Assessment of chemotherapy response in non-Hodgkin lymphoma involving the neck utilizing diffusion kurtosis imaging: a preliminary study

PURPOSE:We aimed to examine the utility of non-Gaussian diffusion kurtosis imaging (DKI) for assessment of chemotherapy response in patients with cervical (neck) non-Hodgkin lymphoma (NHL).METHODS:Patients with cervical NHL underwent 3.0 T magnetic resonance imaging with maximal b value of 2000 s/mm2 at baseline and seven days after chemotherapy onset. Apparent diffusion coefficient (ADC) value and diffusion kurtosis imaging maps for diffusion coefficient (D) and kurtosis (K) were calculated. Based on clinical examination, laboratory screening, and PET/CTs, patients were classified as responders or nonresponders.RESULTS:Twenty-six patients were enrolled. Among them, 24 patients were classified as responders and two as nonresponders. For responders, mean follow-up ADC and D increased significantly compared with baseline (ADC: 0.92±0.11 ×10-3 mm2/s vs. 0.68±0.11 ×10-3 mm2/s; D: 1.47±0.32 ×10-3 mm2/s vs. 0.98±0.21 ×10-3 mm2/s, P < 0.001 for both). Mean follow-up K decreased significantly compared with baseline (1.14±0.10 vs. 1.47±0.19, P < 0.001) for responders. Dratio showed significant positive correlation and high agreement with ADCratio (r = 0.776, P < 0.001). Likewise, Kratio showed significant negative correlation and high agreement with ADCratio (r = -0.658, P < 0.001).CONCLUSION:The new DKI model may serve as a new biomarker for the evaluation of early chemotherapy response in NHL

The value of blood oxygenation level-dependent (BOLD) MR imaging in differentiation of renal solid mass and grading of renal cell carcinoma (RCC): analysis based on the largest cross-sectional area versus the entire whole tumour.

OBJECTIVES:To study the value of assessing renal masses using different methods in parameter approaches and to determine whether BOLD MRI is helpful in differentiating RCC from benign renal masses, differentiating clear-cell RCC from renal masses other than clear-cell RCC and determining the tumour grade. METHODS:Ninety-five patients with 139 renal masses (93 malignant and 46 benign) who underwent abdominal BOLD MRI were enrolled. R2* values were derived from the largest cross-section (R2*largest) and from the whole tumour (R2*whole). Intra-observer and inter-observer agreements were analysed based on two measurements by the same observer and the first measurement from each observer, respectively, and these agreements are reported with intra-class correlation coefficients and 95% confidence intervals. The diagnostic value of the R2* value in the evaluation was assessed with receiver-operating characteristic analysis. RESULTS:The intra-observer agreement was very good for R2*largest and R2*whole (all > 0.8). The inter-observer agreement of R2*whole (0.75, 95% confidence interval: 0.69~0.79) was good and was significantly improved compared with the R2*largest (0.61, 95% confidence interval: 0.52~0.68), as there was no overlap in the 95% confidence interval of the intra-class correlation coefficients. The diagnostic value in differentiating renal cell carcinoma from benign lesions with R2*whole (AUC=0.79/0.78[observer1/observer2]) and R2*largest (AUC=0.75[observer1]) was good and significantly higher (p=0.01 for R2*largest[observer2] vs R2*whole[observer2], p 0.7) and were not significantly different (p=0.89/0.93 for R2*largest vs R2*whole[observer1/observer2], 0.96 for R2*whole[observer1] vs R2*largest[observer2] and 0.96 for R2*whole [observer2] vs R2*largest[observer1]). CONCLUSIONS:BOLD MRI could provide a feasible parameter for differentiating renal cell carcinoma from benign renal masses and for predicting clear-cell renal cell carcinoma grading. Compared with the largest cross-section, assessing the whole tumour provides better inter-observer agreement in parameter measurement for differentiating renal cell carcinoma from benign renal masses

The R2*_largest and R2*_whole values calculated by both observers.

<p>¹. p value for difference of R2* value between groups of RCCs and benign lesions.</p><p>². p value for difference of R2* value between groups of ccRCCs and renal masses other than cRCC.</p><p>³. p value for difference of R2* value between groups of high-grade and low-grade cRCCs.</p><p>The R2*_largest and R2*_whole values calculated by both observers.</p

Consistency of the parameter measure procedure.

<p>Consistency of the parameter measure procedure.</p

Bland-Altman plots for intra- and inter-observer agreement of R2* measurements based on the largest cross-section and the whole tumour with mean absolute differences (continuous line) and 95% CI of the mean differences (dashed lines).

<p>For intra-observer agreement, measurements from both the first and second MRI scan were included in this analysis. While for the inter-observer agreement, the Bland-Altman plot shows the difference between measurements of two observers against the average measurement. (A) Intra-observer agreement of R2*largest for observer 1. (B) Intra-observer agreement of R2*largest for observer 2. (C) Intra-observer agreement of R2*whole for observer 1. (D) Intra-observer agreement of R2*whole for observer 2. (E) Inter-observer agreement for R2*largest. (F) Inter-observer agreement for R2*whole.</p

MRI scans of angiomyolipoma.

<p>(A) unenhanced T1-weighted in-phase (B) contrast-enhanced T1-weighted with fat suppression at corticomedullary phase (C) contrast-enhanced T1-weighted with fat suppression at nephrographic phase (D) coronal T2-weighted image (E) T2-weighted image with fat suppression (F) colour rate of spin dephasing (R2*) map, mean R2* value</p

MRI scans of cRCC.

<p>(A) unenhanced T1-weighted in-phase (B) contrast-enhanced T1-weighted with fat suppression at nephrographic phase (C) T2-weighted image with fat suppression (D) coronal T2-weighted image (E) colour rate of spin dephasing (R2*) map, mean R2* value of renal cell carcinoma and histogram of R2* value derived based on largest cross-section and the whole tumour (F).</p

The R2*_largest and R2*_whole values calculated by both observers.

<p>¹. p value for difference of R2* value between groups of RCCs and benign lesions.</p><p>². p value for difference of R2* value between groups of ccRCCs and renal masses other than cRCC.</p><p>³. p value for difference of R2* value between groups of high-grade and low-grade cRCCs.</p><p>The R2*_largest and R2*_whole values calculated by both observers.</p