Significant Difference In Apparent Diffusion Coefficient Values Research Articles

The value of T2 mapping for evaluating the pathological type, grade and depth of myometrial invasion in endometrial carcinoma

Objective: To investigate the value of T2 map and synthetic T2WI generated by T2 mapping in evaluating the histological type, pathological classification and depth of myometrial invasion of endometrial carcinoma (EC). Methods: Seventy-three patients with pathologically proven EC diagnosed at the First Affiliated Hospital of Zhengzhou University from December 2019 to December 2021 and 42 healthy volunteers were enrolled in the study. All subjects underwent conventional MRI, diffusion weighted imaging (DWI) and T2 mapping sequence for the pelvic cavity to test the T2 values and the apparent diffusion coefficient (ADC) of the focus nidus of the patients and the normal endometrium of the volunteers. The T2 and ADC values of EC vs normal endometrium, and those of different histological types and pathological grades were compared. The receiver operating characteristic (ROC) curves were constructed to evaluate the diagnostic performance of T2 and ADC values in determining the pathological type and classification of EC. In addition, two radiologists used synthetic T2WI combined with T2 map and conventional T2WI combined with DWI, respectively, to evaluate the depth of myometrial invasion, and compared the imaging results with the results of pathological diagnosis to evaluate the diagnostic efficacy of the two methods in determining the depth of myometrial invasion. Results: The T2 and ADC values of endometrial carcinoma were 85.0 (80.8, 92.5) ms and 0.71 (0.64, 0.77) ×10(-3) mm(2)/s, respectively, which were significantly lower than those of normal endometrium [147.4 (123.4, 176.7) ms and 1.46 (1.26, 1.76)×10(-3) mm(2)/s, respectively; both P<0.05]. The T2 values of endometrioid carcinoma (EA) [84.1 (79.5, 88.7) ms] were significantly lower than those of non-EA [98.8 (92.1, 102.8) ms; P<0.05]. There was no significant difference in ADC values between EA and non-EA (P=0.075). The T2 values of G1, G2 and G3 groups in EA were 89.1 (84.4, 94.4) ms, 83.6 (80.9, 86.2) ms, and 76.5 (71.4, 80.3) ms, respectively. There were significant differences in the T2 values between G1 vs G2, G1 vs G3, and G2 vs G3 groups, respectively (all P<0.017). Significant difference was also found in the ADC values between the G1 and G3 groups (P<0.017). The area under the ROC curve (AUC) of T2 values in distinguishing EA from non-EA was 0.867. The AUC of T2 values, ADC values and their combination in predicting high-grade EA was 0.888, 0.730 and 0.895, respectively. The accuracy of synthetic T2WI+ T2 map and conventional T2WI+ DWI in the diagnosis of deep myometrial invasion was 78.1% and 79.5%, respectively, with no significant difference (P>0.05). Conclusions: T2 mapping has great potential in preoperative evaluation of EC. The quantitative T2 value can be used in the diagnosis, pathological classification and grading of EC. The combination of synthetic T2WI and T2 map may be helpful to determine the depth of myometrial invasion.

Diffusion-weighted imaging in the assessment of cervical cancer: comparison of reduced field-of-view diffusion-weighted imaging and conventional techniques.

Cervical cancer (CC) is the second most common cancer in women worldwide. Diffusion-weighted imaging (DWI) plays an important role in the diagnosis of CC, but the conventional techniques are affected by many factors. To compare reduced-field-of-view (r-FOV) and full-field-of-view (f-FOV) DWI in the diagnosis of CC. Preoperative magnetic resonance imaging (MRI) with r-FOV and f-FOV DWI images were collected. Two radiologists reviewed the images using a subjective 4-point scale for anatomical features, magnetic susceptibility artifacts, visual distortion, and overall diagnostic confidence for r-FOV and f-FOV DWI. The objective features included the region of interest (ROI) signal intensity of the cervical lesion (SIlesion) and gluteus maximus muscle (SIgluteus), standard deviation of the background noise (SDbackground), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). The differences of measured apparent diffusion coefficient (ADC) values between the two examinations in pathological grades and FIGO tumor stages were compared. A total of 200 patients were included (170 with squamous cell carcinoma and 30 with adenocarcinoma). The scores of anatomical features, magnetic susceptibility artifacts, visual distortion, and overall diagnostic confidence for r-FOV DWI were significantly higher than those for f-FOV DWI. There was no difference in SNR and CNR between r-FOV DWI and f-FOV DWI. There were significant differences in ADC values between the two groups in all comparisons (P < 0.05). Compared with f-FOV DWI, r-FOV DWI might provide clearer imaging, fewer artifacts, less distortion, and higher image quality for the diagnosis of CC and might assist in the detection of CC.

Magnetic resonance imaging changes and clinical features of reversible posterior leukoencephalopathy syndrome.

Reversible posterior leukoencephalopathy syndrome (RPLS) is a rare clinical imaging syndrome. The causes of RPLS are complex and diverse, the pathogenesis is not yet clear. The onset is urgent and the onset age span is large, ranging from children to the elderly. The clinical symptoms of RPLS have no significant specificity, which can be manifested as headache, blurred vision, disturbance of consciousness or seizures. Clinicians have little knowledge on the disease, which may lead to misdiagnosis or missed diagnosis. This study aims to analyze and summarize the MRI changes and clinical characteristics regarding RPLS patients, so as to provide basis for rapid diagnosis and timely intervention for this disease. The clinical data and complete imaging data of 77 patients with RPLS diagnosed in Xiangya Hospital of Central South University from January 2012 to March 2021 were retrospectively collected. The main image data include T1 weighted imaging (T1WI), T2 weighted imaging (T2WI), T2 liquid attenuation inversion recovery (T2-FLAIR), diffusion weighted imaging (DWI) (b value=1 000×10-6 mm2/s), and apparent diffusion coefficient (ADC). The case group included 63 patients who underwent DWI examination, and 71 normal controls matched in age and sex. The characteristics of patients' magnetic resonance signals and the ADC value of 19 regions of interest (ROI) were analyzed. The differences in bilateral ADC value in the case group, the difference of ADC value between the case group and the normal control group, and the difference of ADC value in the case group before and after treatment were compared. Compared with the normal control group, the ADC value of the right frontal lobe, bilateral parietal lobe, bilateral thalamus, bilateral head of caudate nucleus, left lenticular nucleus, right internal capsule, bilateral temporal lobe and pons in the case group were significantly higher (all P<0.01). There was no significant difference in ADC value of bilateral sides of the case group and before and after treatment in the case group (all P>0.01). The lesions of RPLS were widely distributed and multiple, usually high signal in the posterior parieto temporo occipital lobe or pons of the brain, and involved the cortex and subcortical white matter. Most of them were bilateral, but not completely symmetrical. The imaging manifestations of RPLS and the occurrence and development of clinical symptoms are basically synchronous. The imaging manifestations are specific. Magnetic resonance imaging can show the range of involvement of RPLS. ADC value can provide information on the severity of the disease and predict the prognosis. There are few reversible diseases. It is very important to fully understand and timely diagnose the disease.

Study of bone marrow microstructure in healthy young adults using intravoxel incoherent motion diffusion-weighted MRI.

Bone marrow is one of the most important organs in the human body. The evaluation of bone marrow microstructure and gender-related cellular and capillary networks in healthy young adults can help to better understand the process of bone metabolism. Intravoxel incoherent motion (IVIM) provides both diffusion and perfusion quantifications without requiring intravenous contrast agent injection. In this prospective study, 60 healthy young age-matched volunteers (30 men and 30 women) underwent MRI scans at 1.5 T using multi-b-value diffusion-weighted imaging on sagittal planes covering the lumbar bone marrow. The apparent diffusion coefficient (ADC), true ADC (D), pseudo-ADC (D*), and perfusion fraction (f) were calculated from the diffusion-weighted images using the mono- and bi-exponential models. Lumbar cancellous bone (L2-L4) was selected as the region of interest. An independent t-test was used to detect significant differences in ADC values and IVIM parameters between men and women. The differences in IVIM parameters among the L2, L3, and L4 groups were compared with analysis of variance. The D and f values in women were significantly higher than that in men (p = 0.001, 0.026). However, D* was significantly lower in women than that in men (p = 0.001). Furthermore, there was no significant gender difference for the conventional ADC value (p = 0.186). Moreover, there were no significant differences in the D, f, and D* values among the L2, L3, and L4 vertebras of women or men. IVIM parameters can show differences in bone marrow between young women and men. As a non-invasive method, it can assess bone marrow microstructure, such as cellularity and perfusion.

ADC Values of Cytologically Benign and Cytologically Malignant 18 F-FDG PET-Positive Lymph Nodes of Head and Neck Squamous Cell Carcinoma.

Simple SummaryIn squamous cell carcinoma of the head and neck, 18F-fluordeoxyglucose positron emission tomography (FDG-PET), diffusion-weighted magnetic resonance imaging (DW-MRI) and ultrasound-guided fine needle aspiration are commonly used imaging tools for nodal staging (N-staging). Although FDG-PET has good performance in nodal detection, it is still difficult to distinguish between PET-positive reactive and malignant nodes for the purpose of selecting nodes to be aspirated. DW-MRI can help to detect small lymph node metastases, and an inverse correlation with FDG uptake is expected. We found a mild negative correlation between SUVmax and ADC. Comparing the apparent diffusion coefficient (ADC) values between PET-positive and PET-negative nodes, ADC was significantly higher in PET-negative nodes. Whereas no significantly lower ADC value of cytological malignant nodes could be found overall, in the subgroup of non-HPV-related nodes, the ADC values of cytologically malignant PET-positive nodes were significantly lower than in cytologically benign nodes. This finding might be helpful in selecting nodes for puncture.Nodal staging (N-staging) in head and neck squamous cell carcinoma (HNSCC) is essential for treatment planning and prognosis. 18F-fluordeoxyglucose positron emission tomography (FDG-PET) has high performance for N-staging, although the distinction between cytologically malignant and reactive PET-positive nodes, and consequently, the selection of nodes for ultrasound-guided fine needle aspiration cytology (USgFNAC), is challenging. Diffusion-weighted magnetic resonance imaging (DW-MRI) can help to detect nodal metastases. We aim to investigate the potential of the apparent diffusion coefficient (ADC) as a metric to distinguish between cytologically reactive and malignant PET-positive nodes in order to improve node selection criteria for USgFNAC. PET-CT, real-time image-fused USgFNAC and DW-MRI to calculate ADC were available for 78 patients offered for routine N-staging. For 167 FDG-positive nodes, differences in the ADC between cytologically benign and malignant PET-positive nodes were evaluated, and both were compared to the ADC values of PET-negative reference nodes. Analyses were also performed in subsets of nodes regarding HPV status. A mild negative correlation between SUVmax and ADC was found. No significant differences in ADC values were observed between cytologically malignant and benign PET-positive nodes overall. Within the subset of non-HPV-related nodes, ADCb0-200-1000 was significantly lower in cytologically malignant PET-positive nodes when compared to benign PET-positive nodes. ADCb0-1000 and ADCb0-200-1000 were significantly lower (p = 0.018, 0.016, resp.) in PET-negative reference nodes than in PET-positive nodes. ADC was significantly higher in PET-negative reference nodes than in PET-positive nodes. The non-HPV-related subgroup showed significantly (p = 0.03) lower ADC values in cytologically malignant than in cytologically benign PET-positive nodes, which should help inform the node selection procedure for puncture.

Native T1-mapping and diffusion-weighted imaging (DWI) can be used to identify lung cancer pathological types and their correlation with Ki-67 expression.

BackgroundThis study aimed to explore the value of native T1-mapping and diffusion-weighted imaging (DWI) in differentiating the pathological types and degree of tumor differentiation of lung cancer and their correlation with Ki-67 protein expression.MethodsA total of 78 consecutive lung cancer patients who received chest magnetic resonance imaging (MRI) scans between May 2020 and June 2021 were enrolled in this study. Two radiologists independently analyzed the apparent diffusion coefficient (ADC) and T1 values for each lesion. The intraclass correlation coefficient (ICC) and Bland-Altman plots were generated to assess interobserver agreement of the T1 and ADC mean values in lesions. The difference in ADC and T1 values among different pathological types, as well as between high- and low-differentiated lung cancers were analyzed, and diagnostic efficacy was evaluated by receiver operating characteristic (ROC) curve analysis. The correlation between ADC value, T1 value, and Ki-67 protein expression index was determined.ResultsThe ADC and T1 values showed excellent interobserver agreement (ICC 0.820, 0.942, respectively). There was a significant difference in ADC values between small cell carcinoma and squamous carcinoma (P<0.05), and between small cell carcinoma and adenocarcinoma (P<0.05), but not between squamous carcinoma and adenocarcinoma (P>0.05). A significant difference in T1 values was observed between small cell carcinoma (P<0.05) and adenocarcinoma, and between squamous carcinoma (P<0.05) and adenocarcinoma, but not between squamous carcinoma and small cell carcinoma (P>0.05). There were statistically significant differences in ADC and T1 values between the moderately and highly differentiated group and the poorly differentiated group (P<0.05). ROC curve analysis showed that the T1 combined with ADC value had high diagnostic value for the degree of differentiation of the tumor [area under the curve (AUC) =0.912]. Pearson correlation analysis showed a significant positive correlation between T1 value and Ki-67 index (r=0.66, P<0.001) and a significant negative correlation between ADC value and Ki-67 index (r=−0.45, P<0.01).ConclusionsT1 and ADC values can be used to distinguish the pathological type and differentiation degree of lung cancer.

Brain diffusion MRI with multiplexed sensitivity encoding for reduced distortion in a pediatric patient population

BackgroundDiffusion-weighted imaging (DWI) is a valuable tool for routine imaging of the pediatric brain. However, the commonly used single-shot (ss) echo-planar imaging (EPI) DWI sequence is prone to geometric distortions and T2*-blurring. This study aimed to investigate in a pediatric population the benefits of using multiplexed sensitivity-encoding (MUSE) without and with reversed polarity gradients (RPG) instead. MethodsThis retrospective study compared image quality, geometric distortions, and diffusion values between three different approaches for DWI (ssEPI, MUSE, and RPG-MUSE) in 14 patients (median age = 4 (0.6–15) years, 11 males). Distortion levels were quantified and compared in two brain regions, i.e., the brain stem and the temporal lobes, using the Dice Coefficient and the Hausdorff Distance, with T2-weighted images as reference. Expected geometrical distortion was further evaluated by comparing the effective echo spacing between the DWI sequences. Apparent diffusion coefficient (ADC) values were determined in the genu of the corpus callosum and the optic nerves. Two raters graded overall image quality and image distortions on a Likert scale. ResultsDistortion levels assessed with Dice coefficient and Hausdorff distance were significantly lower for MUSE (p < 0.05) and RPG-MUSE (p < 0.01) compared to ssEPI. No significant difference in ADC values was observed between methods. The RPG-MUSE method was graded by one rater as significantly higher in overall image quality than ssEPI (p < 0.05) and by both raters as significantly lower in levels of image distortions than both MUSE (p < 0.05) and ssEPI (p < 0.05). These results were in agreement with the reduced effective echo spacing was that was attained with MUSE and RPG-MUSE. ConclusionFor imaging of the pediatric brain, MUSE and even more so RPG-MUSE offers both improved geometric fidelity and image quality compared to ssEPI.

Characterization of Hepatic Focal Lesions by Diffusion Tensor Imaging and How Far it Can Predict Post-Treatment Response?

Abstract Background: Liver diseases have been known to be a major health problem principally because of their world-wide distribution. Focal liver disease is a common diagnostic problem referred to radiologists for evaluation owing to its nonspecific clinical presentation and marked interobserver variation on clinical examination. Aim of Study: The purpose of this study is to evaluate the role of diffusion tensor imaging in characterization of hepatic focal lesions and its value in post-treatment response. Patients and Methods: This prospective study included 30 patients previously diagnosed to have hepatic focal lesions (HFLs) by their characteristic triphasic computed tomography (CT), dynamic magnetic resonance imaging (MRI) features and/or biopsy. The study included 43 lesions in 30 patients (16 benign lesions, 23 malignant lesions, and 4 treated malig-nant lesions). MRI with diffusion tensor imaging (DTI) was performed for all patients. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values were evaluated for all lesions. Results: There was a statistically significant difference in ADC values between the benign and malignant lesions (p 1.42x 10-3 mm2/s with 95.7% sensitivity and 82.8% specificity. The best cut-off ADC value to differ-entiate between treated malignant and malignant lesions respectively was >1.65x 10-3 mm2/s with 97.8% sensitivity and 95.7% specificity. The best cut-off FA value to differentiate between malignant and benign lesions respectively was >0.29 with 95% sensitivity and 70% specificity. The best cut-off FA value to differentiate between treated malignant and untreated malignant lesions respectively was <0.297 with 100% sensitivity and 69.2% specificity. Conclusion: Diffusion tensor imaging is an evolving technique that can be used to characterize different hepatic focal lesions either benign or malignant with significant additive value to dynamic contrast enhanced MRI examination. It can also be used to monitor treatment response.

Hepatic sclerosed hemangioma and sclerosing cavernous hemangioma: a radiological study

PurposeTo investigate and compare the CT and MRI features of hepatic sclerosed hemangioma (HSH) and sclerosing cavernous hemangioma (SCH).Materials and methodsTwelve HSH cases and 36 SCH cases were included, the imaging findings on CT (9 HSH and 34 SCH) and MRI (8 HSH and 10 SCH) were analyzed. Qualitative image analysis included the location, size, shape, capsular retraction, density, calcification, signal intensity on T1-weighted image (T1WI) and T2-weighted image (T2WI), presence of diffusion restriction, apparent diffusion coefficient (ADC) map, transient hepatic attenuation difference around the lesion, and the dynamic enhancement patterns.ResultsThe presence of liver cirrhosis in patients with HSH (3/12) was higher than SCH (1/36) (P = 0.043). The morphology appearance before enhancement showed no significant difference between HSH and SCH. Moreover, SCH had a stronger trend of centripetal enhancement patterns of cavernous hemangiomas (83.3%) compared to HSH (25%) (P < 0.001). Due to more frequent atypical enhancement features, containing rim-like enhancement, no enhancement, and peripheral heterogeneous enhancement, the misdiagnosis rate of HSH (75%) was significantly higher than that of SCH (16.7%) (P < 0.001). Furthermore, the ADC values of HSH and SCH were both higher than that of the surrounding liver parenchyma (P = 0.009, P = 0.002); however, there was no significant difference in ADC values between themselves (P = 0.613).ConclusionSCH showed the same trend of centripetal enhancement characteristics as typical hemangioma, while HSH exhibited atypical enhancement features due to complete sclerosis. Higher ADC values might contribute to the identification of atypical HSH and SCH from malignancies.

Efficiency of diffusion-weighted MRI for differentiating radiologically similar simple and type I hydatid cysts of the liver.

Determining the nature of purely cystic hepatic lesions is essential because different kinds have different follow-ups, treatment options, and complications. To explore the potential of apparent diffusion coefficient (ADC) values of diffusion-weighted imaging (DWI) for the differentiation of type I hydatid cysts (HC) and simple liver cysts (SLC), which have similar radiological appearances. This single-center prospective study was conducted during 2016-2019. Round, homogenous, anechoic liver cysts >1 cm were classified according to at least two years of imaging follow-up, radiological features, serology, as well as puncture aspiration injection reaspiration procedure and pathology results. ADC values of 95 cysts (50 type I HCs and 45 SLCs) were calculated on DWI. The differences in ADC values were analyzed by independent t-test. Of 51 patients, 28 were female, 23 were male (mean age 32.07 ± 22.95 years; age range 5-82 years). Mean diameter of 45 SLCs was 2.59 ± 1.23 cm (range 1.2-7.6 cm) and ADCmean value was 3.03 ± 0.47 (range 2.64-5.85) while mean diameter of 50 type I HCs was 7.49 ± 2.95 cm (range 2.8-14 cm) and ADCmean value was 2.99 ± 0.29 (range 2.36-3.83). There was no statistically significant difference in ADC values between type I HCs and SLCs. Some studies report that ADC values of type I HCs are statistically significantly lower than those of SLCs. Others suggest no significant difference. In our study with a higher number of cases, using ADC parameters similar to those in previous studies, we did not find any statistically significant difference.

The role of MRI in evaluation of cervical carcinoma

ObjectiveTo review the role of MRI in the diagnosis and staging of cervical carcinoma.BackgroundIt is widely accepted that MRI is the preferred imaging modality for detection of cervical carcinoma nowadays; different techniques are needed for early detection of the disease, its correct staging, and treatment.Patients and methodsThis case–control study included 62 patients divided into a case group of 32 patients diagnosed clinically or by transvaginal ultrasound with cervical cancer, confirmed by biopsy, and a control group of 30 patients who had pelvic MRI for other reasons. All patients were assessed by history and review of previous ultrasound reports and underwent pelvic MRI with diffusion-weighted MRI and dynamic contrast-enhanced MRI.ResultsThis study revealed a statistically significant difference between the case and control groups regarding apparent diffusion coefficient (ADC) value (P < 0.001). There was no significant difference in ADC value between different subtypes of cervical cancer. The diagnostic accuracy of ADC in discrimination of patients and control in defining the best cutoff value of ADC (×10–3), which was 1.10, was 99.5%, with sensitivity of 96.6% and specificity of 96.9%.ConclusionDiffusion-weighted imaging is a potentially useful adjunct to conventional MRI in evaluating cervical carcinoma, thus improving overall diagnostic accuracy, tumor staging, prediction of response to therapy, and treatment follow-up. ADC values may vary not only with different imaging parameters but also with different types of MRI systems.

Parotid gland tumors: comparison of conventional and diffusion-weighted MRI findings with histopathological results.

The aim of this study was to investigate the relationship between pathological classification of parotid gland tumors and conventional MRI - diffusion-weighted imaging findings and also contribute the possible effect of apparent diffusion coefficient (ADC) to diagnosis. 60 patients with parotid masses diagnosed using histopathology and/or cytology were enrolled in this retrospective study. All patients were evaluated using a 1.5 T MRI. Demographic features, conventional MRI findings, and ADC values (mean, minimum, maximum, and relative) were recorded. MRI findings and ADC values were compared between benign-malignant groups and pleomorphic adenoma vs Warthin's tumor groups. 60 tumors (48 benign, 12 malignant) were evaluated in a total of 60 patients (39 males, 21 females). The mean age was 59 (±14, 18-86) years old; the mean lesion size was 26 (±10, 11-61) mm. On the texture of conventional MRI, T2 dominantly hyperintense/with hypointensity signal was seen in 87% of pleomorphic adenomas and T2 dominantly hypointense/with hyperintesity signal was encountered in 64% of all Warthin's tumors. Seven (28%) Warthin's tumors were misdiagnosed as pleomorphic adenomas and two others (8%) as malignant tumors. The commonly used mean ADC value was 1.6 ± 0.6 × 10-3 mm2 s-1 for benign tumors, 0.8 ± 0.3 × 10-3 mm2 s-1 for malign tumors, 1 (0.9-1.8) × 10-3 mm2 s-1 for Warthin's tumors, and 1.9 ± 0.3 × 10-3 mm2 s-1 for pleomorphic adenomas. There was a statistically significant difference in ADC values between benign-malignant tumors and pleomorphic adenomas-Warthin's tumors. Warthin's tumor may occasionally be misdiagnosed as pleomorphic adenoma and malignant tumor because of variable morphologic features. In addition to benign-malignant differentiation, the added ADC measurement may also be useful for differentiating Warthin's tumors from pleomorphic adenomas.

The impact of preoperative MRI-based apparent diffusion coefficients on local recurrence and outcome in patients with cerebral metastases

Background Surgery of single cerebral metastases is standard but frequently fails to achieve local tumour control. Reliable predictors for local tumour progression and overall survival are unknown. MRI-based apparent diffusion coefficients (ADC) correlate with tumour cellularity and invasion. The present study analysed a potential relation between the MRI based apparent diffusion coefficients local recurrence and outcome in patients with brain metastases. Methods A retrospective analysis was performed for patients with cerebral metastases and complete surgical resection evaluated by an early postoperative MRI < 72h. Minimal ADC and mean ADC were assessed in preoperative 1,5T-MRI scans by placing regions of interests in the tumour and the peritumoural tissue. Results Analysis of the relation between ADC values, local progression and outcome was performed in 86 patients with a mean age of 59 years (range 33–83 years). Primary site was NSCLC in 37.2% of all cases. Despite complete resection 33.7% of all patients suffered from local in-brain-progression. There were no significant differences in ADC values in groups based on histology. In the present cohort, the mean ADCmin and the mean ADCmean within the metastasis did not differ significantly between patients with and without a later local in-brain progression (634 × 10−6 vs. 661 × 10−6 mm2/s and 1324 × 10−6 vs. 1361 × 10−6 mm2/s; 1100 × 10−6 vs. 1054 × 10−6 mm2/s; each p > 0.05). Mean ADC values did not correlate significantly with PFS and OAS. Conclusion In the present study analysed ADC values had no significant impact on local in brain progression and survival parameters.

Values of Apparent Diffusion Coefficient and Fractional Anisotropy in the Diagnosis of Brucella Spondylitis

Objective To compare the differences in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) between brucella spondylitis (BS) groups at different stages before treatment and the normal control group and to evaluate the change trend of ADC value and FA value at different time points before and after treatment. Methods Totally 53 patients suspected of BS by conventional magnetic resonance imaging (MRI) and later confirmed as BS patients by serological tests were enrolled in this study. These patients underwent conventional MRI and diffusion tensor imaging scans,and the ADC value and FA value were measured. Independent sample t test was used to compare the ADC value and FA value between the BS group and the control group,the ADC value and FA value between the BS group at each stage. Repeated measurement ANOV was used to compare the ADC values and FA values at different time points before and after treatment. Results FA imaging showed that the color code of BS was different from that of the normal control group,and the color code of FA imaging showed increased singal. The ADC values of BS in the acute,subacute,and chronic stages [(1.45±0.02)×10 -3 mm 2/s,(1.35±0.03)×10 -3 mm 2/s,(1.26±0.05)×10 -3 mm 2/s,respectively] were significantly higher than those in the control group [(1.06±0.09) ×10 -3 mm 2/s](t=2.538,P=0.009;t=1.998,P=0.032;t=1.575,P=0.004),and the FA value (0.55±0.02,0.65±0.03,0.71±0.04,respectively) were significantly lower than those of the control group (0.78±0.02) (t=2.440,P=0.012; t=1.847,P=0.041;t=2.102,P=0.003). Repeated measurement analysis showed that there were statistically significant differences in ADC values and FA values at different time points before and after treatment in the acute,subacute,and chronic stages (ADC:F=12.100,P<0.001;F=8.439,P=0.005;F=9.704,P=0.004,respectively;FA:F=7.080,P=0.002;F=6.607;P=0.003;F=8.868,P=0.001,respectively). The ADC values at different time points after treatment were significantly lower than those before treatment or at a previous time point after treatment (F=332.14,P<0.001),and the FA values were significantly higher than those before treatment or at a previous time point after treatment (F=134.26,P<0.001). Conclusions FA color code can intuitively display differences in BS and normal vertebral bodies and show change of color code before and after treatment. Also,the ADC values and FA values can quantitatively reveal differences between BS and normal vertebral body in different time points and quantify BS vertebral lesion changes before and after treatment. In particular,in BS patients who are recovering from treatment,it can quantify microscopic edema. Therefore,diffusion tensor imaging may be useful objective indicator in evaluating the effectiveness of a specific treatment for BS.

MRI of the Prostate With and Without Endorectal Coil at 3 T: Correlation With Whole-Mount Histopathologic Gleason Score.

OBJECTIVE. The purpose of this article is to prospectively compare image quality and diagnostic accuracy of clinically significant prostate cancer with and without endorectal coil (ERC) at 3 T using a combination of T2-weighted and diffusion-weighted MRI. SUBJECTS AND METHODS. Twenty-three patients with biopsy-proven prostate cancer underwent MRI with and without ERC at the same visit. Patients subsequently underwent radical prostatectomy. Specimens were assessed by whole-mount histopathologic examination. Two radiologists reviewed MR images for image quality (5-point scale) and disease using Prostate Imaging Reporting and Data Systems version 2 (PI-RADSv2). Sensitivity, specificity, and area under the ROC curve (AUC) were calculated with and without ERC. Additionally, apparent diffusion coefficient (ADC) was correlated with Gleason score and ADC values of each lesion were compared with and without ERC. RESULTS. Image quality was comparable with and without ERC (3.8 vs 3.5). Twenty-nine cancer foci larger than 0.5 cm in diameter were found in 23 patients on histopathologic examination; 18 tumors had a Gleason score of 7 or greater. Two radiologists recorded AUC for tumors with a Gleason score of 7 or greater as 0.96 and 0.96 with ERC and 0.88 and 0.91 without ERC. All 13 tumors with a Gleason score of 3 + 4 were detected with ERC, but only 9 were detected without ERC. One of five tumors with Gleason scores less than 3 + 4 was missed with and without ERC. ADC significantly correlated with Gleason score. There was no significant difference in the ADC of a lesion on MRI with and without an ERC. CONCLUSION. MRI with and without ERC was equally accurate at showing prostate cancers with Gleason scores of 4 + 3 or greater. However, MRI with ERC was superior at showing cancer with a Gleason score of 3 + 4. There was no significant difference in ADC values between scores acquired with or without an ERC.

Role of diffusion weighted MRI in differentiation between benign and malignant hepatic focal lesions

Abstract Background Magnetic resonance imaging (MRI) is playing an increasing role in the assessment of patients with liver disease due to its high soft tissue resolution, lack of ionizing radiation and ability to provide functional data. Diffusion-weighted (DW)-MRI is a functional imaging technique that is now widely used as a standard imaging sequence, together with unenhanced T1/T2 weighted imaging and contrast-enhanced imaging for liver evaluation. Objective The aim of this study is to clarify the role of Diffusion Weighted Magnetic Resonance Imaging (DW MRI) in the detection of hepatic focal lesions and its ability to differentiate benign from malignant hepatic focal lesions. Patients and Methods This study carried out in Radiology Department of Ain Shams University Hospitals. This study included 25 patients. All patients were subjected to careful history taking, abdominal US, laboratory examinations, and liver MRI. Result The difference between the mean ADC values of benign and malignant lesions was significant. No significant differences in ADC values among the different benign lesions or among the different malignant lesions. Conclusion Diffusion-weighted imaging (DWI) offers the possibility to obtain criteria for characterization of focal liver lesions with subsequent differentiation between benign and malignant hepatic focal lesions without the need for contrast agent administration-by quantifying diffusion effects via apparent diffusion coefficient (ADC) measurements.

Can quantitative diffusion-weighted MR imaging differentiate between different subtypes of benign and malignant solitary thyroid nodules?

BackgroundDiffusion-weighted MR imaging (DWI) is sensitive to changes in the microstructural organization of tissue that may influence water diffusion. It has been utilized in various forms to evaluate head and neck tumors. The apparent diffusion coefficient (ADC) value is a quantitative parameter for distinguishing malignant from benign thyroid nodule. Determination of different pathologic types of the thyroid nodules is crucial for appropriate therapeutic approach. Our point was to assess the utility of apparent diffusion coefficient values in discriminating different subtypes of benign and malignant solitary thyroid nodules using diffusion MRI with pathological correlation.ResultsThis prospective study included 73 patients who had thyroid nodules. The size of the investigated lesions ranged from 0.6 to 3 cm. Most nodules were benign (79.45%), and most of these benign nodules were adenomatous nodules. There was a significant difference in ADC values of benign and malignant thyroid nodules (P 0.0001), with the mean ADC value for the benign group (1.7 ± 0.12 × 10-3) higher than that for malignant nodule (0.71 ± 0.15 × 10). The sensitivity, specificity, and accuracy of ADC in differentiating between benign and malignant thyroid nodules were 97.5, 94.4, and 99.2%, respectively. We noticed a significant overlap in the ADC value of pathological subtypes and upon reviewing the pathological results, we found insignificant differences in the ADC values of the various subtypes of malignant and benign nodules, with P value ranging from 0.054 to 0.062 between different pathological subtypes. A significant difference was only noted between non-complicated cysts and solid nodules P 0.0001. In our series, an ADC value of 0.92 × 10-3 mm2/s or less could be used as an indicator of malignancy, with a sensitivity of 97.5%, a specificity of 94.4%, and an accuracy of 99.2%.ConclusionDiffusion MRI including ADC values are helpful in differentiation between benign and malignant thyroid nodules but not helpful in differentiating between different subtypes of benign and malignant nodules.

Apparent diffusion coefficient of different areas of brain in foetuses with intrauterine growth restriction.

PurposeThis study aimed to compare the apparent diffusion coefficient (ADC) values of different brain areas between two groups of intrauterine growth restricted (IUGR) foetuses and control cases.Material and methodsA total of 38 foetuses with IUGR and 18 normal control foetuses with similar gestational age were compared using a 3T magnetic resonance scanner. IUGR cases included 23 foetuses with clinical severity signs (group A) and 15 foetuses without clinical severity signs (group B). ADC values were measured in different brain regions and compared among groups. Foetuses with structural brain abnormalities were excluded from the study.ResultsAll foetuses had normal foetal structural brain anatomy. Head circumference (HC) < 5% was more common in IUGR group A compared to IUGR group B (56.5% vs. 13.3%, p < 0.0001). In comparison to the normal group, the ADC values in IUGR foetuses were significantly lower in cerebellar hemispheres (CH) (1.239 vs. 1.280.5 × 10–3 mm2/s, p = 0.045), thalami (1.205 vs. 1.285 × 10–3 mm2/s, p = 0.031) and caudate nucleus (CN) (1.319 vs. 1.394 × 10–3 mm2/s, p = 0.04). However, there were no significant differences in ADC values between IUGR subtypes. Among all brain regions, pons had the lowest ADC values.ConclusionsADC values of thalami, CN, and CH were significantly lower in IUGR than control foetuses, while there was no significant difference among IUGR groups. Further studies are needed to evaluate the prognostic value of ADC changes in IUGR foetuses.

VALIDITY OF DIFFUSION WEIGHTED MAGNETIC RESONANCE IMAGING AND APPARENT DIFFUSION COEFFICIENT MAP IN DIFFERENTIATING BENIGN FROM MALIGNANT UTERINE ENDOMETRIAL PATHOLOGIES

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.

Apparent diffusion coefficient cannot predict molecular subtype and lymph node metastases in invasive breast cancer: a multicenter analysis

BackgroundRadiological imaging plays a central role in the diagnosis of breast cancer (BC). Some studies suggest MRI techniques like diffusion weighted imaging (DWI) may provide further prognostic value by discriminating between tumors with different biologic characteristics including receptor status and molecular subtype. However, there is much contradictory reported data regarding such associations in the literature. The purpose of the present study was to provide evident data regarding relationships between quantitative apparent diffusion coefficient (ADC) values on DWI and pathologic prognostic factors in BC.MethodsData from 5 centers (661 female patients, mean age, 51.4 ± 10.5 years) were acquired. Invasive ductal carcinoma (IDC) was diagnosed in 625 patients (94.6%) and invasive lobular carcinoma in 36 cases (5.4%). Luminal A carcinomas were diagnosed in 177 patients (28.0%), luminal B carcinomas in 279 patients (44.1%), HER 2+ carcinomas in 66 cases (10.4%), and triple negative carcinomas in 111 patients (17.5%). The identified lesions were staged as T1 in 51.3%, T2 in 43.0%, T3 in 4.2%, and as T4 in 1.5% of the cases. N0 was found in 61.3%, N1 in 33.1%, N2 in 2.9%, and N3 in 2.7%. ADC values between different groups were compared using the Mann–Whitney U test and by the Kruskal-Wallis H test. The association between ADC and Ki 67 values was calculated by Spearman’s rank correlation coefficient.ResultsADC values of different tumor subtypes overlapped significantly. Luminal B carcinomas had statistically significant lower ADC values compared with luminal A (p = 0.003) and HER 2+ (p = 0.007) lesions. No significant differences of ADC values were observed between luminal A, HER 2+ and triple negative tumors. There were no statistically significant differences of ADC values between different T or N stages of the tumors. Weak statistically significant correlation between ADC and Ki 67 was observed in luminal B carcinoma (r = − 0.130, p = 0.03). In luminal A, HER 2+ and triple negative tumors there were no significant correlations between ADC and Ki 67.ConclusionADC was not able to discriminate molecular subtypes of BC, and cannot be used as a surrogate marker for disease stage or proliferation activity.