OBJECTIVES: An animal experiment clarified that insertion of an orthodontic apparatus activated the trigeminal neurons of the medulla oblongata. Orthodontic tooth movement is known to be associated with the sympathetic nervous system and controlled by the nucleus of the hypothalamus. However, the transmission of both has not been demonstrated in humans. The purpose of this study were to examine the activated cerebral areas using brain functional magnetic resonance imaging (MRI), when orthodontic tooth separators were inserted, and to confirm the possibility of the transmission route from the medulla oblongata to the hypothalamus. METHODS: Two types of alternative orthodontic tooth separators (brass contact gauge and floss) were inserted into the right upper premolars of 10 healthy volunteers. Brain functional T2*-weighted images and anatomical T1-weighted images were taken. RESULTS: The blood oxygenation level dependent (BOLD) signals following insertion of a brass contact gauge and floss significantly increased in the somatosensory association cortex and hypothalamic area. CONCLUSION Our findings suggest the possibility of a transmission route from the medulla oblongata to the hypothalamus.
Brain Mapping ; methods ; Healthy Volunteers ; Humans ; Hypothalamus ; diagnostic imaging ; Magnetic Resonance Imaging ; methods ; Medulla Oblongata ; diagnostic imaging ; Tooth Movement Techniques ; instrumentation

Rectal cancer is one of the common cancers which poses a threat to the health of mankind. In recent years. Multi-modality treatment strategies for locally advanced rectal cancer improve the treatment efficiency. Accurate prediction of the treatment response after the neoadjuvant chemoradiotherapy (CRT) can guide more suitable treatment strategy. MERCURY study proved the prognostic value of post-CRT standard morphologic MRI(T2-weighted) assessment of tumor regression grade(TRG), and MRI assessment of circumferential resection margin can guide the definitive surgery. Compared with standard morphologic MRI (T2-weighted), functional MRI, including diffusion weighted imaging (DWI) and dynamic contrast enhanced (DCE) MRI, has shown more promising results for the prediction of therapeutic response in rectal cancer. The addition of diffusion-weighted images to T2-weighted images improves the accuracy of restaging examinations for determination of complete pathologic responders. DCE can reflect the tumor micro-vascular environment, and the change of perfusion in response to treatment. These images have the potential to improve the accuracy of therapeutic response in rectal cancer.
Chemoradiotherapy ; statistics & numerical data ; Contrast Media ; Diffusion Magnetic Resonance Imaging ; statistics & numerical data ; Humans ; Magnetic Resonance Imaging ; methods ; statistics & numerical data ; Margins of Excision ; Neoadjuvant Therapy ; statistics & numerical data ; Neoplasm Staging ; instrumentation ; methods ; statistics & numerical data ; Prognosis ; Rectal Neoplasms ; blood supply ; diagnostic imaging ; pathology

To evaluate the efficacy and safety of drug-eluding beads transarterial chemoembolization (DEB-TACE) in treatment of unrecectable hepatocellular carcinoma (HCC).The clinical data of 42 consecutive HCC patients undergoing TACE were retrospectively analyzed, including 20 cases received conventional TACE (cTACE group) and 22 cases received TACE with epirubicine-loaded microspheres (CalliSpheres) (DEB-TACE group). MRI scans were performed 1 week before and 1, 3 and 6 months after initial therapy. The response to treatment, disease recurrence, complications and adverse effects were documented and compared between two groups.There were no significant differences in 1-month, 3-month and 6-month objective response rate (CR+PR) and disease control rate (CR+PR+SD), disease recurrence, complications and adverse effects of interventional therapy between cTACE group and DEB-TACE group. Additionally, there were no significant differences about locoregional biliary injuries, intrahepatic biloma, and newly detected intra- or extrahepatic HCC on MRI between cTACE group and DEB-TACE group.There were no statistically significant differences between cTACE group and DEB-TACE group with regard to the short-term response, disease recurrence, complications and side effects. Hepatic-locoregional complications may be more frequent in DEB-TACE group than those in cTACE group.
Carcinoma, Hepatocellular ; diagnostic imaging ; therapy ; Chemoembolization, Therapeutic ; adverse effects ; instrumentation ; methods ; Comparative Effectiveness Research ; Drug Delivery Systems ; instrumentation ; methods ; Epirubicin ; administration & dosage ; therapeutic use ; Humans ; Liver Neoplasms ; Magnetic Resonance Imaging ; Microspheres ; Neoplasm Recurrence, Local ; Retrospective Studies ; Treatment Outcome

ObjectiveTo analyze the MRI manifestations of Peyronie's disease and investigate the value of high-field MRI in the diagnosis of the disease.

METHODSUsing a small surface coil, we performed 3.0 Tesla MRI for 14 patients with clinically diagnosed Peyronie's disease. The MRI protocol included routine sequences (T1WI, T2WI, and enhanced T1WI) and susceptibility-weighted imaging (SWI). Each patient had received 2－4 penile ultrasound examinations previously. We compared the MRI findings with the results of ultrasonography.

RESULTSMRI manifested 25 penile plaques in the 14 patients, 3 (7 plaques) with inflammation, 4 (8 plaques) with fibrosis, and the other 7 (10 plaques) with calcification displaying a low signal intensity on SWI. Ultrasonography had revealed the 10 calcified plaques in all the 20 examinations, but exhibited the 7 inflammatory and 8 fibrotic ones in only 3 of the 23 examinations. The combination of MRI SWI sequences was necessitated for the detection of calcified plaques and achieved higher detection rates than ultrasonography for inflammatory and fibrotic plaques (P<0.05).

CONCLUSIONSHigh-field MRI has high sensitivity and accuracy in the diagnosis of Peyronie's disease, which can effectively display penile plaques of different nature in the early stage through multi-parametric sequences.

Calcinosis ; diagnostic imaging ; Fibrosis ; Humans ; Magnetic Resonance Imaging ; instrumentation ; methods ; Male ; Penile Induration ; diagnostic imaging ; Penis ; diagnostic imaging ; pathology ; Sensitivity and Specificity ; Ultrasonography

BACKGROUND: This study aimed to evaluate the clinical and radiological outcomes of arthroscopic bioabsorbable screw fixation in osteochondritis dissecans (OCD) in adolescent patients with unstable lesions causing pain. METHODS: The study included 11 patients (10 males and 1 female) with OCD who underwent arthroscopic bioabsorbable screw fixation between July 2007 and February 2014 and were available for follow-up for more than 12 months. The mean age at diagnosis was 16.3 years (range, 11 to 19 years), and the average follow-up period was 51 months (range, 12 to 91 months). Clinical results were evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS), Lysholm knee score, and International Knee Documentation Committee (IKDC) score measured before surgery and at follow-up. Functional evaluation was made using the Tegner activity scale. Magnetic resonance imaging (MRI) and second-look arthroscopy were performed at the 12-month follow-up. RESULTS: Between the preoperative assessment and follow-up, improvements were seen in the KOOS (range, 44.9 to 88.1), Lysholm knee score (range, 32.6 to 82.8), and IKDC score (range, 40.8 to 85.6). The Tegner activity scale also improved from 2.8 to 6.1. Based on postoperative MRI, there were eight Dipaola grade I cases and three grade II cases. No complications due to fixation failure developed in any case. Second-look arthroscopy at 12 months postoperatively revealed that the lesion was covered with cartilage in all cases. CONCLUSIONS: For unstable OCD lesions causing pain in adolescents, arthroscopic bioabsorbable screw fixation provided favorable outcomes with reduced pain and restoration of movement. Therefore, it should be considered as an effective treatment for OCD.
*Absorbable Implants ; Adolescent ; Adult ; Arthroscopy/adverse effects/*instrumentation/methods ; *Bone Screws ; Child ; Female ; Follow-Up Studies ; Humans ; Magnetic Resonance Imaging ; Male ; Osteochondritis Dissecans/*diagnostic imaging/*surgery ; Range of Motion, Articular ; Treatment Outcome ; Young Adult

OBJECTIVE: The purpose of this study was to correlate permeability parameters measured with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using a clinical 3-tesla scanner with extravasation of Evans blue in a rat model with transient cerebral ischemia. MATERIALS AND METHODS: Sprague-Dawley rats (n = 13) with transient middle cerebral artery occlusion were imaged using a 3-tesla MRI with an 8-channel wrist coil. DCE-MRI was performed 12 hours, 18 hours, and 36 hours after reperfusion. Permeability parameters (K(trans), v(e), and v(p)) from DCE-MRI were calculated. Evans blue was injected after DCE-MRI and extravasation of Evans blue was correlated as a reference with the integrity of the blood-brain barrier. Correlation analysis was performed between permeability parameters and the extravasation of Evans blue. RESULTS: All permeability parameters (K(trans), v(e), and v(p)) showed a linear correlation with extravasation of Evans blue. Among them, K(trans) showed highest values of both the correlation coefficient and the coefficient of determination (0.687 and 0.473 respectively, p < 0.001). CONCLUSION: Permeability parameters obtained by DCE-MRI at 3-T are well-correlated with Evans blue extravasation, and K(trans) shows the strongest correlation among the tested parameters.
Animals ; Blood-Brain Barrier/pathology ; Capillary Permeability ; Contrast Media ; Disease Models, Animal ; Evans Blue/analysis ; Ischemic Attack, Transient/*diagnosis ; Magnetic Resonance Imaging/instrumentation/*methods ; Male ; Rats ; Rats, Sprague-Dawley ; Stroke/diagnosis

A mechanical shimming method and device for permanent magnet of MRI system has been developed to meet its stringent homogeneity requirement without time-consuming passive shimming on site, installation and adjustment efficiency has been increased.
Magnetic Resonance Imaging ; instrumentation ; methods ; Magnets

OBJECTIVE: To assess whether multi-echo Dixon magnetic resonance (MR) imaging with simultaneous T2* estimation and correction yields more accurate fat-signal fraction (FF) measurement of the lumbar paravertebral muscles, in comparison with non-T2*-corrected two-echo Dixon or T2*-corrected three-echo Dixon, using the FF measurements from single-voxel MR spectroscopy as the reference standard. MATERIALS AND METHODS: Sixty patients with low back pain underwent MR imaging with a 1.5T scanner. FF mapping images automatically obtained using T2*-corrected Dixon technique with two (non-T2*-corrected), three, and six echoes, were compared with images from single-voxel MR spectroscopy at the paravertebral muscles on levels L4 through L5. FFs were measured directly by two radiologists, who independently drew the region of interest on the mapping images from the three sequences. RESULTS: A total of 117 spectroscopic measurements were performed either bilaterally (57 of 60 subjects) or unilaterally (3 of 60 subjects). The mean spectroscopic FF was 14.3 +/- 11.7% (range, 1.9-63.7%). Interobserver agreement was excellent between the two radiologists. Lin's concordance correlation between the spectroscopic findings and all the imaging-based FFs were statistically significant (p < 0.001). FFs obtained from the T2*-corrected six-echo Dixon sequences showed a significantly better concordance with the spectroscopic data, with its concordance correlation coefficient being 0.99 and 0.98 (p < 0.001), as compared with two- or three-echo methods. CONCLUSION: T2*-corrected six-echo Dixon sequence would be a better option than two- or three-echo methods for noninvasive quantification of lumbar muscle fat quantification.
Adult ; Aged ; Aged, 80 and over ; Female ; Humans ; Image Processing, Computer-Assisted ; Low Back Pain/*radiography ; Magnetic Resonance Imaging/instrumentation/*methods ; Male ; Middle Aged ; Muscles/radiography ; Spinal Cord

OBJECTIVE: To validate the usefulness of a diffusional anisotropic capillary array phantom and to investigate the effects of diffusion tensor imaging (DTI) parameter changes on diffusion fractional anisotropy (FA) and apparent diffusion coefficient (ADC) using the phantom. MATERIALS AND METHODS: Diffusion tensor imaging of a capillary array phantom was performed with imaging parameter changes, including voxel size, number of sensitivity encoding (SENSE) factor, echo time (TE), number of signal acquisitions, b-value, and number of diffusion gradient directions (NDGD), one-at-a-time in a stepwise-incremental fashion. We repeated the entire series of DTI scans thrice. The coefficients of variation (CoV) were evaluated for FA and ADC, and the correlation between each MR imaging parameter and the corresponding FA and ADC was evaluated using Spearman's correlation analysis. RESULTS: The capillary array phantom CoVs of FA and ADC were 7.1% and 2.4%, respectively. There were significant correlations between FA and SENSE factor, TE, b-value, and NDGD, as well as significant correlations between ADC and SENSE factor, TE, and b-value. CONCLUSION: A capillary array phantom enables repeated measurements of FA and ADC. Both FA and ADC can vary when certain parameters are changed during diffusion experiments. We suggest that the capillary array phantom can be used for quality control in longitudinal or multicenter clinical studies.
Anisotropy ; Diffusion Magnetic Resonance Imaging/*instrumentation/*methods ; Diffusion Tensor Imaging/*instrumentation/*methods ; Humans ; *Phantoms, Imaging ; Research Design ; Signal-To-Noise Ratio

Neurogastroenterology and motility disorders of the gastrointestinal (GI) tract encompass a broad spectrum of diseases involving the GI tract and central nervous system. They have varied pathophysiology, clinical presentation and management, and make up a substantial proportion of outpatient clinic visits. Typically, patients experience persistent symptoms referable to the GI tract despite normal endoscopic and radiologic findings. An appropriate evaluation is thus important in the patient's care. Advances in technology and understanding of the disease pathophysiology have provided better insight into the physiological basis of disease and a more rational approach to patient management. While technological advances serve to explain patients' persistent symptoms, they should be balanced against the costs of diagnostic tests. This review highlights the GI investigative modalities employed to evaluate patients with persistent GI symptoms in the absence of a structural lesion, with particular emphasis on investigative modalities available locally and the clinical impact of such tools.
Electrophysiology ; Endoscopy ; Esophagus ; physiopathology ; Gastric Emptying ; Gastroenterology ; instrumentation ; methods ; Gastrointestinal Diseases ; diagnosis ; Gastrointestinal Tract ; physiopathology ; Humans ; Hydrogen-Ion Concentration ; Intestine, Small ; physiopathology ; Magnetic Resonance Imaging