Computed Tomography-Based Tumor Volume in Non-Hodgkin Lymphoma: Clinical Correlation and Comparison With Magnetic Resonance Imaging

A semi-automatic segmentation method for the structural analysis of carotid atherosclerotic plaques by computed tomography angiography

AIM

Computed tomography angiography (CTA) is currently the most reliable imaging technique for evaluating and planning the treatment of atherosclerosis. The drawbacks of the technique are its low spatial resolution and challenging manual measurements. The purpose of this study was to develop a semi-automatic method to segment vessel walls, surrounding tissue, and the carotid artery lumen to measure the severity of stenosis.

METHODS

In vivo contrast CTA images from eight patients undergoing endarterectomy were analyzed using a tailored five-step process involving an adaptive segmentation algorithm and region growing to measure the maximum percent stenosis in the cross-sectional area of the carotid artery. The accuracy of this method was compared with that of manual measurements made by physicians.

RESULTS

There were no significant differences between the maximum percent stenosis value obtained using the semi-automatic tool and that obtained using manual measurements (6%; p=0.31). The data acquisition and analysis required an average of 145 seconds.

CONCLUSION

This new semi-automatic segmentation method for CTA provides a fast and reliable tool to quantify the severity of carotid artery stenosis.

PET imaging in a longitudinal non-Hodgkin's lymphoma study: association with tumor volume

BACKGROUND

Computed tomography (CT) is generally used in the evaluation of the treatment response of non-Hodgkin's lymphoma (NHL) patients. Instead of morphological images, positron emission tomography (PET) shows metabolic information that is connected to tumor activity, cell proliferation rate, and, thus, prognosis.

PURPOSE

To determine the prognostic value of PET for tumor volume reduction measured by CT and magnetic resonance imaging (MRI) along with clinical characteristics in NHL patients.

MATERIAL AND METHODS

We imaged 21 B-cell type NHL patients using whole-body 18F-FDG-PET at the onset and the completion of treatment and at six-month follow-up. The maximum standardized uptake value (SUV(max)) was calculated. Morphological tumor volume calculations were assessed using both MRI and CT. Additionally, patients underwent thorough clinical examination including several laboratory tests.

RESULTS

A high SUV(max) was able to predict significant tumor volume reduction at the beginning of treatment, but the relation to pure tumor volume was poor.

CONCLUSION

The SUV(max) values derived from FDG-PET seemed to correlate with volume changes but not with their absolute values or laboratory tests. Unlike MRI and CT, FDG-PET showed the disappearance of active tumors after treatment.