Acute mild traumatic brain injury is not associated with white matter change on diffusion tensor imaging.

This study was designed to (i) evaluate the influence of age on diffusion tensor imaging measures of white matter assessed using tract-based spatial statistics; (ii) determine if mild traumatic brain injury is associated with microstructural changes in white matter, in the acute phase following injury, in a large homogenous sample that was carefully screened for pre-injury medical, psychiatric, or neurological problems; and (iii) examine if injury severity is related to white matter changes. Participants were 75 patients with acute mild traumatic brain injury (age = 37.2 ± 12.0 years, 45 males and 30 females) and 40 controls (age = 40.6 ± 12.2 yrs, 20 males and 20 females). Age effects were analysed by comparing control subgroups aged 31-40, 41-50, and 51-60 years against a group of 18-30-year-old control subjects. Widespread statistically significant areas of abnormal diffusion tensor measures were observed in older groups. Patients and controls were compared using age and gender as covariates and in age- and gender-matched subgroups. Subgroups of patients with more severe injuries were compared to age-and gender-matched controls. No significant differences were detected in patient-control or severity analyses (all P-value > 0.01). In this large, carefully screened sample, acute mild traumatic brain injury was not associated with diffusion tensor imaging abnormalities detectable with tract-based spatial statistics.

Hemispheric asymmetry measured by texture analysis and diffusion tensor imaging in two multiple sclerosis subtypes.

BACKGROUND: This paper addresses two subtypes of multiple sclerosis (MS), primary progressive multiple sclerosis (PPMS) and relapsing-remitting multiple sclerosis (RRMS). The separation of PPMS and RRMS is challenging in certain cases. PURPOSE: To quantitatively determine MS subtypes using texture analysis (TA) and diffusion tensor imaging (DTI). MATERIAL AND METHODS: T1-weighted (T1W) magnetic resonance imaging (MRI) and DTI of the left and right brain hemispheres of 17 patients with PPMS and 19 patients with RRMS were studied. Areas of the caudate nucleus and thalamus were investigated as normal appearing gray matter (NAGM), and areas of the cerebral peduncle and centrum semiovale were investigated as normal appearing white matter (NAWM). The described locations were symmetrical and were accurately marked. TA was performed on the T1W images, and the fractional anisotropy and apparent diffusion coefficient were determined from the DTI data. RESULTS: Hemispherical differences were found with both TA and DTI. Several texture and diffusion tensor parameter values calculated for the left and right hemispheres of the patients showed statistically significant differences. The patients with RRMS had greater significant differences (P < 0.01) in the thalamus between the hemispheres than did the patients with PPMS. The TA classification accuracy of the PPMS and RRMS subtypes was above 80%. CONCLUSION: TA can be helpful when distinguishing between PPMS and RRMS, while DTI appears to reveal the hemispherical asymmetry of RRMS patients.

MR image texture in Parkinson's disease: a longitudinal study.

BACKGROUND: Few of the structural changes caused by Parkinson's disease (PD) are visible in magnetic resonance imaging (MRI) with visual inspection but there is a need for a method capable of observing the changes beyond the human eye. Texture analysis offers a technique that enables the quantification of the image gray-level patterns. PURPOSE: To investigate the value of quantitative image texture analysis method in diagnosis and follow-up of PD patients. MATERIAL AND METHODS: Twenty-six PD patients underwent MRI at baseline and after 2 years of follow-up. Four co-occurrence matrix-based texture parameters, describing the image homogeneity and complexity, were calculated within clinically interesting areas of the brain. In addition, correlations with clinical characteristics (Unified Parkinson's Disease Ranking Scales I-III and Mini-Mental State Examination score) along with a comparison to healthy controls were evaluated. RESULTS: Patients at baseline and healthy volunteers differed in their brain MR image textures mostly in the areas of substantia nigra pars compacta, dentate nucleus, and basilar pons. During the 2-year follow-up of the patients, textural differences appeared mainly in thalamus and corona radiata. Texture parameters in all the above mentioned areas were also found to be significantly related to clinical scores describing the severity of PD. CONCLUSION: Texture analysis offers a quantitative method for detecting structural changes in brain MR images. However, the protocol and repeatability of the method must be enhanced before possible clinical use.

Correlation of electrocardiogram and regional cardiac magnetic resonance imaging findings in ST-elevation myocardial infarction: a literature review.

BACKGROUND: Patients with acute ST-elevation myocardial infarction (STEMI) benefit substantially from emergent coronary reperfusion. The principal mechanism is to open the occluded coronary artery to minimize myocardial injury. Thus the size of the area at risk is a critical determinant of the patient outcome, although other factors, such as reperfusion injury, have major impact on the final infarct size. Acute coronary occlusion almost immediately induces metabolic changes within the myocardium, which can be assessed with both the electrocardiogram (ECG) and cardiac magnetic resonance (CMR) imaging. METHODS: The 12-lead ECG is the principal diagnostic method to detect and risk-stratify acute STEMI. However, to achieve a correct diagnosis, it is paramount to compare different ECG parameters with golden standards in imaging, such as CMR. In this review, we discuss aspects of ECG and CMR in the assessment of acute regional ischemic changes in the myocardium using the 17 segment model of the left ventricle presented by American Heart Association (AHA), and their relation to coronary artery anatomy. RESULTS: Using the 17 segment model of AHA, the segments 12 and 16 remain controversial. There is an important overlap in myocardial blood supply at the antero-lateral region between LAD and LCx territories concerning these two segments. CONCLUSION: No all-encompassing correlation can be found between ECG and CMR findings in acute ischemia with respect to coronary anatomy.

Diffusion tensor imaging of the cervical spinal cord in healthy adult population: normative values and measurement reproducibility at 3T MRI.

BACKGROUND: Compared to diffusion tensor imaging (DTI) of the brain, there is a paucity of reports addressing the applicability of DTI in the evaluation of the spinal cord. Most normative data of cervical spinal cord DTI consist of relatively small and arbitrarily collected populations. Comprehensive normative data are necessary for clinical decision-making. PURPOSE: To establish normal values for cervical spinal cord DTI metrics with region of interest (ROI)- and fiber tractography (FT)-based measurements and to assess the reproducibility of both measurement methods. MATERIAL AND METHODS: Forty healthy adults underwent cervical spinal cord 3T MRI. Sagittal and axial conventional T2 sequences and DTI in the axial plane were performed. Whole cord fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were determined at different cervical levels from C2 to C7 using the ROI method. DTI metrics (FA, axial, and radial diffusivities based on eigenvalues λ1, λ2, and λ3, and ADC) of the lateral and posterior funicles were measured at C3 level. FA and ADC of the whole cord and the lateral and posterior funicles were also measured using quantitative tractography. Intra- and inter-observer variation of the measurement methods were assessed. RESULTS: Whole cord FA values decreased and ADC values increased in the rostral to caudal direction from C2 to C7. Between the individual white matter funicles no statistically significant difference for FA or ADC values was found. Both axial diffusivity and radial diffusivity of both lateral funicles differed significantly from those of the posterior funicle. Neither gender nor age correlated with any of the DTI metrics. Intra-observer variation of the measurements for whole cord FA and ADC showed almost perfect agreement with both ROI and tractography-based measurements. There was more variation in measurements of individual columns. Inter-observer agreement varied from moderate to strong for whole cord FA and ADC. CONCLUSION: Both ROI- and FT-based measurements are applicable methods yielding reproducible results for cervical spinal cord DTI metrics. Normative values for both measurement methods are presented.

Comparison of different MRI sequences in lesion detection and early response evaluation of diffuse large B-cell lymphoma--a whole-body MRI and diffusion-weighted imaging study.

To compare different MRI sequences for the detection of lesions and the evaluation of response to chemotherapy in patients with diffuse large B-cell lymphoma (DLBCL), 18 patients with histology-confirmed DLBCL underwent 3-T MRI scanning prior to and 1 week after chemotherapy. The MRI sequences included T1-weighted pre- and post-contrast, T2 -weighted with and without fat suppression, and a single-shot echo-planar diffusion-weighted imaging (DWI) with two b values (0 and 800 s/mm(2)). Conventional MRI sequence comparisons were performed using the contrast ratio between tumor and normal vertebral body instead of signal intensity. The apparent diffusion coefficient (ADC) of the tumor was measured directly on the parametric ADC map. The tumor volume was used as a reference for the evaluation of chemotherapy response. The mean tumor volume was 374 mL at baseline, and decreased by 65% 1 week after chemotherapy (p < 0.01). The T2 -weighted image with fat suppression showed a significantly higher contrast ratio compared with images from all other conventional MRI sequences, both before and after treatment (p < 0.01, respectively). The contrast ratio of the T2 -weighted image with fat suppression decreased significantly (p < 0.01), and that of the T1 -weighted pre-contrast image increased significantly (p < 0.01), after treatment. However, there was no correlation between the change in contrast ratio and tumor volume. The mean ADC value was 0.68 × 10(-3) mm(2)/s at baseline; it increased by 89% after chemotherapy (p < 0.001), and the change in ADC value correlated with the change in tumor volume (r = 0.66, p < 0.01). The baseline ADC value also correlated inversely with the percentage change in ADC after treatment (r = -0.62, p < 0.01). In conclusion, this study indicates that T2-weighted imaging with fat suppression is the best conventional sequence for the detection of lesions and evaluation of the efficacy of chemotherapy in DLBCL. DWI with ADC mapping is an imaging modality with both diagnostic and prognostic value that could complement conventional MRI.

Repeatability and variation of region-of-interest methods using quantitative diffusion tensor MR imaging of the brain.

BACKGROUND: Diffusion tensor imaging (DTI) is increasingly used in various diseases as a clinical tool for assessing the integrity of the brain's white matter. Reduced fractional anisotropy (FA) and an increased apparent diffusion coefficient (ADC) are nonspecific findings in most pathological processes affecting the brain's parenchyma. At present, there is no gold standard for validating diffusion measures, which are dependent on the scanning protocols, methods of the softwares and observers. Therefore, the normal variation and repeatability effects on commonly-derived measures should be carefully examined. METHODS: Thirty healthy volunteers (mean age 37.8 years, SD 11.4) underwent DTI of the brain with 3T MRI. Region-of-interest (ROI) -based measurements were calculated at eleven anatomical locations in the pyramidal tracts, corpus callosum and frontobasal area. Two ROI-based methods, the circular method (CM) and the freehand method (FM), were compared. Both methods were also compared by performing measurements on a DTI phantom. The intra- and inter-observer variability (coefficient of variation, or CV%) and repeatability (intra-class correlation coefficient, or ICC) were assessed for FA and ADC values obtained using both ROI methods. RESULTS: The mean FA values for all of the regions were 0.663 with the CM and 0.621 with the FM. For both methods, the FA was highest in the splenium of the corpus callosum. The mean ADC value was 0.727 ×10-3 mm2/s with the CM and 0.747 ×10-3 mm2/s with the FM, and both methods found the ADC to be lowest in the corona radiata. The CV percentages of the derived measures were < 13% with the CM and < 10% with the FM. In most of the regions, the ICCs were excellent or moderate for both methods. With the CM, the highest ICC for FA was in the posterior limb of the internal capsule (0.90), and with the FM, it was in the corona radiata (0.86). For ADC, the highest ICC was found in the genu of the corpus callosum (0.93) with the CM and in the uncinate fasciculus (0.92) with FM. CONCLUSIONS: With both ROI-based methods variability was low and repeatability was moderate. The circular method gave higher repeatability, but variation was slightly lower using the freehand method. The circular method can be recommended for the posterior limb of the internal capsule and splenium of the corpus callosum, and the freehand method for the corona radiata.

MRI texture analysis of femoral neck: Detection of exercise load-associated differences in trabecular bone.

PURPOSE: To assess the ability of co-occurrence matrix-based texture parameters to detect exercise load-associated differences in MRI texture at the femoral neck cross-section. MATERIALS AND METHODS: A total of 91 top-level female athletes representing five differently loading sports and 20 referents participated in this cross-sectional study. Axial T1-weighted FLASH and T2*-weighted MEDIC sequence images of the proximal femur were obtained with a 1.5T MRI. The femoral neck trabecular bone at the level of the insertion of articular capsule was divided manually into regions of interest representing four anatomical sectors (anterior, posterior, superior, and inferior). Selected co-occurrence matrix-based texture parameters were used to evaluate differences in apparent trabecular structure between the exercise loading groups and anatomical sectors of the femoral neck. RESULTS: Significant differences in the trabecular bone texture, particularly at the superior femoral neck, were observed between athletes representing odd-impact (soccer and squash) and high-magnitude exercise loading (power-lifting) groups and the nonathletic reference group. CONCLUSION: MRI texture analysis provides a quantitative method for detecting and classifying apparent structural differences in trabecular bone that are associated with specific exercise loading.

Diffusion tensor imaging of the brain in a healthy adult population: Normative values and measurement reproducibility at 3 T and 1.5 T.

BACKGROUND: Diffusion tensor imaging (DTI) is an increasingly used method for investigation of brain white matter integrity in both research and clinical applications. Familiarity with normal variation of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values and measurement reproducibility is essential when DTI measurements are interpreted in clinical patients. PURPOSE: To establish normal values for FA and ADC in a healthy adult population at 1.5 T and 3 T MRI based on region of interest (ROI) analysis, and to study the inter- and intra-observer reproducibility of the measurements. MATERIAL AND METHODS: Forty healthy volunteers (26 women, 14 men, mean age 38.3, SD 11.6 years) underwent conventional MRI and DTI of the brain, 30 with 3 T and 10 with 1.5 T clinical scanners. ROI-based measurements for FA and ADC values were performed in five different anatomic locations of each hemisphere and in three locations within the corpus callosum. Mean values for FA and ADC for each region were calculated. Inter-observer variation of ROI measurements was evaluated by comparing the results of the two observers, intra-observer variation by repeated measurement of 10 subjects by both observers. RESULTS: The FA values varied considerably between different regions. The highest values were found in the genu and splenium of the corpus callosum and the lowest in the corona radiata, respectively. In general, ADC values showed less variation; the highest values were found in the body of the corpus callosum and the lowest in the corona radiata. The reproducibility of both inter- and intra-observer measurements also varied regionally. The highest agreement was found for the corpus callosum and the lowest for the corona radiata and centrum semiovale. CONCLUSION: In a normal adult population FA and ADC values of the brain white matter show regional variation. The repeatability of the ROI measurements also varies regionally. This regional variability must be acknowledged when these measurements are interpreted in clinical patients.

Dynamic Contrast-Enhanced Imaging as a Prognostic Tool in Early Diagnosis of Prostate Cancer: Correlation with PSA and Clinical Stage.

Background and Purpose: Although several methods have been developed to predict the outcome of patients with prostate cancer, early diagnosis of individual patient remains challenging. The aim of the present study was to correlate tumor perfusion parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and clinical prognostic factors and further to explore the diagnostic value of DCE-MRI parameters in early stage prostate cancer. Patients and Methods: Sixty-two newly diagnosed patients with histologically proven prostate adenocarcinoma were enrolled in our prospective study. Transrectal ultrasound-guided biopsy (12 cores, 6 on each lobe) was performed in each patient. Pathology was reviewed and graded according to the Gleason system. DCE-MRI was performed and analyzed using a two-compartmental model; quantitative parameters including volume transfer constant (K trans), reflux constant (K ep), and initial area under curve (iAUC) were calculated from the tumors and correlated with prostate-specific antigen (PSA), Gleason score, and clinical stage. Results: K trans (0.11 ± 0.02 min-1 versus 0.16 ± 0.06 min-1; p < 0.05), K ep (0.38 ± 0.08 min-1 versus 0.60 ± 0.23 min-1; p < 0.01), and iAUC (14.33 ± 2.66 mmoL/L/min versus 17.40 ± 5.97 mmoL/L/min; p < 0.05) were all lower in the clinical stage T1c tumors (tumor number, n=11) than that of tumors in clinical stage T2 (n=58). Serum PSA correlated with both tumor K trans (r=0.304, p < 0.05) and iAUC (r=0.258, p < 0.05). Conclusions: Our study has confirmed that DCE-MRI is a promising biomarker that reflects the microcirculation of prostate cancer. DCE-MRI in combination with clinical prognostic factors may provide an effective new tool for the basis of early diagnosis and treatment decisions.

Diffusion-weighted MRI Provides a Useful Biomarker for Evaluation of Radiotherapy Efficacy in Patients with Prostate Cancer.

BACKGROUND: Diffusion-weighted imaging (DWI) with measurement of apparent diffusion coefficient (ADC) allows for assessment of tumor aggressiveness. The objective of this study was to evaluate the changes of ADC value in prostate cancer after volumetric-modulated arc radiotherapy (VMAT) and to identify magnetic resonance imaging (MRI) biomarkers for monitoring tissue changes after radiotherapy. PATIENTS AND METHODS: Thirty-seven patients with biopsy-proven prostate cancer treated with VMAT underwent serial MRI examinations including DWI before radiotherapy, and at 3 and 12 months after radiotherapy. ADC values of the tumor and healthy prostate tissue were measured and compared at these three time points. RESULTS: The tumor ADC value increased significantly 3 months after radiotherapy (p<0.0001). There was a further increase of tumor ADC from 3 to 12 months after radiotherapy (p<0.01). The ADC of healthy prostate tissue did not show any significant changes. CONCLUSION: The ADC value is a useful biomarker for evaluating the efficacy of radiotherapy in prostate cancer.

MRI Texture Analysis and Diffusion Tensor Imaging in Chronic Right Hemisphere Ischemic Stroke.

BACKGROUND AND PURPOSE: Diffusion tensor imaging (DTI) is shown to reveal changes caused by cerebral infarction. The aim of this study is to reveal those changes also in the conventional magnetic resonance (MR) images using a quantitative image analysis method, texture analysis (TA). METHODS: Thirty patients who had suffered their first ever infarction located on the right hemisphere underwent DTI and conventional MRI studies in the chronic phase. DTI parameters fractional anisotropy and mean diffusivity, as well as four second-order texture parameters were calculated. Interhemispheric differences and correlations between DTI and TA parameters were evaluated. RESULTS: Our DTI findings supported earlier studies as fractional anisotropy values were lowered and mean diffusivity values elevated in the lesion site, and ipsilateral cerebral peduncle, thalamus, and centrum semiovale compared to the unaffected side. Textural homogeneity parameters showed lower and complexity parameters higher values in the lesion site and ipsilateral centrum semiovale compared to the contralateral hemisphere. Correlation between the two methods was found in ipsilateral mesencephalon. CONCLUSIONS: In addition to DTI method, TA could assist in revealing the changes caused by infarction, also outside the lesion site. Damaged areas were found more heterogeneous and random in texture compared to unaffected sites.

Influence of exercise loading on magnetic resonance image texture of thigh soft tissues.

Adaptation to exercise training can affect bone marrow adiposity; muscle-fat distribution; and muscle volume, strength and architecture. The objective of this study was to identify exercise-load-associated differences in magnetic resonance image textures of thigh soft tissues between various athlete groups and non-athletes. Ninety female athletes representing five differently loading sport types (high impact, odd impact, high magnitude, repetitive low impact and repetitive non-impact), and 20 non-athletic clinically healthy female controls underwent magnetic resonance imaging. Five thigh muscles, subcutaneous fat and femoral bone marrow were analysed with co-occurrence matrix-based quantitative texture analysis at two anatomical levels of the dominant leg. Compared with the controls thigh muscle textures differed especially in high-impact and odd-impact exercise-loading groups. However, all sports appeared to modulate muscle textures to some extent. Fat tissue was found different among the low-impact group, and bone marrow was different in the high-impact group when compared to the controls. Exercise loading was associated with textural variation in magnetic resonance images of thigh soft tissues. Texture analysis proved a potential method for detecting apparent structural differences in the muscle, fat and bone marrow.

Parkinson's disease: interhemispheric textural differences in MR images.

RATIONALE AND OBJECTIVES: Early-stage diagnosis of Parkinson's disease (PD) is essential in making decisions related to treatment and prognosis. However, there is no specific diagnostic test for the diagnosis of PD. The aim of this study was to evaluate the role of texture analysis (TA) of magnetic resonance images in detecting subtle changes between the hemispheres in various brain structures in patients with early symptoms of parkinsonism. In addition, functional TA parameters for detecting textural changes are presented. MATERIALS AND METHODS: Fifty-one patients with symptoms of PD and 20 healthy controls were imaged using a 3-T magnetic resonance device. Co-occurrence matrix-based TA was applied to detect changes in textures between the hemispheres in the following clinically interesting areas: dentate nucleus, basilar pons, substantia nigra, globus pallidus, thalamus, putamen, caudate nucleus, corona radiata, and centrum semiovale. The TA results were statistically evaluated using the Mann-Whitney U test. RESULTS: The results showed interhemispheric textural differences among the patients, especially in the area of basilar pons and midbrain. Concentrating on this clinically interesting area, the four most discriminant parameters were defined: co-occurrence matrix correlation, contrast, difference variance, and sum variance. With these parameters, differences were also detected in the dentate nucleus, globus pallidus, and corona radiata. CONCLUSIONS: On the basis of this study, interhemispheric differences in the magnetic resonance images of patients with PD can be identified by the means of co-occurrence matrix-based TA. The detected areas correlate with the current pathophysiologic and neuroanatomic knowledge of PD.

Brain iron deposition and sequence characteristics in Parkinsonism: comparison of SWI, T2* maps, T2-weighted-, and FLAIR-SPACE.

OBJECTIVES: To compare quantitatively T2- and T2*-based magnetic resonance imaging sequences in patients with symptoms of Parkinson disease and to evaluate the information content of those sequences regarding brain iron concentration. MATERIALS AND METHODS: We imaged 51 patients with symptoms of Parkinson disease on 3-T magnetic resonance imaging with T2-weighted sampling perfection with application optimized contrasts using different flip-angle evolution (SPACE), fluid attenuation inversion recovery (FLAIR)-SPACE, susceptibility-weighted imaging (SWI), and parametric T2* sequence (MapIt). Signal analysis was performed in 22 regions of interest in the brain. RESULTS: Correlations (r2 = 0.82...0.96) with brain iron concentration were excellent. Contrast and tissue separability ratios were best in the T2* maps and FLAIR-SPACE, respectively. Good correlations of contrast were reached between SWI and both T2-weighted SPACE and FLAIR-SPACE. Their relation to quantitative T2* values was reminiscent of a quadratic curve shape. However, separation into gray and white matter revealed a linear positive and negative correlation, respectively. CONCLUSIONS: SWI showed potential in differentiating illnesses characterized by brain iron deposition. Closely similar information was given by T2-weighted SPACE and FLAIR-SPACE, whereas other sequence comparisons revealed dispersion from intersequence agreement.

Characterization of breast cancer types by texture analysis of magnetic resonance images.

RATIONALE AND OBJECTIVES: This novel study aims to investigate texture parameters in distinguishing healthy breast tissue and breast cancer in breast magnetic resonance imaging (MRI). A specific aim was to identify possible differences in the texture characteristics of histological types (lobular and ductal) of invasive breast cancer and to determine the value of these differences for computer-assisted lesion classification. MATERIALS AND METHODS: Twenty patients (mean age 50.6 + or - SD 10.6; range 37-70 years), with histopathologically proven invasive breast cancer (10 lobular and 10 ductal) were included in this preliminary study. The median MRI lesion size was 25 mm (range, 7-60 mm). The selected T1-weighted precontrast, post-contrast, and subtracted images were analyzed and classified with texture analysis (TA) software MaZda and additional statistical tests were used for testing the parameters separability. RESULTS: All classification methods employed were able to differentiate between cancer and healthy breast tissue and also invasive lobular and ductal carcinoma with classification accuracy varying between 80% and 100%, depending on the used imaging series and the type of region of interest. We found several parameters to be significantly different between the regions of interest studied. The co-occurrence matrix based parameters proved to be superior to other texture parameters used. CONCLUSIONS: The results of this study indicate that MRI TA differentiates breast cancer from normal tissue and may be able to distinguish between two histological types of breast cancer providing more accurate characterization of breast lesions thereby offering a new tool for radiological analysis of breast MRI.

Mild traumatic brain injury: tissue texture analysis correlated to neuropsychological and DTI findings.

RATIONALE AND OBJECTIVES: The aim of this study was to evaluate whether texture analysis (TA) can detect subtle changes in cerebral tissue caused by mild traumatic brain injury (MTBI) and to determine whether these changes correlate with neuropsychological and diffusion tensor imaging (DTI) findings. MATERIALS AND METHODS: Forty-two patients with MTBIs were imaged using 1.5T magnetic resonance imaging within 3 weeks after head injury. TA was performed for the regions corresponding to the mesencephalon, centrum semiovale, and corpus callosum. Using DTI, the fractional anisotropic and apparent diffusion coefficient values for the same regions were evaluated. The same analyses were performed on a group of 10 healthy volunteers. Patients also underwent a battery of neurocognitive tests within 6 weeks after injury. RESULTS: TA revealed textural differences between the right and left hemispheres in patients with MTBIs, whereas differences were minimal in healthy controls. A significant correlation was found between scores on memory tests and texture parameters (sum of squares, sum entropy, inverse difference moment, and sum average) in patients in the area of the mesencephalon and the genu of the corpus callosum. Significant correlations were also found between texture parameters for the left mesencephalon and both fractional anisotropic and apparent diffusion coefficient values. CONCLUSIONS: The data suggest that heterogeneous texture and abnormal DTI patterns in the area of the mesencephalon may be linked with verbal memory deficits among patients with MTBIs. Therefore, TA combined with DTI in patients with MTBIs may increase the ability to detect early and subtle neuropathologic changes.