Diffusion-weighted single-shot echo planar MR imaging of normal human prostate using different b values

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.

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

To evaluate if normal and pathological prostate tissue can be distinguished by using apparent diffusion coefficient (ADC) values on magnetic resonance imaging (MRI) and to understand if it is possible to differentiate among pathological prostate tissues using ADC values. Our population consisted in 81 patients (mean age 65.4 years) in which 84 suspicious areas were identified. Regions of interest were placed over suspicious areas, detected on MRI, and over areas with normal appearance, and ADC values were recorded. Statistical differences between ADC values of suspicious and normal areas were evaluated. Histopathological diagnosis, obtained from targeted biopsy using MRI-US fusion biopsies in 39 patients and from prostatectomy in 42 patients, were correlated to ADC values. Histopathological diagnosis revealed 58 cases of prostate cancer (PCa), 19 patients with indolent PCa (Gleason Score ≤6) and 39 patients with clinically significant PCa (Gleason Score ≥7), 16 of high-grade prostatic intraepithelial neoplasia (HG-PIN) and 10 of atypical small acinar proliferation (ASAP). Significant statistical differences between mean ADC values of normal prostate tissue versus PCa (P<0.00001), HG-PIN (P<0.00001) and ASAP (P<0.00001) were found. Significant differences were observed between mean ADC values of PCa versus HG-PIN (P<0.00001) and ASAP (P<0.00001) with many overlapping values. Differences between mean ADC values of HG-PIN versus ASAP (P=0.015) were not significant. Significant differences of ADC values were also observed between patients with indolent and clinically significant PCa (P<0.00001). ADC values allow differentiation between normal and pathological prostate tissue and between indolent and clinically significant PCa but do not allow a definite differentiation between PCa, HG-PIN, and ASAP.

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.

To measure for the first time the apparent diffusion coefficient (ADC) values in anatomical regions of the prostate for normal and patient groups, and to investigate its use as a differentiating parameter between healthy and malignant tissue within the patient group. Single-shot diffusion-weighted echo-planar imaging (DW-EPI) was used to measure the ADC in the prostate in normal (N = 7) and patient (N = 19) groups. The spin-echo images comprised 96 x 96 pixels (field of view of 16 cm, TR/TE = 4000/120 msec) with six b-factor values ranging from 64 to 786 seconds/mm(2). The ADC values averaged over all patients in non-cancerous and malignant peripheral zone (PZ) tissues were 1.82 +/- 0.53 x 10(-3) (mean +/- SD) and 1.38 +/- 0.52 x 10(-3) mm(2)/second, respectively (P = 0.00045, N = 17, paired t-test). The ADC values were found to be higher in the non-cancerous PZ (1.88 +/- 0.48 x 10(-3)) than in healthy or benign prostatic hyperplasia central gland (BPH-CG) region (1.62 +/- 0.41 x 10(-3)). For the normal group, the mean values were 1.91 +/- 0.46 x 10(-3) and 1.63 +/- 0.30 x 10(-3) mm(2)/second for the PZ and CG, respectively (P = 0.011, N = 7). Significant overlap exists between individual values among all tissue types. Furthermore, ADC values for the same tissue type showed no statistically significant difference between the two subject groups. ADC is quantified in the prostate using DW-EPI. Values are lower in cancerous than in healthy PZ in patients, and in BPH-CG than PZ in volunteers.

To prospectively determine apparent diffusion coefficient (ADC) values of normally developing fetal lungs over gestation, as obtained by diffusion-weighted (DW) magnetic resonance imaging (MRI) and to investigate its potential application in fetuses with congenital diaphragmatic hernia (CDH). Informed consent was obtained for this cross-sectional study of 93 fetuses with normal lungs and 14 with isolated left-sided CDH, assessed between 18 and 40 weeks of gestation. MRI delineation of left and right lungs was performed on the native DW image, b0, and three values of ADC, corresponding to the overall value (ADC(avg)), and values for low and high values of b (ADC(low) and ADC(high), respectively) were calculated. Regression analysis was used to assess the relationship between gestational age and b0-values as well as calculated ADC values. The b0 and ADC values of normal and CDH fetuses were compared with normal ranges using the Mann-Whitney U-test. In fetuses with normal lungs, there was a negative correlation between gestational age and b0 values as well as with ADC(high), a positive correlation with ADC(low) but no correlation with ADC(avg). When measurable, ADC(high) values were lower in CDH as compared to fetuses with normal lungs and ADC(low) values were higher. ADC(low) was unrelated to lung volume. There is a significant relationship between ADC(low) and ADC(high) values and gestational age in normal fetal lungs. This relationship is most probably explained by developmental changes during the last three stages of lung development, which involve intense peripheral growth of airways and vessels as well as maturation. In CDH, measurement of ADC(low) might be useful as a predictor of postnatal outcome that is independent of lung volume.

Objective:The study aims to determine whether apparent diffusion coefficient (ADC) can help differentiate benign and malignant bone tumors.Materials and Methods:From January 2012 to February 2013, we prospectively included 26 patients. Of these 15 patients were male and 11 were female; ranging in age from 8 to 76 years (mean age, 34.5 years). Diffusion-weighted magnetic resonance (MR) imaging was obtained with a single-shot echo-planar imaging sequence using a 1.5T MR scanner. We grouped malignant lesions as primary, secondary, and primary tumor with chondroid matrix. The minimum ADC was measured in the tumors and mean minimum ADC values were selected for statistical analysis. ADC values were compared between malignant and benign tumors using the Mann-Whitney U-test and receiver operating curve analysis were done to determine optimal cut-off values.Results:The mean ADC values from the area with lowest ADC values of benign and malignant tumors were 1.99 ± 0.57 × 10−3 mm2/s and 1.02 ± 1.0 × 10−3 mm2/s, respectively. The mean minimum ADC values of benign and malignant tumors were statistically different (P = 0.029). With cut-off value of 1.37 (10−3 mm2/s), sensitivity was 77.8% and specificity was 82.4%, for distinguishing benign and malignant lesion. Benign and secondary malignant tumors showed statistically significant difference (P = 0.002). There was some overlap in ADC values between benign and malignant tumors. The mean minimum ADC values of benign and malignant chondroid tumors were high. Giant cell tumor, non-ossifying fibroma and fibrous dysplasia showed lower ADC values.Conclusion:Although there is some overlap, ADC values of benign and malignant bone tumors seem to be different. Further studies with larger patient groups are needed to find an optimal cut-off ADC value.

We conducted a prospective study to demonstrate the feasibility of using diffusionweighted (DW) magnetic resonance imaging (MRI) for the detection of urinary bladder carcinomas. Between January to June 2007, 43 patients with single bladder tumor were included in our study. Before taking a biopsy, DW MRI was obtained in the axial plane under free breathing scanning with a multisection, spin-echo type, single-shot echo planar sequence with a body coil. Moreover, the apparent diffusion coefficient (ADC) value was measured in a circular region of interest within the carcinoma, urine, normal bladder wall, prostate, and seminal vesicle. All carcinomas in the 43 patients were clearly shown as high signal intensity relative to the surrounding structure. The sensitivity and positive predictive values of DW MRI were 100% in terms of correctly detecting the carcinomas. The ADC value in the carcinoma (1.40 ± 0.51) was significantly lower compared with that of urine (3.50 ± 0.43) (p < 0.001), normal bladder wall (2.29 ± 0.78) (p < 0.001), peripheral zone of prostate (1.77 ± 0.44) (p < 0.05), transition zone of prostate (1.88 ± 0.54) (p < 0.05), and the seminal vesicle (2.12 ± 0.43) (p < 0.001). There was no statistical difference in ADC values between different histological subtypes. There was no overlap between the ADC values of the tumors and the urine, but there was no clear cutoff between the tumor and bladder wall, prostate, or seminal vesicles. Bladder carcinomas have significantly lower ADC when compared to surroundings. Clinical experience with this method is still preliminary and further studies are required.

Purpose: To determine the relationship between apparent diffusion coefficient (ADC) values measured by diffusion-weighted MR imaging and split renal function determined by renal scintigraphy in patients with hydronephrosis. Material and Methods: Diffusion-weighted imaging on a 1.5 T MR unit and renal scintigraphy were performed in 36 patients with hydronephrosis (45 hydronephrotic kidneys, 21 non-hydronephrotic kidneys). ADC values of the individual kidneys were measured by diffusion-weighted MR imaging. Split renal function (glomerular filtration rate (GFR)) was determined by renal scintigraphy using 99mTc-DTPA. The relationship between ADC values and split GFR was examined in 66 kidneys. The hydronephrotic kidneys were further classified into three groups (severe renal dysfunction, GFR 25 ml/min, n=28), and mean values for ADCs were calculated. Results: In hydronephrotic kidneys, there was a moderate positive correlation between ADC values and split GFR (R 2=0.56). On the other hand, in non-hydronephrotic kidneys, poor correlation between ADC values and split GFR was observed (R 2=0.08). The mean values for ADCs of the dysfunctioning hydronephrotic kidneys (severe renal dysfunction, 1.32×10−3±0.18×10−3 mm2/s; moderate renal dysfunction, 1.38×10–3±0.10×10−3 mm2/s) were significantly lower than that of the normal functioning hydronephrotic kidneys (1.63×10−3±0.12±10−3 mm2/s). Conclusion: These results indicated that measurement of ADC values by diffusion-weighted MR imaging has a potential value in the evaluation of the functional status of hydronephrotic kidneys.

PurposeTo retrospectively evaluate the effect of post-prostate-biopsy hemorrhage on the interpretation of magnetic resonance diffusion-weighted (MRDW) and magnetic resonance spectroscopic (MRS) imaging in the detection of prostate cancer. We also investigated the optimal timing for magnetic resonance examination after prostate biopsy.Materials and MethodsWe reviewed the records of 135 men. All patients underwent prostate magnetic resonance imaging (MRI). The prostate was divided into eight regions according to the biopsy site. Subsequently, we measured hemorrhage on apparent diffusion coefficient (ADC) values and (choline+creatinine)/citrate ([Cho+Cr]/Cit) ratios in the same regions on the MRI. We investigated the effect of hemorrhage at ADC values and (Cho+Cr)/Cit ratios on MRI and the relationship between prostate biopsy results and MRI findings.ResultsThe mean patient age was 68.7 years and the mean time between biopsy and MRI was 23.5 days. The total hemorrhagic score demonstrated no significant associations with intervals from biopsy to MRI. Higher hemorrhagic scores were associated with higher ADC values, prostate cancer, and noncancer groups, respectively (p<0.001). ADC values were lower in tumors than in normal tissue (p<0.001), and ADC values were inversely correlated with tumor Gleason score in biopsy cores (p<0.001). However, (Cho+Cr)/Cit ratios did not exhibit any association with prostate biopsy results and hemorrhage.ConclusionsHemorrhage had no significant associations with the interval from biopsy to MRI. ADC values may help to detect prostate cancer and predict the aggressiveness of cancer; however, it is important to consider the bias effect of hemorrhage on the interpretation of MRDW imaging given that hemorrhage affects ADC values.

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 compare the apparent diffusion coefficient (ADC) values of upper abdominal organs with 2 different 3.0 tesla MR systems and to investigate the usefulness of normalization using the spleen.Materials and MethodsForty-one patients were enrolled in this prospective study, of which, 35 patients (M:F, 27:8; mean age ± standard deviation, 62.3 ± 12.3 years) were finally analyzed. In addition to the routine liver MR protocol, single-shot spin-echo echo-planar diffusion-weighted imaging using b values of 0, 50, 400, and 800 s/mm2 in 2 different MR systems was performed. ADC values of the liver, spleen, pancreas, kidney and liver lesion (if present) were measured and analyzed. ADC values of the spleen were used for normalization. The Pearson correlation, Spearman correlation, paired sample t test, Wilcoxon signed rank test and Bland-Altman method were used for statistical analysis.ResultsFor all anatomical regions and liver lesions, both non-normalized and normalized ADC values from 2 different MR systems showed significant correlations (r = 0.5196–0.8488). Non-normalized ADC values of both MR systems differed significantly in all anatomical regions and liver lesions (p < 0.001). However, the normalized ADC of all anatomical regions and liver lesions did not differ significantly (p = 0.065–0.661), with significantly lower coefficient of variance than that of non-normalized ADC (p < 0.009).ConclusionNormalization of the abdominal ADC values using the spleen as a reference organ reduces differences between different MR systems, and could facilitate consistent use of ADC as an imaging biomarker for multi-center or longitudinal studies.

Context: The purpose of this study was to assess the role of diffusion-weighted-magnetic resonance imaging (DW-MRI) and apparent diffusion coefficient (ADC) values in the evaluation of different benign and malignant brain mass lesions with histopathological correlation. Aims: To assess the role of DW-MRI in the evaluation of different mass lesions of the brain with histopathological correlation. To evaluate the role of ADC values in characterization and differentiation of benign and malignant mass lesions of the brain. Settings and Design: The study design was a cross-sectional study and it was done in patients who were referred to Victoria Hospital attached to Bangalore Medical College and Research Institute (BMC and RI), Bengaluru between December 2012 and November 2014. The sample size of the study was 50. Subjects and Methods: We retrospectively reviewed 50 MR examinations of patients who were referred to Department of Radio Diagnosis, BMC, and RI, Bengaluru for intracranial mass lesion evaluation with MRI. All of them had undergone conventional MRI examination with Siemens AVANTO 1.5T scanner, and we determined ADC values and signal intensities on DW images (DWIs). In all patients with contrast-enhanced tumors, region of interests (ROIs) were placed in the enhanced region. In patients with nonenhancing tumors, ROIs were placed in the solid part of the lesion. We also evaluated the correlation between ADC values and cellularity in the mass lesions. Additional clinical details and histopathological findings were correlated with the DWI and ADC findings for radiologic-pathologic concordance. Statistical Analysis: Brain MRI results of 50 patients with histologically verified or clinically diagnosed brain mass lesions were subjected to analysis. They ranged in age from 2 to 72 years (mean, 43.5 years). The examinations were performed with a 1.5T scanner, an 8-channel surface head coil. The examination protocol included the following sequences and images: Turbo spin-echo (SE) T2-weighted images (3920/102/1), fluid-attenuated inversion recovery (2500/9000/111/1) ([inversion time/repetition time (TR)/echo time (TE)/excitations], and SE T1-weighted images [488/10/1] [TR/TE/excitations]), carried out in three planes, before and after contrast medium administration (in a standard dose). Results: A positive correlation was found in the comparison of mean ADC values for high-grade gliomas (1.19 × 10−3 mm 2 /s ± 0.2) and metastasis (0.833 × 10−3 mm 2 /s ± 0.2), low-grade gliomas (1.34 × 10−3 mm 2 /s ± 0.2), and medulloblastomas (0.68 × 10−3 mm΂/s ± 0.075), as well as for in epidermoid cyst and necrotic areas in malignant tumors. Conclusion: ADC is useful in the differentiation of various brain mass lesions, in grading brain tumors, and differentiation of benign cystic and malignant necrotic areas. The combination of routine image interpretation and ADC had a higher predictive value. The ADCs of glioma, metastasis, and meningioma are related to tumor cellularity. We believe that DWIs and ADCs can provide information useful to diagnose brain mass lesions that cannot be obtained with conventional MRI alone.

To determine the value of adding diffusion-weighted (DW) magnetic resonance (MR) imaging to dynamic contrast material-enhanced MR imaging when distinguishing between benign and malignant parotid tumors. This retrospective study was approved by the institutional review board, and the informed consent requirement was waived. The authors analyzed MR images of 50 lesions (36 benign, 14 malignant) in 47 patients. DW MR imaging and dynamic contrast-enhanced MR imaging were performed in all patients. Time-intensity curve (TIC) patterns were categorized as follows: type A, time to peak was more than 120 seconds; type B, time to peak was 120 seconds or less with high washout ratio (> or = 30%); type C, time to peak was 120 seconds or less with low washout ratio (< 30%); and type D, flat. The apparent diffusion coefficient (ADC) values were measured on DW MR images. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated for type A, B, and D tumors regarded as benign and for type C tumors regarded as malignant. On the basis of DW MR imaging results, ADC threshold values between pleomorphic adenomas and carcinomas and between Warthin tumors and carcinomas were selected. Diagnostic accuracy was compared before and after modification diagnosis referring to the ADC value obtained with the McNemar test. P < .05 was considered to indicate a significant difference. ADC threshold values were 1.4 x 10(-3) mm(2)/sec between pleomorphic adenomas and carcinomas and 1.0 x 10(-3) mm(2)/sec between Warthin tumors and carcinomas. Accuracy (82% vs 94%) and positive predictive value (67% vs 92%) significantly improved with the addition of ADC values in the evaluation of patients with type B or C tumors. A persistent or flat TIC pattern on dynamic contrast-enhanced MR images indicates benign disease, but there is added value from including the ADC value in the evaluation of tumors that show a plateau or washout TIC pattern.

To establish whether T2 relaxation and apparent diffusion coefficient (ADC) in normal prostate and tumour are related and to investigate the effects of glandular compression from an enlarged transition zone (TZ) on peripheral zone (PZ) T2 and ADC by correlating them with the peripheral zone fractional volume (PZFV). 48 consecutive patients prospectively underwent multiecho T2 weighted (T2W) (echo times 20, 40, 60, 80, 100 ms) and diffusion-weighted (b=0, 100, 300, 500, 800 s mm(-2)) endorectal MRI. In 43 evaluable patients, single slice whole PZ, TZ and tumour (focal hypointense signal on T2W images in a biopsy-positive octant) regions of interest were transferred to T2 and ADC maps by slice matching. T2 and ADC values were correlated, and PZ values were correlated with PZFV. T2 and ADC values were significantly different among groups [T2 mean±standard deviation (SD) PZ, 149±49 ms; TZ, 125±26 ms; tumour, 97±23 ms; PZ vs TZ, p=0.002; PZ vs tumour, p<0.0001; TZ vs tumour, p<0.0001; ADC×10(-6) mm(2) s(-1) mean±SD PZ, 1680±215; TZ, 1478±139; tumour, 1030±205; p<0.0001]. Significant positive correlations existed between T2 and ADC for PZ, TZ, PZ and TZ together, but not for tumour (r=0.515, p<0.0001; r=0.300, p=0.03; r=0.526, p<0.0001; and r=0.239, p=0.32, respectively). No significant correlation existed between PZFV and PZ T2 (r=0.10, p=0.5) or ADC (r=0.03, p=0.8). The correlation between T2 and ADC that exists in normal prostate is absent in tumour. PZ compression by an enlarged TZ does not alter PZ T2 or ADC to affect tumour-PZ contrast. Microstructural features of tumours alter diffusivity independently of their effects on T2 relaxation.