Assessment of peripheral neuropathy in type 2 diabetes by diffusion tensor imaging

To determine the diagnostic accuracy and interobserver performance of diffusion tensor imaging (DTI) in diabetic peripheral neuropathy (DPN) and detect correlations with electrophysiology. Twelve healthy volunteers (controls) and ten DPN patients were enrolled to undergo MR examinations. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of tibial nerve (TN) and common peroneal nerve (CPN) were measured. Unpaired t test and Levene tests were performed to assess differences between the two groups. Receiver operating characteristic (ROC) analysis was performed for FA and ADC values. Pearson correlation coefficient was used to assess the correlation between DTI and electrophysiology parameters in the patient group. The FA values of TN and CPN in the DPN group were significantly lower and ADC were higher than the control group (p < 0.05). Interobserver agreement was excellent. FA positively correlated and ADC negatively correlated with motor nerve conduction velocity (MCV) (p < 0.05). There were no significant differences between motor nerve conduction amplitude and DTI parameters (p > 0.05). Moderate diagnostic accuracy of DTI was seen in the diagnosis of DPN. DTI demonstrates moderate diagnostic accuracy and excellent interobserver performance in the detection of DPN involving the TN and CPN. There is moderate correlation with MCV. • FA values of TN and CPN are significantly lower in DPN. • ADC values of TN and CPN are significantly higher in DPN. • DTI demonstrates moderate diagnostic accuracy in detection of DPN. • There is excellent interobserver performance in DTI measurements. • Moderate correlation is seen between DTI parameters and MCV.

The purpose of this study is to investigate the correlation of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values with fatty infiltration in the thigh muscles of patients with Duchenne muscular dystrophy (DMD) using diffusion-tensor imaging (DTI). Twenty-one boys with DMD were recruited. The grade of fatty infiltration and the ADC and FA values of four thigh muscles (rectus femoris, semitendinosus, sartorius, and gracilis) were measured, and the FA and ADC values were compared with the grade of fatty infiltration. Twenty age-matched healthy boys were enrolled as the control group. The differences in the ADC and FA values of the thigh muscles between patients with DMD and the control group were compared. The patients with DMD showed lower FA values and higher ADC values in all measured muscles when compared with the control group. The FA and ADC values were correlated with the grade of fatty infiltration. For the rectus femoris muscle, r = -0.753 and p = 0.007 for FA, and r = 0.685 and p = 0.001 for ADC. For the semitendinosus muscle, r = -0.621 and p = 0.041 for FA, and r = 0.705 and p = 0.021 for ADC. For the sartorius muscle, r = -0.662 and p = 0.027 for FA, and r = 0.701 and p = 0.017 for ADC. For the gracilis muscle, r = -0.618 and p = 0.043 for FA, and r = 0.695 and p = 0.022 for ADC. Damage to the thigh muscles in patients with DMD can be detected by ADC and FA values using DTI. DTI can be used to assess the severity of the disease.

To evaluate cyclic changes of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of normal uterus in different age groups during the menstrual cycle, and the correlation with serum female hormone levels. 29 normal volunteers accepted diffusion tensor imaging of the uterus on menstrual phase (MP), follicular phase (FP), ovulatory phase (OP) and luteal phase. FA and ADC values of different uterine layers on midsagittal images were measured. Differences between two age groups during the menstrual cycle were evaluated using liner mixed models and one-way analysis of variance. Pearson correlation analysis compared variation of FA and ADC values with serum female hormone levels measured in MP. During menstrual cycle, endometrial FA values declined, whereas ADC values increased with significant differences (p < 0.05). Serum oestradiol (E) levels correlated moderately with variations of FA values between MP-FP (p = 0.045; r = 0.389) and MP-OP (p = 0.008; r = 0.511). FA and ADC values of junctional zones showed no significant difference (p > 0.05) as well as FA values of myometrium (p = 0.0961), while ADC values of myometrium showed significant increase from menstrual phase to luteal phase (p < 0.05). FA and ADC values of uterine three zonal structures showed significant differences (p < 0.05) at each phase during the menstrual cycle. No significant difference of FA and ADC values was found between age groups (p > 0.05). Dynamic changes of uterine FA and ADC values were observed during menstrual cycle. Variation of FA values between MP-FP, MP-OP correlated moderately with serum E levels. No publications on the relationship between FA and ADC values and the female hormone levels were found; our study prospectively investigated the cyclic changes of FA and ADC values of the normal uterus and the correlation with the basic serum female hormone levels in MP.

To determine whether there is adifference in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values in white matter pathways in the subacute period after COVID-19 infection and to evaluate the correlation between diffusion tensor imaging (DTI) metrics and laboratory findings. The study included 64 healthy controls and 91patients. Patients were classified as group1 (all patients, n = 91), group2 (outpatients, n = 58), or group3 (inpatients, n = 33). The ADC and FA values were calculated from 10distinct neuroanatomic localizations; DTI values were compared between groups. Decreased FA values in the cingulum, corpus callosum splenium and genu (CCS-CCG), forceps major, inferior fronto-occipital fasciculus (IFOF), and middle cerebellar peduncle (MCP) observed in group1 compared with the control group. Group1 showed elevated ADC values in CCG. Lower FA and higher ADC values in CCG were shown in group3. The FA values for CCS, IFOF, and MCP in group3 were lower than those in the control group. Group3 had the highest ADC values in the CCS. Additionally, the FA values of the CCG were lower in group3 than in group2. Oxygen saturation levels and FA values in the CCG and SFOF exhibited apositive correlation. We speculate that DTI changes in white matter pathways may be associated with axonal damage and demyelination due to impaired white matter integrity following COVID-19 infection during the subacute period. Our study showed with DTI findings that there is microstructural damage in white matter pathways in the subacute period of COVID-19 infection and that this damage is related to oxygen saturation levels. Many studies in the literature show that microstructural damage in white matter pathways can lead to clinical neurocognitive dysfunction. We suggest that these cases require more comprehensive studies investigating whether chronic white matter damage is reversible and examining its relationship with neurocognitive dysfunctions in the future. Neurological involvement is not rare in COVID-19 infection. We examined various white matter pathways with DTI during the subacute period of COVID-19 infection. We showed changes in DTI parameters indicating adecrease in white matter integrity and microstructural damage in the subacute period follow-up of cases with COVID-19. We found that there was apositive correlation between oxygen saturation levels and decreased FA values in white matter tracts.

[This corrects the article DOI: 10.1371/journal.pone.0160115.].

ObjectivesTo evaluate the feasibility of differentiating between acute pancreatitis (AP) and healthy pancreas using diffusion tensor imaging (DTI) and correlate apparent diffusion coefficient (ADC) /fractional anisotropy (FA) values with the severity of AP.Material and Methods66 patients diagnosed with AP and 20 normal controls (NC) underwent DTI sequences and routine pancreatic MR sequences on a 3.0T MRI scanner. Average ADC and FA values of the pancreatic were measured. Differences of FA and ADC values between the AP group and the NC group with AP and healthy pancreas were compared by two-sample independent t-test. The severity of AP on MRI was classified into subgroups using MR severity index (MRSI), where the mean FA and ADC values were calculated. Relationship among the FA values, ADC values and MRSI were analyzed using Spearman's rank correlation coefficients.ResultsThe pancreatic mean ADC value in the AP group (1.68 ± 0.45×10−3mm2/s) was significantly lower than in the NC group (2.09 ± 0.55×10−3mm2/s) (P = 0.02); the same as mean FA value (0.39 ± 0.23 vs 0.54 ± 0.12, P = 0.00). In the subgroup analysis, the pancreatic ADC and FA value of edema AP patients was significantly higher than necrosis AP patients with P = 0.000 and P = 0.001respectively. In addition, as severity of pancreatitis increased according to MRSI, lower pancreatic ADC (r = -0.635) and FA value (r = -0.654) were noted.ConclusionBoth FA and ADC value from DTI can be used to differentiate AP patients from NC. Both ADC and FA value of pancreas have a negative correlation with the severity of AP.

Objective: To determine whether apparent diffusion coefficient (ADC) values and fractional anisotropy (FA) values can detect early pathological involvement in multiple system atrophy (MSA), and be used to differentiate MSA-P...

The development of a noninvasive, objective, and accurate method to assess peripheral nerve disorders in Guillain-Barre syndrome (GBS) is of clinical significance. Diffusion tensor imaging (DTI) has been used to evaluate some peripheral nerve disorders. To investigate the feasibility of DTI in evaluating the peripheral nerve disorders in patients with GBS. Case control. Twenty GBS patients and 16 healthy volunteers. 3.0T, T1 WI-SE, T2 WI-SPAIR, DTI; electrophysiology. MRI data were analyzed by two radiologists blindly and independently. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusion coefficient (AD), and radial diffusion coefficient (RD) values of tibial nerve (TN) and common peroneal nerve (CPN) were recorded. Motor nerve conduction velocity (MCV) and motor nerve conduction amplitude of TN and CPN were recorded. Intraclass correlation coefficient (ICC), t-test, receiver-operating characteristic (ROC), and area under the curve (AUC) analysis, Pearson correlation coefficient. The FA and AD values of TN and CPN in the GBS group were significantly lower and the ADC and RD values were higher than those in the controls (P <0.05). The AUC of the FA values (0.970 for TN and 0.927 for CPN) were higher than that of the ADC, AD, and RD values. FA and AD values were positively correlated and ADC, RD values were negatively correlated with MCV and motor nerve conduction amplitude, respectively (P <0.05). The correlations between FA value and electrophysiology parameters were the highest. DTI quantitative parameters could evaluate the disorders of peripheral nerves in patients with GBS. A moderate correlation was observed between DTI and electrophysiology parameters. 3 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2019;49:1356-1364.

Objective To study the vascular compression on the ponline cistern of the trigeminal with magnetic resonance diffusion tensor imaging (DTI) and explore the clinical application value of DTI.Methods Sixty patients who were conformed by operation as having trigeminal neuralgia (TN) caused by responsible vascular compression (TN group) and 50 healthy volunteers (control group) were performed conventional MRI and horizontal DTI to measure the apparent diffusion coefficient (ADC)value and fractional anisotropy (FA) value. Results The ADC value and FA value of trigeminal nerve in control group were (1.76±0.98)×10-3 mm2/s, and (0.40±18), respectively, no significant differences of the ADC value and FA value between the left and right trigeminal nerves were found (P>0.05). The ADC and FA values of the trigeminal nerve among the controls, patients with mild or severe compression and the patients with compression combined with neuratrophia were statistically difrerent(P<0.05). The ADC value in the oppression region was increased in 28 patients and unchanged in 4; the average ADC value in the NT group was significantly higher than that in the control group. FA value in the oppression region decreased in 15 patients, unchanged in11 and increased in 5; the average FA value in the NT group was lower than that in the control group. Conclusion DTI has its value in determining the vascular compression of the trigeminal nerve; the greater the degree of trigeminal nerve compression is, the higher the ADC value and the lower the FA value are. Key words: Trigeminal neuralgia; Vascular compression; Magnetic resonance imaging; Diffusion tensor imaging

Background: A disturbance in the level of consciousness is a classical clinical sign of several seizure types. Recent studies have shown that altered states of consciousness in seizures are associated with structural and functional changes of several brain regions. Prominent among these are the thalamus, the brain stem and the default mode network, which is part of the consciousness system. Our study used diffusion tensor imaging (DTI) to evaluate these brain regions in patients with three different types of epilepsies that are associated with altered consciousness: complex partial seizures (CPS), primary generalized tonic–clonic seizures (PGTCS) or secondary generalized tonic–clonic seizures (SGTCS). Additionally, this study further explores the probable mechanisms underlying impairment of consciousness in seizures. Materials and methods: Conventional MRI and DTI scanning were performed in 51 patients with epilepsy and 51 healthy volunteers. The epilepsy group was in turn subdivided into three subgroups: CPS, PGTCS or SGTCS. Each subgroup comprised 17 patients. Each subject involved in the study underwent a DTI evaluation of the brain to measure the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of nine regions of interest: the postero-superior portion of midbrain, the bilateral dorsal thalamus, the bilateral precuneus/posterior cingulate, the bilateral medial pre-frontal gyri and the bilateral supramarginalgyri. The statistical significance of the measured ADC and FA values between the experimental and control groups was analysed using the paired t-test, and one-way analysis of variance was performed for a comparative analysis between the three subgroups. Results: Statistically significantly higher ADC values ( p < 0.01) were observed in the bilateral dorsal thalamus and postero-superior aspect of the midbrain in the three patient subgroups than in the control group. There were no significant changes in the ADC values ( p > 0.05) in the bilateral precuneus/posterior cingulate, bilateral medial pre-frontal gyri or bilateral supramarginalgyri in the experimental group. Among the three patient subgroups and the ADC values of corresponding brain regions, there were no statistically significant changes. Statistically significantly lower FA values ( p < 0.05) were observed in the bilateral dorsal thalamus of the patients in the three subgroups than in the control group. Significantly lowered FA values from the postero-superior aspect of the mid brain ( p < 0.01) were observed in patients with PGTCS compared with the control group. There were no significant changes in the FA values ( p > 0.05) from the bilateral precuneus/posterior cingulate, bilateral medial frontal gyri or bilateral supramarginalgyri in the experimental group. Among the three patient subgroups and the FA values of the corresponding brain regions, there were no statistically significant changes. Conclusion: In epileptic patients with CPS, PGTCS or SGTCS, there seems to be a long-lasting neuronal dysfunction of the bilateral dorsal thalamus and postero-superior aspect of the midbrain. The thalamus and upper brain stem are likely to play a key role in epileptic patients with impaired consciousness.

The microstructure of the spinal cord in syringomyelia has not been well studied. The aim of this study was to evaluate the microstructure of the cervical cord in patients with syringomyelia using diffusion tensor imaging (DTI) and to investigate the association between DTI parameters and the size of the syrinx cavity. Thirty patients with syringomyelia and 11 age-matched controls were included in this study. DTI and T1/T2-weighted MRI were used to estimate spinal microstructure. The patients were divided into a clinical symptom group (group A) and a non-clinical symptom group (group B) according to ASIA assessments. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values (mm2/s) were measured and compared between patients and controls. Correlation between FA/ADC and the size of the syrinx cavity was examined with a bivariate analysis. FA values were lower (P < 0.000) and ADC values were higher (P < 0.000) compared to the controls at the level of all syrinxes examined in patients with syringomyelia; both FA values and ADC values reached normal values either above or below the syrinx levels (all P > 0.05). FA values and ADC values at all cervical levels were not significantly different either in controls or outside of the syrinx (all P > 0.05). FA values of group A was significantly lower than those of group B (P < 0.000). There was a negative association between FA values and the size of syrinx cavity, and a positive association between ADC values and the size of syrinx cavity (FA: P < 0.05, ADC: P < 0.05). The microstructure of the cervical spinal cord is different across all patients with syringomyelia. DTI is a promising tool for estimating quantitative pathological characteristics that are not visible with general MRI.

Objective: To measure diffusion tensor imaging (DTI) parameters in healthy adults and analyze the distribution characteristics and influencing factors. Methods: In this case-series study, high resolution diffusion tensor imaging was performed on the anterior visual pathway in 38 healthy adults at the physical examination center of Fuzhou General Hospital from November 2015 to May 2016 using 3.0T magnetic resonance imaging. The fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were measured on the anterior visual pathway, including the bilateral optic nerve center, midpoint of chiasma, and the midpoint of optic tract. The anterior visual pathway fiber bundle was reconstructed by diffusion tensor tracking (DTT) to observe the morphology of the anterior optic fiber bundle. Pearson correlation, independent samples t-test, and one-way analysis of variance were used to analyze the data. Results: The structure of the DTI sequence diagram of FA, FA color encoding, and ADC can distinguish the anterior visual pathway. DTT can be used to track with 3D effects the white matter fiber bundle structure of optic chiasma. The FA and ADC values of the midpoint of optic chiasma were 0.491±0.075, and 1.267±0.204×10-3/mm2. There was a significant negative correlation between FA and ADC (r=-0.642, P<0.001). FA and ADC values were independent of gender and age. Differences between FA and ADC in optic nerve, optic tract, or optic chiasma were significant (F=11.575, P<0.001; F=5.024, P<0.001). The FA value was the smallest (P<0.001) in the optic chiasma, and the ADC value was the largest at the same location (P<0.001). Conclusions: High resolution DTI parameters FA and ADC are sensitive and reliable in the anterior visual pathway of healthy adults. The high resolution DTI technique can satisfactorily display small deformations of the anterior visual pathway fiber bundle structure. Attention should be paid to the influence of different positions of the anterior visual pathway in quantitative analyses. Key words: anterior visual pathway; magnetic resonance spectroscopy; diffusion tensor imaging; diffusion tensor tracking; adults

Objective To survey the apparent diffusion coefficient (ADC) value and fractional anisotropy (FA) value ofpontine cistern section of the trigeminal nerve, and understand the characteristics of various parameters of trigeminal nerve pontine cistern section. Methods The distances from pontine cistern section of the trifacial nerve to 0, 3, 6 and 9 mm of brain stem in 50 healthy volunteers were recorded, and fusion images of magnetic resonance diffusion tensor imaging (DTI) with B-TFE or THRIVE were achieved to improve the spatial resolution of the pontine cistern section of the trifacial nerve; their ADC value and FA value were recorded, separately. Tracing image formation was noted in the pontine cistern section of the trigeminal or trifacial nerve. Results The ADC and FA results of the left side and right flank of pontine cistern section of the trifacial nerve in these healthy volunteers were not statistically different (P＜0.05). The closer to the brain stem, the more asymmetrical tendency of distance from pontine cistern section of the trifacial nerve to 0, 3, 6 and 9 mm of brain stem between both sides. DTI indicated that the ADC values between each 2 distances from pontine cistern section of the trifacial nerve to 0, 3, 6 and 9 mum of brain stem between both sides were significantly different: the ADC values increased along with the distance elevating gradually, but rotated suddenly at the line of 6-9 mm. The FA value increased in 0-6 mm along with the distance reducing gradually, and the neighboring 2 distances had remarkably statistical difference, but the FA value no longer obviously changed from the line of 6-9 mm. Conclusion DTI can distinguish the two-sided trigeminal nerve brain pond section clearly, and may realize each item of DTI. Regular changes are noted in FA and ADC values along with the different distances from pontine cistern section of the trifacial nerve to 0, 3, 6 and 9 mm of brain stem,indicating that DTI enjoys perspective in being clear about the discrimination of cranial nerve CNS section, the change-over portion and the PNS section, and in detecting the cranial nerve vascular compression. Key words: Diffusion tensor imaging; Apparent diffusion coefficient; Fractional Anisotrop

The aim of this study is to evaluate if diffusion tensor imaging (DTI) can distinguish the disease process of radiation-induced brain injury when combined with apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values. Twenty-one rabbits received irradiation of 100 Gy in the right brain hemisphere. Twelve rabbits were screened with magnetic resonance imaging (MRI) and DTI before radiation, and imaged at every week until week 9 following radiation. The rabbits that had MRI were euthanized at week 9 for histologic evaluation, while other nine rabbits without MRI were randomly killed for histologic evaluation at weeks 2, 4 and 6, respectively. From the DTI, the ADC and FA values were measured, and rADC and rFA were calculated. After radiation, the trend of the ADC value can be divided into three stages. In the first stage, the ADC value of the target tissues gradually decreased. In the second stage, the ADC value of white matter in the target tissues showed a recovery trend, back to the initial level similar to that in contralateral. In the third stage, the ADC value of white matter in the target tissue continues to increase over the ADC value of baseline and contralateral white matter. The FA value of radiation-targeted area showed continuous decreasing tendency. Pathological evaluation showed the different features in three stages. DTI can distinguish the different disease stages when combined with the ADC and FA values.

Study DesignRetrospective observational study.PurposeTo examine fractional anisotropy (FA) values and apparent diffusion coefficient (ADC) values of damaged nerves to discriminate between lumbar intraspinal stenosis (IS) and foraminal stenosis (FS) using diffusion tensor imaging (DTI)Overview of LiteratureIt is important in the selection of surgical procedure to discriminate between lumbar IS and FS, but such discrimination is difficult.MethodsThere were 9 cases of IS, 7 cases of FS, and 5 healthy controls. The regions of interest were established in the lumbar intraspinal zone (Iz), nerve root (N), and extraforaminal zone (Ez). The FA and ADC values were measured on the affected and unaffected sides of the nerves. The FA ratio and the ADC ratio were calculated as the affected side/unaffected side ×100 (%).ResultsIn the Ez, the FA value was significantly lower in FS than in IS (p<0.01). FA ratio was significantly lower in FS than in IS for the Ez (p<0.01). In the Iz, the ADC value was significantly higher in IS than FS (p<0.01). ADC ratio was significantly higher in FS than in IS for the N and Ez (p<0.05). For the Ez, receiver operating characteristic analysis of parameters revealed that the FA values showed a higher accuracy for the diagnosis of FS than the ADC values, and the FA value cut-off value was 0.42 (sensitivity: 85.7%, false positive: 11.1%) and the FA ratio cut-off value was 83.9% (sensitivity: 85.7%, false positive: 22.2%).ConclusionsThe low FA value in the extraforaminal zone suggests the presence of foraminal stenosis. When the FA value and FA ratio cut-off value were established as 0.42 and 83.9%, respectively, the accuracy was high for the diagnosis of foraminal stenosis. It may be possible to use DTI parameters to help in the discrimination between IS and FS.