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PurposeTo investigate whole-body magnetic resonance imaging in diagnosis of idiopathic inflammatory myopathy (IIM), and to guide clinical treatment.Materials and Methods Twenty-six patients clinically diagnosed IIM including 19 dermatomyositis and 7 polymyositis were analyzed retrospectively. Whole-body MRI was performed in all patients including whole-body coronal scan and axial scan of both sides of thigh. Short tau inversion recovery (STIR) sequences were used in the coronal scan and T1WI and fat-suppressed T2WI were performed in the axial scan. Ten healthy volunteers were recruited as control group. MRI findings were compared between the two groups.Results Whole body MRI showed that muscles were homogeneously low signal intensity in the control group. Imaging findings of the patients with IIM included muscle inflammation, fascitis, subcutaneous tissue edema, muscle atrophy and fatty infiltration. The most common distribution site of muscle inflammation of dermatomyositis patients was thigh (n=18), followed by gluteus (n=14), great psoas muscle (n=13), shoulder muscles (n=11), leg muscle (n=11), erector spinae (n=10) and neck muscles (n=9). Findings out of muscles included cavities in the both lungs, infarction in femurs and tibias, avascular necrosis of femoral head, adrenal mass and thyroid nodules. The most common distribution site of muscle inflammation of polymyositis was thigh (n=5), followed by gluteus (n=3), great psoas muscle (n=3), shoulder muscles (n=2), leg muscles (n=2), erector spinae (n=1) and neck muscles (n=1). Findings out of muscles included 1 case of infarction in femurs and tibias.Conclusion Whole-body MRI can not only comprehensively evaluate the activity of IIM but also detect complications such as bone infarction. It's a powerful tool for diagnosis, guiding treatment and monitoring of IIM.
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ObjectiveTo evaluate the value of MRI diffusion weighted imaging in localization of prostate cancer with whole-mount step section pathology.MethodsWe treated 36 patients using laparoscopic radical prostatectomy from Oct. 2009 to Jun. 2010. Patients who did not have an MRI/DWI examination or a surgical history of prostate and previous hormonal therapy were excluded, leaving 19 patients in our study. We analyzed the MRI and DWI collected before radical prostetectomy surgey and the post-surgery step section pathology made by the whole mount technique. The prostatic gland was divided into six sections. Two doctors read the MRI/DWI without knowing the patients' information and scored, using a 5 point scale, for each section. The tissue was graded according to the following scale: 1-definitely no cancer, 2-probably no cancer, 3-possible cancer, 4-probable cancer and 5-definite cancer. When the average score ≥4 the region was assumed to be the prostate cancer region by MRI or MRI/DWI.ResultsIn 19 patients with 114 regions, there were 48 (42％) prostate cancer regions approved by whole-mount step section pathologically.The number of prostate cancer regions was 15 (39％), 21 (55％) and 12 (32％) in base, mid and apex parts respectively. The sensitivity and specificity of the MRI was 62.5％ and 69.7％. When considering DWI, the specificity and sensitivity was elevated to 79.1％ and 83.3％. As for the apex and mid parts, the sensitivities of MRI were a little bit low (46.7％ and 66.7％ ). But the sensitivities of localization of prostate cancer for the apex and mid of prostate were elevate to 73.3％ and 85.7％ respectively when DWI was also used.ConclusionsWith whole-mount step-section pathology, the combination of MRI and DWI can improve the sensitivity of MRI for localized diagnosis in prostate cancer, especially in apex and mid parts of the prostate.