Multidetector Computed Tomography Findings in Pulmonary Hamartomas: A New Fat Detection Threshold

Area of Science:

• Radiology
• Pulmonary Medicine
• Medical Imaging

Background:

• Pulmonary hamartomas (PHs) are benign lung tumors.
• Accurate diagnosis of PHs is crucial for appropriate patient management.
• Multidetector computed tomography (MDCT) is a key imaging modality for evaluating lung nodules.

Purpose of the Study:

• To assess the accuracy of MDCT in diagnosing histologically confirmed pulmonary hamartomas.
• To specifically evaluate the effectiveness of fat detection in identifying PHs.
• To determine optimal CT density thresholds for fat detection in PHs.

Main Methods:

• Retrospective analysis of 64-slice thoracic MDCT data from 55 patients with confirmed PH.
• Evaluation of lesion characteristics, including size, margins, and presence of fat and calcifications.
• Comparison of fat detection accuracy at different Hounsfield Unit (HU) thresholds.

Main Results:

• Pulmonary hamartomas typically appeared as peripheral nodules with lobulated margins.
• Fat content was identified in 78.2% of surgical specimens.
• A CT density threshold of -33 HU for fat detection achieved 95.3% accuracy, 100% sensitivity, and 96.3% specificity.

Conclusions:

• Utilizing a lower HU threshold (<-33) for fat detection significantly improves MDCT's ability to diagnose pulmonary hamartomas.
• Fat detection is a critical imaging feature for identifying PHs.
• While calcifications are less common, they can be present alongside fat in PHs.