Stromal tumor-infiltrating lymphocytes level as a prognostic factor for resected intrahepatic cholangiocarcinoma and its prediction by apparent diffusion coefficient

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) are a prognostic factor or an indicator of chemotherapy response for various malignancies. The aim of this study was to investigate the prognostic impact of TILs in resected intrahepatic cholangiocarcinoma (IHCC). We also investigated the usefulness of the apparent diffusion coefficient (ADC) in diffusion-weighted magnetic resonance imaging (DW-MRI) to predict TILs.

METHODS

We enrolled 23 patients with IHCC who underwent initial hepatic resection in Tokushima University Hospital from 2006 to 2017. We evaluated stromal TILs in the tumor marginal area and central area in surgical specimens. Patients were divided into low vs high stromal TILs groups. We analyzed the patients' clinicopathological factors, including prognosis, according to the degree of stromal TILs. We also analyzed the correlation between stromal TILs and the minimum ADC value.

RESULTS

Stromal TILs in the marginal area reflected overall survival more accurately than that in the central area. Additionally, marginal low TILs was significantly associated with lymph node metastasis and portal vein invasion. Both overall- and disease-free survival rates in the marginal low TILs group were significantly worse than those in the marginal high TILs group (P < 0.05). In the multivariate analysis, marginal low TILs were an independent prognostic factor for both overall- and disease-free survival (P < 0.05), and marginal low TILs were significantly associated with lower minimum ADC values (P < 0.02).

CONCLUSIONS

Stromal TILs, especially in the marginal area, might demonstrate prognostic impact in patients with IHCC. Moreover, the ADC values from MRI may predict TILs in IHCC tumor tissue.

SUVmax/ADC Ratio as a Molecular Imaging Biomarker for Diagnosis of Biopsy-Naïve Primary Prostate Cancer

Background:

Gallium-68-prostate-specific membrane antigen (⁶⁸Ga-PSMA) positron emission tomography/computed tomography (PET/CT) has recently been shown to be very high accuracy in biopsy-naïve prostate cancer (PCa) detection and can potentially improve the low specificity noted with diffusion-weighted magnetic resonance imaging (DW-MRI), especially in instances of prostate inflammation. We aimed to compare the diagnostic accuracy of DW-MRI and PSMA PET/CT using apparent diffusion coefficient (ADC) and maximum standardized uptake (SUV_max) values in the diagnosis of PCa.

Patients and Methods:

A retrospective study comparing and analyzing the diagnostic accuracy of prebiopsy DW-MRI and ⁶⁸Ga-PSMA PET/CTs done in patients with suspected PCa (raised prostate specific antigen [PSA] and/or positive digital rectal examination) from January 2019 to December 2020. The standard of reference was transrectal ultrasound-guided biopsies.

Results:

Sixty-seven patients were included in the study, mean age: 70 years (range 49–84), mean PSA: 23.2 ng/ml (range 2.97–45.6). Biopsy was positive for PCa in 56% (n = 38) and negative in 43% (n = 29). Of the benign results, benign hyperplasia was noted in 75% (n = 22) and prostatitis in 25% (n = 7). Of the PCa, 55% (n = 21) of were high International Society of Urological Pathology (ISUP) grade (4–5) and 45% (n = 17) low/intermediate ISUP grade (1–3). Overall the sensitivity/specificity/Accuracy for prediction of PCa of MRI using prostate imaging and reporting data system version 2 criteria and PSMA PET/CT using PCa molecular imaging standardized evaluation criteria was 92.1%/65.5%/80.5% and 76.3%/96.5%/85.1% respectively. Mean apparent diffusion co-efficient (mean ADC) value of benign lesions and PCa was 1.135 × 10^-3 mm²/s and 0.723 × 10^-3 mm²/s, respectively (P = 0.00001). Mean SUV_max and ADC of benign and PCa lesions was 4.01 and 16.4 (P = 0.000246). Mean SUV_max/ADC ratio of benign and malignant lesions was 3.8 × 103 versus 25.21 × 103 (P < 0.000026). Inverse correlation was noted between ADC and SUV_max values (R = −0.609), inverse correlation noted between ADC and Gleason's score (R = −0.198), and positive correlation of SUV_max and SUV_max/ADC with Gleason's score (R = 0.438 and R = 0.448). Receiver operating characteristic curve analysis revealed a SUV_max cutoff 6.03 (sensitivity/specificity - 76%/90%, area under the curve (AUC) - 0.935, Youden index (YI) - 0.66), ADC cutoff of 0.817 × 10⁻³ mm²/s (sensitivity/specificity – 79%/86%, AUC – 0.890, YI - 0.65), and SUV_max/ADC ratio cutoff of 7.43 × 103 (sensitivity/specificity – 87%/98%, AUC - 0.966, YI - 0.85) for PCa diagnosis.

Conclusion:

For diagnosis of biopsy-naïve PCas, the combination of diffusion-weighted MRI and PSMA PET/CT (i.e., SUV_max/ADC ratio) shows better diagnostic accuracy than either used alone and the combination of PET and MRI is especially useful when distinguishing cancer from prostatitis.

Diffusion-weighted imaging for the differentiation of Ewing sarcoma from osteosarcoma

OBJECTIVE

The purpose of this study is to assess the ability of apparent diffusion coefficient (ADC) values in differentiating Ewing sarcoma and osteosarcoma.

MATERIALS AND METHODS

This retrospective cross-sectional observational study included a total of 35 patients with a recent diagnosis of Ewing sarcoma (n = 13) and osteosarcoma (n = 22) who underwent conventional MRI and diffusion-weighted imaging (DWI). Three ADC measurements from the areas of the lowest diffusivity in ADC maps (ADC_min), and other areas with low diffusivity (ADC_other), were made independently by two observers on pre-treatment MRI, and the means of these measurements were compared using independent samples t-test. Intraclass correlation coefficient was calculated for inter-observer agreement.

RESULTS

There was a significant difference between the ADC_min (P < 0.001) and ADC_other (P < 0.001) in Ewing sarcoma and osteosarcoma for both observers. For Ewing sarcoma and osteosarcoma, mean ADC_min was 0.566 ± 0.07 and 1.193 ± 0.33 × 10^-3 mm²/s; 0.551 ± 0.08 and 1.182 ± 0.33 × 10^-3 mm²/s; and mean ADC_other was 0.813 ± 0.11 and 1.510 ± 0.35 × 10^-3 mm²/s; 0811 ± 0.12 and 1.501 ± 0.33 × 10^-3 mm²/s for observers 1 and 2, respectively. Inter-observer correlation coefficient for mean ADC_min was 0.994 and for mean ADC_other was 0.995.

CONCLUSION

Diffusion-weighted imaging and ADC values could be used in the differentiation of Ewing sarcoma and osteosarcoma in borderline cases.

The role of apparent diffusion coefficient as a predictive factor for tumor recurrence in patients with cerebellopontine angle epidermoid tumor

Intracranial epidermoid tumors are slowly growing benign tumors, but due to adjacent critical neurovascular structures, surgical resection is challenging, with the risk of recurrence. The apparent diffusion coefficient (ADC) has been used to evaluate the characteristics of brain tumors, but its utility for intracranial epidermoid tumors has not been specifically explored. This study analyzed the utility of preoperative ADC values in predicting tumor recurrence for patients with intracranial epidermoid tumors. Between 2008 and 2019, 21 patients underwent surgery for cerebellopontine angle (CPA) epidermoid tumor, and their preoperative ADC data were analyzed. The patients were divided into two groups: the recurrence group, defined by regrowth of the remnant tumor or newly developed mass after gross total resection on magnetic resonance imaging (MRI); and the stable group, defined by the absence of growth or evidence of tumor on MRI. Receiver operating characteristic (ROC) analysis was used to obtain the ADC cutoff values for predicting tumor recurrence. The prognostic value of the ADC was assessed using Kaplan-Meier curves. The minimum ADC values were significantly lower in the recurrence group than in the stable tumor group (P = 0.020). ROC analysis showed that a minimum ADC value lower than 804.5 × 10^-6 mm²/s could be used to predict higher recurrence risk of CPA epidermoid tumors. Non-total resection and mean and minimum ADC values lower than the respective cutoffs were negative predictors of recurrence-free survival. Minimum ADC values could be useful in predicting the recurrence of CPA epidermoid tumors.

Whole-lesion ADC histogram analysis versus single-slice ADC measurement for the differentiation of benign and malignant soft tissue tumors

PURPOSE

To evaluate and compare the diagnostic performances of whole-lesion apparent diffusion coefficient (ADC) histogram analysis and single-slice ADC measurement in the differentiation of benign and malignant soft tissue tumors.

METHODS

Fifty-three patients (mean age: 48.5 ± 21.4) with soft tissue tumors (27 benign and 26 malignant) were evaluated with diffusion-weighted MRI. Whole-lesion ADC histogram parameters (mean, median, 10^th percentile, 90^th percentile, minimum, maximum, range, mean absolute deviation, interquartile range, kurtosis, skewness, root mean squared, variance and inhomogeneity) of the lesions were measured using the whole solid tumor volume region of interest (ROI). In other sessions, five ROIs were manually drawn on the tumor slices, and mean ADC and minimum ADC of the measurements were calculated. Diagnostic accuracies of the two methods were assessed and compared.

RESULTS

Mean, median, minimum, 10^th percentile, 90^th percentile, range, root mean squared and inhomogeneity of ADC histogram analysis, and mean ADC and minimum ADC of single-slice ADC measurement were significantly different between malignant and benign lesions (p < 0.001 - p = 0.002). Among the ADC histogram parameters, 10^th percentile had the highest diagnostic performance (AUC = 0.825) followed by mean (AUC = 0.792) and median (AUC = 0.789). For the single-slice ADC measurement, the AUC of mean ADC and minimum ADC were 0.842 and 0.786, respectively. Mean ADC of single-slice measurement had a similar diagnostic performance with the 10^th percentile, mean, and median of ADC histogram analysis (p = 0.070-1.000).

CONCLUSIONS

Both whole-lesion ADC histogram analysis and single-slice ADC measurement can differentiate benign and malignant soft tissue tumors with similar diagnostic performances.

The signal intensity characteristics of normal bone marrow in diffusion weighted imaging at various menstrual status women

PURPOSE

Diffuse hyperintensities of the bone marrow in whole-body diffusion-weighted (DW) imaging (DWI) have been encountered more frequently in females aged 21-50 compared to elder females or men. Therefore, we aimed to visually evaluate DWI among pre-, peri- and postmenopausal women and to verify whether it correlates also quantitatively with hormonal status.

METHOD

The prospective study was approved by our institutional review board and informed consent was obtained in a total of 70 healthy premenopausal, perimenopausal, and postmenopausal women aged 40-58 years from February 2017 to October 2017. The bone marrow DW imaging signal characteristics were visually evaluated in comparison to the erector spinae muscle. Imaging data were acquired using a 1.5 T MRI yielding signal intensity values from a DWI-pulse sequence (b-value of 800 s/mm²; apparent diffusion coefficient (ADC) maps from b-values of 0-800 s/mm²), and a T2 mapping sequence covering the L2-L4 lumbar vertebrae. Serous estradiol (E2), follicle stimulating hormone (FSH), and luteinizing hormone (LH) were measured through venous blood assay. The relationship of the mean DW signal intensity (SI_DWI) with T2 values, female hormone level, and mean ADC were analyzed using Spearman's rho test.

RESULTS

The proportion of diffuse DWI hyperintensities of the bone marrow was significantly higher in premenopausal (91% (21/23)) women compared to peri- (75% (18/24)) and postmenopausal (8% (2/23)) women. A positive correlation was observed for the mean SI_DWI (median [interquartile range], 47.33 [30.14]) and mean T2 (mean ± SD, 121.01 ± 13.54) (r = 0.438, p < 0.001) as well as for the mean SI_DWI and E2 (median [interquartile range], 52.45 [92.78]) (r = 0.407, p < 0.001). A negative correlation was observed for the mean SI_DWI and serous FSH (median [interquartile range], 15.55 [42.08]) as well as for the mean SI_DWI and serous LH (median [interquartile range], 6.96 [31.06]) (r = -0.557, p < 0.001; r = -0.535, p < 0.001; respectively), but no significant correlation was found for mean SI_DWI and mean ADC (mean ± SD, 599.36 ± 82.70) (r = 0.099, p = 0.415). A negative correlation was also encountered for the mean T2 values and serous FSH (r = -0.339, p = 0.004) as well as for the mean T2 values and serous LH (r = -0.281, p = 0.018).

CONCLUSIONS

The mean SI_DWI correlates positively with mean T2 and serous E2 values, while there's no significant correlation with mean ADC, indicating that T2 shine-through effects might interfere with bone marrow signaling on DW images. Knowledge of the bone marrow signal characteristics changing in DW images in close relationship with menstrual status is essential to correctly interpret DWI in clinical practice.

Combining volumetric apparent diffusion coefficient histogram analysis with vesical imaging reporting and data system to predict the muscle invasion of bladder cancer

OBJECTIVE

The objective of this study was to explore whether volumetric apparent diffusion coefficient (ADC) histogram analysis can provide additional value to Vesical Imaging Reporting and Data System (VI-RADS) in differentiating muscle-invasive bladder cancer (MIBC) from non-muscle-invasive bladder cancer (NMIBC).

MATERIALS AND METHODS

80 patients were retrospectively reviewed with pathologically proven NMIBC (n = 53) or MIBC (n = 27). All patients underwent MRI including diffusion-weighted imaging (DWI) (b = 0, 800 s/mm²), and the VI-RADS score was evaluated based on DWI. Volumetric ADC histogram parameters were calculated from the volumetric of interest (VOI) on DWI, including the min ADC, mean ADC, median ADC, max ADC, 10th, 25th, 75th, 90th percentiles ADC, skewness, kurtosis, and entropy. The Mann-Whitney U-test was used to compare histogram parameters between NMIBC and MIBC. Receiver operating characteristic analysis was used to evaluate the diagnostic value of each significant parameter.

RESULTS

Among all parameters, the VI-RADS yield the highest Area Under the Curve (AUC, 0.88; sensitivity, 88.89%; specificity, 83.61%). MIBC had significantly lower min ADC, mean ADC, median ADC, 10th, 25th, 75th, and 90th percentiles ADC than NMIBC (p = 0.002, p < 0.001, p < 0.001, p = 0.003, p = 0.004, p < 0.001, p < 0.001). Skewness and kurtosis of MIBC were significantly higher than those of NMIBC (p < 0.001, p < 0.001). The combination of VI-RADS and skewness showed significantly higher AUC (AUC 0.923; 95% CI 0.847-0.969) than only with VI-RADS (AUC 0.880; 95% CI 0.793-0.940).

CONCLUSION

Volumetric ADC histogram analysis and VI-RADS are both useful methods in differentiating MIBC from NMIBC, and the volumetric ADC histogram analysis can provide additional value to VI-RADS.

Diffusion-weighted MRI of solid pancreatic lesions: Comparison between reduced field-of-view and large field-of-view sequences

PURPOSE

To compare the image quality, presence of artifacts and apparent diffusion coefficient (ADC) values of reduced field-of-view (rFOV) and large FOV (lFOV) single-shot spin-echo echo-planar diffusion-weighted imaging (DWI) in the evaluation of solid pancreatic lesion.

METHOD

The 3T MR examinations of 60 patients with solid pancreatic lesions were examined. Two Readers independently performed qualitative analysis and quantitative measurements of the ADC values of the solid pancreatic lesions in both rFOV and lFOV DWI sequence. The qualitative analysis parameters included: 1) Sharpness, 2) Distortion, Ghosting, Motion and Susceptibility artifacts, 3) Lesion Conspicuity and 4) Overall Image Quality. These parameters were evaluated using a 4-point scale. The T-test for paired data was used to compare qualitative scores and the ADC values of the rFOV and lFOV DWI sequences, and to assess inter-reader agreement.

RESULTS

The qualitative analysis yielded scores for the rFOV DWI sequence, which were better for sharpness, artifacts, and overall image quality as compared to the lFOV DWI sequence according to the only Reader 2 (the most experienced) (p ≤ 0.001). As to lesion conspicuity, no significant difference was found by either Reader (p ≥ 0.245). As to quantitative analysis, both Readers found no significant difference between the two sequences in the ADC values of various solid pancreatic lesions (p ≥ 0.156).

CONCLUSIONS

The rFOV DWI sequence of the pancreas provides better anatomic structure visualization, reduced artifacts, and better overall image quality as compared to the lFOV DWI sequence according to the Reader with the more experience in abdominal MRI. The ADC values were not significantly different in the two sequences. The rFOV DWI sequence could be included in the standard MRI protocol for the pancreas.

Quantitative diffusion-weighted imaging and dynamic contrast-enhanced MR imaging for assessment of tumor aggressiveness in prostate cancer at 3T

PURPOSE

To compare diffusion-weighted imaging (DWI) and dynamic contrast-enhanced MR imaging (DCE-MRI) for characterization of prostate cancer (PC).

METHODS

104 PC patients who underwent prostate multiparametric MRI at 3T including DWI and DCE-MRI before MRI-guided biopsy or radical prostatectomy. Apparent diffusion coefficient (ADC) with histogram analysis (mean, 0-25th percentile, skewness, and kurtosis), intravoxel incoherent motion model including D and f; stretched exponential model including distributed diffusion coefficient (DDC) and a; and permeability parameters including K^trans, K_ep, and V_e were obtained from a region of interest placed on the dominant tumor of each patient.

RESULTS

ADC_mean, ADC_0-25, D, DDC, and V_e were significantly lower and K_ep was significantly higher in GS ≥ 3 + 4 tumors (n = 89) than in GS = 3 + 3 tumors (n = 15), and also in GS ≥ 4 + 3 tumors (n = 57) than in GS ≤ 3 + 4 tumors (n = 47) (P < 0.001 to P = 0.040). f was significantly lower in GS ≥ 4 + 3 tumors than in GS ≤ 3 + 4 tumors (P = 0.022), but there was no significant difference between GS = 3 + 3 tumors and GS ≥ 3 + 4 tumors, or between the remaining metrics in both comparisons. In metrics with area under the curve (AUC) >0.80, there was a significant difference in AUC between ADC_0-25 and D, and DDC for separating GS ≤ 3 + 4 tumors from GS ≥ 4 + 3 tumors (P = 0.040 and P = 0.022, respectively). There were no significant differences between metrics with AUC > 0.80 for separating GS = 3 + 3 tumors from GS ≥ 3 + 4 tumors. ADC_0-25 had the highest correlation with Gleason grade (ρ = -0.625, P < 0.001).

CONCLUSIONS

DWI and DCE-MRI showed no apparent clinical superiority of non-Gaussian models or permeability MRI over the mono-exponential model for assessment of tumor aggressiveness in PC.

Diagnostic value of thyroid micronodules with high b-value diffusion weighted imaging: Comparative study with high-resolution ultrasound

PURPOSE

This study aims to compare the diagnostic performance of two imaging methods for thyroid nodules ≤1.0 cm and reduce unnecessary overdiagnosis.

METHODS

A retrospective study was conducted on 80 patients with pathologically confirmed solitary thyroid micronodules underwent both high-resolution ultrasound (HRUS) and High b-value (2000 s/mm²) diffusion weighted imaging (DWI). Intra- and interobserver agreement (Intraclass correlation coefficient) was followed by Kruskal-Wallis test to detect whether the quantitative apparent diffusion coefficient (ADC) and thyroid nodule subgroups were related. Cohen's kappa analysis was applied to assess the interobserver consistency of DWI and HRUS characteristics. The receiver operating characteristic curves were adopted for evaluating the diagnostic performance of thyroid malignancy. The sensitivity, specificity, and accuracy of the two imaging methods were compared using the McNemar's test and Kappa test.

RESULTS

A total of 80 patients were included, consisting of 43 malignant and 37 benign micronodules. The sensitivity, specificity and accuracy of DWI combined with rADC (ADCmin to ADCn ratio) for the diagnosis of thyroid micronodules were 83.7%, 89.2% and 86.3%, respectively. The area under the curve (AUC) was 0.91 (95% confidence interval [CI]: 0.84-0.97). The sensitivity, specificity and accuracy of HRUS diagnosis were 100%, 62.16% and 82.5%, respectively.

CONCLUSION

High b-value DWI is superior to HRUS for evaluating the diagnostic performance of solid thyroid micronodules. DWI and its ADC quantitative analysis could be added to the evaluation of thyroid micronodules to improve the specificity of diagnosis, reduce overdiagnosis and avoid unnecessary biopsies or surgeries.

Textural differences based on apparent diffusion coefficient maps for discriminating pT3 subclasses of rectal adenocarcinoma

BACKGROUND

The accuracy of discriminating pT3a from pT3b-c rectal cancer using high-resolution magnetic resonance imaging (MRI) remains unsatisfactory, although texture analysis (TA) could improve such discrimination.

AIM

To investigate the value of TA on apparent diffusion coefficient (ADC) maps in differentiating pT3a rectal adenocarcinomas from pT3b-c tumors.

METHODS

This was a case-control study of 59 patients with pT3 rectal adenocarcinoma, who underwent diffusion-weighted imaging (DWI) between October 2016 and December 2018. The inclusion criteria were: (1) Proven pT3 rectal adenocarcinoma; (2) Primary MRI including high-resolution T2-weighted image (T2WI) and DWI; and (3) Availability of pathological reports for surgical specimens. The exclusion criteria were: (1) Poor image quality; (2) Preoperative chemoradiation therapy; and (3) A different pathological type. First-order (ADC values, skewness, kurtosis, and uniformity) and second-order (energy, entropy, inertia, and correlation) texture features were derived from whole-lesion ADC maps. Receiver operating characteristic curves were used to determine the diagnostic value for pT3b-c tumors.

RESULTS

The final study population consisted of 59 patients (34 men and 25 women), with a median age of 66 years (range, 41-85 years). Thirty patients had pT3a, 24 had pT3b, and five had pT3c. Among the ADC first-order textural differences between pT3a and pT3b-c rectal adenocarcinomas, only skewness was significantly lower in the pT3a tumors than in pT3b-c tumors. Among the ADC second-order textural differences, energy and entropy were significantly different between pT3a and pT3b-c rectal adenocarcinomas. For differentiating pT3a rectal adenocarcinomas from pT3b-c tumors, the areas under the curves (AUCs) of skewness, energy, and entropy were 0.686, 0.657, and 0.747, respectively. Logistic regression analysis of all three features yielded a greater AUC (0.775) in differentiating pT3a rectal adenocarcinomas from pT3b-c tumors (69.0% sensitivity and 83.3% specificity).

CONCLUSION

TA features derived from ADC maps might potentially differentiate pT3a rectal adenocarcinomas from pT3b-c tumors.

[Quantitative evaluation of lumbar spine osteoporosis by apparent diffusion coefficient and signal intensity ratio of magnetic resonance diffusion-weighted magnetic resonance imaging]

OBJECTIVE

To investigate the application value of apparent diffusion coefficient (ADC) and signal intensity ratio (SIR) of MR diffusion-weighted imaging (DWI) in quantitative evaluation of lumbar spine osteoporosis.

METHODS

A total of 175 patients with lumbar spine diseases who received dualenergy X-ray absorption (DXA) bone mineral density (BMD), routine MRI and DWI of the lumbar spine from May 2017 to October 2019 were selected. According to the T-value of DXA, the patients were divided into osteoporosis group (64 cases), osteopenia group (53 cases) and normal bone mass group (58 cases). The ADC and SIR values of L₂-L₄ were measured and compared among the three groups and the correlation between ADC, SIR and BMD was analyzed. The ROC curve was used to evaluate the differential diagnosis value of ADC and SIR for osteoporosis, osteopenia and normal bone mass.

RESULTS

There were statistically significant differences in ADC and SIR values among three groups (F=41.386, 37.114, all P=0.000). The ADC value of the osteoporosis group was lower than that of the osteopenia group and the normal bone mass group, and the difference was statistically significant (t=3.540, 9.069, P=0.001, 0.000);the SIR value of the osteoporosis group was higher than that of the osteopenia group and the normal bone mass group, and the difference was statistically significant (t=5.083, 8.523, all P=0.000). Spearman correlation analysis showed that ADC value was positively correlated with BMD (r=0.313, P=0.004);SIR value was negatively correlated with BMD (r=- 0.589, P=0.000). Receiver operator characteristic (ROC) curve analysis showed that the area under curve (AUC), sensitivity andspecificity of ADC and SIR in the diagnosis of lumbar osteoporosis and osteopenia were 0.742, 89.1% , 52.8% and 0.729, 89.1%, 50.9% respectively (P=0.000);the AUC, sensitivity and specificity of ADC and SIR in the diagnosis of lumbar osteoporosis and normal bone mass were 0.815, 100.0%, 50.0% and 0.856, 65.6%, 93.1%, respectively (P=0.000);the AUC, sensitivity and specificity of ADC and SIR in the diagnosis of lumbar osteoporosis were 0.78, 89.1%, 51.4% and 0.795, 50.0% and 94.6% respectively (P=0.000);All have a certain diagnostic value.

CONCLUSION

ADC and SIR can better reflect the BMD of patients with lumbar diseases, and can quantitatively evaluate the vertebral body of osteoporosis, which play an important role in the diagnosis of lumbar osteoporosis.

Alterations of brain metrics in fetuses of women with polycystic ovary syndrome : a retrospective study based on fetal magnetic resonance imaging

Background

Maternal polycystic ovary syndrome (PCOS) has potential detrimental effects on the neurodevelopment of offspring. This study aimed to evaluate the brain metrics in fetuses of women with PCOS based on fetal magnetic resonance imaging (MRI).

Methods

This retrospective study included 60 pregnant women with PCOS (PCOS group) and 120 pregnant non-PCOS women (control group). Fetal MRI was performed followed an ultrasound and for numerous clinical indications including known or suspected fetal pathology, history of fetal abnormality in previous pregnancy or in a family member. Fetal brain biometry and apparent diffusion coefficient (ADC) value were analysed.

Results

After adjusting for potential confounders, fetuses in the PCOS group showed the following characteristics compared to fetuses in the control group: (1) smaller cerebral fronto-occipital diameter (FOD), vermian height (VH) and anteroposterior diameter of the pons (APDP) (evident before 32 weeks; P = 0.042, P = 0.002 and P = 0.016, respectively); (2) larger left and right biparietal index (evident before 32 weeks; P = 0.048 and P = 0.025, respectively); (3) smaller left lateral ventricle (LV) (evident after 32 weeks; P = 0.005); (4) larger anteroposterior diameter of the vermis (APDV) and hippocampal infolding angle (HIA) (evident after 32 weeks; P = 0.003 and P < 0.001, respectively); (5) higher ADC value in frontal white matter (FWM) and in basal ganglia (BG) (evident before and after 32 weeks; all P < 0.05).

Conclusions

There exist a different pattern of brain metrics in PCOS offspring in utero.

Neuroprotective effects of low-intensity transcranial ultrasound stimulation combined with Baicalin intervention on traumatic brain injury in animals

Low-intensity transcranial ultrasound stimulation (LITUS) can improve the inflammatory reaction after traumatic brain injury (TBI), and Baicalin also has a good protective effect on TBI. The purpose of this study was to observe the neuroprotective effect of LITUS combined with Baicalin intervention in the TBI rats. Sprague Dawley (SD) rats were randomly divided into 5 groups (n = 15) which were Sham control group, TBI group, LITUS group, Baicalin group, LITUS combined with Baicalin group (LB group). The rats were scanned with 3.0 T magnetic resonance imager, and the apparent diffusion coefficient (ADC) and the fractional anisotropy (FA) of the brain injury cortical area were determined at 3 h, 1, 3, 7 and 10 d after TBI. The ADC value, FA value, neurological function score and Nissl staining were used to assess the level of brain damage of rats. The results showed that on the 10th day after TBI, the ADC values of the TBI group, the LITUS group and the Baicalin group were remarkable greater than that of the L-B group (all adjusted P <  0.05), FA values were remarkable smaller than that of the L-B group (all adjusted P <  0.05), neurological function scores were remarkable greater than that of the L-B group (all adjusted P <  0.05), and Nissl body loss rates were remarkable greater than that of the L-B group (all adjusted P <  0.001). This study indicated that compared with the LITUS group and the Baicalin group, the L-B group can more effectively reduce level of brain damage after TBI, and the method of LITUS combined with Baicalin intervention was a more effective neuroprotection for brain injury.

Retrospective analysis of schwannoma in the oral and maxillofacial region: clinicopathological characteristics and specific pathology of ancient change

Schwannomas are benign tumours that originate from the Schwann cells of the nerve. Despite the frequency of their occurrence in the head and neck, data relating to their clinicopathological features in the region are limited. This study reviews the clinicopathological characteristics and specific pathology of ancient (degenerative) change in 40 cases in the oral and maxillofacial region. Medical records were reviewed of the 40 cases treated at Tokyo Medical and Dental University Hospital Faculty of Dentistry between 2000 and 2020. The most frequently involved site was the tongue, and the average tumour size was 13.2 mm. Degenerative changes were observed in eight cases. All tumours were completely excised through biopsy or local excision, and no recurrence was observed on clinical follow up. Statistical analyses revealed significant associations (p < 0.05) between ancient change and tumour size, and between ancient change and the apparent diffusion coefficient (ADC) value derived from diffusion-weighted magnetic resonance imaging (MRI). Analysis suggests that schwannoma progresses over a long period and subsequently undergoes secondary ancient changes. Pathological events such as cystic formation and haemorrhage that are associated with ancient changes, cause hypocellularity and lead to high ADC values. These values may indicate ancient change and should be considered when distinguishing schwannoma from other lesions.

Comparison of fractional anisotropy and apparent diffusion coefficient among hypoxic ischemic encephalopathy stages 1, 2, and 3 and with nonasphyxiated newborns in 18 areas of brain

Purpose

To determine the area and extent of injury in hypoxic encephalopathy stages by diffusion tensor imaging (DTI) using parameters apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values and their comparison with controls without any evidence of asphyxia. To correlate the outcome of hypoxia severity clinically and significant changes on DTI parameter.

Materials and Methods

DTI was done in 50 cases at median age of 12 and 20 controls at median age of 7 days. FA and apparent diffusion coefficient (ADC) were measured in several regions of interest (ROI). Continuous variables were analyzed using Student's t-test. Categorical variables were compared by Fisher's exact test. Comparison among multiple groups was done using analysis of variance (ANOVA) and post hoc Bonferroni test.

Results

Abnormalities were more easily and accurately determined in ROI with the help of FA and ADC values. When compared with controls FA values were significantly decreased and ADC values were significantly increased in cases, in ROI including both right and left side of thalamus, basal ganglia, posterior limb of internal capsule, cerebral peduncle, corticospinal tracts, frontal, parietal, temporal, occipital with P value < 0.05. The extent of injury was maximum in stage-III. There was no significant difference among males and females.

Conclusion

Compared to conventional magnetic resonance imaging (MRI), the evaluation of FA and ADC values using DTI can determine the extent and severity of injury in hypoxic encephalopathy. It can be used for early determination of brain injury in these patients.

Role of exponential apparent diffusion coefficient in characterizing breast lesions by 3.0 Tesla diffusion-weighted magnetic resonance imaging

Objective:

To evaluate the role of exponential apparent diffusion coefficient (ADC) as a tool for differentiating benign and malignant breast lesions.

Patients and Methods:

This prospective observational study included 88 breast lesions in 77 patients (between 18 and 85 years of age) who underwent 3T breast magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) using b-values of 0 and 800 s/mm² before biopsy. Mean exponential ADC and ADC of benign and malignant lesions obtained from DWI were compared. Receiver operating characteristics (ROC) curve analysis was undertaken to identify any cut-off for exponential ADC and ADC to predict malignancy. P value of <0.05 was considered statistically significant. Histopathology was taken as the gold standard.

Results:

According to histopathology, 65 lesions were malignant and 23 were benign. The mean ADC and exponential ADC values of malignant lesions were 0.9526 ± 0.203 × 10⁻³ mm²/s and 0.4774 ± 0.071, respectively, and for benign lesions were 1.48 ± 0.4903 × 10⁻³ mm²/s and 0.317 ± 0.1152, respectively. For both the parameters, differences were highly significant (P < 0.001). Cut-off value of ≤0.0011 mm²/s (P < 0.0001) for ADC provided 92.3% sensitivity and 73.9% specificity, whereas with an exponential ADC cut-off value of >0.4 (P < 0.0001) for malignant lesions, 93.9% sensitivity and 82.6% specificity was obtained. The performance of ADC and exponential ADC in distinguishing benign and malignant breast lesions based on respective cut-offs was comparable (P = 0.109).

Conclusion:

Exponential ADC can be used as a quantitative adjunct tool for characterizing breast lesions with comparable sensitivity and specificity as that of ADC.

Conventional and advanced brain MR imaging in patients with sickle cell anemia

Background:

Sickle cell disease (SCD) is an autosomal recessive hemolytic disorder; its cerebrovascular complications include silent cerebral ischemia, infarct, and brain atrophy. Conventional magnetic resonance imaging (MRI) often underestimates the extent of injury. Diffusion tensor imaging (DTI) can demonstrate and quantify microstructural brain changes in SCD cases having normal routine MRI.

Objective:

To identify various neurological abnormalities in asymptomatic sickle cell patients using routine MRI and to evaluate the microstructure of various regions of the brain using DTI.

Materials and Methods:

A prospective, randomized case–control study was conducted over a period of 2 years. A total of 58 cases of SCD and 56 age- and sex-matched controls were included. Routine MRI and DTI were performed in both the groups following a standard protocol. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were calculated in certain pre-defined regions. Primary data were analyzed using MS excel version 17. Analysis of variance test was performed and statistical significance was set at P < 0.05.

Results:

Thirty regions of interest with 60 variables were included in the final analysis. Patients with SCD showed statistically significant reduced FA values, increased ADC values, or both, clustered in several brain areas, including pons, cerebral peduncle, corpus callosum, frontal, temporal, parietal white matter, centrum semiovale, periventricular areas, basal ganglia, and left thalamus (P < 0.05).

Conclusion:

DTI is a promising method for characterizing microstructural changes, when conventional MRI is normal.

Apparent diffusion coefficient is associated with seizure outcome after magnetic resonance-guided laser interstitial thermal therapy for mesial temporal lobe epilepsy

BACKGROUND

Magnetic resonance-guided laser interstitial thermal therapy (MRgLiTT) is becoming a first-line surgical therapy for mesial temporal lobe epilepsy (mTLE) due to good seizure control and low complication risk. However, seizure outcomes after MRgLiTT remain highly variable and there is a need to improve patient selection and post-operative prognostication. In this retrospective study, we investigated whether the pre-operative MRI-derived apparent diffusion coefficient (ADC), used as a marker of tissue pathology in the mesial temporal structures could help predict seizure outcome.

METHODS

Thirty-five patients who underwent MRgLiTT at our institution between 2014 and 2019 were included in the study. Demographic and clinical data were retrospectively collected. Seizure outcome was defined as good (ILAE Class I-II) and poor (ILAE Class III-VI). Volumetrics were performed on pre-ablation hippocampus and amygdala. Ablation volumes, and the proportion of ablated hippocampus and amygdala calculated via their respective mean voxel-wise ADC intensities were quantified from pre-operative and intra-operative post-ablation MRIs and statistically compared between the two outcome cohorts. Univarate and multivariate regression analysis was performed to identify demographic, clinical, and radiographic predictors of seizure outcome.

RESULTS

Mean age at LiTT was 36 years and 14 (40 %) were female. Mean follow-up duration was 1.90 ± 0.17 years. Twenty-seven (77 %) patients had mesial temporal sclerosis. There was no significant difference in the ablation volumes and proportion of ablated volume of hippocampus and amygdala between the two outcome groups. Patients with good seizure outcome had significantly higher normalized ADC intensities in the ablated mesial temporal structures compared to those with poor outcome (0.01 ± 0.08 vs.-0.29 ± 0.06; p = 0.015).

CONCLUSIONS

mTLE patients with higher ADC intensities in the ablated regions of the hippocampus and the amygdala are more likely to have good seizure outcome following MRgLiTT. Our results suggest that pre-operative ADC analysis may improve both patient selection and epileptogenic zone targeting during MRgLiTT. Further investigation with large, prospective cohorts is needed to validate the clinical utility of ADC in improving seizure outcome following MRgLiTT.

The value of the apparent diffusion coefficient in differentiating type II from type I endometrial carcinoma

BACKGROUND

Diagnostic type II endometrial carcinoma (EC) is considered more aggressive and has a poorer prognosis than type I EC; differentiation between them is helpful for preoperative clinical decision-making. However, the diagnostic value of the apparent diffusion coefficient (ADC) in differentiating them remains unclear.

PURPOSE

To investigate the value of ADC in differentiating type II EC from type I EC.

MATERIAL AND METHODS

Ninety-four patients with EC who underwent diffusion-weighted imaging (DWI) were retrospectively included and divided into type I and type II subgroups, based on the postoperative pathologic results. We analyzed the clinical characteristics, conventional magnetic resonance imaging manifestations, and ADC mean values (ADC_mean), ADC minimum values (ADC_min), and ADC max values (ADC_max). Receiver operating characteristic (ROC) curve analysis was further used to assess the predictive performance.

RESULTS

The ADC_mean, ADC_min, and tumor size differed significantly between the two subtypes. The area under the ROC curve (AUC) for ADC_mean and ADC_min was 0.787 (95% confidence interval [CI] = 0.692-0.88) and 0.835 (95% CI = 0.751-0.919) for predicting type II EC, respectively. The optimal cut-off value of ADC_mean for prediction was 0.757 × 10^-3 mm²/s with a sensitivity of 91%, a specificity of 58%, and an accuracy of 74%, while for ADC_min was 0.637 × 10^-3 mm²/s with a sensitivity of 82%, a specificity of 73%, and an accuracy of 75%.

CONCLUSION

EC with lower ADC_mean and ADC_min values derived from DWI, and a larger size, are indicative of type II EC.

Differentiation of Benign and Malignant Parotid Gland Tumors with MRI and Diffusion Weighted Imaging

Objective

This study investigated the effectivity of Magnetic Resonance Imaging (MRI) findings and Apparent Diffusion Coefficient (ADC) value in evaluating parotid gland tumors (PGTs), and aimed to reduce the biopsy procedure before surgery.

Methods

This retrospective study included 54 PGTs of 42 patients' (24 female, 18 male, mean age; 51.4±15.9). All of the patients had an MRI, and histopathologic diagnosis. The signal intensity [T1 and T2 Weighted (W), T1W after intravenous contrast agent injection] and mean ADC values of the PGTs were measured. Also contrast enhancement pattern (homogenous, heterogeneous, peripheral or none), margin features (well or ill-defined), sizes, location (superficial lobe/deeplobe/both), perineural spread, presence of lymphadenopathy, and extension to adjacent structures were noted.

Results

The distribution of PGTs was; 21 pleomorphic adenomas, 18 Warthin tumors, 2 lymph nodes, 2 mucoepidermoid carcinomas, 5 adenoid cystic carcinoma, 1 basal cell carcinoma,2 metastases and 2 lymphomas; (13 malignant and 41 benign lesions). Morphologic parameters; ill-defined margin, perineural spread, lymphadenopathy, and extension to adjacent structures were found to be significantly associated with malign lesions (p<0.01). There was a significant difference between ADC values of malignant and benign PGTs (p<0.05). Also ADC values and T2 signal intensity was significantly lower in Warthin tumors rather than pleomorphic adenomas (p<0.05).

Conclusions

Mean ADC values when considered with morphological features may be accessible methods to distinguish benign and malignant PGTs, also ADC values and T2 signal intensity may be useful for differentiating pleomorphic adenomas from Warthin tumors, thereby reducing the number of biopsies and thus complications.

Correlation between 18F-FDG PET/CT and diffusion-weighted MRI parameters in head and neck squamous cell carcinoma at baseline and after chemo-radiotherapy. A retrospective single institutional study

OBJECTIVES

The relationship between glucose metabolism and tumor cellularity before chemo-radiotherapy in patients with head and neck squamous cell carcinoma (SCC) has never been compared with that of patients evaluated after treatment. This retrospective study analyzed the correlation between glucose metabolism parameters expressed by standardized uptake value (SUV) derived from 18F-fluorodeoxyglucose (18F-FDG) PET/CT and cellularity tumor parameters expressed by apparent diffusion coefficients (ADC) derived from diffusion-weighted (DW) MRI in untreated and treated patients with head and neck SCC.

METHODS

In 19 patients with no previous exposure to any treatment and 17 different chemo-radiotreated patients with head and neck SCC, we correlated the semi-quantitative uptake values (SUVmax, SUVpeak, and SUVmean) with the ADC functional parameters (ADCmin, ADCmean) including the standard deviation of ADC values (ADCsd).

RESULTS

No significant correlation was found between glucose metabolism parameters and ADCmin or ADCmean in untreated and treated patient groups. However, in untreated patients, significant inverse correlations were found between ADCsd and SUVmax (P = 0.039, r = -0.476), SUVpeak (P = 0.003, r = -0.652) and SUVmean (P = 0.039, r = -0.477). Analyses after chemo-radiotherapy in 17 patients showed no significant correlation between glucose metabolism parameters and DW MRI values, excluding a persistent significant (but lower intensity) inverse correlation between SUVpeak and ADCsd (P = 0.033, r = -0.519).

CONCLUSIONS

The demonstrated relationships suggest complex interactions especially between metabolic activity and heterogeneity of tumoral tissue, which might play a complementary role in the assessment of head and neck SCC.

TRIAL DATE OF REGISTRATION AND REGISTRATION NUMBER

Our retrospective study was registered on April 9th, 2020 by the Ethics Committee of the Coordinating Center "Area Vasta Nord Ovest" (CEAVNO) with Registration Number CEAVNO09042020.

Correlations between apparent diffusion coefficient values of WB-DWI and clinical parameters in multiple myeloma

Background

Whole-body diffusion-weighted imaging (WB-DWI) is a method for evaluating bone marrow infiltration in multiple myeloma (MM). This study seeks to elucidate the correlation between the apparent diffusion coefficient (ADC) value and some selected clinical parameters.

Methods

A total of 101 Chinese patients with MM who had undergone WB-DWI from May 2017 to May 2019 were enrolled in this study. The ADC values of the MM lesions and the clinical parameters were quantified at the first (baseline) visit and after four-course induction chemotherapy. Multiple linear regression and logistic analyses were carried out to find the implicit inherent relationships within the patients’ data.

Results

The paired Wilcoxon test showed that the ADC values at the baseline visit (ADC₀) were significantly lower than the values after four-course induction chemotherapy (ADC_{4 c}) (p < 0.001), including different therapeutic responses. The Revised International Staging System (RISS) stage, type of MM, and β2-microglobulin (β2-MG) were predictors of clinically significant increases or decreases in the ADC values (p < 0.05). Multiple linear regression showed that the ADC₀ was negatively associated with β2-MG (p < 0.001) and immunoglobulin heavy chain gene rearrangement (p = 0.012), while the RISS Stage III (p = 0.001), type IgG λ (p = 0.005), and albumin were negatively associated with ADC_{4 c} (p = 0.010). The impacts of the therapeutic response were associated with ADC₀ and immunoglobulin heavy chain gene rearrangement (p < 0.001).

Conclusion

The ADC values of WB-DWI may be associated with clinical parameters of MM including the fluorescence in situ hybridization result, and may be useful in the prognosis of patients with MM.

Trial Registration: ChiCTR2000029587

Empirical validation of gradient field models for an accurate ADC measured on clinical 3T MR systems in body oncologic applications

PURPOSE

To empirically corroborate vendor-provided gradient nonlinearity (GNL) characteristics and demonstrate efficient GNL bias correction for human brain apparent diffusion coefficient (ADC) across 3T MR systems and spatial locations.

METHODS

Spatial distortion vector fields (DVF) were mapped in 3D using a surface fiducial array phantom for individual gradient channels on three 3T MR platforms from different vendors. Measured DVF were converted into empirical 3D GNL tensors and compared with their theoretical counterparts derived from vendor-provided spherical harmonic (SPH) coefficients. To illustrate spatial impact of GNL on ADC, diffusion weighted imaging using three orthogonal gradient directions was performed on a volunteer brain positioned at isocenter (as a reference) and offset superiorly by 10-17 cm (>10% predicted GNL bias). The SPH tensor-based GNL correction was applied to individual DWI gradient directions, and derived ADC was compared with low-bias reference for human brain white matter (WM) ROIs.

RESULTS

Empiric and predicted GNL errors were comparable for all three studied 3T MR systems, with <1.0% differences in the median and width of spatial histograms for individual GNL tensor elements. Median (±width) of ADC (10-3mm2/s) histograms measured at isocenter in WM reference ROIs from three MR systems were: 0.73 ± 0.11, 0.71 ± 0.14, 0.74 ± 0.17, and at off-isocenters (before versus after GNL correction) were respectively 0.63 ± 0.14 versus 0.72 ± 0.11, 0.53 ± 0.16 versus 0.74 ± 0.18, and 0.65 ± 0.16 versus 0.76 ± 0.18.

CONCLUSION

The phantom-based spatial distortion measurements validated vendor-provided gradient fields, and accurate WM ADC was recovered regardless of spatial locations and clinical MR platforms using system-specific tensor-based GNL correction for routine DWI.

Accuracy of apparent diffusion coefficient in differentiation of glioblastoma from metastasis

BACKGROUND

Brain metastasis and glioblastoma multiforme are two of the most common malignant brain neoplasms. There are many difficulties in distinguishing these diseases from each other.

PURPOSE

The purpose of this study was to determine whether the mean apparent diffusion coefficient and absolute standard deviation derived from apparent diffusion coefficient measurements can be used to differentiate glioblastoma multiforme from brain metastasis based on cellularity levels.

MATERIAL AND METHODS

Magnetic resonance images of 34 patients with histologically verified brain tumors were evaluated retrospectively. Apparent diffusion coefficient and standard deviation values were measured in the enhancing tumor, peritumoral region, and contralateral healthy white matter. Then, to determine whether there was a statistical difference between brain metastasis and glioblastoma multiforme, we analyzed different variables between the two groups.

RESULTS

Neither mean apparent diffusion coefficient values and ratios nor standard deviation values and ratios were significantly different between glioblastoma multiforme and brain metastasis. Receiver operating characteristic curve analysis of the logistic model with backward stepwise feature selection yielded an area under the curve of 0.77, a specificity of 84%, a sensitivity of 67%, a positive predictive value of 83.33%, and a negative predictive value of 78.26% for distinguishing between glioblastoma multiforme and brain metastasis. The absolute standard deviation and standard deviation ratios were significantly higher in the peritumoral edema compared to the tumor region in each case.

CONCLUSION

Apparent diffusion coefficient values and ratios, as well as standard deviation values and ratios in peritumoral edema, cannot be used to differentiate edema with infiltration of tumor cells from vasogenic edema. However, standard deviation values could successfully characterize areas of peritumoral edema from the tumoral region in each case.