(A–C) Comparison of the subsets of the randomly
selected 30 patients evaluated by the radiologists, whereby the
convolutional neural network (CNN) succeeded in convincing at least one
radiologist (17 patients) that it was the multiecho spin-echo (MESE) map
and where it did not (13 patients). In B, age is presented
in years. (D) Comparison between the success and failure
sets of multiecho spin-echo (MESE) T2 and CNN T2 in the six different
cartilage subregions. (E, F) Sample (E) MESE
T2 map and (F) CNN T2 map in a patient for which both
readers failed to recognize which map was the CNN T2 map. (G,
H) Sample (G) MESE T2 map and (H)
CNN T2 map on which both readers accurately recognized which image was
the CNN T2 map but one or both deemed the CNN T2 map to be better in
terms of signal-to-noise ratio, sharpness, artifacts, and overall
quality. (I) Root-mean-square difference (RMSD) and average
absolute difference (Av abs diff) between the MESE T2 and CNN T2 maps.
(J) Coefficients of variation (CV) for the MESE and CNN
maps. (K) Comparison of average values from the MESE and
CNN T2 maps. Plot shows the results for all 456 patients in the test
dataset. One point represents one patient. The solid line represents the
least-squares fit line through the points, while the dashed line
represents the y equal to x line. DA = deep anterior, DC = deep central,
diff = difference, DP = deep posterior, KL = Kellgren-Lawrence, SA =
superficial anterior, SC = superficial central, SP = superficial
posterior.