Combining Washout and Noncontrast Data From Adrenal Protocol CT: Improving Diagnostic Performance.

Area of Science:

• Radiology
• Medical Imaging
• Oncology

Background:

• Accurate differentiation of adrenal lesions is crucial for patient management.
• Conventional computed tomography (CT) criteria often have limitations in distinguishing benign from malignant adrenal lesions.
• Delayed-phase contrast-enhanced CT offers additional information for adrenal lesion characterization.

Purpose of the Study:

• To evaluate if combining noncontrast and washout data from delayed adrenal CT enhances diagnostic performance.
• To develop and validate an optimized analytical framework for adrenal lesion classification.

Main Methods:

• Retrospective analysis of 97 adrenal lesions in 96 patients with pathologically proven diagnoses.
• Assessment of lesion CT attenuation (Hounsfield units) and percent enhancement washout (absolute and relative) from noncontrast and delayed-phase CT.
• Recursive partitioning analysis to determine optimal sequential parameter thresholds for malignancy detection.

Main Results:

• The optimized sequential criteria (noncontrast ≥24.75 HU, followed by APEW ≤63.49%) achieved 100.0% sensitivity, 85.3% specificity, and 90.7% accuracy.
• This combined approach demonstrated statistically significant improvements in diagnostic accuracy compared to conventional single-parameter criteria.
• Conventional criteria yielded lower accuracies, ranging from 54.6% to 78.4%.

Conclusions:

• Sequential analysis of noncontrast and washout parameters in delayed adrenal CT significantly improves diagnostic performance for adrenal lesions.
• The developed sequential classifier offers enhanced accuracy in differentiating benign from malignant adrenal tumors.
• Further validation is recommended to refine threshold values and confirm the sequential ordering.