Pulmonary Nodules: Contrast-Enhanced Volumetric Variation at Different CT Scan Delays

Abstract

We recommend comparing volume of pulmonary nodules obtained from CT examinations only if they are all performed with or without contrast material, whereas nodule volumes obtained by use of enhanced CT performed with different scan delays are comparable.

British Thoracic Society guidelines for the investigation and management of pulmonary nodules: accredited by NICE

“…Adequate segmentation was achieved in 71–86% of nodules, with variability in volumetry between 16.4% and 22.3%. Rampinelli et al 356 assessed the effect of intravenous contrast on volumetric calculation on 35 pulmonary nodules, comparing scans performed without contrast (unenhanced) with scans performed after injected contrast at 30, 60, 120, 180 and 300 s delays. Contrast-enhanced scans resulted in significantly larger volumes than unenhanced scans, with variations in volume of 4–7%.…”

A retrospective study of volume doubling time in surgically resected non‐small cell lung cancer

“…We tried to minimize measurement error from differing imaging parameters by pairing the most similar scans whenever possible. Contrast administration is also a factor that has been shown to affect nodule size but has not been controlled for in many VDT studies other than ours …”

The Effects of Iodine Attenuation on Pulmonary Nodule Volumetry using Novel Dual-Layer Computed Tomography Reconstructions

“…Since prior information about the effect of virtual non-contrast and mono-energetic reconstructions on pulmonary nodule volumetry is lacking, a sample size could not be calculated adequately. Several previous studies investigated the effect of contrast material on pulmonary nodule volumetry and included a median number of 60 nodules [ 4 , 5 , 9 , 15 , 16 ]. Therefore, at least 60 nodules should be included to allow for a comparison with those studies.…”

“…A volume change of ≥25% is considered a significant growth. Volume measurements can be affected by several parameters, including slice thickness, reconstruction method, volumetry software package, and the use of contrast media [ 4 – 9 ].…”