Clinical Trial: Utility of Diffusion-weighted MR Imaging

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Utility of Diffusion-weighted MR Imaging in Guiding Selective Percutaneous Drainage of Postoperative Intra-abdominal Abscesses After Colorectal Resection

Brief Summary: To determine whether DW-MRI is applicable in the evaluation of post-operative collections, and whether utilization of DW-MRI can enhance application of percutaneous drainage and prevent unnecessary drainage.

Detailed Summary:

Percutaneous drainage of intra-abdominal abscesses occurring as a complication of colon and rectal resection has been a major advance in the management of surgical patients. Proper patient selection is critical for safe and effective management in this population. Almost ¾ of patients undergoing CT scan after colorectal resection due to clinical suspicion of intrabdominal process will have at least one fluid collection identified. These collections can represent a spectrum of clinical entities and there is not a consensus on the most effective management of these collections or even the definition of abscess. Currently, reliance on radiologic criteria in isolation can lead to overuse of interventional procedures. For example, 40% of rim-enhancing collections are sterile on aspiration. The surgeons' clinical suspicion for abscess and radiologic proximity to an anastomosis are the only criteria that are useful in predicting abscess versus sterile collection. A further consideration is the natural history of these abscesses. Studies in the diverticulitis literature have demonstrated that abscesses less than 3 cm in greatest dimension are successfully managed with antibiotics alone, while abscesses greater than 6.5 cm are likely to require intervention. However, this leaves a great number of abscesses between 3 cm and 6.5 cm that fall into uncertain grounds. In contrast to diverticulitis, where it can be reasonably inferred that an associated abdominopelvic collection is indeed and abscess, management of fluid collections identified post-operatively and determination of who will benefit from drainage is less clear. A novel radiologic technique with high discrimination between sterile and infected collection would be of great clinical utility in the post-operative management of fluid collections after colorectal resection.

The proposed research project seeks to broaden ap
Sponsor: University of Chicago

Current Primary Outcome: Apparent diffusion coefficient (ADC) from infected post-operative fluid collections [ Time Frame: 1 year ]

Two radiologists will independently review the MR images for detection of collections. ADC maps will be generated for each patient. Each radiologist will assign a 1-5 point score based on the level of confidence in the diagnosis of abscess. These radiologists will then measure ADC of the collections in each patient on ADC maps. Mean and 10th percentile ADC values will be computed by placement of region of interest (ROI) on ADC maps using DW images as guide. Each ROI will be placed in the center of the collection over the darkest pixels on ADC maps keeping size as large as possible and avoiding the volume averaging from the surrounding tissue. The reference standard for the diagnosis of abscess will be based on the analysis of aspiration fluid from the collection. Following statistical analysis, an ROC curve will be constructed for ADC values, and area under the curve measured forthe overall ability of ADC in differentiation of abscess from non-infected collections


Original Primary Outcome: Same as current

Current Secondary Outcome:

Original Secondary Outcome:

Information By: University of Chicago

Dates:
Date Received: February 23, 2017
Date Started: February 15, 2017
Date Completion: April 15, 2018
Last Updated: March 13, 2017
Last Verified: March 2017