J Korean Radiol Soc.  2006 Aug;55(2):137-142. 10.3348/jkrs.2006.55.2.137.

Malignant Solitary Pulmonary Nodule: Enhancement Patterns on Contrast-enhanced Dynamic CT with the Histopathologic Evaluation

• Cho YM
• Kim YH
• Seon HJ
• Park JG
• Kim JK
• Jeong GW
• Kang HK

• KMID: 2103810
• DOI: http://doi.org/10.3348/jkrs.2006.55.2.137

Abstract

PURPOSE
We wanted to evaluate the potential role of dynamic incremental computed tomography (CT) for making the diagnosis of malignant solitary pulmonary nodule (SPN) by investigating the dynamic enhancement patterns.
MATERIALS AND METHODS
Forty patients with presumed malignant SPN (diameter < 30 mm) were selected for dynamic incremental chest CT scanning. Histopathologic diagnoses of the malignant SPNs were obtained by surgical excision (n=8) and transthoracic needle biopsy (n=32), and they were squamous cell carcinoma (n=16), adenocarcinoma (n=14), small cell carcinoma (n=5), bronchioloalveolar carcinoma (n=3), and large cell carcinoma (n=2). CT scans were performed at the region of interest (ROI) of the lung nodule before and after contrast enhancement. The dynamic incremental CT scans after contrast enhancement were performed at 15 seconds, 30 seconds, 45 seconds, 60 seconds, 90 seconds, 2 minutes, 3 minutes and 4 minutes. The degree of contrast enhancement according to the time course and the time of maximum enhancement of the malignant nodules were recorded by measuring the Hounsfield Unit (HU) of the nodules at the ROI. We assessed the differences of the contrast enhancement patterns among the histopathologic subtypes of malignant SPN.
RESULTS
In malignant SPN, the average time of maximum contrast enhancement was 62.2+/-16.2 seconds, and the average degree of maximum contrast enhancement was 66.4+/-22.17 HU. Most primary lung cancer showed rapid contrast enhancement with slow washout. The differences of the enhancement patterns among the histopathologic subtypes were not statistically significant (p > 0.05).
CONCLUSION
Dynamic incremental chest CT was useful for making the diagnosis of malignant SPN that showed an established dynamic contrast enhancement pattern regardless of the histopatholgic subtypes.

Keyword

Lung neoplasms, diagnosis; Lung, nodule; Computed tomography (CT)

MeSH Terms

Adenocarcinoma
Adenocarcinoma, Bronchiolo-Alveolar
Biopsy, Needle
Carcinoma, Large Cell
Carcinoma, Small Cell
Carcinoma, Squamous Cell
Diagnosis
Humans
Lung
Lung Neoplasms
Solitary Pulmonary Nodule*
Tomography, X-Ray Computed