478 DIFFUSION-WEIGHTED IMAGING IMPROVES OUTCOME PREDICTION IN ADULTS WITH DIFFUSE AXONAL INJURY.

Simple SummaryIn this study quantified diffusion weitgthed imaging in MRI was analized in neuroblastoma. We were able to show a significant increase of apparent diffusion coefficient in regressive diseases and a decrease for progressive diseases. This was even true within the first 120 days after the start of therapy.Neuroblastoma is the most common extracranial, malignant, solid tumor found in children. In more than one-third of cases, the tumor is in an advanced stage, with limited resectability. The treatment options include resection, with or without (neo-/) adjuvant therapy, and conservative therapy, the latter even with curative intent. Contrast-enhanced MRI is used for staging and therapy monitoring. Diffusion-weighted imaging (DWI) is often included. DWI allows for a calculation of the apparent diffusion coefficient (ADC) for quantitative assessment. Histological tumor characteristics can be derived from ADC maps. Monitoring the response to treatment is possible using ADC maps, with an increase in ADC values in cases of a response to therapy. Changes in the ADC value precede volume reduction. The usual criteria for determining the response to therapy can therefore be supplemented by ADC values. While these changes have been observed in neuroblastoma, early changes in the ADC value in response to therapy are less well described. In this study, we evaluated whether there is an early change in the ADC values in neuroblastoma under therapy; if this change depends on the form of therapy; and whether this change may serve as a prognostic marker. We retrospectively evaluated neuroblastoma cases treated in our institution between June 2007 and August 2014. The examinations were grouped as ‘prestaging’; ‘intermediate staging’; ‘final staging’; and ‘follow-up’. A classification of “progress”, “stable disease”, or “regress” was made. For the determination of ADC values, regions of interest were drawn along the borders of all tumor manifestations. To calculate ADC changes (∆ADC), the respective MRI of the prestaging was used as a reference point or, in the case of therapies that took place directly after previous therapies, the associated previous staging. In the follow-up examinations, the previous examination was used as a reference point. The ∆ADC were grouped into ∆ADCregress for regressive disease, ∆ADCstable for stable disease, and ∆ADC for progressive disease. In addition, examinations at 60 to 120 days from the baseline were grouped as er∆ADCregress, er∆ADCstable, and er∆ADCprogress. Any differences were tested for significance using the Mann–Whitney test (level of significance: p < 0.05). In total, 34 patients with 40 evaluable tumor manifestations and 121 diffusion-weighted MRI examinations were finally included. Twenty-seven patients had INSS stage IV neuroblastoma, and seven had INSS stage III neuroblastoma. A positive N-Myc expression was found in 11 tumor diseases, and 17 patients tested negative for N-Myc (with six cases having no information). 26 patients were assigned to the high-risk group according to INRG and eight patients to the intermediate-risk group. There was a significant difference in mean ADC values from the high-risk group compared to those from the intermediate-risk group, according to INRG. The differences between the mean ∆ADC values (absolute and percentage) according to the course of the disease were significant: between ∆ADCregress and ∆ADCstable, between ∆ADCprogress and ∆ADCstable, as well as between ∆ADCregress and ∆ADCprogress. The differences between the mean er∆ADC values (absolute and percentage) according to the course of the disease were significant: between er∆ADCregress and er∆ADCstable, as well as between er∆ADCregress and er∆ADCprogress. Forms of therapy, N-Myc status, and risk groups showed no further significant differences in mean ADC values and ∆ADC/er∆ADC. A clear connection between the ADC changes and the response to therapy could be demonstrated. This held true even within the first 120 days after the start of therapy: an increase in the ADC value corresponds to a probable response to therapy, while a decrease predicts progression. Minimal or no changes were seen in cases of stable disease.

Malignant peripheral nerve sheath tumors (MPNSTs) are rare neoplasms requiring differentiation from benign neurogenic tumors on diagnostic imaging. We evaluated the diagnostic utility of texture analysis (TA) in distinguishing seven pathologically confirmed MPNSTs from eight schwannomas using magnetic resonance imaging (MRI), including T1- (T1WI) and T2-weighted imaging (T2WI), and apparent diffusion coefficient (ADC) maps. TA's performance was compared with that of conventional approaches using ADC values alone. Tumors were segmented, and 90 texture features were extracted using LIFEx software. Significantly different features (p < 0.05) were identified using the Mann-Whitney U test and evaluated through receiver operating characteristic (ROC) analysis. ADC maps were used to measure the minimum, mean, and maximum ADC values, followed by ROC analysis. Two T2WI-based texture features (neighborhood grey-tone difference matrix Contrast and grey-level size zone matrix Grey Level Variance) demonstrated the highest diagnostic performance (area under the curve = 0.911 [95% confidence interval (CI):0.755-1.000]), comparable to the minimum and mean ADC values (area under the curve = 0.898 [95% CI:0.691-1.000]). TA may help differentiate MPNSTs from schwannomas. T2WI-based TA offers a viable alternative when ADC maps are limited by magnetic susceptibility artifacts. J. Med. Invest. 72 : 367-374, August, 2025.

To investigate the role of diffusion-weighted magnetic resonance imaging (DW-MRI) in the diagnosis of gastric tumors and discuss the diagnostic importance and potential use of apparent diffusion coefficient (ADC) measurements. Beginning in March 2009, DW-MRI was added to the routine abdominal and pelvic MR examination for all patients imaged at our institution. A total of 21 patients (12 men and 9 women; mean age 55±6.3SD, range: 39-74 years) with known gastric malignancy were referred to our MR unit. All MRI examinations were performed using a 1.5-T MRI scanner (Magnetom Avanto, Siemens Healthcare). The evaluation of the DW-MRI examinations was made by radiologists' consensus. Changes in the signal intensity of the lesions were determined by their appearance in images at b=50, 400, and 800 s/mm(2) and in ADC maps. Results were compared with histopathological findings. All of the gastric tumors in this study showed high signal intensity in DW-MRI and low signal intensity in ADC maps. Mean ADC values for gastric tumor and normal gastric wall were 0.892±0.23 SD mm(2)/s and 1.453±0.35 SD mm(2)/s respectively. The mean ADC values of gastric tumors were significantly lower than that of the normal gastric wall. DW-MRI and ADC values together can successfully differentiate gastric tumors from normal gastric wall.

To investigate and determine the optimal b-values for Diffusion Weighted Imaging(DWI) for Apparent Diffusion Coefficient(ADC) maps in differentiating normal, benign and malignant breast tissue. Twenty-five patients underwent diffusion-weighted magnetic resonance imaging (DWI-MRI) and conventional breast MRI with suspicious breast fmdings(BIRADS >4). Breast lesions were defined by pathology. The DWI was acquired with different b-values ranging from 0,500, 600,750 and 1000s/mm2 . Apparent Diffusion Coefficient(ADC) maps of breast tissue were constructed using different b-values, e.g., using either 2 b-values(0- 1000) or combinations of 3 or more (0,500,1000 or 0,600,750,1000). Quantitative analyses of the ADC maps of glandular, fatty and lesion tissue were obtained. Ratios of lesion to glandular tissue(L/GT) and signal to noise(SNR) were assessed. Paired t-tests were performed for statistical significance. Eighteen patients had invasive ductal carcinoma and 7 had benign breast lesions. The mean ADC value for malignant lesions using all b values was 1.17±0.16×10-3mm2 /s with a lesion to glandular(L/GT) ratio=0.65. The benign lesions, ADC map value was 1.86±0.03×10-3mm2 /s with L/GT=0.98. There was a significant difference(P<0.05) between benign and malignant lesions ADC map value.The lowest SNR(12±6) was with single b-values. There was a significant difference(P<0.05) in SNR with multiple b-values(34±6) compared to single b-values. The highest SNR was given by using two b values greater than 500. Finally, the background noise for all combinations was surprising stable and ranged between 60±20%. This is the first study to investigate the effect of changing different b values in DWI breast imaging. There were significant differences in the SNR between single and multiple b values. Our data show suggest that the recommended b-values for DWI in breast are 0, and two that are 500 or greater. Therefore use of at least 3 b-values in DWI/ADC mapping of breast lesions are needed for better characterization of benign and malignant breast tissue. P50CA88843, Avon Foundation for Women:01-2008-012, U01CA070095, andU01CA140204.

Objective: The consistency of pituitary macroadenomas can be a confounding factor during transnasal transsphenoidal decompression, often necessitating incomplete removal and need for a transcranial approach for complete tumor excision. Very few studies have evaluated preoperative tumor consistency in relation to imaging findings. Our objective was to determine whether conventional magnetic resonance images and diffusion-weighted (DW) imaging with apparent diffusion coefficient (ADC) maps are predictive of the consistency of pituitary macroadenomas. Methods: A retrospective study of 31 patients who had undergone surgery for pituitary macroadenoma in our hospital. Preoperative magnetic resonance images were reviewed and regions of interest were drawn on the macroadenoma and normal white matter on DW images independently by 2 neuroradiologists. Consistency of macroadenomas was determined from the surgical records and was classified into soft, intermediate, or hard. Mean ADC values, signal intensity ratio of tumor to white matter within regions of interest on conventional and DW images, and degree of enhancement were compared with tumor consistency using analysis of variance. Results: The mean ADC values in the soft group was 0.754×10−3 mm2/s, in the intermediate group was 0.963×10−3 mm2/s, and in the hard group was 1.312×10−3 mm/s. Statistical analysis revealed a significant correlation between consistency and ADC values (P<0.004). There was no significant association between tumor consistency and signal intensity or degree of contrast enhancement. Conclusions: The findings in this study suggest that DW images with ADC maps are useful for preoperative prediction of consistency of pituitary macroadenomas.

Background: This study aimed at evaluating apparent diffusion coefficient (ADC) values of nasopharyngeal carcinoma (NPC) in the pre-treatment stages of NPC for establishing comparative quantitative parameters between children and adolescents compared to adults. Methods: A retrospective multicentric imaging study was conducted in three medical centers by collecting patient data over a 5-year timeframe. Patients were included in the study based on the following criteria: histopathologically proven carcinoma of the nasopharynx with all available medical records. The total sample included 20 patients (6 pediatric patients and 14 adults). A quantitative analysis of the ADC maps was performed. Two radiologists manually drew the region of interest (ROI) on ADC maps using the whole tumor on all magnetic resonance imaging (MRI) slices. The mean ADC was extracted for each patient and each radiologist's evaluation. Differences in ADC values between pediatric and adult patients were evaluated using an independent samples t-test, with normality and variance assumptions tested via the Shapiro-Wilk and Levene's tests, respectively. p-values less than 0.05 were considered statistically significant. Results: The mean ADC values extracted from the initial pre-treatment diffusion-weighted imaging (DWI) data from magnetic resonance imaging (MRI) in children were 712.22 × 10-6 mm2/s, compared to adults in whom the mean ADC values were 877.34 × 10-6 mm2/s. We found a statistically significant difference between the mean ADC values of pediatric patients and adult patients, t (17.44) = -3.15, p = 0.006, with the mean ADC values of pediatric patients (M = 712.22, standard deviation [SD] = 57.03) being lower, on average, than the mean ADC values of adult patients (M = 877.34, SD = 175.25). Conclusions: Our results showed significantly lower ADC values in pediatric patients than in adults, independent of tumor T-stage. Additionally, early-stage tumors, particularly in children, tended to exhibit even lower ADC values, suggesting potential biological distinctions across age groups.

The objective was to study the relationship of 3-Tesla (3T) diffusion-weighted magnetic resonance imaging (DW-MRI) with apparent diffusion coefficient (ADC) value for distinction of reactive and metastatic lymph nodes (LNs) in head-and-neck carcinoma (HNC) patients and to determine the ADC cutoff value for metastatic LNs at various levels. 3T DW and T1- and T2-weighted imaging sequences were done in 34 patients with biopsy-proven primary HNC of 100 cervical LNs ≥1 cm in diameter. The mean ADC values were compared with histopathologically proven LNs using the independent t-test. ADC cutoff value was evaluated with sensitivity, specificity, accuracy, positive predictive value, negative predictive value and a receiver operating characteristic curve analysis. The mean ADC value of reactive LN was 1.2933 × 10-3 mm2/s and metastatic LN was 0.908 × 10-3 mm2/s. An ADC cutoff value was 0.868 × 10-3 mm2/s with 84% sensitivity, 96% specificity, 93% accuracy, 87.5% positive predictive value, and 94.7% negative predictive value. A significant difference in mean ADC value between reactive and metastatic LNs was noted (P< 0.001). 3T DW-MRI is useful in differentiating reactive and metastatic cervical LNs in HNC patients. However, studies with larger sample size have to be performed to validate ADC threshold value with 3T DW-MRI in differentiating between reactive and metastatic LNs for clinical practice.

Diffusion-weighted magnetic resonance imaging (DW-MRI) and 2-deoxy-2-[18F]fluoro-D-glucose-positron emission tomography/computed tomography (PET/CT) is increasingly recognized as important for assessing tumor malignancy in oncology. Apparent diffusion coefficient (ADC) and standardized uptake value (SUV) are negatively correlated in some types of cancer based on tumor aggressiveness. To evaluate relationships between ADC of magnetic resonance imaging and SUV of PET/CT in pancreatic adenocarcinomas. Twenty-nine patients histopathologically diagnosed with pancreatic adenocarcinomas were evaluated. ADC maps were generated from 3 T-MRI using b values (b = 0, 800 s/mm(2)). PET/CT was performed 60 min after intravenous injection of FDG (3.7 MBq/kg). The margins of tumors on DW-MRI and PET/CT were assessed to measure ADC and SUV of tumor appropriately. For tumors considered well-marginated, minimal and mean ADC as well as maximal and mean SUV were measured. The correlation of ADC and SUV were statistically evaluated and survival period stratified on ADC and SUV also evaluated. Twenty-two tumors on DW-MRI and 25 on PET/CT were deemed well-marginated. Minimal ADC was significantly and negatively correlated with maximal and mean SUV (r = -0.61, P = 0.0040; r = -0.66, P = 0.0015), and mean ADC also showed significantly and negatively correlation with maximal and mean SUV (r = -0.50, P = 0.024; r = -0.54, P = 0.012). There was no significant difference on overall survival stratified on ADC and SUV. ADC and SUV were significantly correlated in pancreatic adenocarcinomas, although no significant findings were observed in overall survival.

Objective To study the effect of diffusion-weighted magnetic resonance imaging (DW-MRI) in the differential diagnosis of hydronephrosis and pyonephrosis. Methods From March 2015 to October 2017, 50 patients with renal stone and highly suspected infectious hydronephrosis underwent renal DW-MRI, and clinical materials were collected and analyzed retrospectively. Seventeen male and 33 female patients were enrolled with a mean age of (49.40±10.51) years. The median maximum diameter of renal stone was 30.30 (17.38, 56.01) mm and hydronephrosis was 46.39 (34.33, 56.55) mm. No pyonephrosis was diagnosed by preoperative ultrasound or CT, while 29 cases of hydronephrosis and 21 cases of pyonephrosis were reported by preoperative DW-MRI. Final diagnoses of hydronephrosis and pyonephrosis were made according to whether the pelvic urine drainage was purulent or not during the surgery. DW-MRI reports and characteristics of DW images were analyzed retrospectively. Apparent diffusion coefficient (ADC) was calculated and ADC map constructed, which was compared between the two groups. Receiver operating characteristic curve (ROC) was drawn to analyze the area under curve (AUC) and the optimal cutoff of ADC value, with sensitivity and specificity. Results Thirty-three patients of hydronephrosis and 17 pyonephrosis were confirmed intraoperatively. The overall accuracy of diagnosis using DW-MRI was 84.00% (42/50), with sensitivity of 88.24% (15/17) and specificity of 81.82% (27/33). Among 30 patients who underwent CT scan in our hospital, mean CT value of 18 hydronephrosis was (7.03±3.26) HU and that of 12 pyonephrosis was (8.67±3.52) HU, with no statistical significance (P>0.05). On DW image, when b≥500 s/mm2, hydronephrosis signal intensity was lowered apparently, whereas pyonephrosis signal intensity was intensified. On ADC map, hydronephrosis appeared as hyperintensity, whereas pyonephrosis appeared as hypointensity. The mean ADC value of pyonephrosis group was lower than hydronephrosis group [(1.53±0. 58)×10-3 mm2/s vs. (2.86±0.56)×10-3 mm2/s, P<0.01]. ROC analysis revealed that AUC=0.92(95%CI 0.80-0.98), and the cut-off value of ADC for pyonephrosis diagnosis was 1.39×10-3 mm2/s, of which the sensitivity and specificity was 94.12% and 84.85% respectively. Conclusions Signal of pyonephrosis was enhanced on DW image, while decreased on ADC image. The ADC value of pyonephrosis was much lower than that of hydronephrosis, with which the differential diagnosis between pyonephrosis and hydronephrosis could be made efficiently. Key words: Hydronephrosis; Pyonephrosis; Urosepsis; Diffusion-weighted imaging; Apparent diffusion coefficient

Significance of diffusion-weighted imaging and apparent diffusion coefficient maps for the evaluation of pyogenic ventriculitis

To determine the apparent diffusion coefficient (ADC) values of lipid and hemorrhage in atherosclerotic plaque in human carotid arteries in vivo and compare the values obtained from ex vivo carotid endarterectomy specimens. In vivo diffusion-weighted imaging (DWI) of carotid plaques was performed using a 2D single shot Interleaved Multislice Inner Volume Diffusion Weighted Echo Planar Imaging (2D ss-IMIV DWEPI) on 8 subjects who subsequently underwent carotid endarterectomy. A total of 32 slices used to construct the ADC maps were reviewed for the measurement of the mean ADC values in vessel wall, hemorrhage, and lipid necrotic core. The 8 endarterectomy specimens were scanned using by three-dimensional ms-IV-DWEPI. After the ADC maps were created, the mean ADC values in the same locations selected for in vivo values were calculated. The mean ADC values obtained from in vivo DWI in normal vessel wall, lipid rich core, and hemorrhage were 1.27 ± 0.16, 0.38 ± 0.1, and 0.98 ± 0.25 × 10(-3) mm(2)/s, respectively. The mean ADC values in ex vivo lipid necrotic core, and hemorrhage were 0.33 ± 0.08, 1.28 ± 0.10 × 10(-3) mm(2)/s, respectively. These components mean ADC values obtained from in vivo and ex vivo ADC maps were compared. ADC values of the carotid plaque components in vivo are consistent with values obtained from ex vivo endarterectomy specimens. The ability to obtain consistent plaque ADC values in vivo indicates that this technique could be an integral part of the basis for plaque component identification in conjunction with other MRI techniques.

Motion and deformation are common in prostate diffusion-weighted magnetic resonance imaging (DWI) during acquisition. These misalignments lead to errors in estimating an apparent diffusion coefficient (ADC) map fitted with DWI. To address this problem, we propose an image registration algorithm to align the prostate DWI and improve ADC map. First, we apply affine transformation to DWI to correct intraslice motions. Then, nonrigid registration based on free-form deformation (FFD) is used to compensate for intraimage deformations. To evaluate the influence of the proposed algorithm on ADC values, we perform statistical experiments in three schemes: no processing of the DWI, with the affine transform approach, and with FFD. The experimental results show that our proposed algorithm can correct the misalignment of prostate DWI and decrease the artifacts of ROI in the ADC maps. These ADC maps thus obtain sharper contours of lesions, which are helpful for improving the diagnosis and clinical staging of prostate cancer.

The purpose of this work was to evaluate whether diffusion-weighted MR imaging can be used in differentiating residual or recurrent head and neck tumors from postoperative or postradiation changes. This study included 32 patients clinically suspected for recurrent head and neck tumor after surgery (n=3), radiation therapy (n=13), or both (n=16). Diffusion-weighted MR imaging was done by using a single-shot spin-echo echo-planar sequence. The apparent diffusion coefficient (ADC) value of the suspected lesion was calculated and correlated with pathologic results. Adequate diffusion-weighted MR images and ADC maps were obtained in 30 patients (93.8%). The mean ADC value of residual or recurrent lesions (1.17 +/- 0.33 x 10(-3) mm(2)/s) was less than that of posttherapeutic changes (2.07 +/- 0.25 x 10(-3) mm(2)/s), and the difference was statistically significant (P<.001). When an ADC value of 1.30 x 10(-3) mm(2)/s was used as a threshold value for differentiation, the best results were obtained with an accuracy of 87%, sensitivity of 84%, specificity of 90%, positive predictive value of 94%, and negative predictive value of 76%. Diffusion-weighted MR imaging with ADC measurement has promising results for differentiating residual or recurrent head and neck tumors from postoperative or postradiation changes.

The present study aimed to investigate the value of diffusion-weighted magnetic resonance imaging (DWI) in the grading of well-differentiated pancreatic neuroendocrine tumors (PanNETs). A total of 44 patients with histologically proven well-differentiated PanNET [grade 1 (G1) and grade 2 (G2) according to the World Health Organization (WHO) criteria] underwent pretreatment magnetic resonance imaging (MRI), which was retrospectively analyzed. The location, size, cystic or solid appearance, boundary, presence or absence of tumor contrast enhancement, and MRI signal of the tumor were assessed. Apparent diffusion coefficients (ADCs) within the primary tumor were measured on ADC maps. Receiver operating characteristic curves were used to determine ADC cut-off values and the sensitivity and specificity of the grade prediction. Spearman's rank correlation was utilized to probe the association between ADC value and PanNET grade or pathological parameters. G1 tumors exhibited a well-circumscribed border more often than G2 tumors. No marked differences were observed between PanNET G1 and PanNET G2 for cystic or solid appearance, enhancement, and T1- and T2-weighted imaging signals. Marked hyperintensities were more common in PanNET G2 tumors than in PanNET G1 tumors (P<0.01). The mean ADC values were statistically different between the normal pancreas and G1 and G2 tumors (P<0.01), and between PanNET G1 and PanNET G2 (P<0.05). Correlation analysis showed that ADC value was negatively correlated with PanNET grade, mitotic count and Ki-67 proliferation index (P<0.05). The cut-off ADC value was 0.930×10−3 mm2/sec, which identified G2 tumors with 82.4% sensitivity and 79.5% selectivity. ADC value therefore represents a non-invasive and valuable imaging parameter in predicting the WHO grade of tumors in well-differentiated PanNET.

A delayed stroke-like leukoencephalopathy has been observed in patients receiving methotrexate (MTX) for childhood leukemia. Diffusion-weighted MRI (DWI) may help to distinguish between ischemic stroke and chemotherapy-related leukoencephalopathy. Although conventional MRI correlates have been described for this stroke-like syndrome, DWI data are largely unavailable. Our objective is to present a retrospective analysis of the DWI findings in four patients who suffered subacute neurotoxicity after intrathecal MTX. We reviewed the medical records of four patients, who were seen by us between July 2000 and February 2004 for sudden onset of a central neurological syndrome within days of intrathecal MTX. Patients underwent standardized MRI within 48 h of symptom onset; MRI included DWI and apparent diffusion coefficient (ADC) maps. DWI of all patients revealed well-demarcated hyperintense lesions within the subcortical white matter corresponding to areas of restricted proton diffusion on ADC maps. Lesions exceeded the confines of adjacent vascular territories. Complete resolution of symptoms within 1-4 days was accompanied by normalization of ADC abnormalities. DWI findings in this cohort seem to reflect cytotoxic edema within cerebral white matter suggesting a reversible metabolic derangement, rather than ischemia, as the basis for this syndrome.