Colorectal carcinoma: Ex vivo evaluation using q-space imaging; Correlation with histopathologic findings

J Magn Reson Imaging. 2018 Oct;48(4):1059-1068. doi: 10.1002/jmri.26018. Epub 2018 Mar 30.

Abstract

Background: Although the prognosis of colorectal carcinoma (CRC) patients depends on the histologic grade (HG) and lymph node metastasis (LNM), accurate preoperative assessment of these prognostic factors is often difficult.

Purpose: To assess the HG and extent of LNM by q-space imaging (QSI) for preoperative diagnosis of CRC.

Study type: Prospective.

Specimen: A total of 20 colorectal tissue samples containing adenocarcinomas and resected lymph nodes (LNs).

Field strength/sequence: QSI was performed with a 3T MRI system using a diffusion-weighted echo-planar imaging sequence: repetition time, 10,000 msec; echo time, 216 or 210 msec; field of view, 113 × 73.45 mm; matrix, 120 × 78; section thickness, 4 mm; and 11 b values ranging from 0 to 9000 s/mm2 .

Assessment: The mean displacement (MDP; μm), zero-displacement probability (ZDP; arbitrary unit [a.u.]), kurtosis (K; a.u.), and apparent diffusion coefficient (ADC) were analyzed by two observers and compared with histopathologic findings.

Statistical tests: Spearman's rank correlation coefficient, Mann-Whitney U-test, and ROC curve analyses.

Results: For all 20 carcinomas, the MDP, ZDP, K, and ADC were 8.87 ± 0.37 μm, 82.0 ± 6.2 a.u., 74.3 ± 3.0 a.u., and 0.219 ± 0.040 × 10-3 mm2 /s, respectively. The MDP (r = -0.768; P < 0.001), ZDP (r = 0.768; P < 0.001), and K (r = 0.785; P < 0.001) were significantly correlated with the HG of CRC, but not the ADC (r = 0.088; P = 0.712). There were also significant differences in the MDP, ZDP, and K between metastatic and nonmetastatic LNs (all, P < 0.001), but not the ADC (P = 0.082). In the HG of CRC and LNM, the area under the curve was significantly greater for MDP, ZDP, and K than for ADC.

Data conclusion: QSI provides useful diagnostic information to assess the HG and extent of LNM in CRC.

Level of evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:1059-1068.

Keywords: MR imaging; colon; colorectal carcinoma; diffusion-weighted imaging; q-space imaging; rectum.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Algorithms
  • Area Under Curve
  • Colorectal Neoplasms / diagnostic imaging*
  • Diffusion Magnetic Resonance Imaging*
  • Female
  • Humans
  • Image Interpretation, Computer-Assisted / methods
  • Image Processing, Computer-Assisted / methods*
  • Lymphatic Metastasis / diagnostic imaging*
  • Male
  • Middle Aged
  • Preoperative Period
  • Prognosis
  • Prospective Studies
  • ROC Curve
  • Reproducibility of Results
  • Sensitivity and Specificity