Adriano Massimiliano Priola1, Sandro Massimo Priola2, Daniela Parlatano2, Dario Gned2, Maria Teresa Giraudo3, Roberto Giardino4, Bruno Ferrero5, Francesco Ardissone4, Andrea Veltri2. 1. Department of Diagnostic Imaging, San Luigi Gonzaga University Hospital, Regione Gonzole 10, 10043, Orbassano, Torino, Italy. adriano.priola@inwind.it. 2. Department of Diagnostic Imaging, San Luigi Gonzaga University Hospital, Regione Gonzole 10, 10043, Orbassano, Torino, Italy. 3. Department of Mathematics "Giuseppe Peano", University of Torino, Via Carlo Alberto 10, 10123, Torino, Italy. 4. Department of Thoracic Surgery, San Luigi Gonzaga University Hospital, Regione Gonzole 10, 10043, Orbassano, Torino, Italy. 5. Department of Neurology, San Luigi Gonzaga University Hospital, Regione Gonzole 10, 10043, Orbassano, Torino, Italy.
Abstract
OBJECTIVES: To investigate inter-reader reproducibility of five different region-of-interest (ROI) protocols for apparent diffusion coefficient (ADC) measurements in the anterior mediastinum. METHODS: In eighty-one subjects, on ADC mapping, two readers measured the ADC using five methods of ROI positioning that encompassed the entire tissue (whole tissue volume [WTV], three slices observer-defined [TSOD], single-slice [SS]) or the more restricted areas (one small round ROI [OSR]), multiple small round ROI [MSR]). Inter-observer variability was assessed with interclass correlation coefficient (ICC), coefficient of variation (CoV), and Bland-Altman analysis. Nonparametric tests were performed to compare the ADC between ROI methods. The measurement time was recorded and compared between ROI methods. RESULTS: All methods showed excellent inter-reader agreement with best and worst reproducibility in WTV and OSR, respectively (ICC, 0.937/0.874; CoV, 7.3 %/16.8 %; limits of agreement, ±0.44/±0.77 × 10-3 mm2/s). ADC values of OSR and MSR were significantly lower compared to the other methods in both readers (p < 0.001). The SS and OSR methods required less measurement time (14 ± 2 s) compared to the others (p < 0.0001), while the WTV method required the longest measurement time (90 ± 56 and 77 ± 49 s for each reader) (p < 0.0001). CONCLUSIONS: All methods demonstrate excellent inter-observer reproducibility with the best agreement in WTV, although it requires the longest measurement time. KEY POINTS: • All ROI protocols show excellent inter-observer reproducibility. • WTV measurements provide the most reproducible ADC values. • ROI size and positioning influence ADC measurements in the anterior mediastinum. • ADC values of OSR and MSR are significantly lower than other methods. • OSR and WTV methods require the shortest and longest measurement time, respectively.
OBJECTIVES: To investigate inter-reader reproducibility of five different region-of-interest (ROI) protocols for apparent diffusion coefficient (ADC) measurements in the anterior mediastinum. METHODS: In eighty-one subjects, on ADC mapping, two readers measured the ADC using five methods of ROI positioning that encompassed the entire tissue (whole tissue volume [WTV], three slices observer-defined [TSOD], single-slice [SS]) or the more restricted areas (one small round ROI [OSR]), multiple small round ROI [MSR]). Inter-observer variability was assessed with interclass correlation coefficient (ICC), coefficient of variation (CoV), and Bland-Altman analysis. Nonparametric tests were performed to compare the ADC between ROI methods. The measurement time was recorded and compared between ROI methods. RESULTS: All methods showed excellent inter-reader agreement with best and worst reproducibility in WTV and OSR, respectively (ICC, 0.937/0.874; CoV, 7.3 %/16.8 %; limits of agreement, ±0.44/±0.77 × 10-3 mm2/s). ADC values of OSR and MSR were significantly lower compared to the other methods in both readers (p < 0.001). The SS and OSR methods required less measurement time (14 ± 2 s) compared to the others (p < 0.0001), while the WTV method required the longest measurement time (90 ± 56 and 77 ± 49 s for each reader) (p < 0.0001). CONCLUSIONS: All methods demonstrate excellent inter-observer reproducibility with the best agreement in WTV, although it requires the longest measurement time. KEY POINTS: • All ROI protocols show excellent inter-observer reproducibility. • WTV measurements provide the most reproducible ADC values. • ROI size and positioning influence ADC measurements in the anterior mediastinum. • ADC values of OSR and MSR are significantly lower than other methods. • OSR and WTV methods require the shortest and longest measurement time, respectively.
Entities:
Keywords:
Anterior mediastinum; Apparent diffusion coefficient; Diffusion-weighted magnetic resonance imaging; Inter-observer variability; Region of interest
Authors: Jakob Møllenbach Møller; Mikkel Østergaard; Henrik S Thomsen; Stine Hangaard; Inge J Sørensen; Ole Rintek Madsen; Susanne J Pedersen Journal: BJR Open Date: 2020-12-21