PDF(Pubmed)
Abstract：
BACKGROUND: Perianal abscess is a clinical infective and/or inflammatory collection in the perianal region, one entity of a large group of anal and perianal disorders. Perianal abscesses are often seen as a complication of grade 2 and grade 4 perianal fistulas from St. James\'s University Hospital classification. Several imaging modalities have been tried in the past for adequate assessment of perianal abscess with contrast-enhanced magnetic resonance imaging (CE-MRI) providing the most accurate results. Diffusion-weighted imaging (DWI) is an emerging sequence that can provide comparable results to CE-MRI in diagnosing and characterizing perianal abscess. The main objective of this study is to assess the role of DWI in adequate identification and assessment of perianal abscess and compare the final results with contrast-enhanced images.
METHODS: Twenty patients with complicated perianal fistula with clinically suspected perianal abscess were evaluated with DWI and CE-MRI. This study was a comparative cross-sectional study conducted in the Department of Radiodiagnosis and Imaging, All India Institute of Medical Sciences, Bhopal, India. Chi-square test was done to find the association between categorical variables. Kappa test was used to find the agreement between two different tests. Receiver operating characteristics (ROC) analysis was done to estimate the area under the curve in predicting the outcome. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were used to measure the validity of the tests.
RESULTS: DWI is a very sensitive MRI sequence and is equivalent to CE-MRI to detect the location and analyzing the loco-regional extent of abscess in complicated perianal fistula cases. DWI is also very sensitive and superior to T2 short tau inversion recovery (STIR) in differentiating perianal abscess from perianal inflammation without abscess.
CONCLUSIONS: DWI can be used as an alternative to post-contrast fat-suppressed MRI in precisely defining the location and extent of anal and perianal abscesses and disease activity in complicated fistula cases.
METHODS: Twenty patients with complicated perianal fistula with clinically suspected perianal abscess were evaluated with DWI and CE-MRI. This study was a comparative cross-sectional study conducted in the Department of Radiodiagnosis and Imaging, All India Institute of Medical Sciences, Bhopal, India. Chi-square test was done to find the association between categorical variables. Kappa test was used to find the agreement between two different tests. Receiver operating characteristics (ROC) analysis was done to estimate the area under the curve in predicting the outcome. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were used to measure the validity of the tests.
RESULTS: DWI is a very sensitive MRI sequence and is equivalent to CE-MRI to detect the location and analyzing the loco-regional extent of abscess in complicated perianal fistula cases. DWI is also very sensitive and superior to T2 short tau inversion recovery (STIR) in differentiating perianal abscess from perianal inflammation without abscess.
CONCLUSIONS: DWI can be used as an alternative to post-contrast fat-suppressed MRI in precisely defining the location and extent of anal and perianal abscesses and disease activity in complicated fistula cases.
摘要：
背景：肛周脓肿是肛周区域的临床感染性和/或炎性集合，一大组肛门和肛周疾病的一个实体。根据圣詹姆斯大学医院分类，肛周脓肿通常被视为2级和4级肛周瘘的并发症。过去已经尝试了几种成像方式，以通过对比增强磁共振成像（CE-MRI）提供最准确的结果来充分评估肛周脓肿。弥散加权成像（DWI）是一种新兴的序列，可以在诊断和表征肛周脓肿方面提供与CE-MRI相当的结果。这项研究的主要目的是评估DWI在充分识别和评估肛周脓肿中的作用，并将最终结果与对比增强图像进行比较。
方法：对20例临床怀疑肛周脓肿的复杂性肛瘘患者进行DWI和CE-MRI评估。这项研究是在放射诊断和成像部门进行的比较横断面研究，全印度医学科学研究所，博帕尔,印度。进行卡方检验以找到分类变量之间的关联。使用Kappa检验来发现两个不同测试之间的一致性。进行受试者工作特征（ROC）分析以估计预测结果的曲线下面积。灵敏度,特异性，正预测值，阴性预测值和准确性用于衡量测试的有效性.
结果：DWI是一种非常敏感的MRI序列，相当于CE-MRI，可以检测复杂性肛瘘病例中脓肿的位置并分析其局部范围。DWI在区分肛周脓肿与无脓肿的肛周炎症方面也非常敏感，优于T2短tau倒置恢复（STIR）。
结论：DWI可作为对比后脂肪抑制MRI的替代方法，用于精确确定复杂性瘘管病例中肛门和肛周脓肿的位置和范围以及疾病活动。
方法：对20例临床怀疑肛周脓肿的复杂性肛瘘患者进行DWI和CE-MRI评估。这项研究是在放射诊断和成像部门进行的比较横断面研究，全印度医学科学研究所，博帕尔,印度。进行卡方检验以找到分类变量之间的关联。使用Kappa检验来发现两个不同测试之间的一致性。进行受试者工作特征（ROC）分析以估计预测结果的曲线下面积。灵敏度,特异性，正预测值，阴性预测值和准确性用于衡量测试的有效性.
结果：DWI是一种非常敏感的MRI序列，相当于CE-MRI，可以检测复杂性肛瘘病例中脓肿的位置并分析其局部范围。DWI在区分肛周脓肿与无脓肿的肛周炎症方面也非常敏感，优于T2短tau倒置恢复（STIR）。
结论：DWI可作为对比后脂肪抑制MRI的替代方法，用于精确确定复杂性瘘管病例中肛门和肛周脓肿的位置和范围以及疾病活动。
