If an abbreviated HBP protocol liver MR with gadobenate dimeglumine is shown clinically comparable to standard of care liver MR with gadoxetate disodium for detecting hepatic metastasis from colorectal cancer, its use will save time, cost, and patients' effort.
The goal is to: * Estimate and compare the diagnostic performance, including sensitivity, specificity, positive/negative predictive value, and area under the receiver operating characteristics (AUROC), of abbreviated protocol liver magnetic resonance (MR) with hepatobiliary phase (HBP) using gadobenate dimeglumine for detecting liver metastases, with 1) abbreviated protocol liver MR with HBP using gadoxetate disodium, 2) standard of care complete protocol liver MR using gadoxetate disodium, and 3) complete protocol liver MR using gadobenate dimeglumine. * Estimate and compare quantitative measures of HBP images (liver enhancement ratio, lesion contrast to noise and signal to noise ratios \[CNR and SNR\]) for both gadobenate dimeglumine and gadoxetate disodium. * Qualitatively assess the preference, or lack thereof, of radiologists regarding the images generated by abbreviated protocol liver MR with HBP using gadobenate dimeglumine versus abbreviated protocol liver MR with HBP using gadoxetate disodium.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
DIAGNOSTIC
Masking
SINGLE
Enrollment
10
Gadoxetate disodium is now mainly used for the purpose of HBP liver MR imaging to save MR scanner time and total examination time.
The most commonly used MR contrast agent in abdominal imaging is gadobenate dimeglumine, which has mainly the characteristics of an extracellular agent used for most indications of MR examinations.
University of Colorado Hospital
Aurora, Colorado, United States
Diagnostic Performance of gadobenate dimeglumine
The primary performance diagnostic will be sensitivity, similar to the recently published retrospective study by Canellas et al. (2019). In addition to other diagnostic performance metrics of interest (e.g., specificity, AUROC), lesions will be analyzed descriptively in terms of number of metastases detected and lesion size.
Time frame: 1 month
Quantitative Measures of hepatobiliary phase images
Mixed effects regression models will again be used to compare the three outcomes between methods, accounting for correlated data. The specific link function of the regression models will depend on the distributional characteristics of each outcome (e.g., logit link for dichotomous outcomes; linear regression for continuously measured outcomes).
Time frame: 1 month
Preference of radiologists for the images generated by amHBP versus aeHBP
The quality of amHBP and aeHBP images will be assessed with ordinal response mixed effect models that include right/left image as a covariate. We will assess if there was any reader specific and/or general bias to prefer an image on the left or the right of a screen, regardless of the amHBP or aeHBP, and consider this when modeling the probability of preference of amHBP over aeHBP. We will estimate the relative probabilities of no-preference, amHBP preference, or aeHBP preference.
Time frame: 1 month
Compare Sensitivity and Specificity,
The primary analysis will use pathology as the gold standard, if available, but will revert to long term imaging in the absence of pathology. To address the potential impact of this limitation, we will also conduct an exploratory analysis to compare the sensitivity and specificity of the imaging methods by each gold standard.
Time frame: 1 month
Test Validity of Imaging Methods
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We will also conduct an exploratory analysis to test the validity of long term imaging as a gold standard against available pathology reports.
Time frame: 1 month
Compare Patient Time Associated with Imaging Method
In addition to analyses for the primary aims, additional analyses will be conducted to examine patient time associated with each imaging method; time metrics can be compared between imaging methods in absolute terms, but also proportionally to sensitivity.
Time frame: 1 month
Compare Cost Associated with Imaging Method
In addition to analyses for the primary aims, additional analyses will be conducted to examine cost associated with each imaging method; cost metrics can be compared between imaging methods in absolute terms, but also proportionally to sensitivity.
Time frame: 1 month