Bowel Preparation for CT Colonography: Blinded Comparison of Magnesium Citrate and Sodium Phosphate for Catharsis 1
Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, G3/310 CSC MC 3252, Madison, WI 53792-3252, USA. Radiology
(Impact Factor: 6.87).
01/2010; 254(1):138-44. DOI: 10.1148/radiol.09090398
To compare colonic cleansing and fluid retention of double-dose magnesium citrate with those of single-dose sodium phosphate in patients undergoing computed tomographic (CT) colonography.
This retrospective HIPAA-compliant clinical study had institutional review board approval; informed consent was waived. The study included 118 consecutive patients given single-dose sodium phosphate for bowel catharsis and 115 consecutive patients at risk for phosphate nephropathy, who were instead given double-dose magnesium citrate. The bowel preparation regimen was otherwise identical. Four-point scales were used to assess residual stool and fluid in the six colonic segments, and attenuation of residual fluid was measured. An a priori power analysis was performed, and unpaired t tests with Welch correction were used to compare the two groups on stool and fluid scores and fluid attenuation.
Both cathartic regimens offered excellent colon cleansing, with no significant difference for residual stool in any of the six segments. Stool scores of 1 or 2 (ie, no residual stool or residual stool <5 mm) were recorded in 88.6% (627 of 708) of colonic segments in the sodium phosphate group and in 88.1% (608 of 690) in the magnesium citrate group. No clinically important differences were seen in residual fluid scores in any of the six segments, with the only significant difference seen in the sigmoid colon (2.17 for sodium phosphate vs 2.44 for magnesium citrate; P< 0.01). Fluid attenuation was significantly different between magnesium citrate and sodium phosphate groups (790 HU +/- 216 vs 978 HU +/- 160; P <.001).
Both sodium phosphate and magnesium citrate provided excellent colon cleansing for CT colonography. Residual stool and fluid were similar in both groups, and fluid attenuation values were closer to optimal in the magnesium citrate group. Since bowel preparation provided by both cathartics was comparable, magnesium citrate should be considered for CT colonography, particularly in patients at risk for phosphate nephropathy.
Available from: Seung Soo Lee
- "Likewise, in the CTC group, all false-positive patients (n = 2) and patients with poor bowel preparation (n = 3) had been prepared with magnesium citrate. Magnesium citrate has a less potent cathartic effect than sodium phosphate or PEG, and a double dose of magnesium citrate (592 mL) was required to achieve the same level of colon cleansing as 45 mL of sodium phosphate in one study (35). Nevertheless, we only used a moderate amount of magnesium citrate in our patients, since it should be used with caution in patients with renal impairment, even if it is safer than sodium phosphate, which should not be used in patients with decreased renal function (15, 36-39). "
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ABSTRACT: To compare the CT colonography (CTC) and double-contrast barium enema (DCBE) for colonic evaluation in patients with renal insufficiency.
Two sequential groups of consecutive patients with renal insufficiency who had a similar risk for colorectal cancer, were examined by DCBE (n = 182; mean ± SD in age, 51 ± 6.4 years) and CTC (n = 176; 50 ± 6.7 years), respectively. CTC was performed after colon cleansing with 250-mL magnesium citrate (n = 87) or 4-L polyethylene glycol (n = 89) and fecal tagging. DCBE was performed after preparation with 250-mL magnesium citrate. Patients with colonic polyps/masses of ≥ 6 mm were subsequently recommended to undergo a colonoscopy. Diagnostic yield and positive predictive value (PPV) for colonic polyps/masses, examination quality, and examination-related serum electrolyte change were retrospectively compared between the two groups.
Both the CTC and DCBE were positive for colonic polyps/masses in 28 (16%) of 176 and 11 (6%) of 182 patients, respectively (p = 0.004). Among patients with positive findings, 17 CTC and six DCBE patients subsequently underwent a colonoscopy and yielded a PPV of 88% (15 of 17 patients) and 50% (3 of 6 patients), respectively (p = 0.089). Thirteen patients with adenomatous lesions were detected in the CTC group (adenocarcinoma [n = 1], advanced adenoma [n = 6], and non-advanced adenoma [n = 6]), as compared with two patients (each with adenocarcinoma and advanced adenoma) in the DCBE group (p = 0.003). Six (3%) of 176 CTC and 16 (9%) of 182 DCBE examinations deemed to be inadequate (p = 0.046). Electrolyte changes were similar in the two groups.
In patients with renal insufficiency, CTC has a higher diagnostic yield and a marginally higher PPV for detecting colorectal neoplasia, despite a similar diagnostic yield for adenocarcinoma, and a lower rate of inadequate examinations as compared with DCBE.
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ABSTRACT: This article proposes a solution to the problem of multi-criterion filter design. In contrast to standard method it allows one to solve problems of filter design with all sorts of limitations. To solve these large constraint problems, modifying differential evolution (DE) is used as an effective way for penalty function minimization that describes required deviation. This technique has been applied to computer filter design and some results are pretty good.
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ABSTRACT: Colorectal cancer is second only to lung cancer as the leading cause of death among North Americans of both sexes. Although screening rates for colorectal cancer in the United States have increased over the past decade, these rates (in the range of 45%-60%) are still lower than the screening rates for breast cancer (approximately 80%). Optical colonoscopy has been recognized as the preferred method for colorectal cancer screening in the United States, but computed tomography colonography has recently been gaining favor. This article compares the 2 methods with respect to both advantages and disadvantages.
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