Magnetic Resonance Imaging Diffusion Coefficient Research Articles

Determination of hemorrhagic transformation risk in acute ischemic cerebrovascular disease: The relationship between ADC values and GRE hemo sequence microhemorrhage.

<p>To determine the risk of hemorrhagic transformation in patients with acute ischemic cerebrovascular disease, we investigated the relationship between Apparent Diffusion Coefficient Magnetic Resonance Imaging values measured within the infarct area and microbleeds observed on Gradient Echo Sequence Magnetic Resonance Imaging.</p>. <p>A total of 172 patients who were hospitalized to the Neurology Clinic of the Istanbul Provincial Directorate of Health Erenkoy Mental and Nervous Diseases Training and Research Hospital between June 2019 and March 2020 were included in this cross-sectional study. The patients were classified according to their demographic and clinical characteristics, by age, gender, hypertension, diabetes mellitus, smoking, and alcohol use. In the Cranial Magnetic Resonance Imaging taken in the application for the diagnosis of acute ischemic cerebrovascular disease, the infarction area in Apparent Diffusion Coefficient sequences with the Region of Interest value and the relationship between microhemorrhage observed in Gradient Echo hemo-sequence was evaluated in Magnetic Resonance Imaging applied between 3-7 days. While calculating spherical Region of Interest values, 5 Region of Interest values were obtained for lesions larger than 1.5x1.5 cm, and their arithmetic mean was obtained, and single spherical Region of Interest value was taken for smaller ones. Apparent Diffusion Coefficient Magnetic Resonance Imaging Region of Interest mean values were divided into 2 groups as &lt;500x10&ndash;6 mm2 /s and &gt;500x10&ndash;6 mm2/s.&nbsp;</p>. <p>Patients in the group with Apparent Diffusion Coefficient Region of Interest mean values below 500x10-6 mm2/s, had a significantly higher probability for microhemorrhage observes in Gradient Echo Sequence Magnetic Resonance Imaging (p: 0.001) and also more likely to experience microhemorrhage in other areas, which was statistically significant (p: 0.001).The probability of another micro-bleeding observed in patients with microhemorrhage Gradient Echo Sequence Magnetic Resonance Imaging was also statistically significant (p: 0,001). The risk of microbleeding in areas other than ischemia was also found to be significantly higher in patients with microbleeding in the ischemia area in Gradient Echo Sequence Magnetic Resonance Imaging.</p>. <p>In our study, a statistically significant relationship was found between the microhemorrhage in the infarct area and the Apparent Diffusion Coefficient Region of Interest values. When the literature was reviewed, no such study was found to determine the risk of bleeding.</p>.

Apparent diffusion coefficient magnetic resonance imaging (ADC-MRI) in the axillary breast cancer lymph node metastasis detection: a narrative review.

The presence of axillary lymph nodes metastases in breast cancer is the most significant prognostic factor, with a great impact on morbidity, disease-related survival and management of oncological therapies; for this reason, adequate imaging evaluation is strictly necessary. Physical examination is not enough sensitive to assess breast cancer nodal status; axillary ultrasonography (US) is commonly used to detect suspected or occult nodal metastasis, providing exclusively morphological evaluation, with low sensitivity and positive predictive value. Currently, sentinel lymph node biopsy (SLNB) and/or axillary dissection are the milestone for the diagnostic assessment of axillary lymph node metastases, although its related morbidity. The impact of magnetic resonance imaging (MRI) in the detection of nodal metastases has been widely investigated, as it continues to represent the most promising imaging modality in the breast cancer management. In particular, diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values represent additional reliable non-contrast sequences, able to improve the diagnostic accuracy of breast cancer MRI evaluation. Several studies largely demonstrated the usefulness of implementing DWI/ADC MRI in the characterization of breast lesions. Herein, in the light of our clinical experience, we perform a review of the literature regarding the diagnostic performance and accuracy of ADC value as potential pre-operative tool to define metastatic involvement of nodal structures in breast cancer patients. For the purpose of this review, PubMed, Web of Science, and SCOPUS electronic databases were searched with different combinations of "axillary lymph node", "breast cancer", "MRI/ADC", "breast MRI" keywords. All original articles, reviews and metanalyses were included.

Pituitary macroadenoma: Accuracy of apparent diffusion coefficient magnetic resonance imaging in grading tumor aggressiveness.

The purpose of this study is to evaluate the accuracy of apparent diffusion coefficient magnetic resonance imaging in grading tumor aggressiveness using histogram apparent diffusion coefficient values. Eighteen patients with surgically proved pituitary macroadenomas were included in this study. Diffusion-weighted imaging with single-shot echo-planar sequence at 3-T with a 32-channel head coil was performed with b values of 0 and 1000 s/mm2. Calculated apparent diffusion coefficient maps were generated, and a 3-D volume of interest was placed on the tumor while superimposing contrast-enhanced magnetic resonance images. All apparent diffusion coefficient values within the volume of interest were used to compute the average apparent diffusion coefficient of the tumor. The apparent diffusion coefficient values were binned to construct the apparent diffusion coefficient histogram. Using the histogram, the mean, percentiles, skewness, and kurtosis of the apparent diffusion coefficient of the entire tumor were computed. Apparent diffusion coefficient histogram parameters were compared with the MIB-1 index, invasiveness, and recurrence for grading tumor aggressiveness of pituitary adenomas. The skewness of the apparent diffusion coefficient histogram only showed significant differences among MIB-1 indices ( p = 0.030). All apparent diffusion coefficient histogram parameters showed no significant differences between negative and positive invasion. The skewness and kurtosis of the apparent diffusion coefficient histogram showed significant differences between positive and negative recurrence (skewness p = 0.011, kurtosis p = 0.011). Receiver-operating characteristics analysis between positive and negative recurrence showed that both skewness and kurtosis of the apparent diffusion coefficient achieved area under the curve at 0.967. Skewness and kurtosis of the apparent diffusion coefficient histogram were the predictive parameters for assessing tumor proliferative potential and recurrence of pituitary adenomas.

Оценка потенциала измеряемого коэффициента диффузии мультипараметрической магнитно-резонансной томографии в определении низкой степени злокачественности рака предстательной железы после радикальной простатэктомии

Оценка потенциала измеряемого коэффициента диффузии мультипараметрической магнитно-резонансной томографии в определении низкой степени злокачественности рака предстательной железы после радикальной простатэктомии

Ipsilateral Infarct in Newly Diagnosed Cervical Internal Carotid Artery Atherosclerotic Occlusion

Objective: We aimed to determine factors associated with recent infarct (RI) in patients with newly identified atherosclerotic cervical internal carotid artery occlusion (CICAO). Methods: This was a retrospective review of consecutive patients who underwent cervical CT angiography from 2002 to 2006 at a single tertiary center. RI was defined by positive diffusion-weighted imaging/apparent diffusion coefficient magnetic resonance imaging (MRI) in the correspondent CICAO territory. Subjects were dichotomized into those with a RI versus patients with no RI (No-RI). Results: Of 2,459 patients with cervical CT angiograms in the study period, 108 (4.4%) had complete medical records and brain MRI and were included. The mean age was 64 ± 13 years, 58% were men, and 62 (57%) had a RI. The demographics of the RI and No-RI patients were comparable, with the exception that those with RI had a lower frequency of coronary artery disease (CAD, 13 vs. 54%; p < 0.01) and dyslipidemia (38 vs. 69%; p < 0.01). The use of antiplatelets was not statistically different between the groups (56 vs. 71%; p = 0.1). Subjects with RI were less likely on statins (21 vs. 56%; p < 0.01) and antihypertensives (9 vs. 71%; p < 0.01). Multivariate regression revealed that CAD, the use of statins, and the use of antihypertensives were associated with No-RI CICAO presentation. Conclusion: The use of statins and antihypertensives is associated with a decreased risk of RI atherosclerotic CICAO.

Oxidative stress and light-evoked responses of the posterior segment in a mouse model of diabetic retinopathy.

To test the hypothesis that in a mouse model of diabetic retinopathy, oxidative stress is linked with impaired light-evoked expansion of choroidal thickness and subretinal space (SRS). We examined nondiabetic mice (wild-type, wt) with and without administration of manganese, nondiabetic mice deficient in rod phototransduction (transducin alpha knockout; GNAT1(-/-)), and diabetic mice (untreated or treated with the antioxidant α-lipoic acid [LPA]). Magnetic resonance imaging (MRI) was used to measure light-evoked increases in choroidal thickness and the apparent diffusion coefficient (ADC) at 88% to 100% depth into the retina (i.e., the SRS layer). Choroidal thickness values were similar (P > 0.05) between all untreated nondiabetic dark-adapted groups and increased significantly (P < 0.05) with light; this expansion was subnormal (P < 0.05) in both diabetic groups. Apparent diffusion coefficient values in the SRS layer robustly increased (P < 0.05) in a light duration-dependent manner, and this effect was independent of the presence of Mn(2+). The light-stimulated increase in ADC at the location of the SRS was absent in GNAT1(-/-) and diabetic mice (P > 0.05). In diabetic mice, the light-dependent increase in SRS ADC was significantly (P < 0.05) restored with LPA. Apparent diffusion coefficient MRI is a sensitive method for evaluating choroid thickness and its light-evoked expansion together with phototransduction-dependent changes in the SRS layer in mice in vivo. Because ADC MRI exploits an endogenous contrast mechanism, its translational potential is promising; it can also be performed in concert with manganese-enhanced MRI (MEMRI). Our data support a link between diabetes-related oxidative stress and rod, but not choroidal, pathophysiology.

Elastic registration of multimodal prostate MRI and histology via multiattribute combined mutual information

By performing registration of preoperative multiprotocol in vivo magnetic resonance (MR) images of the prostate with corresponding whole-mount histology (WMH) sections from postoperative radical prostatectomy specimens, an accurate estimate of the spatial extent of prostate cancer (CaP) on in vivo MR imaging (MRI) can be retrospectively established. This could allow for definition of quantitative image-based disease signatures and lead to development of classifiers for disease detection on multiprotocol in vivo MRI. Automated registration of MR and WMH images of the prostate is complicated by dissimilar image intensities, acquisition artifacts, and nonlinear shape differences. The authors present a method for automated elastic registration of multiprotocol in vivo MRI and WMH sections of the prostate. The method, multiattribute combined mutual information (MACMI), leverages all available multiprotocol image data to drive image registration using a multivariate formulation of mutual information. Elastic registration using the multivariate MI formulation is demonstrated for 150 corresponding sets of prostate images from 25 patient studies with T2-weighted and dynamic-contrast enhanced MRI and 85 image sets from 15 studies with an additional functional apparent diffusion coefficient MRI series. Qualitative results of MACMI evaluation via visual inspection suggest that an accurate delineation of CaP extent on MRI is obtained. Results of quantitative evaluation on 150 clinical and 20 synthetic image sets indicate improved registration accuracy using MACMI compared to conventional pairwise mutual information-based approaches. The authors' approach to the registration of in vivo multiprotocol MRI and ex vivo WMH of the prostate using MACMI is unique, in that (1) information from all available image protocols is utilized to drive the registration with histology, (2) no additional, intermediate ex vivo radiology or gross histology images need be obtained in addition to the routinely acquired in vivo MRI series, and (3) no corresponding anatomical landmarks are required to be identified manually or automatically on the images.