Evaluation of normal cadaveric Achilles tendon and enthesis with ultrashort echo time (UTE) magnetic resonance imaging and indentation testing.

Entheses are regions where tendons and ligaments attach to bone, and are the primary target in seronegative and other diseases of the musculoskeletal (MSK) system. MRI has been widely used for visualizing features of inflammatory and degenerative MSK disease; however, normal tendons and entheses have short transverse relaxation times (T2 ), and show little or no signal with conventional clinical MRI pulse sequences, making it difficult to investigate their MR properties. In this study we examined the normal MR morphology of the cadaveric Achilles tendon and enthesis at 3 T using novel three-dimensional ultrashort echo time (3D UTE) Cones sequences, and at 11.7 T using conventional MRI sequences. We also studied the MR properties of the Achilles tendon and enthesis including T2 *, T1 , and magnetization transfer ratio (MTR). In addition, MT modeling of macromolecular proton fractions was investigated using 3D UTE Cones sequences at 3 T. Indentation testing was performed to investigate the mechanical properties of the tendons and entheses, and this was followed by histological examination. In total five specimens (<50 years) were investigated. On average, tendons and entheses respectively had T2 * values of 0.93 ± 0.48 ms and 2.77 ± 0.79 ms, T1 values of 644 ± 22 ms and 780 ± 55 ms, MTRs of 0.373 ± 0.03 and 0.244 ± 0.009 with an MT power of 1000° and frequency offset of 2 kHz, and macromolecular proton fractions of 18.0 ± 2.2% and 13.9 ± 1.9%. Compared with the tendon, the enthesis generally had a longer T2 *, a longer T1 , a lower MTR, and a lower macromolecular proton fraction as well as both a higher Young's modulus and stiffness. Results from this study are likely to provide a useful baseline for identifying deviations from the normal in seronegative arthritis and other disease of the entheses.

Effect of Long-Term Diving on the Morphology and Growth of the Distal Radial Epiphyseal Plate of Young Divers: A Magnetic Resonance Imaging Study.

OBJECTIVE: To investigate the effects of long-term diving on the morphology and growth of the distal radial epiphyseal plate in young divers. STUDY DESIGN: Cohort study. SETTING: Guangzhou Sport University. PARTICIPANTS: Thirty-eight professional divers, aged 10 to 17 years, and 25 age-matched volunteers. INTERVENTIONS: Each subject received a physical examination at the beginning of the study and underwent bilateral magnetic resonance imaging of the wrist. The divers were divided into 2 groups depending on the status of the epiphyseal plate: group A (positive distal radial epiphyseal plate injury) and group B (no positive distal radial epiphyseal plate injury). A third group, group C, consisted of the 25 volunteers. MAIN OUTCOME MEASURES: The frequency of distal radial epiphyseal plate injury and the thickness of the distal radial epiphyseal plate were analyzed across the 3 groups. RESULTS: Twenty-nine cases (29/76, 38.15%) of distal radial epiphyseal plate injury were observed in 20 divers (20/38, 52.63%). The incidence of injury to the right hand was higher than that for the left (P = 0.009). There were statistically significant differences (P = 0.000) among the 3 groups in terms of epiphyseal plate thickness; group A > group B > group C. CONCLUSIONS: Distal radial epiphyseal plate injury is common in divers, and more injuries are seen in the right hand. Moreover, growth of the radius was impaired in divers relative to controls. We consider that loading during diving may influence growth of the epiphyseal plate in either a transient or permanent manner.

Role of quantitative intravoxel incoherent motion parameters in the preoperative diagnosis of nodal metastasis in patients with rectal carcinoma.

PURPOSE: To evaluate the diagnostic value of intravoxel incoherent motion imaging (IVIM) in differentiating metastatic and nonmetastatic lymph nodes in patients with rectal carcinoma. MATERIALS AND METHODS: In all, 68 patients with histologically proven rectal carcinoma underwent an IVIM sequence (b = 0, 25, 50, 75, 100, 150, 200, 400, 600, 800, 1000, 1200, 1500, and 2000 s/mm(2) ) on a 3.0T MRI scanner. The IVIM parameters (D, D*, f, and apparent diffusion coefficient [ADC] values) in metastatic and nonmetastatic lymph nodes were measured and calculated. Receiver-operating characteristic (ROC) analyses were conducted to determine the optimal thresholds, the sensitivities, and specificities for differentiation. RESULTS: Mean D, f, and ADC values of metastatic lymph nodes were significantly greater than those of the normal lymph nodes (P < 0.01), whereas the mean D* value of metastatic lymph node was statistically lower (P = 0.03). The AUC, sensitivity, specificity, and the cutoff value, respectively, for differentiating metastatic from nonmetastatic lymph nodes for D, D*, f, and ADC were as follows: D, 0.9460, 89.25%, 91.04%, and 1.14 × 10(-3) mm(2) /s; D*, 0.6930, 64.18%, 82.80%, and 7.02 × 10(-3) mm(2) /s; f, 0.7810, 92.47%, 55.22%, and 0.27%; ADC, 0.8970, 87.10%, 88.06%, and 0.80 × 10(-3) mm(2) /s. The ROC curves demonstrated that the area under the ROC (AUC) of the D, ADC, f, and D* values successively decreased, and D had the highest AUC, with D* values being lowest. CONCLUSION: An IVIM sequence may be helpful in diagnosing metastatic lymph nodes of rectal carcinoma. Average D and ADC values are more sensitive than f and D* values in this differentiation. J. MAGN. RESON. IMAGING 2016;44:1031-1039.

[Correlation between Fractional Anisotropy and Amyotrophic Lateral Sclerosis, and Effect of Inte- grative Medical Treatment on ALS].

OBJECTIVE: To explore whether fractional anisotropy (FA) value could be taken as a quantitative indicator for tracing and reexamining amyotrophic lateral sclerosis (ALS), and to analyze the correlation between FA value and integrative medical treatment. METHODS: Totally 18 ALS patients were recruited in this study. All patients received diffusion tensor imaging (DTI) using 3. OT (Propeller HD) MRI twice. Six regions of interest (ROI) were selected to measure FA values. Survival analyses were performed in 11 cases of end point events. RESULTS: (1) Three ROI (cerebral peduncle, posterior limb of internal capsule, and corona radiata) all indicated that FA value was the highest in patients with mild health status scale of amyotrophic lateral sclerosis (ALS/HSS). (2) There was statistical difference in the means of FA values in cerebral peduncle, posterior limb of internal capsule, and corona radiata of 18 cases between initial examination and reexamination (P < 0.01). (3) Kaplan-Meier survival curve showed the survival rate of ALS patients decreased as time went by, with the median survival time of 48 months. CONCLUSIONS: FA value was inversely proportional to the severity of ALS, the more severe, the lower FA values. FA value was an objective indicator for assessing the severity of ALS. ALS is an incurable disease till now. Integrative medical treatment might become one direction for ALS patients.

Identifying the unmet needs of post-treatment colorectal cancer survivors: A critical literature review.

PURPOSE: Following treatment completion, colorectal cancer (CRC) survivors experience various unmet needs. This review aims to synthesize the unmet needs of CRC survivors after treatment and to identify demographic, disease or treatment-related, healthcare-related, and psychosocial factors correlated with unmet needs. METHOD: English or Chinese articles that focused on CRC survivors' post-treatment unmet needs were systematically searched from the five electronic databases, which included CINAHL, PubMed, Embase, PsycINFO, and the China Academic Journal Full-text Database, from the launch of databases to July 2023. The reference lists of the subsequent articles were further screened. RESULTS: 136 individual needs extracted from 50 manuscripts were classified into nine domains based on the Supportive Care Framework. The top four unmet needs identified by CRC survivors were assistance with fears of cancer recurrence, information about managing illness and side effects at home, emotional or psychological support and reassurance, and help with sexuality problems. Following surgery, CRC survivors showed strong demand in the physical, psychological, and information domains. Survivors completed treatment within 1-year had more diverse needs than those who completed 1-3 years. Unmet needs may be greater among CRC survivors who were young, female, more educated, and unmarried. Furthermore, greater unmet needs were associated with distress, anxiety, depression, and worse quality of life. CONCLUSIONS: Despite diverse needs experienced by post-treatment CRC survivors, a predominant focus on fears of cancer recurrence, information, psychological support, and sexuality needs is noted. Future studies should further explore the needs of CRC survivors after specific treatment and in different post-treatment periods.

Prospective evaluation of term neonate brain damage following preceding hypoxic sentinel events using enhanced T2* weighted angiography (eSWAN).

PURPOSE: To evaluate the brain damage of term neonates with evidence of a preceding hypoxic sentinel event using eSWAN prospectively. METHODS: The study was approved by the institutional research ethics committee. Among the neonates who were examined during the first 8 days after birth with conventional magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI) and eSWAN, 39 neonates with a preceding acute hypoxic sentinel event were divided into two groups: the hypoxic ischaemic encephalopathy (HIE) group and the high-risk group. Twenty-five neonates were normal control subjects. Conventional MRI, DWI, and T2* and R2* maps from eSWAN were assessed. T2* and R2* values from T2* and R2* maps were calculated in predefined regions in the HIE and high-risk groups and then compared with those in control subjects. RESULTS: The neonates in the HIE and high-risk groups showed a high percentage of cerebral oedema and periventricular white-matter (PWM) lesions. Cerebral oedema and haemorrhagic lesions of PWM were more highly visible on the T2* map compared with conventional MRI: cerebral oedema was illustrated as a high T2* area and haemorrhagic lesions had a significantly lower T2* on the T2* map. Lower R2* values of lentiform nuclei (LN) and a higher T2* and lower R2* of frontal white matter (FWM) were found in neonates in the HIE group relative to those of normal controls. The T2* value of LN in the high-risk group was higher than that of the normal controls. CONCLUSIONS: The T2* map from eSWAN is useful in detecting cerebral oedema and haemorrhagic lesions of PWM in neonates. The measurement of T2* and R2* values is helpful in assessing the LN and FWM damage in neonates following a hypoxic sentinel event.

Early detection of secondary damage in ipsilateral thalamus after acute infarction at unilateral corona radiata by diffusion tensor imaging and magnetic resonance spectroscopy.

BACKGROUND: Traditional magnetic resonance (MR) imaging can identify abnormal changes in ipsilateral thalamus in patients with unilateral middle cerebral artery (MCA) infarcts. However, it is difficult to demonstrate these early changes quantitatively. Diffusion tensor imaging (DTI) and proton magnetic resonance spectroscopy (MRS) are potentially sensitive and quantitative methods of detection in examining changes of tissue microstructure and metabolism. In this study, We used both DTI and MRS to examine possible secondary damage of thalamus in patients with corona radiata infarction. METHODS: Twelve patients with unilateral corona radiata infarction underwent MR imaging including DTI and MRS at one week (W1), four weeks (W4), and twelve weeks (W12) after onset of stroke. Twelve age-matched controls were imaged. Mean diffusivity (MD), fractional anisotropy (FA), N-acetylaspartate (NAA), choline(Cho), and creatine(Cr) were measured in thalami. RESULTS: T1-weighted fluid attenuation inversion recovery (FLAIR), T2-weighted, and T2-FLAIR imaging showed an infarct at unilateral corona radiate but no other lesion in each patient brain. In patients, MD was significantly increased at W12, compared to W1 and W4 (all P< 0.05). NAA was significantly decreased at W4 compared to W1, and at W12 compared to W4 (all P< 0.05) in the ipsilateral thalamus. There was no significant change in FA, Cho, or Cr in the ipsilateral thalamus from W1 to W12. Spearman's rank correlation analysis revealed a significant negative correlation between MD and the peak area of NAA, Cho, and Cr at W1, W4, and W12 and a significant positive correlation of FA with NAA at W1. CONCLUSIONS: These findings indicate that DTI and MRS can detect the early changes indicating secondary damage in the ipsilateral thalamus after unilateral corona radiata infarction. MRS may reveal the progressive course of damage in the ipsilateral thalamus over time.

A prospective study of dual-energy computed tomography for differentiating metastatic and non-metastatic lymph nodes of colorectal cancer.

BACKGROUND: Colorectal cancer (CRC) is the third most common malignancy worldwide, and lymph node metastasis is considered to be a risk factor for local recurrence and a poor prognosis in colorectal cancer. However, there remains a lack of reliable and non-invasive biomarkers to identify the lymph node status of CRC patients preoperatively. The purpose of this study was to explore the ability of dual-energy computed tomography (DECT) to differentiate metastatic from non-metastatic lymph nodes in colorectal cancer. METHODS: Seventy-one patients with primary colorectal cancer underwent contrast-enhanced dual-energy computed tomography imaging preoperatively. The colorectal specimen was scanned postoperatively, and lymph nodes were matched to the pathology report. The following dual-energy computed tomography quantitative parameters were analyzed: dual-energy curve slope value (λHU), standardized iodine concentration (n△HU), iodine water ratio (nIWR), electron density value (nρeff), and effective atom-number (nZ), based on metastatic and non-metastatic lymph node differentiation. Also, sensitivity and specificity analyses were performed using receiver operating characteristic curves. RESULTS: In all patients, one hundred and fifty lymph nodes, including 66 non-metastatic and 84 metastatic lymph nodes, were matched using the radiological-pathological correlation. Metastatic nodes had significantly greater λHU, n△HU, and nIWR values than non-metastatic nodes in both the arterial and venous phases (P<0.01). The area under curve (AUC), sensitivity, and specificity were 0.80, 80%, and 66% for λHU; 0.86, 70%, and 95% for n△HU; and 0.88, 71%, and 95% for nIWR in the arterial phase. There was no significant difference in electron density and effective Z values between metastatic and non-metastatic lymph nodes. CONCLUSIONS: DECT quantitative parameters may help differentiate between metastatic and normal lymph nodes in patients with CRC.

Gadolinium-enhanced magnetic resonance imaging of the knee: an experimental approach.

PURPOSE: The purpose of this study was to examine gadolinium-enhanced magnetic resonance imaging (MRI) for monitoring cartilage degeneration. METHODS: This is a proof-of-concept study in an animal model. Adult New Zealand rabbits were randomly stratified into five groups. Papain was injected intra-articularly in the right knee in four groups to establish the stages of cartilage degeneration. The left knee and group 5 served as controls. Bilateral MRI was performed 24 h after the initial injection of papain, and 1 week, 1 month, and 3 months following three papain injections. Injection of the contrast agent was followed by bilateral MRI examination immediately upon injection, and at 2 and 4 h post-injection. Signal intensities of articular cartilage and peripheral soft tissues were obtained before animals were sacrificed. Post-mortem bilateral cartilage specimens were studied histologically. RESULTS: Histopathology results verified the staged degeneration of papain-treated articular cartilage. Differences in cartilage signal intensity were significant for the staged model using a special three-dimensional MRI method (P < 0.05) but not using ordinary MRI. No differences were observed within or between the control groups (P > 0.05). CONCLUSIONS: Contrast-enhanced MRI examination may be a viable tool for early diagnosis of osteoarticular disease. Prospective studies are warranted to evaluate the potential for clinical application.

Progression of pathological changes in the middle cerebellar peduncle by diffusion tensor imaging correlates with lesser motor gains after pontine infarction.

BACKGROUND: Wallerian degeneration in pyramidal tract following supratentorial stroke has been detected by some studies using diffusion tensor imaging (DTI), but the Wallerian degeneration in middle cerebellar peduncle after pontine infarction and its potential clinical significance remain to be confirmed. METHODS: Seventeen patients with a recent focal pontine infarct underwent 3 DTIs at week 1 (W1), week 4 (W4), and week 12 (W12) after onset. Seventeen age-matched and gender-matched controls underwent DTI one time. Mean diffusivity and fractional anisotropy (FA) were measured in the basis pontis and bilateral middle cerebellar peduncles. Neurological deficit, motor deficit, functional independence, and limbs ataxia were assessed with the National Institutes of Health (NIH) Stroke Scale, Fugl-Meyer scale, Barthel Index, and the second part of International Cooperative Ataxia Rating Scale. RESULTS: FA values at the bilateral middle cerebellar peduncles decreased significantly from W1 to W12 progressively (P<.01). The patients improved on the NIH Stroke Scale, Fugl-Meyer scale, and Barthel Index over time (P<.01). Greater absolute value of percentage reduction of FA at the bilateral middle peduncles, however, was associated with the less absolute value of percentage reduction of the NIH Stroke Scale and less increase in the Fugl-Meyer scale, as well as greater ataxia over time. CONCLUSIONS: Wallerian degeneration in the middle cerebellar peduncle revealed by DTI may hinder the process of neurological recovery following a focal pontine infarct.

Longitudinal investigations on the anterograde and retrograde degeneration in the pyramidal tract following pontine infarction with diffusion tensor imaging.

BACKGROUND: Secondary degeneration following supratentorial stroke has been detected by some studies using diffusion tensor imaging (DTI), but the anterograde and retrograde degeneration in pyramidal tract after pontine infarction and its potential clinical significance are not well understood. METHODS: Fourteen patients with a recent pontine infarct underwent three DTIs at week 1, week 4, and week 12 after onset. Fourteen age- and gender-matched controls underwent DTI once. Mean diffusivity and fractional anisotropy (FA) were measured. Neurological deficit, motor deficit and life independence were assessed with the NIH Stroke Scale, Fugl-Meyer scale and Barthel index, respectively, 2 h before each DTI examination. RESULTS: FA values at the ipsilateral medulla and the proximal portion of the pyramidal tract, including centrum semiovale, internal capsule and cerebral peduncle, significantly decreased progressively from week 1 to week 12 (p < 0.01). The NIH Stroke Scale decreased; Fugl-Meyer scale and Barthel index increased significantly over the time points (p < 0.01). The absolute values of percent reduction of FA value at the ipsilateral medulla and the proximal portion of pyramidal tract correlated negatively with the absolute values of percent reduction of the NIH Stroke Scale and percent increase of the Fugl-Meyer scale. CONCLUSIONS: Progressive anterograde and retrograde degeneration in pyramidal tract revealed by DTI may hinder the process of neurological recovery after a pontine infarct. To confirm the clinical significance, future studies with a longer observation period and a larger sample size of patients with more homogeneous pontine infarcts are still needed.

Three-dimensional ultrashort echo time cones (3D UTE-Cones) magnetic resonance imaging of entheses and tendons.

We present three-dimensional ultrashort echo time Cones (3D-UTE-Cones) imaging as well as quantification of T2* and magnetization transfer ratio (MTR) of Achilles tendon and its enthesis of healthy volunteers and patients with psoriatic arthritis (PsA) using a 3T scanner. Quantitative T2*, T2 and magnetization transfer ratio (MTR) measurements of Achilles tendon and its enthesis were performed on healthy volunteers (n=7) and PsA patients (n=9) with 3D-UTE-Cones and clinical sequences at 3T. T2* was measured via single-component fitting of UTE images from two interleaved dual echo 3D-UTE-Cones acquisitions. MTR was measured with a dual echo 3D-UTE-Cones-MT sequence. Clinical morphological imaging and quantification of T2 with a Carr-Purcell-Meiboom-Gill (CPMG) sequence and MTR with a gradient recalled echo (GRE) sequence were also performed on each subject. T2* and MTR were analyzed for the two groups and the significance was evaluated. The 3D-UTE-Cones sequence provided high resolution imaging of entheses and tendons. Cones-T2* and Cones-MTR values were significantly higher for the PsA patients. GRE-MTR values showed no significant differences between the groups. No reliable T2 measurement could be achieved with the CPMG sequence due to insufficient signal from entheses and tendons. The 3D-UTE-Cones sequences can be used for morphological and quantitative evaluation of entheses and tendons in PsA patients.

A prospective study of secondary degeneration following subcortical infarction using diffusion tensor imaging.

BACKGROUND: Secondary degeneration of the pyramidal tract distal to the primary lesion after a stroke has been detected by some studies using diffusion tensor imaging (DTI) but its potential clinical significance and the degeneration of the fibre tract proximal to the primary lesion have received little attention. METHODS: Twelve patients underwent DTI on the 1st, 4th and 12th week following a subcortical infarct involving the posterior limb of the internal capsule, and 12 age and sex matched controls underwent DTI once. The DTI parameters mean diffusivity and fractional anisotropy (FA), and the clinical scores before DTI examination, including the National Institutes of Health Stroke Scale (NIHSS), the Fugl-Meyer (FM) scale and the Barthel index (BI), were assessed. The relations between the per cent changes in DTI parameters and clinical scores were analysed. RESULTS: From the 1st to the 12th week after stroke onset, FA values decreased (p<0.01, respectively) in the fibre tract above and below the internal capsule, and the NIHSS decreased (p<0.01) but the FM scale and BI increased (p<0.01, respectively) progressively. The per cent reductions in FA value in the fibre tract above and below the internal capsule were negatively correlated with the per cent changes in NIHSS and FM scale (p<0.05, respectively). CONCLUSIONS: Secondary degeneration of the fibre tract proximal and distal to a primary lesion can be detected by DTI clearly and quantitatively and deteriorates with time progressively, which may hamper functional recovery after a subcortical cerebral infarct.

The influences of walking, running and stair activity on knee articular cartilage: Quantitative MRI using T1 rho and T2 mapping.

OBJECTIVE: To explore the different influences of walking, running and stair activity on knee articular cartilage with T1 rho and T2 mapping sequences. MATERIALS AND METHODS: MRI (3.0-T) scans of the right knee were performed in twenty-three young healthy adults immediately after 30 minutes of rest, walking, running and stair activity respectively. Articular cartilage was quantitatively assessed based on T1 rho and T2 relaxation times. Analysis of variance for random block design data, bonferroni test and paired samples t tests were performed to estimate the different influences of physiological activities on articular cartilage. RESULTS: T1 rho and T2 values had reductions after physiological activities in all regions of articular cartilage. T1 rho and T2 values were decreased more after running than walking. T1 rho and T2 values were decreased more after stair activity than running, except for femoral cartilage. The superficial layer of patella cartilage had higher reduction rates than the deep layer. The T1 rho and T2 values of articular cartilage were reduced in the following order: patellofemoral cartilage> medial tibiofemoral cartilage> lateral tibiofemoral cartilage. Patellofemoral cartilage experienced reductions in the following order: lateral part> middle part> medial part. Tibiofemoral cartilage had reductions in the following order: posterior part> middle part> anterior part. CONCLUSIONS: T1 rho and T2 mapping sequences can quantitatively reflect the different influences of physiological activities on knee articular cartilage. Fluid shifts, collagen fiber deformation, spatial heterogeneity, inherent differences in material properties and tissue stiffness have close relationship with cartilage loading characteristics.

Mesoporous titanium dioxide nanocarrier with magnetic-targeting and high loading efficiency for dual-modal imaging and photodynamic therapy.

Photodynamic therapy (PDT), by producing reactive oxygen species (ROS), inhibits cancer cells and is an emerging and pioneering cancer therapeutic modality which can eliminate some of the drawbacks of other traditional anticancer therapies. To combine near-infrared (NIR) mediated PDT, chemotherapy and gene therapy in a synergistic manner, a novel NIR light activated photosensitizer for PDT was designed based on TiO2-coated Fe3O4 nanoparticle core/shell nanocarriers (Fe3O4@TiO2@mTiO2). The chemotherapeutic drug doxorubicin hydrochloride (DOX) was conjugated to the surface of the TiO2 mesopores through pH-reversible hydrazone bond linking and ß-catenin siRNA was loaded in the mesopores. Fe3O4@TiO2@mTiO2-DOX/siRNA delivery systems have features and functions of magnetic targeting, fluorescence imaging, MRI diagnosis, and combination therapy through the simultaneous maneuvering of a magnet and NIR-mediated PDT. In vitro, Fe3O4@TiO2@mTiO2-DOX/siRNA effectively silences ß-catenin gene, induces tumor cell apoptosis and consequently significantly enhances the cancer suppression effect of the synergistic therapeutic agent. Meanwhile, under NIR irradiation, excess ROS produced can further trigger tumor cell apoptosis. In vivo investigation confirmed that Fe3O4@TiO2@mTiO2-DOX/siRNA exhibited high tumor targeted specificity through MRI and fluorescence imaging, and optimal anti-tumor efficacy. The results verified its significant therapeutic effects on tumors by combination therapy consisting of magnetic targeting and NIR-mediated PDT.

Diffusion Weighted Imaging, Diffusion Tensor Imaging, and T2* Mapping of Lumbar Intervertebral Disc in Young Healthy Adults.

BACKGROUND: Although conventional magnetic resonance imaging (MRI) could provide excellent detection of morphological changes in the diagnosis of lumbar disc degeneration (LDD), it has some difficulties in discriminating minimal changes associated with early LDD before morphological or clinical alterations. Therefore, newer MRI techniques have emerged for investigation of early LDD. OBJECTIVES: The aim of this study was to use diffusion weighted imaging (DWI), diffusion Tensor Imaging (DTI) and T2* mapping to detect lumbar discs in healthy young adults, to evaluate if they could depict the microstructural changes of early LDD. PATIENTS AND METHODS: Apparent diffusion coefficient (ADC), fractional anisotropy (FA), and T2* images of the lumbar discs were obtained for 40 asymptomatic young subjects (19 males and 21 females; mean age of 24.3 years), using DWI, DTI and T2* mapping with a 1.5-T MRI scanner. ADC, FA, and T2* values were measured to compare five regions of interest (ROI) selected in each nucleus pulposus (NP) of the images. RESULTS: The ADC, FA, and T2* values were different (P < 0.05) among different ROIs within the same disc or among corresponding ROIs in different level discs. While the average values of ADC increased regularly with the lowering of the anatomical location (P < 0.05), the average FA and T2* values also associated with the anatomic locations, showed an increase in L4-L5 and L5-S1 discs (P < 0.05). CONCLUSION: ADC, FA, and T2* values may quantitatively reflect the microstructural characteristics of NP, therefore they could be used to detect the minimal changes of early LDD.

Quantitative assessment of amyotrophic lateral sclerosis with diffusion tensor imaging in 3.0T magnetic resonance.

Diffusion tensor imaging (DTI) was used to measure the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) value in amyotrophic lateral sclerosis (ALS) patients to determine their diagnostic value. 69 ALS patients and 23 healthy controls were scanned with DTI sequence in 3.0T MR, and FA and ADC values in 18 regions were evaluated. Compared with the controls, the ADC values of patients in bilateral centrum semiovale, deep frontal and parietal white matter were significantly increased (P < 0.05), while the FA values in cerebral peduncle, posterior limb of internal capsule (PLIC), corona radiata, centrumsemiovale, bilateral deep frontal white matter, the genu and the splenium of the corpus callosum were significantly decreased (P < 0.05). When the FA cut-off value was set to ≤ 0.6860 for the cerebral peduncle, sensitivity (SE) and specificity (SP) of ALS were 95.7% and 83.9% respectively. When the cut-off value was set to ≤ 0.7085 for PLIC, SE and SP were 95.7% and 85.7% respectively. When the cut-off value was set to ≤ 0.6950 for corona radiata, SE and SP were 100.0% and 95.7%, respectively. DTI can be used to quantitatively evaluate injury in ALS patients.

Similarities of biochemical abnormalities between major depressive disorder and bipolar depression: a proton magnetic resonance spectroscopy study.

BACKGROUND: Depression in the context of bipolar disorder (BD) is often misdiagnosed as major depressive disorder (MDD), leading to mistreatments and poor clinical outcomes for many bipolar patients. Previous neuroimaging studies found mixed results on brain structure, and biochemical metabolism of the two disorders. To eliminate the compounding effects of medication, and aging, this study sought to investigate the brain biochemical changes of treatment-naïve, non-late-life patients with MDD and BD in white matter in prefrontal (WMP) lobe, anterior cingulate cortex (ACC) and hippocampus by using proton magnetic resonance spectroscopy ((1)H-MRS). METHODS: Three groups of participants were recruited: 26 MDD patients, 20 depressed BD patients, and 13 healthy controls. The multi-voxel (1)H-MRS [repetition time (TR)=1000ms; echo-time (TE)=144ms] was used for the measurement of N-acetylaspartate(NAA), choline containg compounds (Cho), and creatine (Cr) in three brain locations: white matter in prefrontal (WMP) lobe, anterior cingulate cortex (ACC), and hippocampus. Two ratios of NAA/Cr and Cho/Cr as a measure of brain biochemical changes were compared among three experimental groups. RESULTS: On the comparison of brain biochemical changes, both MDD patients and BD patients showed many similarities compared to the controls. They both had a significantly lower NAA/Cr ratio in the left WMP lobe. There were no significant differences among three experimental groups for Cho/Cr ratio in the WMP lobe, and for the ratios of NAA/Cr and Cho/Cr in the bilateral ACC and hippocampus. The only difference between MDD and BD patients existed for the NAA/Cr ratio in the right WMP lobe. While MDD patients had a significantly lower NAA/Cr ratio than controls, BD patients showed no such differences. On the comparison of correlation of medical variables and brain biochemical changes, all participants demonstrated no significant correlations. CONCLUSION: Reduced NAA/Cr ratio at the left WMP lobe indicated the dysfunction of neuronal viability in deep white matter, in both MDD and BD patients who shared similarities of brain biochemical abnormalities, which might imply an overlap in neuropathology of depression.

Assessment of levator ani morphology and function in asymptomatic nulliparous women via static and dynamic magnetic resonance imaging.

OBJECTIVE: To evaluate levator ani morphology and function in healthy nulliparous women using static and dynamic magnetic resonance imaging. METHODS: Eighty asymptomatic, healthy nulliparous Chinese women (mean age, 25.3±3.5years) volunteered for the present study. Static T2-weighted fast spin-echo images were employed to evaluate levator ani morphology; dynamic T2-weighted fast imaging employing steady-state acquisition was used to evaluate its function. A 2 samples t test was employed to compare groups. RESULTS: No morphologic abnormality was detected in the 80 healthy nulliparous women. However, 15% (12/80) of women had various degrees of pelvic organ descent below the pubococcygeal line. In these women, the width of the pubic portion of the levator ani was significantly reduced during straining, whereas the levator plate angle, the levator hiatus area, and the H and M line lengths were enlarged. These changes were associated with weakened levator ani function and pelvic floor laxity. CONCLUSION: Functional abnormality of the levator ani muscle was noted in nulliparous women at static and dynamic magnetic resonance imaging. Further follow-up investigation is needed to confirm whether women with functional abnormality are more likely to develop a prolapse after vaginal birth.

Assessment of brain maturation in the preterm infants using diffusion tensor imaging (DTI) and enhanced T2 star weighted angiography (ESWAN).

PURPOSE: To assess the brain maturation of preterm infants using diffusion tensor imaging (DTI) and enhanced T2 star weighted angiography (ESWAN). MATERIALS AND METHODS: Conventional magnetic resonance imaging (MRI), DTI and ESWAN were performed in 60 preterm infants and 21 term controls. 60 preterm infants were subgrouped to two groups according to the age at imaging: before and at term-equivalent age (TEA). Fractional anisotropy (FA), apparent diffusion coefficient (ADC) map from DTI, T2 and R2 maps from ESWAN were post-processed at an off-line workstation. The values of FA, ADC, T2 and R2 from the posterior limb of internal capsule (PLIC), frontal white matter (FWM), occipital white matter (OWM) and lentiform nuclei (LN) were determined. These parameters were compared between preterm and term infants. Correlations of DTI and ESWAN parameters with the gestational age, postmenstrual age and postnatal age were analyzed. RESULTS: ADCs of FWM, OWM and LN, and T2 values of the PLIC and LN were higher in the preterm infants at TEA compared with the term controls. The correlations were existed between the postmenstrual age and the values of FA, ADC, T2, R2 from the PLIC, values of ADC, T2, R2 from the LN, T2 value from the OWM. The correlations were also found between the postnatal age and the values of FA, ADC, T2 from the PLIC, and T2 value from the LN. CONCLUSION: The maturity of preterm brain around TEA was different from that of term controls and appeared to be independent of the prematurity at birth. T2 was one of valuable indices to evaluate brain maturation in preterm infants.