title: Type 1 papillary renal cell carcinoma: differentiation from Type 2 papillary RCC on multiphasic MDCT.
abstract: To investigate whether multiphasic MDCT enhancement can help differentiate type 1 papillary renal cell carcinoma (RCC) from type 2 papillary RCC.
  
  
  
  With IRB approval for this HIPAA-compliant retrospective study, we derived a cohort of 36 type 1 papillary RCCs and 33 type 2 papillary RCCs with preoperative multiphasic MDCT with up to four phases (unenhanced, corticomedullary, nephrographic, and excretory) from 2000 to 2013. Following segmentation, a computer-assisted detection (CAD) algorithm selected a 0.5 cm-diameter region of maximal attenuation within each lesion in each phase; a 0.5 cm-diameter region of interest was manually placed on uninvolved renal cortex in each phase. The relative attenuation of each lesion was calculated as [(Lesion attenuation-cortex attenuation)/cortex attenuation] × 100. Absolute and relative attenuation values were compared using Mann-Whitney tests with Bonferroni correction for multiple comparisons.
  
  
  
  Relative excretory phase attenuation of type 2 papillary RCCs was significantly greater than that of type 1 papillary RCCs (2.0 vs. -18.3, p = 0.005). Relative excretory phase attenuation differentiated type 1 papillary RCCs from type 2 papillary RCCs with an accuracy of 73% (36/49), sensitivity of 87% (26/30), positive predictive value of 74% (26/35), and negative predictive value of 71% (10/14).
  
  
  
  Multiphasic MDCT enhancement may assist in differentiating type 1 papillary RCCs from type 2 papillary RCCs, if prospectively validated.
authors.affiliation: Department of Radiology, David Geffen School of Medicine at UCLA, Ronald Reagan-UCLA Medical Center, 757 Westwood Plaza, Suite 1638, Los Angeles, CA, USA. jryoung@ucla.edu.
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Young
authors.affiliation: Department of Radiology, David Geffen School of Medicine at UCLA, Ronald Reagan-UCLA Medical Center, 757 Westwood Plaza, Suite 1638, Los Angeles, CA, USA.
authors.forename: Heidi
authors.initials: H
authors.lastname: Coy
authors.affiliation: Department of Radiology, David Geffen School of Medicine at UCLA, Ronald Reagan-UCLA Medical Center, 757 Westwood Plaza, Suite 1638, Los Angeles, CA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Douek
authors.affiliation: Department of Radiology, David Geffen School of Medicine at UCLA, Ronald Reagan-UCLA Medical Center, 757 Westwood Plaza, Suite 1638, Los Angeles, CA, USA.
authors.forename: Pechin
authors.initials: P
authors.lastname: Lo
authors.affiliation: Department of Radiology, David Geffen School of Medicine at UCLA, Ronald Reagan-UCLA Medical Center, 757 Westwood Plaza, Suite 1638, Los Angeles, CA, USA.
authors.forename: James
authors.initials: J
authors.lastname: Sayre
authors.affiliation: Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Pantuck
authors.affiliation: Department of Radiology, David Geffen School of Medicine at UCLA, Ronald Reagan-UCLA Medical Center, 757 Westwood Plaza, Suite 1638, Los Angeles, CA, USA.
authors.forename: Steven S
authors.initials: SS
authors.lastname: Raman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging* / Q000473:pathology*; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: Multidetector computed tomography; Renal cell carcinoma; Type 1 papillary renal cell carcinoma; Type 2 papillary renal cell carcinoma