scholarly journals Diagnostic Accuracy of Transabdominal Ultrasound and Computed Tomography in Chronic Pancreatitis: A Head-to-Head Comparison

2021 ◽  
Vol 07 (01) ◽  
pp. E35-E44
Author(s):  
Ingrid Kvåle Nordaas ◽  
Trond Engjom ◽  
Odd Helge Gilja ◽  
Roald Flesland Havre ◽  
Dag André Sangnes ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Chronic Pancreatitis ◽  
Diagnostic Accuracy ◽  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Transabdominal Ultrasound ◽  
Characteristic Curves ◽  
Receiver Operating Characteristic Curves ◽  
Mayo Score ◽  
Receiver Operating

Abstract Purpose Computed tomography (CT) is the most used imaging modality for diagnosing chronic pancreatitis (CP), but advances in transabdominal ultrasound (US) technology have given US a position as a viable alternative. We aimed to evaluate the diagnostic accuracy of abdominal CT and pancreatic US compared to the reference standard, a modified Mayo score. Materials and Methods CT, US, and endoscopic ultrasound (EUS) were performed in patients referred due to suspected CP. The modified Mayo score included EUS results, clinical presentation, and results from exocrine and endocrine pancreatic function tests. We scored CT findings according to the modified Cambridge classification and US findings according to the Rosemont classification. Results In total, 73 patients were included. 53 patients (73%) were categorized as CP and 20 (27%) as non-CP. CT and US yielded similar sensitivities (68% and 64%, respectively) and specificities (75 and 85%, respectively) and similar areas under the receiver operating characteristic curves for diagnosing CP. We found no significant differences between the areas under the receiver operating characteristic curves (AUROCs) for CT (AUROC 0.75, 95% CI 0.63–0.87) and US (AUROC 0.81, 95% CI 0.71–0.91). Conclusion We conclude that CT and US had comparable, moderate accuracy in diagnosing CP. Neither modality had high enough sensitivity to exclude the diagnosis as a standalone method.

Distal Medium Vessel Occlusions Can Be Accurately and Rapidly Detected Using Tmax Maps

Stroke ◽  
2021 ◽  
Author(s):  
Shalini A. Amukotuwa ◽  
Angel Wu ◽  
Kevin Zhou ◽  
Inna Page ◽  
Peter Brotchie ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Ct Perfusion ◽  
Rank Test ◽  
Characteristic Analysis ◽  
Stroke Patients ◽  
Characteristic Curves ◽  
Receiver Operating Characteristic Curves ◽  
Receiver Operating

Background and Purpose: Distal medium vessel occlusions (DMVOs) are increasingly considered for endovascular thrombectomy but are difficult to detect on computed tomography angiography (CTA). We aimed to determine whether time-to-maximum of tissue residue function ( Tmax ) maps, derived from CT perfusion, can be used as a triage screening tool to accurately and rapidly identify patients with DMVOs. Methods: Consecutive code stroke patients who underwent multimodal CT were screened retrospectively. Two experienced readers evaluated all patients’ Tmax maps in consensus for presence of delay in an arterial territory (territorial Tmax delay). The diagnostic accuracy of this surrogate for identifying DMVOs was determined using receiver-operating characteristic analysis. CTA, interpreted by 2 experienced neuroradiologists with access to all imaging data, served as the reference standard. Diagnostic performance of 4 other readers with different levels of experience for identifying DMVOs on Tmax versus CTA was also assessed. These readers independently assessed patients’ Tmax maps and CTAs in 2 separate timed sessions, and areas under the receiver-operating characteristic curves were compared using the DeLong algorithm. The Wilcoxon signed-rank test was used to comparatively assess diagnostic speed. Results: Three hundred seventy-three code stroke patients (median age, 70 years; 56% male, 70 with a DMVO) were included. Territorial Tmax delay had a sensitivity of 100% (CI 95 , 94.9%–100%) and specificity of 87.8% (CI 95 , 83.6%–91.3%) for presence of a DMVO, yielding an area under the receiver-operating characteristic curves of 0.939 (CI 95 , 0.920–0.957). All 4 readers achieved sensitivity >95% and specificity >84% for detecting DMVOs using Tmax maps, with diagnostic accuracy (area under the receiver-operating characteristic curves) and speed that were significantly ( P <0.001) higher than on CTA. Conclusions: Territorial Tmax delay had perfect sensitivity and high specificity for a DMVO. Tmax maps were accurately and rapidly interpreted by even inexperienced readers, and causes of false positives are easy to recognize and dismiss. These findings encourage the use of Tmax to identify patients with DMVOs.

A conditional approach for the receiver operating characteristic curve construction to evaluate diagnostic test performance in a family-matched case–control design

2021 ◽  
pp. 096228022199595
Author(s):  
Yalda Zarnegarnia ◽  
Shari Messinger
Keyword(s):  
Receiver Operating Characteristic Curve ◽  
Receiver Operating Characteristic ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Case Control ◽  
Paired Data ◽  
Characteristic Curves ◽  
Receiver Operating Characteristic Curves ◽  
Operating Characteristic Curve ◽  
Receiver Operating

Receiver operating characteristic curves are widely used in medical research to illustrate biomarker performance in binary classification, particularly with respect to disease or health status. Study designs that include related subjects, such as siblings, usually have common environmental or genetic factors giving rise to correlated biomarker data. The design could be used to improve detection of biomarkers informative of increased risk, allowing initiation of treatment to stop or slow disease progression. Available methods for receiver operating characteristic construction do not take advantage of correlation inherent in this design to improve biomarker performance. This paper will briefly review some developed methods for receiver operating characteristic curve estimation in settings with correlated data from case–control designs and will discuss the limitations of current methods for analyzing correlated familial paired data. An alternative approach using conditional receiver operating characteristic curves will be demonstrated. The proposed approach will use information about correlation among biomarker values, producing conditional receiver operating characteristic curves that evaluate the ability of a biomarker to discriminate between affected and unaffected subjects in a familial paired design.

Sign in / Sign up

Export Citation Format

Share Document