Reducing data size and radiation dose for CT colonography.

CT colonography at different radiation dose levels: feasibility of dose reduction.

PURPOSE To investigate the sensitivity and specificity of polyp detection and the image quality of computed tomographic (CT) colonography at different radiation dose levels and to study effective doses reported in literature on CT colonography. MATERIALS AND METHODS CT colonography and colonoscopy were performed with 100 mAs in 50 consecutive patients at high risk for colorectal cancer; 50- a...

Reducing the oral contrast dose in CT colonography: evaluation of faecal tagging quality and patient acceptance.

AIM To evaluate the minimal iodine contrast medium load necessary for an optimal computed tomography colonography tagging quality. MATERIALS AND METHODS Faecal occult blood test positive patients were randomly selected for one of three iodine bowel preparations: (1) 3 × 50 ml meglumine ioxithalamate (45 g iodine), (2) 4 × 25 ml meglumine ioxithalamate (30 g iodine); or (3) 3 × 25 ml (22.5 g i...

Size specific dose estimate (SSDE) for estimating patient dose from CT used in myocardial perfusion SPECT/CT

Objective(s): Size specific dose estimate (SSDE) is a new parameter that includes patient size factor in its calculation. Recent studies have produced mixed results on the utility of SSDE, especially when automatic exposure control (AEC) was used. The objective of the study was to find out if there is a relationship between patient size and each of the parameters, SSDE...

CT Colonography Atlas For

Segmentation and Size Measurement of Polyps in CT Colonography

Virtual colonoscopy is a relatively new method for the detection of colonic polyps. Their size, which is measured from reformatted CT images, mainly determines diagnosis. We present an automatic method for measuring the polyp size. The method is based on a robust segmentation method that grows a surface patch over the entire polyp surface starting from a seed. Projection of the patch points alo...