Whole-tumor histogram analysis of synthetic MRI for discriminating benign from malignant sinonasal tumors: correlations with histopathologic factors

Abstract

Background: Histogram parameters from synthetic magnetic resonance imaging (SyMRI) may provide more diagnostic information than mean values in differentiating benign from malignant sinonasal tumors. The histopathologic basis of SyMRI in characterizing malignant sinonasal tumors is still unclear. This study aimed to explore the potential value of SyMRI quantitative maps with whole-lesion histogram analysis in the diagnosis of benign and malignant sinonasal tumors and the correlations between SyMRI-derived histogram metrics and histopathologic features in malignant sinonasal tumors.

Methods: A total of 76 patients (29 benign and 47 malignant) with sinonasal tumors were enrolled. Nine histogram parameters of the whole tumor were extracted from T1, T2, and proton density (PD) quantitative maps, respectively. Univariate and multivariate analyses were utilized to explore the association between benign and malignant sinonasal tumors. Models based on single, combined quantitative maps, and clinical features were established to evaluate the diagnostic performance. The Spearman correlation coefficient was used to assess the correlation between histogram quantitative metrics of SyMRI and histopathological features.

Results: For SyMRI parameters, 18 histogram metrics showed significant differences between benign and malignant sinonasal tumors (all P<0.05). The combined model based on T2 map (T2-90th percentile, Minimum, and Kurtosis) and clinical features (age and bone destruction) attained the best diagnostic performance in discrimination of benign and malignant sinonasal tumors with the highest area under the curve (AUC) of 0.908, sensitivity of 91.5%, and specificity of 82.8%. Moreover, several histogram quantitative parameters of malignancies were correlated with Ki-67 (r=-0.465 to -0.28), p53 (r=-0.476 to 0.414) and epidermal growth factor receptor (EGFR) status (r=-0.428/0.419). The T2-90th Percentile was independently associated with Ki-67 labeling index (LI) (P<0.05).

Conclusions: Whole-tumor histogram quantitative parameters of SyMRI could further improve the diagnostic performance in differentiating benign from malignant sinonasal tumors and may serve as potential biomarkers in assessing the histopathologic features.

Keywords: Synthetic magnetic resonance imaging (SyMRI); diagnosis; histogram; sinonasal tumors.

Figure 1

The workflow diagram of study population selection. MRI, magnetic resonance imaging; SyMRI, synthetic MRI.

Figure 2

Representative SyMRI and whole-tumor histogram analyses. (A-E) Case 1. A 48-year-old female with sinonasal hemangioma. (F-J) Case 2. A 53-year-old female with nasal SCC, respectively. An ROI was placed along the lesion (red circle). Both patients demonstrated well-defined masses in the left nasal cavity. Hemangioma (A) showed hyperintensity and SCC (F) displayed heterogeneous isointensity on T2-weighted imaging of SyMRI. In comparison with hemangioma, SCC showed lower T1, T2, and PD value on T1 map (B,G), T2 map (C,H), and PD map (D,I), respectively. Manual three-dimensional segmentations of tumors (E,J), histograms of T1 map (K), T2 map (L) and PD map (M). PD, proton density; ROI, region of interest; SCC, squamous cell carcinoma; SyMRI, synthetic MRI.

Figure 3

Column charts show the comparison of representative histogram features based on single SyMRI quantitative map in benign and malignant sinonasal tumors. T1 map (A), T2 map (B), and PD map (C). *, P<0.05; **, P<0.01; ***, P<0.001. PD, proton density; SyMRI, synthetic magnetic resonance imaging.

Figure 4

ROC curves of different models and correlation analyses. (A) Comparison of ROC curves of diagnostic models based on single and combined SyMRI quantitative maps. (B) Correlation between the T2-90th percentile and Ki-67 LI (r=−0.465, P<0.001). AUC, area under the curve; LI, labeling index; PD, proton density; ROC, receiver operating characteristic; SyMRI, synthetic magnetic resonance imaging.

Figure 5

ROC curves of representative histogram metrics of SyMRI in each map (T1 map, T2 map and PD map) in differentiating (A) Ki-67, (B) P53 and (C) EGFR expression status of sinonasal malignant tumors. AUC, area under the curve; EGFR, epidermal growth factor receptor; PD, proton density; ROC, receiver operating characteristic; SyMRI, synthetic magnetic resonance imaging.