Increased muscle fiber fractional anisotropy value using diffusion tensor imaging after compression without fiber injury

2021 ◽  
pp. 028418512110582
Author(s):  
Takumi Yokohama ◽  
Motoyuki Iwasaki ◽  
Daisuke Oura ◽  
Sho Furuya ◽  
Yoshimasa Niiya

Background Recent studies have indicated that injuries such as muscle tears modify the microstructural integrity of muscle, leading to substantial alterations in measured diffusion parameters. Therefore, the fractional anisotropy (FA) value decreases. However, we hypothesized that soft tissue, such as muscle tissue, undergoes reversible changes under conditions of compression without fiber injury. Purpose To evaluate the FA change due to compression in muscle tissue without fiber injury. Material and Methods Diffusion tensor imaging (DTI) was performed on both feet of 10 healthy volunteers (mean age = 35.0 ± 10.39 years; age range = 23–52 years) using a 3.0-T magnetic resonance imaging (MRI) scanner with an eight-channel phased array knee coil. An MRI-compatible sphygmomanometer was applied to the individuals’ lower legs and individuals were placed in a compressed state. Then, rest intervals of 5 min were set in re-rest state after compression. The FA value, apparent diffusion coefficient (ADC), and eigenvalues (λ1, λ2, λ3) of the gastrocnemius and soleus muscle were measured at each state. Results The mean FA values increased in all muscles in a compressed state, while the mean λ3 decreased. In all muscles, significant differences were found between the rest and compressed states in terms of mean FA and λ3 ( P < 0.0001). Conclusion We confirmed the reversibility of the DTI metrics, which suggests that there was no muscle injury during this study. In cases of compression without fiber injury, the FA value increases, because fibers are strongly aligned in the longitudinal direction.

2014 ◽  
Author(s):  
Δήμητρα Σαλή

Σκοπός: Η ήπια γνωσιακή διαταραχή (ΗΓΔ) θεωρείται πρόδρομο στάδιο της άνοιας. Ο αμνησικός τύπος της ΗΓΔ του ενός τομέα (amnestic MCI single domain-aMCI) μεταπίπτει συνήθως σε άνοια τύπου Alzheimer. Ο αμνησικός τύπος ΗΓΔ πολλαπλών τομέων (Amnestic MCI multiple domain-mdMCI) φαίνεται να εξελίσσεται πιο γρήγορα από τον αμνησικό τύπο του ενός τομέα. Προσπαθώντας να αναγνωρίσουμε την ομάδα ασθενών υψηλού κινδύνου μελετήσαμε τις αλλαγές της λευκής ουσίας στους υποτύπους της ΗΓΔ χρησιμοποιώντας τον Τανυστή Διάχυσης (Diffusion Tensor Imaging-DTI). Επίσης, συσχετίσαμε τα ευρήματα του DTI με τα αποτελέσματα του νευροψυχολογικού ελέγχου. Μέθοδοι: Σαραντατέσσερεις ασθενείς με aMCI, δεκαεννέα με mdMCI και εικοσιπέντε υγιείς συμπεριλήφθηκαν στην μελέτη. Όλοι οι συμμετέχοντες εκτιμήθηκαν με νευροψυχολογικό έλεγχο. Όλοι εξετάσθηκαν με DTI προκειμένου να μετρηθούν η Κλασματική Ανισοτροπία (Fractional Anisotropy-FA) και ο Συντελεστής Διάχυσης (Apparent Diffusion Coefficient-ADC). Οι περιοχές που μελετήθηκαν ήταν το μεσολόβιο, το οπίσθιο προσαγώγιο, το πρόσθιο προσαγώγιο και η άνω επιμήκης δεσμίδα. Η διάχυση και η ανισοτροπία των περιοχών αυτών συσχετίσθηκαν με τις επιδόσεις στις νευροψυχολογικές δοκιμασίες που ελέγχουν την λεκτική και την ακουστική μνήμη. Αποτελέσματα: Δεν βρέθηκαν διαφορές στις μετρήσεις του DTI ανάμεσα στους δύο υποτύπους της ΗΓΔ. Η διάχυση στην ΗΓΔ ήταν αυξημένη σε σχέση με τους υγιείς στο γόνυ, στο οπίσθιο προσαγώγιο, στο αριστερό πρόσθιο προσαγώγιο και στη δεξιά άνω επιμήκη δεσμίδα. Η ανισοτροπία δεν είχε διαφορές. Η λεκτική μνήμη σχετίσθηκε με την διάχυση στο γόνυ, στο οπίσθιο προσαγώγιο, στη δεξιά άνω επιμήκη δεσμίδα και στο δεξιά πρόσθιο προσαγώγιο καθώς και με την ανισοτροπία στην αριστερή άνω επιμήκη δεσμίδα. Η οπτική μνήμη συσχετίσθηκε με την διάχυση στο γόνυ, στο οπίσθιο προσαγώγιο, στο δεξιό πρόσθιο προσαγώγιο και στην άνω επιμήκη δεσμίδα. Η υψηλότερη συσχέτιση βρέθηκε ανάμεσα στην οπτική μνήμη και στη διάχυση του δεξιού οπίσθιου προσαγωγίου(Spearman ρ=0.,45 p<0.001).Συμπέρασμα: Σύμφωνα με το DTI η διάχυση σε κάποιες περιοχές του εγκεφάλου είναι αυξημένη στην ΗΓΔ. Δεν υπάρχει διαφορά στις μετρήσεις του DTI ανάμεσα στους δύο υποτύπους της ΗΓΔ. Τα ευρήματα του DTI συσχετίζονται με τη νοητική λειτουργία.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaoyan Hu ◽  
Min Kuang ◽  
Bo Peng ◽  
Yang Yang ◽  
Wei Lin ◽  
...  

PurposeThis study aimed to investigate the value of diffusion tensor imaging to assess renal injury in a rat model of preclinical diabetic nephropathy.MethodsTwenty-eight male Sprague Dawley rats were divided into two groups: the normal control (NC) group of 10 rats and the diabetic nephropathy (DN) group of 18 rats. Eight weeks after diabetes induction by streptozotocin, 3.0-T magnetic resonance (MR) imaging (b = 0 and 600 s/mm2, 15 diffusion directions) using a 32-channel knee coil was performed. After MR imaging, we measured serum creatinine, and collected double kidney tissues for pathology. The apparent diffusion coefficients(ADC) and fractional anisotropy(FA) values of the renal cortex and medulla were calculated for all kidneys. Physiological parameters, laboratory parameters, and imaging results were compared between the two groups.ResultsAll DN group animals developed hyperglycemia, polyuria, and emaciation. Serum creatinine was not significantly different between the groups (P &gt; 0.05). Urinary albumin at 2, 4, and 8 weeks was higher in the DN group than in the NC group but &lt;20 µg/min (P &lt; 0.05). Pathologically, renal damage in the DN rats was observed. The ADC value was significantly increased in DN animals in the cortex (1.75×10-3mm2/s),medulla(1.53×10-3mm2/s)compared with NC group(cortex, 1.52×10-3mm2/s; medulla,1.35×10-3mm2/s). The FA value was significantly reduced in DN animals in the cortex (0.21),medulla(0.25)compared with NC group(cortex,0.26;medulla,0.3).ConclusionsIncreased apparent diffusion coefficients and decreased fractional anisotropy values on diffusion tensor imaging were associated with preclinical DN. Diffusion tensor imaging may be useful in early, non-invasive, quantitative detection, and therapy monitoring of DN.


2018 ◽  
Vol 31 (6) ◽  
pp. 581-586 ◽  
Author(s):  
James M Provenzale ◽  
Brian A Taylor ◽  
Elisabeth A Wilde ◽  
Michael Boss ◽  
Walter Schneider

We employed a novel diffusion tensor imaging phantom to study intra- and interscanner reproducibility on two 3T magnetic resonance (MR) scanners. Using a phantom containing thousands of hollow micron-size tubes in complex arrays, we performed two experiments using a b value of 1000 s/ms2 on two Siemens 3T Trio scanners. First, we performed 12-direction scans. Second, on one scanner, we performed two 64-direction protocols with different repetition times (TRs). We used a one-way analysis of variance to calculate differences between scanners and the Mann-Whitney U test to assess differences between 12-direction and 64-direction data. We calculated the coefficient of variation (CoV) for intrascanner and interscanner data. For 12-direction protocols, mean fractional anisotropy (FA) was 0.3003 for Scanner 1 (four scans) and 0.3094 for Scanner 2 (three scans). Lowest FA value on Scanner 1 was 2.56 standard deviations below the mean of Scanner 2. For 64-direction scans, mean FA was 0.2640 for 4000 ms TR and 0.2582 for 13,200 ms TR scans. For 12-direction scans, within-scanner CoV was 0.0326 for Scanner 1 and 0.0240 for Scanner 2; between-scanner CoV was 0.032. For 64-direction scans, CoV was 0.056 for TR 4000 ms and 0.0533 for TR 13,200 ms. The difference between median FA values of 12-direction and 64-direction scans was statistically significant ( p < 0.001). We found relatively good reproducibility on any single MR scanner. FA values from one scanner were sometimes significantly below the mean FA of another scanner, which has important implications for clinical use of DTI.


Author(s):  
Ahmed Sayed Abd El Basset ◽  
Ahmed Hesham Mohamed Saeed ◽  
Mona Hussein Tawfik ◽  
Marwa Shehata Abd El Hady

Abstract Background Conventional MR imaging is not enough for evaluation of symptomatic foraminal stenosis, because there is high incidence of false-positive results in asymptomatic elderly patients. Conventional MR cannot quantitatively assess the severity of the nerve lesion. DTI is a non-invasive way to effectively trace the nerve fiber bundle and quantitatively evaluate the nerve injury. DTI with fiber tracking may describe abnormalities beyond the resolution of conventional MR techniques. The aim of this work was to compare between the mean values of diffusion parameters such as fractional anisotropy and apparent diffusion coefficient of the compressed lumbar spinal nerve roots and of the contralateral normal nerve roots. Correlate these parameters with the severity of neurological symptoms. This is a prospective study that was conducted on 50 patients with symptomatic unilateral posterolateral lumbar disc prolapse at a university hospital. They were investigated with diffusion tensor imaging with tractography on a 1.5-T MR. The changes in the mean fractional anisotropy and apparent diffusion coefficient values of the compressed nerves and the relationship between these changes and the severity of the neurological side effects using Japanese Orthopedic Association score and visual analogue scale were investigated. Results The mean fractional anisotropy values were significantly lower (p ≤ 0.001), and mean apparent diffusion coefficient values were significantly higher (p ≤ 0.001) in compressed nerves than in contralateral intact nerves. There were strong correlations between the DTI parameters and the severity of the neurological symptoms as assessed using the Japanese Orthopedic Association score and the visual analogue scale. Conclusion In patients with lumbar disc prolapse, radicular diffusion parameters are affected in the compressed roots in comparison to the healthy roots and this affection is correlated with the degree of prolapse and with the severity of neurological symptoms. DTI with fiber tracking provide clinically relevant information and describe abnormalities beyond the resolution of conventional MR techniques.


2015 ◽  
Vol 4 (2) ◽  
pp. 204798161454679 ◽  
Author(s):  
Miina Nenonen ◽  
Ullamari Hakulinen ◽  
Antti Brander ◽  
Juha Ohman ◽  
Prasun Dastidar ◽  
...  

Background Diffusion tensor imaging (DTI) is prone to numerous systemic confounding factors that should be acknowledged to avoid false conclusions. Purpose To investigate the possible effects of age, gender, smoking, alcohol consumption, and education on cerebral DTI parameters in a generally healthy homogenous sample with no neurological or psychiatric diseases. Material and Methods Forty ( n = 40) subjects (mean age, 40.3 years; SD, 12.3) underwent brain DTI with 3 T magnetic resonance imaging (MRI). At enrolment, all the subjects were interviewed with respect to general health, education, history of smoking, and alcohol consumption. Studied DTI parameters included: (i) fractional anisotropy (FA); and (ii) apparent diffusion coefficient (ADC). Region-of-interest (ROI)-based measurements were estimated at 13 anatomical locations bilaterally on the axial images, except for the corpus callosum in which the ROIs were placed on the sagittal images. Circular ROI measurements were mainly used. Freehand ROI method was used with the forceps minor, uncinate fasciculus, and thalamus. Intra-observer variability and repeatability were assessed. Results The most consistent finding was that aging decreased FA values in the frontal brain regions. Regarding the other confounding factors, the results were discontinuous and no concrete conclusions could be drawn from these findings. In general, intra-observer repeatability of the DTI measurement was considered relatively good. Conclusion Age should be noted as considerable confounding factors in ROI-based DTI analysis. More research on the effects of gender, smoking, alcohol consumption, and education is needed.


2019 ◽  
Vol 2 (3) ◽  
pp. 107
Author(s):  
Ali Mustofa ◽  
Anggraini Dwi Sensusiati ◽  
Muhaimin Muhaimin ◽  
Sri Andreani Utomo ◽  
Risalatul Latifah

Background: Diffusion Weighted Imaging and Diffusion Tensor Imaging is an advanced technique in MRI that shows the diffusion in brain of ischemic stroke disease. Diffusion Weighted Imaging (DWI) shows the lesions without gadolinium contrast agent and produce Apparent Diffusion Coefficient values. Whereas, Diffusion Tensor Imaging (DTI) shows connectivity’s of central nervous system that cannot be seen by using conventional MRI. Diffusion Tensor Imaging produces Fractional Anisotropy values. Purpose:This study has aim to analyze the Apparent Diffusion Coefficient values and Fractional Anisotropy values in Stroke Ischemic disease. Methods: Total samples used are 14 samples, consist of 7 (50%) man and 7 (50%) woman with ischemic stroke disease. Each sample deals by Diffusion Weighted Imaging and Diffusion Tensor Imaging sequences. The Region of Interest (ROI) is placed in ischemic stroke lesions and contra lateral side of lesions. Results: The result shows that 9 samples of brain tissue lesions located in the right side and 5 samples in the left side. Right lesions have the average ADC stroke: 0.001748; normal ADC: 0.000954; FA stroke: 0.144522; and normal FA: 0.426111. While, left lesions have the average ADC strokes 0.000979; normal ADC: 0.000835; FA stroke: 0.2556; and normal FA 0.4324. Conclusion: So, the conclusion of this study is Apparent Diffusion Coefficient (ADC) values in case of ischemic stroke can decreases or increases depend on the age of stroke. While, the Fractional Anisotropy (FA) values will decrease without being affected by age of stroke.


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