Purpose: To retrospectively determine the additional value of diffusion-weighted magnetic resonance imaging (MRI) to T2-weighted imaging in the evaluation of anal fistulae in comparison with gadolinium (Gd)-enhanced imaging. Materials and Methods: Thirteen patients (mean age, 35.2 years) with 20 anal fistulae were included. The protocol consisted of fat-suppressed T2-weighted fast spin-echo, diffusion-weighted single-shot echo-planar (b factors 0 and 800 s/mm²), and fat-suppressed Gd-enhanced T1-weighted gradient echo sequences. Two radiologists evaluated images in consensus. Results: Eighteen (90%) fistulae were detected on T2-weighted images, and 19 (95%) and 19 (95%) were detected on diffusion-weighted and T2-weighted images combined and on Gd-enhanced and T2-weighted images combined, respectively. There was no statistically significant difference in sensitivity of the techniques (P > 0.5 for all comparison pairs). Confidence scores with diffusion-weighted and T2-weighted images combined or those with Gd-enhanced and T2-weighted images combined were significantly greater than those with T2-weighted images alone (P = 0.0047 and 0.014, respectively). Conclusion: Diffusion-weighted MRI of anal fistulae is a useful sequence and can be a helpful adjunct to T2-weighted imaging, especially in patients with risk factors for contrast agents. J. Magn. Reson. Imaging 2009;30:1021–1026.

A three-dimensional T2-weighted turbo spin-echo MR sequence offers certain advantages over a two-dimensional sequence, and it has the potential to improve the performance of MR imaging for the evaluation of uterine carcinoma. PurposeTo compare a three-dimensional (3D) T2-weighted turbo spin-echo (TSE) magnetic resonance (MR) sequence (VISTA; Philips Medical Systems, Best, the Netherlands) with a two-dimensional (2D) T2-weighted TSE sequence in terms of image quality, signal intensity (SI) difference ratios, conspicuity, and staging of uterine tumors.Materials and MethodsThis retrospective study was approved by the institutional review board, and informed consent was waived. Sixty-one women (mean age, 53.0 years ± 13.7 [standard deviation]; range, 30–87 years) with cervical carcinoma (n = 28), endometrial carcinoma (n = 21), or leiomyoma (n = 30) of the uterus were included. Patients underwent T2-weighted MR imaging at 3 T with both 1-mm-thick 3D and 5-mm-thick 2D T2-weighted TSE sequences. Three-dimensional T2-weighted TSE images were reconstructed at 5-mm thickness with the aid of a workstation. Quantitative analyses of signal-to-noise ratio (SNR) and SI difference ratios between tumors and other tissues and qualitative analy...

Purpose: To prospectively evaluate the efficacy of 3.0-T magnetic resonance (MR) imaging in the preoperative staging of cervical carcinoma compared with that at 1.5-T imaging, with surgery and pathologic analysis as the reference standards. Materials and Methods: Institutional review board approval and informed consent were obtained. Thirty-one consecutive patients (age range, 27–71 years; mean age, 51.1 years) underwent 3.0- and 1.5-T MR imaging. Quantitative and qualitative analyses were performed. Two radiologists independently evaluated images in terms of local-regional staging. MR findings were compared with surgicopathologic findings. Results: Mean tumor signal-to-noise ratios, mean cervical stroma signal-to-noise ratios, and mean tumor-to–cervical stroma contrast-to-noise ratios at 3.0-T imaging were significantly higher than those at 1.5-T imaging (P = 9.1 × 10−6, P = 1.8 × 10−6, and P = .008, respectively). Image homogeneity at 3.0-T imaging was significantly inferior to that at 1.5-T imaging (P ...

The purpose of this study was to evaluate the relationship between the slice thickness and the calculated volume in computed tomography (CT) liver volumetry through the comparison of the results from images [including 3-dimensional (3D) images] with various slice thicknesses. Twenty potential adult liver donors (12 men and 8 women) with a mean age of 39 years (range = 24-64 years) underwent CT with a 64-section multidetector row CT scanner after the intravenous injection of a contrast material. Four image sets with slice thicknesses of 0.625, 2.5, 5, and 10 mm were used. First, a program developed in our laboratory for automated liver extraction was applied to the CT images, and the liver boundaries were determined automatically. Then, an abdominal radiologist reviewed all images onto which automatically extracted boundaries had been superimposed and then edited the boundaries on each slice to enhance the accuracy. The liver volumes were determined via the counting of the voxels within the liver boundaries. The mean whole liver volumes estimated with CT were 1322.5 cm³ from 0.625-mm images, 1313.3 cm³ from 2.5-mm images, 1310.3 cm³ from 5-mm images, and 1268.2 cm³ from 10-mm images. The volumes calculated from 3D (0.625-mm) images were significantly larger than the volumes calculated from thicker images (P < 0.001). The partial liver volumes of right lobes, left lobes, and lateral segments were evaluated in a similar manner. The estimated maximum difference in the calculated volumes of lateral segments was −10.9 cm³ (−4.63%) between 0.625- and 5-mm images. In conclusion, liver volumes calculated from 2.5-mm-thick or thicker images are significantly smaller than liver volumes calculated from 3D images. If a maximum error of 5% in the calculated graft volume will not have a significant clinical impact, 5-mm-thick images are acceptable for CT volumetry. If the impact is significant, 3D images could be essential. Liver Transpl, 2011. © 2011 AASLD.