2-weighted turbo spin-echo sequence in analogous planes with respect to acquisition time, image quality, artifacts, and lesion detection.

Materials And Methods: Forty-four consecutively enrolled women referred for pelvic MRI participated in the study. The protocol included 2D T2-weighted turbo spin-echo sequences in the axial, coronal, and sagittal planes and a single sagittal 3D T2-weighted turbo spin-echo sequence.

Percutaneous abscess drainage in patients with perforated acute appendicitis: effectiveness, safety, and prediction of outcome.

Objective: The purposes of this study were to retrospectively investigate the effectiveness and safety of CT-guided percutaneous drainage in the treatment of patients with acute appendicitis complicated by perforation and to identify CT findings and procedure-related factors predictive of clinical and procedure outcome.

Materials And Methods: From March 2005 through December 2008, 41 consecutively registered patients (24 men, 17 women; age range, 18-75 years) underwent CT-guided percutaneous drainage for the management of acute appendicitis complicated by perforation and abscess. Three board-certified radiologists independently reviewed preprocedure CT images.

Early first trimester fetal dose estimation method in a multivendor study of 16- and 64-MDCT scanners and low-dose imaging protocols.

Objective: The purpose of this study was to corroborate the relation between the estimated absorbed fetal dose derived from directly measured uterine doses early in the first trimester and the volume CT dose index (CTDI(vol)) for 16- and 64-MDCT of the maternal chest, abdomen, and pelvis.

Materials And Methods: Estimated absorbed fetal dose was measured with a metal oxide semiconductor field effect transistor (MOSFET) dosimeter placed in the expected uterine location in an anthropomorphic phantom of a woman and scanned with 16- and 64-MDCT units of one vendor and a 64-MDCT unit of another vendor. A trauma chest, abdomen, and pelvis protocol and an abdomen and pelvis protocol were used.

MDCT of acute appendicitis: value of coronal reformations.

Acute appendicitis is the most common cause of abdominal pain requiring urgent surgery in the United States. The clinical diagnosis can be difficult in patients with atypical presentations and, over the past several decades, computed tomography (CT) has been increasingly utilized to improve diagnostic accuracy. Helical CT has proven to be an excellent tool in the work-up of acute abdominal pain with a diagnostic accuracy for acute appendicitis of 93-99%.