Cutoff Apparent Diffusion Coefficient Value Research Articles

Characteristics and diagnostic performance of nonechoplanar diffusion-weighted imaging in detecting canine tympanokeratoma (cholesteatoma).

Tympanokeratomas (cholesteatomas) are destructive keratinic masses of the middle ear that are often treated surgically. In humans, nonechoplanar (non-EP) diffusion-weighted (DW) MRI is efficient in diagnosing tympanokeratomas and differentiating recurrent tympanokeratomas from granulation or fibrous tissue after surgery. The objectives of this study were to (1) determine the characteristics of non-EP DWI of histologically or cytologically confirmed canine tympanokeratomas, (2) determine the performance of non-EP DW images, apparent diffusion coefficient (ADC) map and ADC values in discriminating between tympanokeratomas and other causes of otitis media in dogs, and (3) find an optimal ADC cut-off value. Medical records of dogs diagnosed on MRI with otitis media in two veterinary hospitals were retrospectively reviewed. Sixty-two ears with a cytological or pathological diagnosis of either tympanokeratoma (36/62) or nontympanokeratoma otitis media (26/62) were selected. Diffusion-weighted images had an accuracy of 77.4%, a sensitivity of 94.4%, and a specificity of 53.8% for the detection of tympanokeratoma. The ADC value of middle ear content ranged from 517 to 1355.10-6mm2/s in tympanokeratoma and from 454 to 2447×10-6mm2/s in nontympanokeratoma otitis media. An ADC value below 916×10-6mm2/s interpreted as a tympanokeratoma yielded an accuracy of 78.7%, a sensitivity of 92.6%, and a specificity of 60%. In the study population, combined qualitative analysis of DW images and ADC maps was the most effective method for diagnosing tympanokeratomas with an accuracy of 80.9%, a sensitivity of 92.6%, and a specificity of 65%.

Usefulness of Combined Advanced Dynamic Contrast-Enhanced and Diffusion-Weighted MRI Over Ultrasonography in Differentiating Cancer From Benign Lesions in Dense Breasts.

Aim To evaluate the role of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging (DWI) in characterizing suspicious lesions in dense breasts compared to ultrasonography (USG). Materials and methods Eighty-two consecutive female patients with suspicious lesions in dense breast parenchyma showing the American College of Radiology Breast Imaging Reporting And Data System (ACR BI-RADS) c/d composition on mammography underwent USG, where 63 lesions of 63 patients were suspicious. They underwent multiparametric MRI, followed by histopathological evaluation (HPE) of the lesions.Statistical analysis was done to calculate the sensitivity, specificity, and accuracy of USG and MRI in lesion characterization and the combined accuracy of DCE-MRI with DWI.The receiver operating characteristic (ROC) curve analysis provided the cut-off for the apparent diffusion coefficient (ADC) value. Results The sensitivity, specificity, and accuracy of USG were 91.7%, 63%, and 79.4%, respectively. Kinetic curve analysis on DCE-MRI showed a type I curve only in benign lesions. Malignant lesions predominantly showed a type III curve.The sensitivity, specificity, and accuracy of DCE-MRI were 95.8%, 78.5%, and 85.7%, respectively.The optimum cut-off ADC value was 1.05x10-3 mm2/s with sensitivity, specificity, and accuracy of 83.3 % each.The specificity and accuracy of combined DCE-MRI with DWI were 94.4% and 88.1%, respectively. Conclusion Advanced MRI, including a combination of DCE-MRI kinetics and DWI, would be more effective and accurate for lesion characterization in dense breasts and act as a superior problem-solving tool compared to USG in differentiating carcinoma from benign lesions.

Added Advantages of DWI MR Imaging and ADC Mapping in the Diagnosis of Active Sacroiliitis of Axial Seronegative SpA

Aim: To evaluate the effectiveness of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) mapping in diagnosing active sacroiliitis in patients with axial seronegative spondyloarthropathy (SpA). Material and Methods: This prospective study comprised 26 patients with MR imaging detected active sacroiliitis categorised as a case group, and compared them with healthy controls. ADC value measurements were obtained from the sacral and iliac sides of the bilateral S.I. joints in each case and control group. Independent samples t-test, Chi-square test, and ROC curve analysis were used. Result: Twenty-six patients had active sacroiliitis in 45 S.I. joints, unilateral active sacroiliitis was observed in seven patients (26.9%), bilateral symmetrical in three patients (11.5%) and bilateral asymmetrical in 16 patients (61.5%). The mean ADC value was 1.447 ± 0.528 [SD] × 10–3 mm 2 /s in the right S.I. joint and 1.630 ± 0.441 [SD] × 10–3 mm 2 /s in the left S.I. joint in active sacroiliitis (case group). The mean ADC value of the right S.I. joint was 0.965 ± 0.123 [SD] × 10–3 mm 2 /s and the left S.I. joint was 0.967 ± 0.96 [SD] × 10–3 mm 2 /s in inactive sacroiliitis (control group). A significant difference was observed statistically between the active sacroiliitis and the inactive sacroiliitis with a P < .0005. A cut-off mean ADC value of 1.034 ×10–3 mm 2 /s was obtained for differentiating active sacroiliitis from inactive sacroiliitis with a sensitivity of 84.6% and specificity of 84.6% from the ROC curve analysis. Conclusion: Diffusion-weighted MRI imaging with ADC value mapping acts as a sensitive diagnostic technique in the detection of active sacroiliitis in axial seronegative spondyloarthropathies and also helps in assessing the treatment response.

Diffusion Weighted Imaging for the Assessment of Lymph Node Metastases in Women with Cervical Cancer: A Meta-analysis of the Apparent Diffusion Coefficient Values

PurposeTo assess the diagnostic performance of Diffusion Weighted Imaging (DWI) and provide optimal apparent diffusion coefficient (ADC) cut-off values for differentiating between benign and metastatic lymph nodes in women with uterine cervical cancer. MethodMEDLINE and EMBASE databases were searched. Methodological quality was assessed with QUADAS-2. Data-analysis was performed for three subgroups: 1. All studies; 2. Studies with maximum b-values of 800 s/mm², and 3. Studies containing b-values of 1000 s/mm². Receiver-operating characteristics (ROC) curves were constructed and the area under the curve (AUC) was calculated. The maximum Youden index was used to determine optimal ADC cut-off values, following calculations of sensitivity and specificity. ResultsSixteen articles (1156 patients) were included. Overall, their quality was limited. For all studies combined, the optimum ADC cut-off value was 0.985 x 10⁻³ mm²/s at maximum Youden Index of 0.77, resulting in sensitivity and specificity of 84%, and 94%, respectively. Studies with b-values up to 800 s/mm², gave an optimum ADC cut-off value of 0.985 x 10⁻³ mm²/s at maximum Youden Index of 0.62, with a sensitivity and specificity of 62%, and 100%. Studies containing b-values of 1000 s/mm² gave an optimum ADC cut-off value of 0.9435 x 10⁻³ mm²/s at maximum Youden Index of 0.93, with a sensitivity and specificity of 100%, and 93%, respectively. ConclusionsStudies using DWI including b-values of 1000 s/mm² have higher sensitivity and specificity than those with b-values up to 800 s/mm². At the cut-off value of 0.9435 x 10⁻³ mm²/s DWI can sufficiently discriminate between benign and metastatic lymph nodes.

The Role of Diffusion-Weighted Imaging in Characterizing Benign and Malignant Breast Lesions: A Retrospective Study.

Introduction Diffusion-weighted imaging (DWI) is a promising magnetic resonance imaging (MRI) technique for differentiating between benign and malignant breast lesions. This study set out to assess the diagnostic utility of DWI and apparent diffusion coefficient (ADC) values in the characterization of breast lesions. Materials and methods A retrospective analysis comprised 30 patients with breast lesions who had breast MRI with DWI. The histopathological findings, ADC readings, and conventional MRI features were all analyzed. The receiver operating characteristic (ROC) curve analysis method was utilized to assess the diagnostic accuracy of DWI. Results Out of the 30 lesions, 22 (73.3%) were benign and eight (26.7%) were malignant. Malignant lesions exhibited significantly lower ADC values (p < 0.001) compared to benign lesions. An ADC cutoff value of 1.1 × 10-3mm2/s was optimal for differentiating benign from malignant lesions, yielding 90.81% sensitivity, 91.51% specificity, and 91.5% accuracy. Conclusion Combining DWI with quantitative ADC analysis is a helpful, non-invasive method for the characterization of breast lesions. It shows excellent diagnostic accuracy in identifying benign and malignant lesions, which may cut down on pointless biopsies and help with patient management.

Qualitative and quantitative MRI analysis of alveolar soft part sarcoma: correlation with histological grade and Ki-67 expression

ObjectiveTo investigate the correlation between MRI findings and histological features for preoperative prediction of histological grading and Ki-67 expression level in alveolar soft part sarcoma (ASPS).MethodsA retrospective analysis was conducted on 63 ASPS patients (Jan 2017–May 2023). All patients underwent 3.0-T MRI examinations, including conventional sequences, dynamic contrast-enhanced scans with time-intensity curve analysis, and diffusion-weighted imaging with apparent diffusion coefficient (ADC) measurements. Patients were divided into low-grade (histological Grade I) and high-grade (histological Grade II/III) groups based on pathology. Immunohistochemistry was used to assess Ki-67 expression levels in ASPS. Statistical analysis included chi-square tests, Wilcoxon rank-sum test, binary logistic regression analysis, Spearman correlation analysis, and receiver operating characteristic curve analysis of various observational data.ResultsThere were 29 low-grade and 34 high-grade patients (26 males and 37 females) and a wide age range (5–68 years). Distant metastasis, tumor enhancement characteristics, and ADC values were independent predictors of high-grade ASPS. High-grade ASPS had lower ADC values (p = 0.002), with an area under the curve (AUC), sensitivity, and specificity of 0.723, 79.4%, and 58.6%, respectively, for high-grade prediction. There was a negative correlation between ADC values and Ki-67 expression (r = −0.526; p < 0.001). When the cut-off value of ADC was 0.997 × 10−3 mm²/s, the AUC, sensitivity, and specificity for predicting high Ki-67 expression were 0.805, 65.6%, and 83.9%, respectively.ConclusionQualitative and quantitative MRI parameters are valuable for predicting histological grading and Ki-67 expression levels in ASPS.Critical relevance statementThis study will help provide a more nuanced understanding of ASPS and guide personalized treatment strategies.Key PointsThere is limited research on assessing ASPS prognosis through MRI.Metastasis, enhancement, and ADC correlated with histological grade; ADC related to Ki-67 expression.MRI provides clinicians with valuable information on ASPS grading and proliferation activity.Graphical

Can maximum, mean or minimum ADC values of the cervix-parametrium boundary estimate parametrial invasion for cervical carcinoma?

Purpose: Diffusion weighted imaging (DWI), which is quantified by apparent diffusion coefficient (ADC), can predict tissue microstructure. It has become an essential part of the gynecological magnetic resonance imaging (MRI) protocol. In our study it was aimed to evaluate the value of the maximum, mean, and minimum ADC values of the cervix-parametrium boundary to estimate parametrial invasion for cervix carcinoma. Material and Method: Totally 50 patients with cervical carcinoma, 18 of which had no parametrial invasion (4811-year-old) and 32 had parametrial invasion (5812-year-old) according to conventional T2 weighted imaging were enrolled. Maximum, mean, and minimum ADC values of cervix-parametrium boundary of primary tumors were statistically compared between the groups without and with parametrial invasion. The diagnostic performances of the maximum, mean and minimum ADC values were evaluated by ROC analysis in terms of estimating parametrial invasion. Results: The mean maximum, mean and minimum ADC values were lower for the patients with parametrial invasion. However, only the minimum ADC values had statistically significant differences between the groups. ROC analysis showed an AUC value of 0.726 for minimum ADC in estimating parametrial invasion. A minimum ADC cut-off value of 0.553x10-3 mm2/s had a sensitivity of 63%, specificity of 73%, negative predictive value of 52% and positive predictive value of 80% and accuracy of 66%. Conclusions: ADC values can be applied for the determination of parametrial invasion of cervical carcinoma. Lower minimum ADC values obtained from cervix-parametrium boundary of primary cervical carcinoma may help parametrial invasion. Especially positive predictive value of the cervix-parametrium boundary ADC is remarkable.

Comparison of conventional diffusion-weighted imaging and intravoxel incoherent motion in differentiating between chromophobe renal cell carcinoma and renal oncocytoma: a preliminary study.

Quantitative comparison of the diagnostic efficacy of conventional diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM) in differentiating between chromophobe renal cell carcinoma (ChRCC) from renal oncocytoma (RO). A total of 48 patients with renal tumours who had undergone DWI and IVIM were divided into two groups-ChRCC (n = 28) and RO (n = 20) groups, and the apparent diffusion coefficient (ADC), true diffusivity (D), pseudo-diffusion coefficient (D*), perfusion fraction (f) and their diagnostic efficacy were compared between the two groups. The D* values were higher in the ChRCCs group compared to the RO groups (0.019 ± 0.003 mm2/s vs 0.008 ± 0.002 mm2/s, P < .05). Moreover, the ADC, D and f values were higher in ROs compared to ChRCCs (0.61 ± 0.08 × 10-3 mm2/s vs 0.51 ± 0.06 × 10-3 mm2/s, 1.02 ± 0.15 × 10-3 mm2/s vs 0.86 ± 0.07 × 10-3 mm2/s, 0.41 ± 0.05 vs 0.28 ± 0.02, P < .05). The areas of the ADC, D, D* and f values under the ROC curves in differentiating ChRCCs from ROs were 0.713, 0.839, 0.856 and 0.906, respectively. The cut-off values of ADC, D, D* and f were 0.54, 0.91, 0.013 and 0.31, respectively. The AUC, sensitivity, specificity and accuracy of the f values were 0.906, 89.3%, 80.0% and 89.6%, respectively. For pairwise comparisons of ROC curves and diagnostic efficacy, IVIM parameters, that is, D, D* and f offered better diagnostic accuracy than ADC in differentiating ChRCCs from ROs (P = .013, .016, and .008) with f having the highest diagnostic accuracy. IVIM parameters presented better performance than ADC in differentiating ChRCCs from ROs. (1) D* values of ChRCCs were higher, while ADC, D and f values were lower than those of RO tumours. (2) f values had the highest diagnostic efficacy in differentiating ChRCC from RO. (3) IVIM parameters, that is, D, D* and f offered better diagnostic accuracy than ADC in differentiating ChRCC from RO (P=.013, .016, and .008).

The diagnostic efficacy of diffusion tensor imaging in children with chronic kidney disease: correlation with histopathology and serum biomarkers

BackgroundChildren with chronic kidney disease (CKD) usually present with disease impact on growth besides cardiovascular problems that not only impact the patient's health during childhood but also affect their adult life. We aimed to identify the diagnostic role of diffusion tensor imaging (DTI) in CKD in pediatric using its metrics: apparent diffusion coefficient (ADC) and fraction anisotropy (FA).ResultsThis prospective study was performed on thirty-five CKD patients (16 girls, 19 boys; mean age 12.3 ± 2.6 years) and 19 sex- and age-matched controls. Both groups underwent renal DTI and renal function tests. Based on renal biopsy, patients with CKD were further categorized into sclerotic CKD (n = 25) and non-sclerotic CKD (n = 10). Mean FA renal medulla/cortex in CKD (0.18 ± 0.18 and 0.20 ± 0.17) was lower significantly (p = 0.001) than volunteers' (0.31 ± 0.19, 0.27 ± 0.18). The cutoff FA of renal medulla/cortex used for CKD diagnosis was 0.22 and 0.23 with AUC of 0.828, 0.838 and accuracy of 80.8%, 82.8%. Mean of renal medulla/cortex ADC in CKD (2.13 ± 0.23 and 1.93 ± 0.22 × 10−3 mm2/s) was higher significantly (p = 0.001) than that of volunteers' (1.67 ± 0.15 and 1.64 ± 0.133 × 10−3 mm2/s. ADC cutoff value of renal medulla/cortex used for CKD diagnosis was 1.86 and 1.74 × 10−3 mm2/s with AUC of 0.827, 0.82, 0.827, and 0.911, and accuracy of 80.6%, 79.6%, 82.8%, and 84.2%. Renal medulla/cortex FA in sclerotic CKD was significantly different (p = 0.001) from non-sclerotic CKD (0.25 ± 0.07 and 0.26 ± 0.08). Cortical and medullary FA in CKD patients correlated with e-GFR (r = 0.363, r = 0.317) and serum creatinine (r = − 0.467, r = − 0.383).ConclusionsRenal cortical/medullary FA can assist in diagnosing pediatric CKD, predict sclerotic CKD, and correlate with some serum biomarkers.

El análisis cuantitativo de las imágenes potenciadas en difusión (DWI) mejora la precisión diagnóstica del sistema de puntuación O-RADS RM en lesiones anexiales indeterminadas

IntroductionDespite the overall high accuracy of the O-RADS MRI scoring system for characterization of indeterminate adnexal lesions, a non-negligible percentage of adnexal lesions remains indeterminate. Given this, the main objective of this study was to evaluate the value of adding quantitative diffusion-weighted imaging (DWI) to Ovarian-Adnexal Reporting and Data System (O-RADS) MRI to improve the diagnostic accuracy of the scoring system in a cohort of indeterminate adnexal lesions according to International Ovarian Tumor Analysis Group Simple Rules (IOTA-SR). Methods and materialSeventy-nine women with 81 pelvic lesions classified as indeterminate according to IOTA-SR underwent 3-Tesla MRI with a conventional multiparametric protocol. DWI was quantitatively analyzed. Lesions were surgically removed or followed-up, according to a local protocol. Sensitivity, specificity, positive and negative predictive values and accuracy were determined for conventional multiparametric MRI and quantitative DWI-derived data. ResultsTwenty masses in 72 patients (27.8%) were malignant. An apparent diffusion coefficient (ADC) cut-off value of 1.30×10-3mm2/s had 89% sensitivity and 80% specificity for malignancy. Overall, adding quantitative DWI to O-RADS MRI increased the specificity (98.08%, P<.001), positive predictive value (94.12%, P<.001), and accuracy (93.06%, P=.05). In the specific O-RADS MRI score 4 subgroup, an ADC cut-off value of 1.22×10-3 mm2/s had 86% sensitivity and 67% specificity for distinguishing benign from malignant lesions. ConclusionIn IOTA-SR indeterminate adnexal lesions, quantitative DWI significantly improves the diagnostic performance of conventional multiparametric MRI in all O-RADS MRI score groups.

Evaluation of Three Imaging Methods to Quantify Key Events in Pelvic Bone Metastasis.

The purpose of this study is to compare turbo spin echo diffusion-weighted images in radial trajectory (BLADE DWI) with multi-shot echoplanar imaging (RESOLVE DWI) for imaging the metastatic lesion in the pelvic bone to find a correlation between ADC values and standardized uptake values (SUVs) of FDG uptake in PET/CT. The study also seeks to compare the values of metastatic lesions with those of benign bone lesions, specifically red marrow hyperplasia. The retrospective IRB-approved study included patients with bone metastasis and red marrow hyperplasia in the pelvic bone who underwent 3.0 T MRI with BLADE/RESOLVE DWI sequences and F-18 FDG PET/CT within one month. BVC (best value comparator) was used in determining the nature of bone lesions. Apparent diffusion coefficient (ADC) and standardized uptake value (SUV) were measured by a radiologist and a nuclear medicine physician. MRI image quality was graded with a Likert scale regarding the visualization of the sacroiliac joint, sacral neural foramen, hamstring tendon at ischial tuberosity, and tumor border. Signal-to-noise ratio (SNR) and imaging time were compared between the two DWIs. Mean, peak, and maximum SUVs between metastatic and benign red marrow lesions were compared. SUVs and ADC values were compared. AUROC analyses and cut-off values were obtained for each parameter. Mann-Whitney U, Spearman's rho, and Kolmogorov-Smirnov tests were applied using SPSS. The final study group included 58 bone lesions (19 patients (male: female = 6:13, age 52.5 ± 9.6, forty-four (75.9%) bone metastasis, fourteen (24.1%) benign red marrow hyperplasia). ADCs from BLADE and RESOLVE were significantly higher in bone metastasis than red marrow hyperplasia. BLADE showed higher ADC values, higher anatomical scores, and higher SNR than RESOLVE DWI (p < 0.05). Imaging times were longer for BLADE than RESOLVE (6 min 3 s vs. 3 min 47 s, p < 0.05). There was a poor correlation between ADC values and SUVs (correlation coefficient from 0.04 to 0.31). The AUROC values of BLADE and RESOLVE MRI ranged from 0.892~0.995. Those of PET ranged from 0.877~0.895. The cut-off ADC values between the bone metastasis and red marrow hyperplasia were 355.0, 686.5, 531.0 for BLADE min, max, and average, respectively, and 112.5, 737.0, 273.0 for RESOLVE min, max, and average, respectively. The cut-off SUV values were 1.84, 5.01, and 3.81 for mean, peak, and max values, respectively (p < 0.05). Compared with RESOLVE DWI, BLADE DWI showed improved image quality of pelvic bone MRI in the aspect of anatomical depiction and SNR, higher ADC values, albeit longer imaging time. BLADE and RESOLVE could differentiate bone metastasis and red marrow hyperplasia with quantifiable cut-off values. Further study is necessary to evaluate the discrepancy between the quantifiers between PET and MRI.

Efficacy of apparent diffusion coefficient values for normal submandibular glands and acute submandibular sialadenitis

AbstractObjectiveThis study aimed to assess the apparent diffusion coefficient (ADC) values of normal salivary glands and acute submandibular sialadenitis (SS).MethodsThis retrospective study included 22 patients who underwent magnetic resonance imaging (MRI) at the Nihon University School of Dentistry between February 2018 and May 2022. ADC values were compared between the acute SS and control group. Data with non‐normality confirmed by Shapiro–Wilk test was analyzed using the Mann–Whitney U test, Spearman's correlation coefficient, and a receiver operating characteristic (ROC) curve. Statistical significance was set at p &lt; 0.05.ResultsThe mean ADC values were 1.03 ± 0. 09 × 10−3 and 1.22 ± 0.17 × 10−3 mm2/s in the normal and acute SS groups, respectively (p &lt; 0.001). ROC analysis revealed a cutoff ADC value of 1.1 for distinguishing acute SS from the normal.ConclusionThese findings suggest that ADC values are useful for the quantitative assessment of acute SS.

The usefulness of the apparent diffusion coefficient value in diagnosing acute spinal cord ischemia.

The purpose of our study was to assess the usefulness of the apparent diffusion coefficient (ADC) value in differentiating between a normal spinal cord and a spinal cord with acute ischemia. Control group of 113 and 8 acute spinal cord ischemia patients were enrolled in this study. The ADC values were measured when diffusion-weighted imaging was first performed after the onset of acute spinal cord ischemia. The mean ADC value each of the control group and acute spinal cord ischemia patients was 0.99 ± 0.19 × 10-3 mm2/s and 0.70 ± 0.15 × 10-3 mm2/s. The mean ADC value in patients with acute spinal cord ischemia was significantly lower than that in patients with a normal spinal cord (P < 0.01). We found the cutoff ADC value (0.86 × 10-3 mm2/s) to be a useful indicator of acute spinal cord ischemia (sensitivity = 100.0%, specificity = 71.7%, AUC = 0.92). In conclusions, it is suggested that the ADC value may be useful in the diagnosis of acute spinal cord ischemia.

Value of CT and MR Imaging in Assessment of Loco-regional Ablated Hepatocellular Carcinoma using LI-RADS Treatment Response Algorithm (version 2018)

Aim: The aim of this work is to evaluate the role of multiphasic CT and dynamic contrast enhanced MRI using LI-RADS treatment response algorithm (version 2018) and the added values of diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps in the assessment of loco-Regional ablated Hepatocellular Carcinoma (HCC). Methods: This study included 45 patients with 50 loco-Regional ablated HCC lesions. All patients underwent multiphasic CT scan, diffusion weighted and dynamic contrast enhanced MRI. The reference standards for assessment were based on serum alpha-fetoprotein level and dynamic contrast enhanced MRI. Results: Multi-phasic CT had moderate sensitivity (87.5%) and high specificity (100%) for assessment of HCC LI-RADS treatment response algorithm. Dynamic contrast enhanced MRI had high sensitivity (100%) and specificity (100%) for the assessment of HCC LI-RADS treatment response algorithm. The sensitivity and specificity of DWI to diagnose HCC malignant residual or recurrence were 93.7% and 100%, respectively, with very good performance. The mean ADC values of the malignant residual or recurrence were significantly lower than that of benign post-ablation tissue changes areas and the best ADC cutoff value for differentiation between viable and nonviable lesions was 1.1x10-3 mm²/s. Conclusion: Performance of dynamic contrast enhanced MRI is better than that of multiphasic CT in the assessment of LIRADS treatment response algorithm. DWI and ADC maps could be used as ancillary methods for differentiation between viable and non-viable loco-regional ablated HCC lesions and should be included in LR-TR treatment response algorithm.

Magnetic resonance imaging for prospective assessment of local recurrence of non-small cell lung cancer after stereotactic body radiation therapy

ObjectivesTo evaluate multi-parametric MRI for distinguishing stereotactic body radiation therapy (SBRT) induced pulmonary fibrosis from local recurrence (LR). Materials and methodsSBRT treated non-small cell lung cancer (NSCLC) patients suspected of LR by conventional imaging underwent MRI: T2 weighted, diffusion weighted imaging, dynamic contrast enhancement (DCE) with a 5-minute delayed sequence. MRI was reported as high or low suspicion of LR. Follow-up imaging ≥12 months or biopsy defined LR status as proven LR, no-LR or not-verified. ResultsMRI was performed between 10/2017 and 12/2021, at a median interval of 22.5 (interquartile range 10.5–32.75) months after SBRT. Of the 20 lesions in 18 patients: 4 had proven LR, 10 did not have LR and 6 were not verified for LR due to subsequent additional local and/or systemic therapy. MRI correctly identified as high suspicion LR in all proven LR lesions and low suspicion LR in all confirmed no-LR lesions. All proven LR lesions (4/4) showed heterogeneous enhancement and heterogeneous T2 signal, as compared to the proven no-LR lesions in which 7/10 had homogeneous enhancement and homogeneous T2 signal. DCE kinetic curves could not predict LR status. Although lower apparent diffusion coefficient (ADC) values were seen in proven LR lesions, no absolute cut-off ADC value could determine LR status. ConclusionIn this pilot study of NSCLC patients after SBRT, multi-parametric chest MRI was able to correctly determine LR status, with no single parameter being diagnostic by itself. Further studies are warranted.

Characterizing Various Posterior Fossa Tumors in Children and Adults With Diffusion-Weighted Imaging and Spectroscopy.

Background Theposterior fossa is situated between thetentorium cerebelli above and the foramen magnum below. Vital structures like the cerebellum, the pons, and the medulla are situated within it; hence, tumors within the posterior fossa are considered one of the most critical brain lesions. Children are more likely to develop posterior fossa tumors than adults. Diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy (MRS) sequences along with the conventional MRI helpin providing additional information in the characterization of the various posterior fossa tumors. We hereby present a series of 30 patients with clinically suspected posterior fossa masses who underwent preoperative MRI. Objectives This study aims to differentiate the neoplastic from non-neoplastic posterior fossa mass by evaluating the diffusion restriction pattern on DWI, quantifying the apparent diffusion coefficient (ADC) map in various posterior fossa tumors, and comparing the different metabolites of various posterior fossa tumors on MRS. Results Out of the 30 patients with posterior fossa lesions, 18 were males and 12 were females. Eight of them were in the pediatric age group, while twenty-two of them were adults. Metastasis was the most common posterior fossa lesionin our study sample and was found in six patients (20%), followed by vestibular schwannomas (17%) and arachnoid cysts (13%), meningiomas, medulloblastoma, and pilocytic astrocytoma (10% each) and epidermoid, ependymoma, and hemangioblastoma (7% each). The mean ADC value of benign tumors was higher than that of malignant tumors, and this difference was found to be significant (p = 0.012). The cut-off ADC value 1.21x 10-3mm2/s had a sensitivity of 81.82% and specificity of 80.47%. MRS metabolites played an additional role in differentiating benign from malignant tumors. Conclusion A combination of conventional MRI, DWI,ADC values, and MRS metabolites showed good diagnostic accuracy to differentiate between the various posterior fossa neoplastic tumors both in adults and children.

Role of Multiparametric Magnetic Resonance Imaging of the Brain in Differentiating Neurocysticercosis From Tuberculoma.

The two most common infectious causes of ring-enhancing lesions are neurocysticercosis (NCC) and tuberculoma. It is a challenge to differentiate NCC and tuberculomas radiologically since they show the same imaging findings on computed tomography (CT). Hence, this study was performed to assess the role of magnetic resonance imaging (MRI) as an additional advanced modality to aptly characterize the lesion. Conventional MRI with additional advanced imaging sequences like diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC), magnetic resonance spectroscopy (MRS), and post-contrast T1-weighted imaging (T1WI) aids in characterizing the lesion and helps in differentiating NCC and tuberculomas. To compare the findings of DWI, ADC cut-off values, spectroscopy, and contrast-enhanced MRI in differentiating NCC from tuberculoma. Individuals who matched the inclusion criterion underwent an MRIof the brain (plain and contrast) in a 1.5 Tesla, 18-channel, magnetic resonance scanner (Magnetom Avanto®, Siemens Healthineers, Erlangen, Germany). The following imaging sequences were included: T1WI (axial and sagittal), T2-weighted imaging (axial and coronal), fluid-attenuated inversion recovery, DWI at 0, 500, and 1000 mm2/sb-values with corresponding ADC values, and single-voxel MRS. Based on MRI features such as number, size, location, margins of lesions, scolex, surrounding edema, DWI features with corresponding ADC values, enhancement pattern of lesions, and spectroscopy findings, we evaluated and differentiated the lesions as NCC or tuberculoma. Radiological diagnoses were correlated in terms of clinical symptoms and response to treatment. In our study, 42 subjects were included, of which the total number of NCC cases was 25 (59.52%) and tuberculoma was 17 (40.47%). The mean age of patients included was 42.85 ± 14.76 years (21 to 78 years). On post-contrast imaging, all 25 cases of NCC (100%) showed thin ring enhancement whereas the majority of tuberculomas (64.7%) showed thick irregular ring enhancement. On MRS, all 25 cases (100%) of NCC showed an amino acid peak and all 17 cases (100%) of tuberculoma showed a lipid lactate peak. On DWI, out of 25 NCC cases, restriction of diffusion was absent in the majority of cases (88%) and out of 17 cases of tuberculoma, restriction of diffusion was present in 12 cases (70.5%) (T2 hyperintense tuberculoma, indicative of caseating tuberculoma with central liquefaction) and was absent in the rest. In our study, the mean ADC value of NCC lesions (1.30 ± 0.137 x 10-3 mm2/s) was found to be greater than that of tuberculoma (0.74 ± 0.090 x 10-3 mm2/s). ADC value of 1.2 x 10-3 was obtained as a cut-off to differentiate NCC and tuberculoma. The ADC cut-off value of 1.2 x 10-3 mm2/s showed a sensitivity of 92% and specificity of 94.1% in differentiating NCC from tuberculoma. Conventional MRI with additional advanced imaging sequences likeDWI, ADC, MRS, and post-contrast T1WI aids in characterizing the lesion and thereby helps in differentiating NCC and tuberculomas. Hence, multiparametric MRI assessment is useful in making a prompt diagnosis and eliminating the need for a biopsy.

Could Apparent Diffusion coefficient (ADC) be used as an imaging marker for proliferative activity in breast carcinoma?

&amp;lt;p&amp;gt;Introduction. Multiparametric magnetic resonance mammography (mMRM) has an important role in detection, evaluation and follow-up of breast lesions. The aim of this study was to explore whether imaging parameters, in particular ADC, can be used as a biomarker of cell proliferation in breast cancer. Methods. This cohort-study included 67 lesions in 50 female patients who underwent mMRM on a 3T scanner. Percutaneous biopsies and surgical excisions were performed after imaging in period up to 3 weeks. The Ki67 index was assessed microscopically. Seven Ki67 categories were defined: 0&amp;amp;ndash;5%, 10&amp;amp;ndash;20%, 20&amp;amp;ndash;40%, 40&amp;amp;ndash;50%, 50&amp;amp;ndash;80% and over 80%. Methods of descriptive statistics were used; correlations were determined using Pearson&amp;amp;rsquo;s correlation test. ROC curve was constructed and analyzed for determination of &amp;amp;ldquo;cut-off&amp;amp;rdquo; values for diagnostic potential. Statistical significance was set at p &amp;amp;lt; 0.05. Results. Different subtypes of breast carcinomas were involved: ductal carcinoma (59.9%), lobular carcinoma (17.9%), metastatic carcinoma (10.5%), ductal carcinoma in situ (9%), and tubular carcinoma (3%). It was not possible to determine whether there was significant difference in values of ADC for histological subtypes of breast carcinoma because of small number of samples in some groups. The cut off value of ADC for breast carcinoma was 0.792 (sensitivity 98.6%, specificity 65.7%). There was no significant difference in values of ADC for categories of Ki67. There was no significant correlation between ADC mean and Ki67 for all histological subtypes of breast carcinomas (r = 0.156, p = 0.243). Conclusion. ADC cannot be used as a reliable imaging marker for proliferative activity in breast cancer.&amp;lt;/p&amp;gt;

Diagnostic value of the apparent diffusion coefficient in differentiating malignant from benign endometrial lesions.

Magnetic resonance imaging (MRI) with its innovative techniques, such as diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC), increases the diagnostic accuracy in distinguishing between malignant and benign lesions of the endometrium. The aim of the study was MRI differentiation between malignant and benign endometrial lesions and correlation with histopathological findings with a special emphasis on quantitative analysis. An additional aim was to correlate the ADC values and histological tumor grades. The prospective study included 119 female patients with or without vaginal bleeding and pathological values of endometrial thickness, who underwent MRI examinations. According to MRI reports the patients were divided into 45 suspicious malignant and 74 suspicious benign endometrial lesions. The radiological diagnosis was compared to the histopathological evaluation, which confirmed 37 malignant lesions while the rest were benign. The mean ADC value for malignant lesions was 0.761 ± 0.13×10-3 mm2/s and for benign lesions was 1.318 ± 0.20×10-3 mm2/s. The ADC values for malignant lesions were expectedly lower than those of benign lesions (p<0.001). The ADC cut-off value was 1.007×10-3 mm2/s with a sensitivity of 100%, specificity of 92.7%, a positive predictive value of 60.3%, and a negative predictive value of 100%. In comparison with the histopathological findings, the sensitivity of MRI was 100%, specificity 90.2%, positive predictive value was 82.2%, and negative predictive value was 100%. Observing the histological grades 1, 2, and 3 of endometrial carcinoma, no statistically significant differences of mean ADC values were found. The mean ADC values for histological tumor grades 1,2 and 3 were 0.803 ± 0.13×10-3 mm2/s, 0.754 ± 0.12×10-3 mm2/s and 0.728 ± 0.13×10-3 mm2/s, respectively. DWI and ADC values represent clinically useful tools for the differentiation between malignant and benign endometrial lesions with high sensitivity and good specificity, but the results failed to demonstrate their usefulness in differentiating histological grades of endometrial cancer.

Diagnostic value of diffusion-weighted MRI using apparent diffusion coefficient (ADC) in evaluation of median nerve in carpal tunnel syndrome

BackgroundThe diagnosis of carpal tunnel syndrome is based on a combination of clinical history, clinical examination and frequent use of electrodiagnostics as nerve conduction study and electromyography which often do not provide the spatial and anatomical localizing information, especially with small nerves of the extremities. Conventional magnetic resonance imaging can reveal morphological changes in carpal tunnel syndrome patients.AimThe purpose of our study was to assess the efficacy of diffusion magnetic resonance imaging as a functional imaging in evaluation of median nerve in carpal tunnel syndrome.Patients and methodsThis prospective study included a group of 33 patients with carpal tunnel syndrome diagnosed by both clinical examination and electromyography; 40 writs were examined. A control group of 20 subjects of matched age group were also included. All the participants were subjected to conventional and diffusion magnetic resonance imaging studies.ResultsMedian nerve apparent diffusion coefficient values of patients are lower than those of controls. The sensitivity and diagnostic accuracy of diffusion conventional magnetic resonance imaging were 95% and 97.5%, respectively, versus 25% and 62.5% of conventional magnetic resonance imaging. A cut-off apparent diffusion coefficient value ≤ 0.99 obtained at distal radio-ulnar joint level and > 1.07 at pisiform level as well as apparent diffusion coefficient ratio at a cut-off ≤ 0.2 was significantly valid for diagnosing carpal tunnel syndrome.ConclusionsDiffusion magnetic resonance imaging provides functional evaluation of median nerve in patients with carpal tunnel syndrome.