Cost Analysis of Diffusion Tensor Imaging and MR Tractography of the Brain

Purpose: To determine the total direct costs (fixed and variable costs) of diffusion tensor imaging (DTI) and MR tractography reconstruction of the brain. Materials and Methods: The direct fixed and variable costs of DTI with MR tractography were determined prospectively with time and motion analysis in a 1.5-Tesla MR scanner using 15 encoding directions. Seventeen patients with seizure disorders, 9 males & 8 females, with mean age of 13 years (age range 2 - 33 years) were studied. Total direct costs were calculated from all direct fixed and variable costs. Sensitivity analyses between 1.5 versus a 3-Tesla MR system, and 15 versus 32 encoding directions were done. Results: The total direct costs of DTI and MR tractography for a 1.5-T system with 15 encoding directions were US $97. Variable cost was $76.80 and fixed cost was $20.20. Total direct costs for a 3-T system with 15 directions decreased to US $94.5 because of the shorter scan time despite the higher cost of the 3-T system. The most costly component of the direct cost was post-processing analysis at US $46.00. Conclusion: DTI with MR tractography has important total direct costs with variable costs higher than the fixed costs. The post processing variable cost is the most expensive component. Developing more accurate automated post-processing software for DTI and MR tractography is important to decrease this variable labor cost. Given the added value of DTI-MR tractography and the costs involved reimbursement codes should be considered.

Correlation between muscular strength and basal nuclei ischemic/hemorrhagic stroke-induced corticospinal tract injury,as detected by diffusion tensor imaging and tractography

BACKGROUND： Conventional neuroimaging diagnosis does not assist with the monitoring or evaluation of basal nuclei ischemic and hemorrhagic stroke, or motor functional recovery. Magnetic resonance, diffusion tensor imaging, and diffusion tensor tractography have all been used to observe features of cerebral white matter fibrous structures. In addition, diffusion tensor tractography is the only non-invasive imaging method to display the corticospinal tract in vivo. OBJECTIVE： To evaluate the impairment degree of corticospinal tract induced by basal nuclei ischemic and hemorrhagic stroke through the use of magnetic resonance, diffusion tensor imaging, and diffusion tensor tractography, and to analyze the correlation to muscular strength. DESIGN, TIME AND SETTING： A retrospective case analysis was performed at the Department of Medical Imaging, Neurology and Neurosurgery, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA between November 2002 and June 2008. PARTICIPANTS： A total of 15 patients with acute or subacute cerebral ischemic stroke and nine with hemorrhagic stroke in the basal nuclei were selected. METHODS： Magnetic resonance, diffusion tensor imaging, and diffusion tensor tractography results and data were analyzed. Fractional anisotropy and directionally encoded color maps were obtained. Three-dimensional tractography of bilateral corticospinal tract was created, and corticospinal tract integrity was graded. Fractional anisotropy of infarct region and corresponding contralateral normal regions were measured, and hematoma volume in hemorrhagic stroke patients was determined. Hand motor function ability was evaluated using Brunstorm criteria. MAIN OUTCOME MEASURES： Fractional anisotropy of infarct region and corresponding contralateral normal regions; hematoma volume in hemorrhagic stroke patients; correlation between muscular strength and corticospinal tract impairment degree in ischemic stroke and hemorrhagic stroke patients before and after treatment. RESULTS： In ischemic stroke patients, the fractional anisotropy value was significantly lower in the infarct area of white matter than in the normal hemisphere （P 〈 0.01）. The impairment degree of corticospinal tract negatively correlated with muscular strength of the corresponding hand （r = -0.97 P 〈 0.01）. The hematoma volume of hemorrhagic stroke patients significantly negatively correlated with Spearman test results for muscular strength of the corresponding hand （r = -0.88, P 〈 0.01）. CONCLUSION： Corticospinal tract impairment severity negatively correlated with muscular strength and motor functional recovery, which suggested that diffusion tensor imaging and diffusion tensor tractography could be used to evaluate corticospinal tract motor function.

Magnetic resonance diffusion tensor imaging and diffusion tensor tractography of human visual pathway

AIM: To investigate the visual pathway in normal subjects and patients with lesion involved by diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT). METHODS: Thirty normal volunteers, 3 subjects with orbital tumors involved the optic nerve (ON) and 33 subjects with occipital lobe tumors involved the optic radiation (OR) (10 gliomas, 6 meningiomas and 17 cerebral metastases) undertook routine cranium magnetic resonance imaging (MRI), DTI and DTT. Visual pathway fibers were analyzed by DTI and DTT images. Test fractional anisotropy (FA) and mean diffusivity (MD) values in different part of the visual pathway. RESULTS: The whole visual pathway but optic chiasm manifested as hyperintensity in FA maps and homogenous green signal in the direction encoded color maps. The optic chiasm did not display clearly. There was no significant difference between the bilateral FA values and MD values of normal visual pathway but optic chiasm, which the FA values tested were much too low (all P>0.05). The ONs of subjects with orbital tumors were compressed and displaced. Only one subject had lower FA values and higher MD values. OR of 9 gliomas subjects were infiltrated, with displacement in 2 and disruption in 7 subjects. All OR in 6 meniongiomas subjects were displaced. OR in 17 cerebral metastases subjects all developed displacement while 7 of them had disruption also. CONCLUSION: MR-DTI is highly sensitive in manifesting visual pathway. Visual pathway can be analyzed quantitatively in FA and MD values. DTT supplies accurate three dimensional conformations of visual pathway. But optic chiasm's manifestation still needs to improve.

Traumatic axonal injury of the cingulum in patients with mild traumatic brain injury: a diffusion tensor tractography study

The cingulum,connecting the orbitofrontal cortex to the medial temporal lobe,involves in diverse cognition functions including attention,memory,and motivation.To investigate the relationship between the cingulum injury and cognitive impairment in patients with chronic mild traumatic brain injury,we evaluated the integrity between the anterior cingulum and the basal forebrain using diffusion tensor tractography in 73 patients with chronic mild traumatic brain injury(39 males,34 females,age 43.29±11.42 years)and 40 healthy controls(22 males,18 females,age 40.11±16.81 years).The patients were divided into three subgroups based on the integrity between the anterior cingulum and the basal forebrain on diffusion tensor tractography:subgroup A(n=19 patients)– both sides of the anterior cingulum were intact;subgroup B(n=36 patients)– either side of the anterior cingulum was intact;and subgroup C(18 patients)– both sides of the anterior cingulum were discontinued.There were significant differences in total Memory Assessment Scale score between subgroups A and B and between subgroups A and C.There were no significant differences in diffusion tensor tractography parameters(fractional anisotropy,apparent diffusion coefficient,and fiber volume)between patients and controls.These findings suggest that the integrity between the anterior cingulum and the basal forebrain,but not diffusion tensor tractography parameter,can be used to predict the cognitive function of patients with chronic mild traumatic brain injury.This study was approved by Yeungnam University Hospital Institutional Review Board(approval No.YUMC-2014-01-425-010)on August 16,2017.

Is combined functional magnetic resonance imaging and diffusion tensor tractography a useful tool for evaluation of somatosensory dysfunction recovery after intracerebral hemorrhage?

Diffusion tensor tractography allows the sensory fiber course of the medial lemniscus to be visualized. But diffusion tensor tractography for accurate evaluation of the repair of injured somatosensory tracts in stroke patients has been rarely reported. A 55-year-old female patient presented with severe somatosensory dysfunction of the left side caused by a spontaneous intracerebral hemorrhage on the right side. The somatosensory function of the affected side recovered to a nearly normal state at 7 weeks from onset. Functional magnetic resonance imaging revealed that at 3 weeks from onset, there was no cortical activation by touch at each hand; at 7 weeks, the contralateral cortex centered on the primary sensory cortex was found to be activated during touch and passive movements, and activation by passive movements was increased compared with that at 3 weeks. Diffusion tensor tractography revealed that a medial lemniscus on the affected （right） hemisphere was not observed at 3 weeks from onset, however, at 7 weeks, the unaffected （left） hemisphere passed along the medial lemniscus pathway from the pons to the primary sensory cortex. These findings indicate that combined functional magnetic resonance imaging and diffusion tensor tractography would allow more accurate evaluation of the architecture and integrity of somatosensory tracts and is a useful method to investigate the recovery of somatosensory dysfunction in stroke patients.

GRADING OF RABBIT SKELETAL MUSCLE TRAUMA BY DIFFUSION TENSOR IMAGING AND TRACTOGRAPHY ON MAGNETIC RESONANCE IMAGING

Objective To distinguish the edema, injury, or rupture in the traumatic skeletal muscle fiber in vivo using diffusion tensor imaging (DTI) and tractography on magnetic resonance imaging (MRI). Methods The skeletal muscle trauma models were made in 4 rabbits (eight hindlimbs) by iron discus (weight 1.0 kg, diameter 6 cm) falling down vertically from 45 cm height to rabbits’ thighs. Conventional sequences and two-dimensional (2D) diffusion-weighted (DW) spin-echo (SE) echo planar imaging (EPI) sequence with fat suppression (b=600 s/mm^2) were performed on 1.5T MRI scanner. The grading of edema, injury, and fiber rupture in the damaged muscle were made according to their histopathological views, which was consistent with the images. The mean apparent diffusion coefficient (ADC) values and fractional anisotropy (FA) values were measured from the region of interests (ROIs) of all groups on 2D DW images used for tractography. Analysis of variance test was performed to analyze all data. Results ADC values of the areas in normal muscle, edema muscle, injury muscle, and ruptured muscle were (6.12±1.34)×10~ -3 , (6.38±1.30)×10~ -3 , (8.06±0.97)×10~ -3 , and (9.57±0.93)×10~ -3 mm~ 2 /s, respectively. There was significant difference among groups (P<0.001), but no difference between edema muscle and normal muscle group (P>0.05). The FA values of normal muscle, edema muscle, injury muscle, and ruptured muscle were 0.42±0.12, 0.36±0.12, 0.26±0.09, 0.12±0.08, respectively, with a significant difference among groups (P<0.001). In the edema muscle, the tracking cross-fiber could be seen but it decreased slightly. In the injury muscle, the tracking fiber decreased markedly. In the ruptured muscle, the transverse-orientation tracking fiber vanished, yet some interrupted longitudinal-orientation tracking fiber could be found. Conclusion The edema, injury, and rupture of muscle fiber in rabbit damaged skeletal muscle can be verified according to the ADC and the FA on DTI and tractography.

Diffusion tensor tractography characteristics of axonal injury in concussion/mild traumatic brain injury

The main advantage of diffusion tensor tractography is that it allows the entire neural tract to be evaluated.In addition,configurational analysis of reconstructed neural tracts can indicate abnormalities such as tearing,narrowing,or discontinuations,which have been used to identify axonal injury of neural tracts in concussion patients.This review focuses on the characteristic features of axonal injury in concussion or mild traumatic brain injury(m TBI)patients through the use of diffusion tensor tractography.Axonal injury in concussion(m TBI)patients is characterized by their occurrence in long neural tracts and multiple injuries,and these characteristics are common in patients with diffuse axonal injury and in concussion(m TBI)patients with axonal injury.However,the discontinuation of the corticospinal tract is mostly observed in diffuse axonal injury,and partial tearing and narrowing in the subcortical white matter are frequently observed in concussion(m TBI)patients with axonal injury.This difference appears to be attributed to the observation that axonal injury in concussion(m TBI)patients is the result of weaker forces than those producing diffuse axonal injuries.In addition,regarding the fornix,in diffuse axonal injury,discontinuation of the fornical crus has been frequently reported,but in concussion(m TBI)patients,many collateral branches form in the fornix in addition to these findings in many case studies.It is presumed that the impact on the brain in TBI is relatively weaker than that in diffuse axonal injury,and that the formation of collateral branches occurs during the fornix recovery process.Although the occurrence of axonal injury in multiple areas of the brain is an important feature of diffuse axonal injury,case studies in concussion(m TBI)have shown that axonal injury occurs in multiple neural tracts.Because axonal injury lesions in m TBI patients may persist for approximately 10 years after injury onset,the characteristics of axonal injury in concussion(m TBI)patients,which are reviewed and categorized in this review,are expected to serve as useful supplementary information in the diagnosis of axonal injury in concussion(m TBI)patients.

Diffusion tensor tractography of the arcuate fasciculus in patients with brain tumors: Comparison between deterministic and probabilistic models

Purpose: The purpose of this study was to compare the deterministic and probabilistic tracking methods of diffusion tensor white matter fiber tractography in patients with brain tumors. Materials and Methods: We identified 29 patients with left brain tumors ciculus was reconstructed using a deterministic Fiber Assignment by Continuous Tracking (FACT) algorithm and a probabilistic method based on an extended Monte Carlo Random Walk algorithm. Tracking was controlled using two ROIs corresponding to Broca’s and Wernicke’s areas. Tracts in tumoraffected hemispheres were examined for extension between Broca’s and Wernicke’s areas, anterior-posterior length and volume, and compared with the normal contralateral tracts. Results: Probabilistic tracts displayed more complete anterior extension to Broca’s area than did FACT tracts on the tumor-affected and normal sides (p rs.

Motor recovery via aberrant pyramidal tract in a patient with traumatic brain injury A diffusion tensor tractography study

The aberrant pyramidal tract is the collateral pathway of the pyramidal tract through the medial lemniscus in the brainstem. A 21-year-old man presented with right hemiparesis due to a traumatic intracerebral hemorrhage in the left corona radiata. His motor function recovered almost to the normal state at 10 months after onset. Through diffusion tensor tractography, the pyramidal tract in the affected （left） hemisphere showed discontinuation at the pontine level at 13 months after onset. An aberrant pyramidal tract was observed, which originated from the primary motor cortex and the supplementary motor area and descended through the corona radiata, then through the posterior limb of the internal capsule and the medial lemniscus pathway from the midbrain to the pons, finally entered into the pyramidal tract area at the pontomedullary junction, it suggests that the motor functions of the right extremities in this patient had recovered by this aberrant pyramidal tract.

Diffusion tensor imaging of neural tract injury in a patient with hypoxic-ischemic brain injury

Hypoxic-ischemic brain injury （HI-BI） is one of the most common causes of severe neurological disability, Some studies have reported diffusion tensor imaging （DTI） findings of neonatal patients with HI-BI. However, very little is known about DTI in the adult brain. The present study reports on a 15-year-old male patient with HI-BI, who exhibited no specific focal lesions on conventional brain MRI at 5 weeks. However, neural tract injuries were revealed by DTI. Seven control subjects were also evaluated. The patient suffered from cardiac arrest due to ventricular fibrillation for a period of 10 15 minutes. At 4 weeks after onset of cardiac arrest, although he was conscious and alert, he exhibited mild quadriparesis and severe cognitive dysfunction. DTI was acquired at 5 weeks after HI-BI onset. Decreased fractional anisotropy or voxel number of neural tracts suggested partial injury of the corticospinal tract, fornix, and cingulum. Disruptions of the fornix and cingulum on DTI confirmed neural tract injury. DTI could serve as a useful tool for evaluating the state of neural tracts in patients with HI-BI.

Age-related changes of lateral ventricular width and periventricular white matter in the human brain: a diffusion tensor imaging study

Introduction Aging is the accumulation of multidimensional deterioration of process- ing of biological, psychological, and social changes with expansion over time （Bowen and Atwood, 2004; Grady, 2012）. Aging-related changes are typically accompanied by decline in cognitive function, urinary control, sensory-motor function, and gait ability （Bradley et al., 1991; Bowen and Atwood, 2004; Hedden and Gabrieli, 2004; Grady, 2012; Moran et al., 2012）. In addition, a number of studies have suggested changes in brain structure with normal aging, such as decrease in cortical thickness or increase in ventricular width （Blatter et al., 1995; Tang et al., 1997; Uylings and de Brabander, 2002; Preul et al., 2006; Apostolova et al., 2012）. In particular, ventricular enlargement has been suggested as a structural biomarker for normal aging and progression of some illnesses, such as Alzheimer＇s disease （Blatter et al., 1995; Tang et al.,

Diffusion Tensor Imaging and Its Application to Traumatic Brain Injury: Basic Principles and Recent Advances

Traumatic axonal injury is a progressive process evoked by shear forces on the brain, gradually evolving from focal axonal alteration and cumulating in neural disconnection. Clinical classifiers and conventional neuroimaging are limited in traumatic axonal injury detection, outcome prediction, and treatment guidance. Diffusion weighted imaging is an advanced magnetic resonance imaging (MRI) technique that is sensitive to the movement of water molecules, providing additional information on the micro-structural arrangement of tissue. Quantitative analysis of diffusion metrics can aid in the localization of axonal injury and/or de(dys)myelination caused by trauma. Diffusion MRI tractography is an extension of diffusion weighted imaging, and can provide additional information about white matter pathways and the integrity of brain neural networks. Both techniques are able to detect the early micro-structural changes caused by Traumatic Brain Injury (TBI), and can be used to increase understanding of the mechanisms of brain plasticity in recovery after brain injury and possibly optimize treatment planning of patients with Traumatic Brain Injury. This review focuses on the theoretical basis and applied advanced techniques of diffusion weighted imaging, their limitations and applications, and future directions in the application to TBI.

Preoperative and Postoperative Diffusion Tensor Imaging in Patients with Extra-Axial Lesions at the Frontal or Temporal Regions of the Brain and Their Correlations with Neuropsychological Outcomes

The underlying changes in the neuronal connectivity adjacent to brain tumours cannot always be depicted by conventional MR imaging. The hypothesis of this study was that preoperative neuropsychological deficits were associated with impairment of diffusivity in association fibre bundles. Hence, we investigated the potential of combined diffusion tensor imaging (DTI) fibre tracking and fractional anisotropy (FA) values of the fibres to determine changes in association fibres and their correlation to neuropsychological scores. Our study consisted of eighteen patients with extra-axial brain tumours in areas adjacent to the frontal and temporal lobes. They were assessed pre- and postoperatively with DTI and neuropsychological assessments. MR examinations were performed on a 3T-scanner. FA values were calculated for the uncinate fasciculus, arcuate fasciculus, superior fronto-occipital fasciculus, inferior fronto-occipital fasciculus and corticospinal tracts ipsilateral and contralateral to the tumor. These values were compared with neuropsychological scores for language, memory and attention. The analysis revealed marked differences in pre- and post-excision of the tumor in both FA values and neuropsychological scores. Quantitative DTI was able to show significant differences in diffusivity of the association fibres before and after the surgery (P < 0.05). The additional use of DTI-fibre integrity and neuropsychological tests may aid in prognostication and decision making prior to surgery.

Photosensitivity detection using diffusion tensor imaging in a traumatic brain injury patient

The present study examined a patient with traumatic brain injury who exhibited visual photosensitivity and axonal iniury of the left optic radiation, which was detected by diftusion tensor imaging. The patient was a 41-year-old man. He began to complain of photosensitivity at 4 months after head trauma. Ophthalmic evaluation, including visual-evoked potential and conventional brain magnetic resonance imaging, did not reveal a pathologic basis for photosensitivity. Axonal injury in the left optic radiation was detected via diffusion tensor imaging at 36 months after head trauma. The lesion was almost recovered at 76 months. However, photosensitivity continued. Therefore, the photosensitivity was considered to be a result of axonal injury to the left optic radiation, which could be a symptom of maladaptive plasticity that occurs during recovery of axonal injury of the left optic radiation.

Weak phonation due to unknown injury of the corticobulbar tract in a patient with mild traumatic brain injury: a diffusion tensor tractography study

In this study,we report on a patient who showed weak phonation following mild traumatic brain injury（TBI）,which was demonstrated by diffusion tensor tractography（DTT）.

Appearance of a neural bypass between injured cingulum and brainstem cholinergic nuclei of a patient with traumatic brain injury on follow-up diffusion tensor tractography images

The human brain is known to contain a maximum of eight cholinergic nuclei： the basal forebrain region： the medial septal nucleus （Ch 1）, the vertical nucleus of the diagonal band （Ch 2）, the horizontal limb of the diago- nal band （Ch 3）, and the nucleus basalis of Meynert （Ch 4）; the brainstem： the pedunculopontine nucleus （Ch 5）, the laterodorsal tegmental nucleus （Ch 6）, and the para- bigeminal nucleus （Ch 8）; and the thalamus： the medial habenular nucleus （Ch 7） （Nieuwenhuys et al., 2008; Naidich and Duvernoy, 2009）. The cingulum is the neu- ral tract extending from the orbitofrontal cortex to the medial temporal lobe （Mufson and Pandya, 1984）. The cingulum plays an important role in memory because it is a passage of the medial cholinergic pathway, which pro- vides cholinergic innervations to the cerebral cortex after originating from Ch 1 and Ch 2 as well as Ch 4 （mainly） （Selden et al., 1998; Nieuwenhuys et al., 2008; Hong and lang, 2010）.

Characteristics of diffusion-tensor imaging for healthy adult rhesus monkey brains

Diffusion-tensor imaging can be used to observe the microstructure of brain tissue. Fractional ani- sotropy reflects the integrity of white matter fibers. Fractional anisotropy of a young adult brain is low in gray matter, high in white matter, and highest in the splenium of the corpus callosum. Thus, we selected the anterior and posterior limbs of the internal capsule, head of the caudate nucleus, semioval center, thalamus, and corpus callosum （splenium and genu） as regions of interest when using diffusion-tensor imaging to observe fractional anisotropy of major white matter fiber tracts and the deep gray matter of healthy rhesus monkeys aged 4-8 years. Results showed no laterality dif- ferences in fractional anisotropy values. Fractional anisotropy values were low in the head of cau- date nucleus and thalamus in gray matter. Fractional anisotropy values were highest in the sple- nium of corpus callosum in the white matter, followed by genu of the corpus callosum and the pos- terior limb of the internal capsule. Fractional anisotropy values were lowest in the semioval center and posterior limb of internal capsule. These results suggest that fractional anisotropy values in major white matter fibers and the deep gray matter of 4-8-year-old rhesus monkeys are similar to those of healthy young people.

Diffusion tensor magnetic resonance imaging in brain white matter diseases

Objective To evaluate the usefulness of diffusion tensor MR imaging in brain white matter diseases. Methods A combined conventional and diffusion tensor MRI were obtained from 10 multiple sclerosis ,10 multiple lacunar infarction,3 cysticercosis,1 angiitis ,1 morphinist and 10 healthy control volunteers. After obtaining mean diffusivity (D) and fractional anisotropy images and image coregistration, the correlations of the lesions and the white matter pathways were investigated. D and AI values were measured form four big lesions which can be seen in T2WI and compared to contralateral white matter. Also D and AI value of four different anatomic locations of normal appearing white matter regions were measured in all patients and controls. Results Whereas the lesions of infarction, cysticercosis and angiitis were in and outside the white matter pathways, all plaques of multiple sclerosis were inside the whit matter pathways. The brain white matter lesions by 1 morphinist were beside the lateral ventricle with big patchy appearance, which was partly inside white matter. For MS, D value was higher in lesions than control white matter. But for other diseases, D value could be seen higher or lower compared to healthy side. AI values were lower in all lesions. D value was higher and AI was lower in normal appearing brain white matter when comparing MS to other cases or healthy control volunteers. Conclusion Diffusion tensor MR images can determine the correlations of the lesions and brain white matter pathways. The changes of D and AI values can improve specificity in differential diagnoses though quantitatively analyzing the tissue damage in lesions and normal appearing brain white matter.

Diffusion tensor imaging assesses white matter injury in neonates with hypoxic-ischemic encephalopathy

With improvements in care of at-risk neonates, more and more children survive. This makes it increasingly important to assess, soon after birth, the prognosis of children with hypoxic-ischemic encephalopathy. Computed tomography, ultrasound, and conventional magnetic resonance imaging are helpful to diagnose brain injury, but cannot quantify white matter damage. In this study, ten full-term infants without brain injury and twenty-two full-term neonates with hypoxic-ischemic encephalopathy （14 moderate cases and 8 severe cases） underwent diffusion tensor imaging to assess its feasibility in evaluating white matter damage in this condition. Results demonstrated that fractional anisotropy, voxel volume, and number of fiber bundles were different in some brain areas between infants with brain injury and those without brain injury. The correlation between fractional anisotropy values and neonatal behavioral neurological assessment scores was closest in the posterior limbs of the internal capsule. We conclude that diffusion tensor imaging can quantify white matter injury in neonates with hypoxic-ischemic encephalopathy.

MRS and diffusion tensor image in mild traumatic brain injuries

Objective:To analyze characters of magnetic resonance spectroscopy(MRS) and diffusion tensor imaging(DTI) in the diagnosis of mild trauma brain injuries(MTBI) in frontal lobe and to compare with conventional magnetic resonance imaging(MRI).Methods:A total of 21 patients were selected,who all aged 12-51 years old and had injury within 24 hours.Computer tomography (CT) and the Glasgow Coma Scale were used to evaluate the degree of injury.All patients were diagnosed as MTBI,and 19 had conventional MRI,MRS and DTI.The major parameters of MRS were Probe-P sequence,TE= 144 or 35 ms,and both single voxel spectrum and chemical shift imging were included.The major parameters of DTI were diffusion directions =15,b value = 1000 s/mm^2. Frational anisotropic(FA) map and average ADC map were obtained to evaluate DTI result. Positive deletion ratio was observed and the imaging changes were compared between injured side and normal side.Results:All 21 patients had CT scan and Glasgow scale.A total of 19 patients had conventional MRI.DTI and MRS.Results of CT and conventional MRI showed no significant abnormality in lobe,and Glasgow scale showed mild type.MRS result showed significant decrease in N-acetyl aspartate(NAA) and NAA/creatine(Cr) in 13 cases(68.4%) (P【0.001),and increase in lactic acid(Lac) in 7 cases(36.8%).FA mapping of the frontal lobe displayed significant changes in 7 cases(36.8%),with 5 out of the 7 cases having increase in FA value.And there was no significant difference in average ADC.Conclusions:MRS and DTI might be more sensible than other methods,such as CT and conventional MRI in diagnosis of MTBI.The particular changes were reduced NAA and increased Lac for MRS.and increased FA values for DTI.