Fig 1.
Overview of the used sequences and field-strengths across the four different cohorts.
Spoiled gradient echo (SPGR), balanced steady-state free precession (bSSFP), chronic obstructive pulmonary disease (COPD), pulmonary arterial hypertension (PAH), cystic fibrosis (CF).
Fig 2.
Representative quantified perfusion maps from each cohort.
In the reproducibility cohort a 52-year-old female with COPD and minor changes after two weeks. In the gadolinium cohort a 64-year-old female with COPD and increased values after GD. In the field-strength cohort an 18-year-old female with CF lower values at 3T. In the sequence cohort a 50-year-old-female patient with COPD and fewer low values.
Fig 3.
Voxelwise correlation of QQuant of each cohort.
Patients are marked in different colors. Extreme values represent central lung vessels which were included in A, C, E, G. Values over 500 ml/min/100ml were excluded in B, D, F, H to evaluate only the distribution within the lung parenchyma. The reproducibility cohort is depicted in A&B, the gadolinium cohort in C&D, the field-strength cohort in E&F and the sequence cohort in G&H.
Fig 4.
Histogram analyses of normalized QQuant of each cohort.
Similar distribution of QQuant values at baseline and follow-up and before and after gadobutrol injection is seen in A and B. Major differences of the value distribution are visible between 1.5T and 3T with a downshift of the values at 3T in C. Smaller differences between the value distributions of both sequences with relatively fewer small values for the bSSFP are depicted in D.
Table 1.
Median values of the perfusion quantification ± interquartile range.
Table 2.
Median regional Pearson correlations of QQuant values ± interquartile range in each cohort.