Shanker Raja MD, Presenter: Nothing to Disclose

Sadeq W. AlDandan MBBS, Abstract Co-Author: Nothing to Disclose

Sharad P. George MD, Abstract Co-Author: Nothing to Disclose

Abdullah AlRashed MBBS, Abstract Co-Author: Nothing to Disclose

Ahmad Lary MD, Abstract Co-Author: Nothing to Disclose

Akintokun Adekunle BS, Abstract Co-Author: Nothing to Disclose

Sven G. Larsson MD, Abstract Co-Author: Nothing to Disclose

Choroid plexus tumors (CPT) are rare pediatric tumors, histologically classified as papilloma (CPP), atypical (atCP), and Ca (CPCa). We explored if ADC histogram moments, percentiles and distances would be helpful for further management of pts. with CPT.

Normalized voxel ADC ratios (tumor/normal tissue) in 11 pts (male=6, female=5; mean age=7 yrs (range=3-516 months), were obtained by co-flagging CPT on coregistered T1W-C+ images and ADC maps (MIMvista workstation, Cleveland, USA). The VOI data were exported to EXCEL for histogram generation, computation of histogram moments (mean, SD, kurtosis, and skewness), percentiles/IQR (interquartile range); in addition intra and inter-group histogram distances (Bhattacharyya distance and Chi-square distance) were estimated. Multiple histogram metrics including SD, 95th percentile, and IQR were correlated with Ki-67 index.

Subtype group means were as follows: SD (0.18, 0.28, 0.36), 95th percentile (1.47, 1.82, 2.40), and IQR (0.18, 0.25, 0.43) in CPCa, CPP and atCP respectively. SD and 95th percentile were good differentiators between CPP and CPCa. Histogram estimates for individual atCP overlapped with those of CPCa and CPP. Intragroup subtype means of the histogram distances were as follows: Bhattacharyya distance (0.73, 0.61, 0.75) and Chi-square distance (1.36, 1.07, 1.38) in CPP, atCP, and CPCa respectively. Intergroup cross histogram distances were not helpful in classifying individual CPT (CPCa vs CPP) . Good correlation between Ki-67 and 95th percentile (r= -0.7), and SD (r= -0.66) were noted.

Detailed analysis of ADC histogram metrics, especially histogram moments and percentiles appears promising for the management of CPT. Our findings need to be confirmed in a larger series.

MR-ADC 95th percentile  and SD were notable differentiators between CPP and CPCa; while the observed overlap of histogram metrics in individual atCP lesions with those of CPP and CPCa may have management implications.

Raja, S, AlDandan, S, George, S, AlRashed, A, Lary, A, Adekunle, A, Larsson, S, MR-ADC Histogram Moments, Distances, and Percentiles in Management of Choroid Plexus Tumors, and Correlation with Histopathology and Ki-67.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14009175.html