Categorical Visualization Score (CVS)
The primary visualization variables (number [no.] of lesions detected, border delineation, contrast enhancement, internal morphology) were condensed to a composite score (CVS). Each variable was considered a category; the CVS was calculated as: CVS=(No. of categories with increase over precontrast)-(No. of categories with decrease over precontrast). The possible outcomes of the CVS for a participant and each reader were in the range of - 3 to +4. The CVS was averaged across the 3 blinded readers, producing 1 mean CVS per participant. The higher the CVS, the more effective the treatment.
Difference in Number of Lesions Detected in Pre-contrast and Combined Pre-/Post-contrast MRI.
Three blinded readers evaluated the unenhanced MRI sets and the combined unenhanced/gadobutrol-enhanced MRI sets to evaluate the number of lesions, which was then averaged to produce an average reader value.
Assessment of Lesion Contrast Enhancement
The blinded readers assessed the degree of contrast enhancement for each lesion on a 4-point scale where 1 = no enhancement and 4 = excellent enhancement, which was then averaged to produce an average reader score.
Assessment of Border Delineation
The blinded readers assessed the delineation for each lesion on a 4-point scale where 1 = none and 4 = excellent, which was then averaged to produce an average reader score.
Assessment of Internal Morphology
The blinded readers assessed the degree of information available about internal morphology and structure for each lesion on a 3-point scale where 1 = poor and 3 = good, which was then averaged to produce an average reader score.
Contrast to Noise Ratio (CNR) Between White and Gray Matter With Gadobutrol Perfusion MRI
CNR between white and gray matter in the perfusion imaging was defined as the signal intensity (SI) difference between white and gray matter divided by the standard deviation of the SI of white matter. An independent radiologist evaluated the gadobutrol-enhanced perfusion MRI for signal intensity.
Accuracy Comparison of Gadobutrol Doses - Detection of Matched Lesions: Blinded Reader 1
The percent accuracy (total number of lesions matching the comparator divided by the total number of lesions identified by gadobutrol) comparison of the 0.03 and 0.1 mmol/kg gadobutrol doses and the 0.1 and 0.3 mmol/kg gadobutrol doses using detection of all comparator-detected matched lesions was performed for blinded reader (BR) 1.
Accuracy Comparison of Gadobutrol Doses - Detection of Matched Lesions: Blinded Reader 2
The percent accuracy (total number of lesions matching the comparator divided by the total number of lesions identified by gadobutrol) comparison of the 0.03 and 0.1 mmol/kg gadobutrol doses and the 0.1 and 0.3 mmol/kg gadobutrol doses using detection of all comparator-detected matched lesions was performed for BR 2
Accuracy Comparison of Gadobutrol Doses - Detection of Matched Lesions: Blinded Reader 3
The percent accuracy (total number of lesions matching the comparator divided by the total number of lesions identified by gadobutrol) comparison of the 0.03 and 0.1 mmol/kg gadobutrol doses and the 0.1 and 0.3 mmol/kg gadobutrol doses using detection of all comparator-detected matched lesions was performed for BR 3
Accuracy Comparison of Gadobutrol Doses - Detection of Matched Enhanced Lesions: Blinded Reader 1
The percent accuracy (total number of lesions matching the comparator divided by the total number of lesions identified by gadobutrol) comparison of the 0.03 and 0.1 mmol/kg gadobutrol doses and the 0.1 and 0.3 mmol/kg gadobutrol doses using detection of all comparator-detected matched enhanced lesions was performed for BR 1
Accuracy Comparison of Gadobutrol Doses - Detection of Matched Enhanced Lesions: Blinded Reader 2
The percent accuracy (total number of lesions matching the comparator divided by the total number of lesions identified by gadobutrol) comparison of the 0.03 and 0.1 mmol/kg gadobutrol doses and the 0.1 and 0.3 mmol/kg gadobutrol doses using detection of all comparator-detected matched enhanced lesions was performed for BR 2
Accuracy Comparison of Gadobutrol Doses - Detection of Matched Enhanced Lesions: Blinded Reader 3
The percent accuracy (total number of lesions matching the comparator divided by the total number of lesions identified by gadobutrol) comparison of the 0.03 and 0.1 mmol/kg gadobutrol doses and the 0.1 and 0.3 mmol/kg gadobutrol doses using detection of all comparator-detected matched enhanced lesions was performed for BR 3
Evaluation of the Correct Diagnosis Following Gadobutrol-enhanced and Unenhanced MRI
The gadobutrol-enhanced and unenhanced MRI diagnoses of the average reader were compared to the final diagnosis.
Evaluation of the Diagnostic Confidence Based on Unenhanced MRI and Combined Unenhanced and Enhanced MRI
The diagnostic confidence, the level of certainty in a diagnosis, was determined based on the average of the blinded readers.
Evaluation of Perfusion Map Quality (Uncorrected Cerebral Blood Volume [CBV]) - Blinded Reader 1
BR 1 evaluated the visibility of the lesion(s) on the uncorrected CBV perfusion map.
Evaluation of Perfusion Map Quality (Uncorrected Cerebral Blood Volume (CBV)) - Blinded Reader 2
BR 2 evaluated the visibility of the lesion(s) on the uncorrected CBV perfusion map.
Evaluation of Perfusion Map Quality (Uncorrected Cerebral Blood Volume (CBV)) - Blinded Reader 3
BR 3 evaluated the visibility of the lesion(s) on the uncorrected CBV perfusion map.
Evaluation of Perfusion Map Quality (Corrected Cerebral Blood Volume (CBV)) - Blinded Reader 1
BR 1 evaluated the visibility of the lesion(s) on the corrected CBV perfusion map.
Evaluation of Perfusion Map Quality (Corrected Cerebral Blood Volume (CBV)) - Blinded Reader 2
BR 2 evaluated the visibility of the lesion(s) on the corrected CBV perfusion map.
Evaluation of Perfusion Map Quality (Corrected Cerebral Blood Volume (CBV)) - Blinded Reader 3
BR 3 evaluated the visibility of the lesion(s) on the corrected CBV perfusion map.
Evaluation of Perfusion Map Quality (Cerebral Blood Flow (CBF)) - Blinded Reader 1
BR 1 evaluated the visibility of the lesion(s) on the CBF perfusion map.
Evaluation of Perfusion Map Quality (Cerebral Blood Flow (CBF)) - Blinded Reader 2
BR 2 evaluated the visibility of the lesion(s) on the CBF perfusion map.
Evaluation of Perfusion Map Quality (Cerebral Blood Flow (CBF)) - Blinded Reader 3
BR 3 evaluated the visibility of the lesion(s) on the CBF perfusion map.
Evaluation of Perfusion Map Quality (Time to Peak (TTP)) - Blinded Reader 1
BR 1 evaluated the visibility of the lesion(s) on the TTP perfusion map.
Evaluation of Perfusion Map Quality (Time to Peak (TTP)) - Blinded Reader 2
BR 2 evaluated the visibility of the lesion(s) on the TTP perfusion map.
Evaluation of Perfusion Map Quality (Time to Peak (TTP)) - Blinded Reader 3
BR 3 evaluated the visibility of the lesion(s) on the TTP perfusion map.
Evaluation of Perfusion Map Quality (Mean Transit Time (MTT)) - Blinded Reader 1
BR 1 evaluated the visibility of the lesion(s) on the MTT perfusion map.
Evaluation of Perfusion Map Quality (Mean Transit Time (MTT)) - Blinded Reader 2
BR 2 evaluated the visibility of the lesion(s) on the MTT perfusion map.
Evaluation of Perfusion Map Quality (Mean Transit Time (MTT)) - Blinded Reader 3
BR 3 evaluated the visibility of the lesion(s) on the MTT perfusion map.
Evaluation of Perfusion Map Quality (Permeability Factor (PF) - Blinded Reader 1
BR 1 evaluated the visibility of the lesion(s) on the PF perfusion map.
Evaluation of Perfusion Map Quality (Permeability Factor (PF) - Blinded Reader 2
BR 2 evaluated the visibility of the lesion(s) on the PF perfusion map.
Evaluation of Perfusion Map Quality (Permeability Factor (PF)) - Blinded Reader 3
BR 3 evaluated the visibility of the lesion(s) on the PF perfusion map.
Evaluation of Perfusion Map Parameter Value (Uncorrected Cerebral Blood Volume (CBV)) - Independent Radiologist
The independent radiologist determined the uncorrected CBV for each lesion. CBV is the volume of blood in the tissue.
Evaluation of Perfusion Map Parameter Value (Corrected Cerebral Blood Volume (CBV)) - Independent Radiologist
The independent radiologist determined the corrected CBV for each lesion. CBV is the volume of blood in the tissue.
Evaluation of Perfusion Map Parameter Value (Cerebral Blood Flow (CBF)) - Independent Radiologist
The independent radiologist determined the CBF for each lesion. CBF is the volume of blood passing through tissue per unit of time.
Evaluation of Perfusion Map Parameter Value (Time to Peak (TTP)) - Independent Radiologist
The independent radiologist determined the TTP for each lesion. TTP is the delay between the arrival of the contrast agent bolus arrival time and the peak of the concentration curve.
Evaluation of Perfusion Map Parameter Value (Mean Transit Time (MTT)) - Independent Radiologist
The independent radiologist determined the MTT for each lesion. The MTT is the time (seconds) for contrast to pass through tissues.
Evaluation of Perfusion Map Parameter Value (Permeability Factor (PF)) - Independent Radiologist
The independent radiologist determined the PF for each lesion
Evaluation of Perfusion Map Artifacts (Uncorrected Cerebral Blood Volume (CBV)) - Blinded Reader
The blinded reader evaluated if artifacts were present on the uncorrected CBV perfusion map and recorded the type of the major artifact. EPI: echo-planar imaging; T2: transversal relaxation time.
Evaluation of Perfusion Map Artifacts (Corrected Cerebral Blood Volume (CBV)) - Blinded Reader
The blinded reader evaluated if artifacts were present on the corrected CBV perfusion map and recorded the type of the major artifact. EPI: echo-planar imaging; T2: transversal relaxation time. CBV is the fraction of the tissue volume occupied by the blood.
Evaluation of Perfusion Map Artifacts (Cerebral Blood Flow (CBF)) - Blinded Reader
The blinded reader evaluated if artifacts were present on the CBF perfusion map and recorded the type of the major artifact. EPI: echo-planar imaging; T2: transversal relaxation time
Evaluation of Perfusion Map Artifacts (Time to Peak (TTP)) - Blinded Reader
The blinded reader evaluated if artifacts were present on the TTP perfusion map and recorded the type of the major artifact. EPI: echo-planar imaging; T2: transversal relaxation time
Evaluation of Perfusion Map Artifacts (Mean Transit Time (MTT)) - Blinded Reader
The blinded reader evaluated if artifacts were present on the MTT perfusion map and recorded the type of the major artifact. EPI: echo-planar imaging; T2: transversal relaxation time
Evaluation of Perfusion Map Artifacts (Permeability Factor (PF)) - Blinded Reader
The blinded reader evaluated if artifacts were present on the PF perfusion map and recorded the type of the major artifact. EPI: echo-planar imaging; T2: transversal relaxation time
Evaluation of MRI Tumor Grade Agreement With Biopsy Results by Dose Group
The blinded readers gave an estimation of the tumor grade of brain tumors (low grade [I or II] or high grade [III or IV]) in terms of malignancy using the information obtained by perfusion imaging, which was compared to the biopsy sample results
Contrast to Noise Ratio (CNR) of Lesion/Gray Matter and Lesion/White Matter
CNR between lesion/gray matter and lesion/white matter in the perfusion imaging was defined as the signal intensity (SI) difference between lesion and gray or white matter divided by the standard deviation of background noise. An independent radiologist evaluated the gadobutrol-enhanced perfusion MRI for signal intensity.