FUNCTIONAL EVALUATION OF HYDRONEPHROSIS BY DIFFUSION-WEIGHTED MR IMAGING. Relationship between apparent diffusion coefficient and split glomerular filtration rate

The aim was to investigate the relationship between apparent diffusion coefficient (ADC) values measured by diffusion-weighted magnetic resonance imaging (DW MRI) and the split glomerular filtration rate (GFR) in infants with congenital hydronephrosis. Diffusion-weighted imaging (DWI) (b = 0 and 700 seconds/mm(2)) was performed with a General Electric Company (GE) Signa 1.5T MR unit in 46 infants suffering single congenital hydronephrosis and in 30 healthy infants as normal control group. The ADCs were calculated with regions of interest (ROIs) positioned in the renal parenchyma. The 46 obstructed kidneys were classified into four groups according to the GFR level: renal dysfunction compensated group, renal dysfunction decompensated group, renal failure group, and uremia group. The renal ADCs in six groups (normal kidneys in control group, contralateral kidneys, and four groups of hydronephrotic kidneys) were compared statistically using analysis of variance (ANOVA), and the correlative relationship between ADCs and GFR was examined by Pearson's correlation test. There were statistically significant differences in renal ADCs among the six groups. The ADCs of hydronephrotic kidneys were lower than that of the normal kidneys. There was a moderate positive correlation between the ADCs of hydronephrotic kidneys and split GFR (r = 0.744). This study indicated that the ADCs of congenital hydronephrotic kidneys were lower than that of normal renal parenchyma, and there was a positive correlation between the ADCs and split renal GFR, which demonstrates that the ADCs can reflect the filtration function of hydronephrotic kidneys and may provide some reference to help clinical physician to explore a novel noninvasive approach to evaluate the single renal function.

Evaluating transcatheter arterial chemoembolization for primary hepatic cancer by magnetic resonance diffusion-weighted imaging

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.

Role of Diffusion-Weighted Magnetic Resonance Imaging in the Diagnosis and Grading of Hepatic Steatosis in Patients With Non-alcoholic Fatty Liver Disease: Comparison With Ultrasonography and Magnetic Resonance Spectroscopy

To investigate the clinical application of diffusion weighted imaging (DWI) in uterine cervical cancer and the apparent diffusion coefficient (ADC) value in diagnosis and predicting treatment response. Twenty-eight patients with advanced primary cervical cancer confirmed by pathology and 10 cases of normal uterine cervix as control were recruited in this prospective clinical trial. To analyze the correlation between tumor volume measured in DWI and tumor maximum diameter measured according to the RECIST criteria. To compare the ADC value differences among the uterine cervical cancer, uterine myometrium, and normal uterine cervix. To compare the ADC values in 17 cancer patients before and after treatment. The illustration of tumor boundary in DWI was superior to conventional T2WI and post-enhancement T1WI. The DWI with higher b value (2000 s/mm(2)) had a better signal-to-noise ratio. The tumor volume measured in DWI has good correlation with tumor maximum diameter according to RECIST criteria (r = 0.759, P < 0.01). When b = 800 s/mm(2), the ADC values of the uterine cervical cancer, uterine myometrium, and normal uterine cervix were (9.85 ± 1.55)×10(-3) mm(2)/s, (14.20 ± 2.80)×10(-3) mm(2)/s, and (14.14 ± 0.45) ×10(-3) mm(2)/s. When b = 2000 s/mm(2), the ADC values of the uterine cervical cancer, uterine myometrium and normal uterine cervix were (7.38 ± 0.98)×10(-3) mm(2)/s, (8.52 ± 2.38)×10(-3) mm(2)/s, and (8.60 ± 0.63)×10(-3) mm(2)/s, respectively. There were significant differences between the cervical cancer and normal cervix or uterine myometrium (P < 0.001 for both). When b = 800 s/mm(2), the ADC value was (9.85 ± 1.55)×110(-3) mm(2)/s before and (13.41 ± 2.93)×10(-3) mm(2)/s after treatment (P < 0.001). When b = 2000 s/mm(2), the ADC value was (7.38 ± 0.98)×10(-3) mm(2)/s before and (8.93 ± 1.92)×10(-3) mm(2)/s after treatment (P = 0.008). Univariate logistic regression analysis showed that 25% ADC, 50%ADC, and 75%ADC in the tumor ADC value histogram before treatment were significantly correlated to the treatment outcome of cervical cancer (P < 0.05 for all). Multivariate regression analysis showed that 25%ADC, 50%ADC, and 75%ADC in the tumor ADC value histogram before treatment were not significantly correlated to the treatment outcome of cervical cancer (P > 0.05 for all). The values of ROC curves were 25%ADC = 0.818, 50%ADC = 0.775, and 75%ADC = 0.716 (P > 0.05), however, the 25% ADC showed a relatively stronger statistical power. DWI helps to confirm the morphology and exact target zone of the tumor for radiotherapy. DWI volume measurement is well correlated with RECIST criteria, particularly in volume measurement of irregular tumors. ADC value has a potential in quantitatively monitoring treatment response and predicting outcome of cervical cancers.

Endometrial pathologies represent a diagnostic challenge for radiologist and gynecologist due to dynamic changes of the endometrium, wide variability in imaging appearance and overlap between benign and malignant causes of endometrial abnormalities. Although tissue analysis via dilatation and curettage, endometrial biopsy or hysteroscopy is the backbone in the diagnosis, these tests are invasive, not without complications and may be difficult to perform in certain circumstances, hence the need for noninvasive imaging methods to aid in the diagnosis and triaging the patient for subsequent invasive procedures as well as contribution in treatment planning. This study aimed to evaluate the role of diffusion weighted imaging (DWI) with apparent diffusion coefficient (ADC) value measurement in differentiating benign from malignant uterine endometrial lesions. The study included 47 patients with endometrial lesions divided into two groups according to the result of histopathological analysis; the malignant group consisting from 18 cases and the benign group consisting from 29 cases, the latter was further subdivided into: polyp, hyperplasia and other benign entities. Pelvic magnetic resonance imaging with DWI performed for each patient with visual evaluation of signal intensity on diffusion and ADC value measurement. Subsequently mean ADC values for each group were calculated and compared, and validity measures for the optimal cut-off values for differentiating benign from malignant lesions were determined. The mean±standard deviation for ADC value (x10-3mm2/sec) for malignant group was 0.71±0.12, and for benign group was 1.52±0.42, with a significant difference between the two groups (P value <0.01), there was no significant difference in ADC value between the subdivision of benign group. At ADC cut-off value of 0.976x10-3mm2/sec, the sensitivity, specificity, positive predictive value and negative predictive value and accuracy of DWI in detecting endometrial carcinoma were 100%, 89.6%, 85.71%, 100% and 93.62% respectively. In conclusion, DWI with ADC value measurement is a valuable non-invasive diagnostic test, aiding in the differentiation of benign from malignant uterine endometrial cavity lesions. Key words: diffusion weighted imaging, apparent diffusion coefficient map, benign endometrial lesions, malignant endometrial lesions.

Renal artery stenosis (RAS) is a vascular disorder linked to secondary hypertension, chronic kidney disease, and renal failure due to interstitial fibrosis. Early diagnosis is crucial as RAS-induced hypertension responds well to angioplasty. Non-invasive imaging techniques, including non-contrast magnetic resonance angiography (NC-MRA), help assess RAS without contrast-related risks. Diffusion-weighted MR imaging (DW-MRI) has emerged as a promising method for evaluating kidney function by measuring the apparent diffusion coefficient (ADC), which correlates with renal pathology. To compare ADC values in hypertensive, RAS, and healthy kidneys, assess the correlation between ADC and stenosis severity, and evaluate its relationship with split glomerular filtration rate (GFR). This prospective observational study which included 86 patients with suspected RAS and twenty normal healthy controls underwent NC-MRA on a 3T-MR-Scanner followed by DW-MRI at b values of 0 and 1000 seconds/mm2 in the transverse plane. ADC maps were created using Functool. ADC values were measured in the cortex and medulla of each kidney's upper, middle, and lower pole, and the average ADC (ADCavg) for cortex and medulla calculated. In patients with RAS, degree of stenosis (DOS) was calculated on NC-MRA. The ADC of 212 kidneys was compared, and the relationship between DOS and ADC was established. In addition, split GFR was calculated in 30 kidneys using 99mTc-DTPA, and correlated with ADC value. The ADC values of kidneys with and without RAS were compared using the Student's t-test. The correlation between ADC and stenosis severity was assessed by Spearman's test, while the relationship between ADC and split GFR was evaluated using Pearson's test. A P value < 0.05 was considered statistically significant. RAS was detected in 58 of 86 (67.44%) hypertensive patients (81 of 172 kidneys), and the ADCavg (P = 0.044) was significantly lower in RAS kidneys than in kidneys with normal arteries and essential hypertension and healthy controls. DW-MRI can be a useful non-invasive technique to estimate the kidney's functional status in RAS patients. It can be used as a complementary assessment tool with NC-MRA to triage patients in need of interventional management.

Orbital infantile hemangioma and rhabdomyosarcoma in children: differentiation using diffusion-weighted magnetic resonance imaging

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.

Purpose:To investigate the feasibility of diffusion-weighted magnetic resonance imaging (DWI) with apparent diffusion coefficient (ADC) values in differentiating endometrial cancer from benign endometrial lesions in postmenopausal patients with vaginal bleeding and endometrial thickening and to predict the depth of myometrial invasion in endometrial cancer.Materials and Methods:Postmenopausal patients with vaginal bleeding and endometrial thickening were enrolled in this prospective study. T2-weighted, pre- and postcontrast T1-weighted and diffusion-weighted images were obtained. The ADC values of all the patients with endometrial pathologies were recorded. The staging accuracies of DWI and postcontrast T1-weighted images in the assessment of myometrial invasion were evaluated in histopathologically proven endometrial cancer patients.Results:Fifty-two patients (mean age: 57 ± 10, range: 41–79) were enrolled in the study. Thirty-eight of the lesions were benign (27 as hyperplasia and endometritis; 11 as polyps). Fourteen of the 52 endometrial lesions were pathologically proven as cancers and underwent hysterectomy, and all the specimens were reported as endometrioid adenocarcinomas. The mean ADC value (10–3 mm2/second) of cancer (0.88 ± 0.10) was significantly lower than that of benign lesions (1.78 ± 0.27, p = 0,001). There was no significant difference between ADC values of endometrial tissue in patients with FIGO stage 1A (0.87 ± 0.11, n = 9) and FIGO stage 1B (0.91 ± 0.07, n = 5). The staging accuracy was 92.9 per cent (13/14) for DWI and 85.7 per cent (12/14) for postcontrast T1-weighted images.Conclusion:ADC values allow benign endometrial lesions to be differentiated from endometrial cancer in postmenopausal patients but do not correlate with the depth of myometrial invasion and histological tumor grading.

Apparent diffusion coefficient (ADC) values, derived from diffusion-weighted magnetic resonance imaging (DW-MRI), increase with age, reflecting microstructural changes in white matter integrity. However, factors beyond chronological aging may influence cerebral diffusion characteristics. We investigated whether anticoagulant use is associated with favorable white matter ADC profiles, suggesting preserved microvascular health. ADC values were analyzed in cerebral white matter across four age-defined adult cohorts (20–59 years). Minimum, mean, and maximum ADC values were extracted. Patients at the lowest and highest ends of the ADC spectrum within each group were identified. The prevalence of anticoagulant use was compared between groups, and a logistic regression model adjusted for age was used to assess the independent association between anticoagulant use and lower ADC values. Across all cohorts (n = 892), anticoagulated patients (n = 89) were significantly overrepresented among individuals with low ADC values consistent with younger diffusion profiles. Of the anticoagulated patients, 93.3% had ADC values below the lower cut-off limit. In contrast, only 30% of non-anticoagulated patients exhibited such profiles. Anticoagulant use was independently associated with low ADC values after adjusting for age (OR = 4.89, p &lt; 0.0001). Anticoagulation is strongly associated with lower, more favorable ADC values in cerebral white matter, independent of age. These findings support the potential neuroprotective role of anticoagulants and suggest that diffusion MRI may serve as a surrogate marker for early microvascular brain health.

ObjectiveTo evaluate perinatal body organ apparent diffusion coefficient (ADC) values at postmortem magnetic resonance imaging (PMMR) in order to evaluate postmortem changes.MethodsPostmortem diffusion-weighted imaging (DWI) of the thorax and abdomen were performed with diffusion gradient values b = 0, 500, and 1000 s/mm2 on 15 foetal and childhood cases (mean 33.3 ± 7.8 weeks gestation) compared to 44 live infants (mean age 75.5 ± 53.4 days). Mean ADC values were calculated from regions of interest (ROIs) for the lungs, liver, spleen and renal cortex, compared to normative live infantile body ADC values of similar gestational age.ResultsMean ADC values were significantly lower in postmortem cases than in normal controls for liver (0.88 10-3 mm2/s ± SD 0.39 vs. 1.13 ± 0.13; p < 0.05) and renal cortex (0.85 ± 0.26 vs. 1.19 ± 0.13; p < 0.05) but not spleen or muscle. Mean lung ADC values were significantly higher than normal controls (1.06 ± 0.18 vs. 0 ± 0; p < 0.001), and there was a significant correlation between postmortem interval and lung ADC (R2 = 0.55).ConclusionLung PMMR ADC values are related to postmortem interval, making them a potential marker of time since death. Further research is needed to understand the organ-specific changes which occur in the postmortem period.Key Points • Liver and spleen PM ADC values were lower than controls. • Lung ADC changes correlate with PM interval. • These findings may be useful in medicolegal cases.

PurposeOur aim was to investigate the diffusion-weighted Imaging (DWI) appearance and apparent diffusion coefficient (ADC) values of normal prostatic gland, prostate carcinoma (PCa) and benign prostate hyperplasia (BPH) and to determine the utility of DWI in their characterization. Materials and methodsDuring a period of 16months, 40 consecutive patients, with elevated PSA level and 12 healthy volunteers with no clinical symptoms or history of prostate disease were prospectively evaluated with DWI of the prostate. MRI was performed using a 1.5T MR scanner equipped with a pelvic phased array coil. For anatomical imaging, T2W FSE in the three orthogonal planes, and T1WI in axial plane were obtained. DWI with b values of 0, 300, 500 and 800s/mm2 were performed in axial plane. The results were confirmed by TRUS-guided biopsy or prostatectomy. ResultsPatients ranged in age from 45 to 85years (mean 66.6±7.9year). Twenty patients were confirmed to have BPH, whereas 20 patients had PCa. The mean and SD of ADC values for the peripheral zone (PZ), central gland (CG), BPH nodules and PCa were 1.839±0.233, 1.469±0.239, 1.359±0.201 and 0.87±0.13 respectively. The mean ADC value of PCa was significantly lower than that of CG, PZ, and BPH nodule, with p value <0.05. ConclusionDW MR imaging characteristics and ADC values can differentiate PCa and BPH. DWI with ADC may be used as a complementary method to conventional MRI in diagnosis of PCa and BPH.

To investigate diffusion-weighted (DW) magnetic resonance (MR) imaging for differentiating borderline from malignant epithelial tumours of the ovary. This retrospective study included 60 borderline epithelial ovarian tumours (BEOTs) in 48 patients and 65 malignant epithelial ovarian tumours (MEOTs) in 54 patients. DW imaging as well as conventional MR imaging was performed. Signal intensity on DW imaging was assessed and apparent diffusion coefficient (ADC) value was measured. The results were correlated with histopathology and cell density. The majority of MEOTs showed high signal intensity on DW imaging, whereas most BEOTs showed low or moderate signal intensity (P = 0.000). The mean ADC value of the solid components in BEOTs (1.562 ± 0.346 × 10(-3) mm(2)/s) was significantly higher than in MEOTs (0.841 ± 0.209 × 10(-3) mm(2)/s). A threshold value of 1.039 × 10(-3) mm(2)/s permitted the distinction with a sensitivity of 97.0%, a specificity of 92.2% and an accuracy of 96.4%. There was an inverse correlation between ADC value and cell density (r = -0.609; P = 0.0000) which was significantly lower in BEOTs than in MEOTs. DW imaging is useful for differentiating borderline from malignant epithelial tumours of the ovary. DW MR imaging is useful for differentiating BEOTs from MEOTs. Patients with BEOTs are treated differently from patients with MEOTs. Conservative fertility-sparing laparoscopic surgery can be performed in patients with BEOTs. BEOTs often affect young women of childbearing age.

This study examined the effect of different b values on diffusion-weighted MR imaging (DWI) of human prostate by using single-shot spin echo echo planar imaging (SE-EPI) sequences, observed the normal appearances and measured apparent diffusion coefficient (ADC) values in anatomical regions of normal prostate. Twenty-four healthy volunteers (mean age: 32 y) were studied by using a 1.5T system with a phased array surface multicoil. Two kinds of single-shot SE-EPI sequence were used to perform DWI in the prostate in volunteers, with five b values being 0, 30, 300, 500 to 1000 s/mm(2). The image quality with different imaging parameters was analyzed and the ADC values in anatomical regions of normal prostate were measured. DWI of prostate was successfully obtained in all volunteers. The images were of good quality, without artifacts containing pixels within the prostate. The contrast was good between the different anatomical regions of the prostatic gland, i.e., the peripheral zone (PZ), which exhibited higher signal intensity, and the central gland (CG). Signal intensity contrast was related to the magnitude of b values. The ADC values in PZ and CG were (1.27+/-0.22)x10(-3) mm(2)/s and (1.01+/-0.17)x10(-3) mm(2)/s, respectively. The ADC values were found to be significantly higher in PZ than in CG (P<0.05, paired t-test). Significant differences were found between the slice-selecting component and both the read-out and phase-encoding components of the ADC values. It is concluded that SE-EPI is a suitable DWI sequence for human prostate. The contrast between PZ and CG is good when b values are low, while the diffusion and ADC values are accurate when b values are high. ADC values are higher in PZ than in CG in normal prostate. Diffusional anisotropy is present in normal prostatic tissue.