Concerns have been raised over alleged overuse of CT scanning and inappropriate selection of scanning methods, all of which expose patients to unnecessary radiation. Thus, it is important to identify clinical situations in which techniques with lower radiation dose such as plain radiography or no radiation such as MRI and occasionally ultrasonography can be chosen over CT scanning. This article proposes the arguments for radiation dose reduction in CT scanning of the chest and discusses recommended practices and studies that address means of reducing radiation exposure associated with CT scanning of the chest.
Human ; *Practice Guidelines ; Radiation Dosage ; Thorax ; Tomography, X-Ray Computed/*adverse effects/*methods

This review article comprehensively discusses multidetector CT urography protocols and their role in imaging of the urinary tract in patients with hematuria.
Hematuria/etiology/*radiography ; Human ; Incidental Findings ; Sensitivity and Specificity ; Tomography, X-Ray Computed/*methods/standards ; Urinary Tract/abnormalities ; Urography/methods/standards ; Urologic Diseases/complications/congenital/radiography

No abstract available.
Gallstones ; Ileus

OBJECTIVE: We evaluated the association between patients' weight and abdominal cross-sectional dimensions and CT image quality. MATERIALS AND METHODS: We prospectively evaluated 39 cancer patients aged more than 65 years with multislice CT scan of abdomen. All patients underwent equilibrium phase contrast-enhanced abdominal CT with 4 slices (from top of the right kidney) obtained at standard tube current (240 280 mA). All other scanning parameters were held constant. Patients' weight was measured just prior to the study. Cross-sectional abdominal dimensions such as circumference, area, average anterior abdominal wall fat thickness and, anteroposterior and transverse diameters were measured in all patients. Two subspecialty radiologists reviewed randomized images for overall image quality of abdominal structures using 5-point scale. Non-parametric correlation analysis was performed to determine the association of image quality with patients' weight and cross-sectional abdominal dimensions. RESULTS: A statistically significant negative linear correlation of 0.46, 0.47, 0.47, 0.58, 0.56, 0.54, and 0.56 between patient weight, anterior abdominal fat thickness, anteroposterior and transverse diameter, circumference, cross-sectional area and image quality at standard scanning parameters was found (p< 0.01). CONCLUSION: There is a significant association between image quality, patients' weight and cross-sectional abdominal dimensions. Maximum transverse diameter of the abdomen has the strongest association with subjective image quality.
Aged ; Aged, 80 and over ; Body Weight/*physiology ; Body Weights and Measures/*statistics & numerical data ; Contrast Media/administration & dosage ; Female ; Human ; Male ; Observer Variation ; Prospective Studies ; Radiation Dosage ; Radiography, Abdominal/*methods ; Statistics, Nonparametric ; Tomography, X-Ray Computed/*methods

Enhanced z-axis coverage with thin overlapping slices in breath-hold acquisitions with multidetector CT (MDCT) has considerably enhanced the quality of multiplanar 3D reconstruction. This pictorial essay describes the improvements in 3D reconstruction and technical aspects of 3D reconstruction and rendering techniques available for abdominal imaging. Clinical applications of 3D imaging in abdomen including liver, pancreaticobiliary system, urinary and gastrointestinal tracts and imaging before and after transplantation are discussed. In addition, this article briefly discusses the disadvantages of thin-slice acquisitions including increasing numbers of transverse images, which must be reviewed by the radiologist.
Adult ; Aged ; Biliary Tract/radiography ; Female ; Gastrointestinal Tract/radiography ; Human ; Image Processing, Computer-Assisted/*methods ; Imaging, Three-Dimensional ; Liver/radiography ; Liver Transplantation/radiography ; Male ; Middle Aged ; Pancreas/radiography ; Radiography, Abdominal/*methods ; Tomography, X-Ray Computed/*methods ; Urography/methods

BACKGROUND/AIMS: Many patients with functional gastrointestinal disorders (FGIDs) rank sensations of bloating and distension among their most debilitating symptoms. Previous studies that have examined intestinal gas volume (IGV) in patients with FGIDs have employed a variety of invasive and imaging techniques. These studies are limited by small numbers and have shown conflicting results. The aim of our study was to estimate, using CT of the abdomen and pelvis (CTAP), IGV in patients attending FGID clinic and to compare IGV in patients with and without FGID. METHODS: All CTAP (n = 312) performed on patients (n = 207) attending a specialized FGID clinic over 10-year period were included in this study. Patients were classified into one of 3 groups according to the established clinical grading system, as organic gastrointestinal disorder (OGID, ie, patients with an organic non-functional disorder, n = 84), FGID (n = 36) or organic and functional gastrointestinal disorder (OFGID, ie, patients with an organic and a functional disorder, n = 87). Two independent readers blinded to the diagnostic group calculated IGV using threshold based 3D region growing with OsiriX. RESULTS: Median IGVs for the FGID, OGID, and OFGID groups were 197.6, 220.6 and 155.0 mL, respectively. Stepwise linear regression revealed age at study, gender, and calculated body mass index to predict the log IGV with an r2 of 0.116, and P < 0.001. There was a significant positive correlation between age and IGV in OGID (Spearman's = 0.253, P = 0.02) but this correlation was non-significant in the other groups. CONCLUSIONS: Although bloating is a classic symptom in FGID patients, IGV may not be increased compared with OGID and OFGID patients.
Abdomen ; Body Mass Index ; Gastrointestinal Diseases ; Humans ; Irritable Bowel Syndrome ; Linear Models ; Pelvis ; Sensation ; Tomography, X-Ray Computed

PURPOSE: Surgical resection for gastric adenocarcinoma is associated with significant post-operative morbidity and mortality. The aim of this study was to assess the prognostic significance of sarcopenia in patients undergoing resection for gastric adenocarcinoma with respect to post-operative morbidity and survival. MATERIALS AND METHODS: A retrospective analysis was conducted on a cohort of consecutive patients who underwent surgical resection for gastric adenocarcinoma between 2008 and 2014. Patient demographics, radiological parameters, and pathological data were collected. OsiriX software (Pixmeo) was used to measure skeletal muscle area, which was normalized for height to calculate skeletal muscle index. RESULTS: A total of 56 patients (41 male, 15 female; mean age, 68.4 ± 11.9 years) met the inclusion criteria. Of these, 36% (20 of 56) of the patients were sarcopenic pre-operatively. Both sarcopenic and non-sarcopenic patient groups were equally matched with the exception of weight and body mass index (P=0.036 and 0.001, respectively). Sarcopenia was associated with a decreased overall survival (log-rank P=0.003) and was an adverse prognostic predictor of overall survival in multivariate analysis (hazard ratio, 10.915; P=0.001). Sarcopenia was a predictor of serious in-hospital complications in multivariate analysis (odds ratio, 3.508; P=0.042). CONCLUSIONS: In patients undergoing curative resection for gastric cancer, there was a statistically significant association between sarcopenia and both decreased overall survival and serious post-operative complications. The measurement and reporting of skeletal muscle index on pre-operative computed tomography should be considered.
Adenocarcinoma ; Body Mass Index ; Cohort Studies ; Demography ; Female ; Humans ; Male ; Mortality* ; Multivariate Analysis ; Muscle, Skeletal ; Prognosis ; Retrospective Studies ; Sarcopenia* ; Stomach Neoplasms* ; Tomography, X-Ray Computed