Richa Patel MD

All Publications

• Improving Diagnosis of Acute Cholecystitis with US: New Paradigms. Radiographics : a review publication of the Radiological Society of North America, Inc Patel, R., Tse, J. R., Shen, L., Bingham, D. B., Kamaya, A. 2024; 44 (12): e240032

  Abstract

  Acute cholecystitis is an inflammatory condition of the gallbladder typically incited by mechanical obstruction. Accurate diagnosis of this common clinical condition is challenging due to variable imaging appearances as well as overlapping clinical manifestations with biliary colic, acute hepatitis, pancreatitis, and cholangiopathies. In acute cholecystitis, increased dilatation and high intraluminal pressures lead to gallbladder inflammation and may progress to gangrenous changes, focal wall necrosis, and subsequent perforation. In acute calculous cholecystitis, gallstones are the cause of obstruction and are often impacted in the gallbladder neck or cystic duct, leading to gallbladder inflammation. In acalculous cholecystitis, patients are typically critically ill, often with hypotensive episodes and prolonged gallbladder stasis, which lead to obstruction, gallbladder ischemia, and inflammation. Helpful sonographic findings of acute cholecystitis include a dilated gallbladder; increased intraluminal pressures in the gallbladder, resulting in a bulging fundus (tensile fundus sign); intraluminal sludge in the setting of right upper quadrant pain; wall hyperemia, which may be quantified by elevated cystic artery velocities or hepatic artery velocities; mucosal ischemic changes, characterized by loss of mucosal echogenicity; pericholecystic inflammation, characterized by hyperechoic pericholecystic fat; and mucosal discontinuity. Extruded complex fluid next to a wall defect is definitive for gallbladder wall perforation, and further evaluation with CT or MRI allows evaluation of the full extent of perforation and other potential complications. The sonographic Murphy sign, while helpful if positive, is relatively insensitive for accurate diagnosis of acute cholecystitis. Thus, overreliance on the sonographic Murphy sign results in surprisingly low diagnostic accuracy in practice.

  View details for DOI 10.1148/rg.240032

  View details for PubMedID 39541246

• Updates on LI-RADS Treatment Response Criteria for Hepatocellular Carcinoma: Focusing on MRI. Journal of magnetic resonance imaging : JMRI Patel, R., Aslam, A., Parikh, N. D., Mervak, B., Mubarak, E., Higgins, L., Lala, K., Conner, J. F., Khaykin, V., Bashir, M., Do, R. K., Burke, L. M., Smith, E. N., Kim, C. Y., Shampain, K. L., Owen, D., Mendiratta-Lala, M. 2023

  Abstract

  As the incidence of hepatocellular carcinoma (HCC) and subsequent treatments with liver-directed therapies rise, the complexity of assessing lesion response has also increased. The Liver Imaging Reporting and Data Systems (LI-RADS) treatment response algorithm (LI-RADS TRA) was created to standardize the assessment of response after locoregional therapy (LRT) on contrast-enhanced CT or MRI. Originally created based on expert opinion, these guidelines are currently undergoing revision based on emerging evidence. While many studies support the use of LR-TRA for evaluation of HCC response after thermal ablation and intra-arterial embolic therapy, data suggest a need for refinements to improve assessment after radiation therapy. In this manuscript, we review expected MR imaging findings after different forms of LRT, clarify how to apply the current LI-RADS TRA by type of LRT, explore emerging literature on LI-RADS TRA, and highlight future updates to the algorithm. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 2.

  View details for DOI 10.1002/jmri.28659

  View details for PubMedID 36872608

• The Rankin Focused Assessment-Ambulation: A Method to Score the Modified Rankin Scale with Emphasis on Walking Ability. Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association Patel, R. D., Starkman, S., Hamilton, S., Craig, S., Grace, A., Conwit, R., Saver, J. L. 2016; 25 (9): 2172-6

  Abstract

  In the assessment of poststroke functional outcome, there are 2 alternative approaches to rating patient independence in motion: (1) focusing solely on patient ambulation (discounting self-use of wheelchair) and (2) focusing broadly on patient mobility (counting self-use of wheelchair). This study was undertaken to create and assess the inter-rater reliability of a version of the Rankin Focused Assessment (RFA) that focuses on ambulation (Rankin Focused Assessment-Ambulation [RFA-A]), as an alternative to the original RFA that focused on mobility (Rankin Focused Assessment-Mobility [RFA-M]).The RFA-A was created by changing instructions in the RFA-M for handling of nonambulatory, wheelchair-using patients. Paired study coordinators then applied the RFA-A to 50 consecutive patients enrolled in a phase 3 acute stroke trial.Among the 50 patients, the mean age was 72 years (range 43-93) and 48% were female. Overall, study coordinator pairs assigned the same modified Rankin Scale (mRS) grades to 48 of the 50 patients, yielding a weighted κ of .98 (95% confidence interval [CI] .96-1.00) and an unweighted κ of .95 (95% CI .89-1.02). At day 90, 43 patients were alive and 7 had died. Among surviving patients, the weighted κ was .98 (95% CI .95-1.00) and the unweighted κ was .94 (95% CI .86-1.02). The κ values for all 6 dichotomizations of the mRS score ranged from .93 to 1.00.The RFA-A demonstrates high inter-rater reliability in grading global functional outcome. The RFA-A is a useful tool for assigning an mRS score in research and clinical practice when functional assessment focused on ambulation is desired.

  View details for DOI 10.1016/j.jstrokecerebrovasdis.2015.10.030

  View details for PubMedID 27450385

• Evolution of reperfusion therapies for acute brain and acute myocardial ischemia: a systematic, comparative analysis. Stroke Patel, R. D., Saver, J. L. 2013; 44 (1): 94-8

  Abstract

  Early reperfusion is the most effective therapy for both acute brain and cardiac ischemia. However, the cervicocephalic circulatory bed offers more challenges to recanalization interventions. The historical development of reperfusion interventions has not previously been systematically compared.Medline search identified all multi-arm, controlled trials of coronary revascularization for acute myocardial infarction and multicenter trials of cerebral revascularization for acute ischemic stroke reporting angiographic reperfusion rates.Thirty-seven trials of coronary reperfusion enrolled 10 908 patients from 1983 to 2009, and 10 trials of cerebral reperfusion enrolled 1064 patients from 1992 to 2009. Coronary reperfusion trials included 10 of intravenous fibrinolysis alone, 8 combined intravenous fibrinolysis and percutaneous transluminal coronary angioplasty with or without stenting, 3 intra-arterial fibrinolysis, and 16 percutaneous transluminal coronary angioplasty with or without stenting. Cerebral reperfusion trials included 1 of intravenous fibrinolysis alone, 3 intra-arterial fibrinolysis, 3 endovascular device alone, and 3 of endovascular treatment ± intravenous fibrinolysis. In both circulatory beds, endovascular treatments were more efficacious at achieving reperfusion than peripherally administered fibrinolytics. In the coronary bed, rates of achieved reperfusion began at high levels in the 1980s and improved modestly over the subsequent 3 decades. In the cerebral bed, reperfusion rates began at modest levels in the early 1990s and increased more slowly. Most recently, in 2005 to 2009, cardiac reperfusion rates substantially exceeded cerebral, partial reperfusion 86.1% versus 61.1%, complete reperfusion 78.6% versus 23.4%.Reperfusion therapies developed more slowly and remain less effective for cerebral than cardiac ischemia. Further, cerebral circulation-specific technical advances are required for physicians to become as capable at safely restoring blood flow to the ischemic brain as the ischemic heart.

  View details for DOI 10.1161/STROKEAHA.112.666925

  View details for PubMedID 23192757