Assessment of Changes in the Cesarean Scar and Uterus Between One and Two Years after Cesarean Section Using 3D T2w SPACE MRI.

Objective To evaluate changes in morphology of the cesarean scar and uterus between one and two years after cesarean section using high-resolution, three dimensional T2-weighted sampling perfection with application optimized contrast using different flip angle evolutions Magnetic Resonance Imaging (3D T2w SPACE MRI). Methods This prospective study was performed to investigate morphological changes in the cesarean scars and uterus from one to two years after cesarean section using high-resolution, 3D T2w SPACE MRI. The healthy volunteers having no childbearing history were recruited as the controls. All data were measured by two experienced radiologists. All data with normal distribution between the one-year and two-year groups were compared using a paired-sample t test or independent t test. Results Finally, 46 women took a pelvic MR examination one year after cesarean section, and a subset of 15 completed the same examination again after two years of cesarean section. Both the uterine length and the anterior wall thickness after two years of cesarean section (5.75 ± 0.46 and 1.45 ± 0.35 cm) were significantly greater than those measured at one year (5.33 ± 0.59 and 1.25 ± 0.27 cm) (t = -2.363 and -2.175, P= 0.033 and 0.048). No significant difference was shown in myometrial thickness two years after cesarean section (1.45 ±0.35 cm) with respect to the control group (1.58 ± 0.21 cm, P= 0.170). Nine women who underwent MRI twice were considered to have scar diverticula one year after cesarean section, and still had diverticula two years after cesarean section. The thickness, height, and width of the uterine scar showed no significant change from one to two years (all P > 0.05). Conclusions 3D T2w SPACE MRI provides overall morphologic details and shows dynamic changes in the scar and the uterus between one and two years after cesarean section. Scar morphology after cesarean section reached relatively stable one year after cesarean section, and uterine morphology was closer to normal two years after cesarean section.

Assessing Liver Function by T1 Maps on Gd-EOB-DTPA-Enhanced MRI for up to 50 Min in Rat Models of Liver Fibrosis: A Longer Hepatobiliary Time Period may Help.

Objectives To investigate whether a longer time period of gadolinium ethoxybenzyl diethylenetriaminepen-taacetic acid (Gd-EOB-DTPA)-enhanced T1 mapping scanning, as well as dynamic contrast-enhanced (DCE) and multiple hepatobiliary phase magnetic resonance imaging (MRI) have the potential to provide information about liver function in rats with liver fibrosis. Methods Forty rats were divided into the carbon tetrachloride-induced hepatic injury groups [carbon tetrachloride for four (n=14), eight (n=8), or twelve (n=8) weeks] and the control group (n=10). Gd-EOB-DTPA-enhanced MRI was performed including T1-mapping (delayed to 50 min), DCE, and multiple hepatobiliary phases. Indocyanine green retention rate at 15 min (ICG-R15) was determined. Parameters such as T1 reduction rate (ΔT1), elimination half-life of ΔT1 (TΔT1 1/2), relative enhancement (RE), time to maximum RE (Tmax), and perfusion parameters were calculated. Pearson correlation analysis was used for correlation analysis between ICG-R15 and each MRI indices. Results ΔT1 at 30, 40, and 50 min showed significant positive correlations with ICG-R15 ( r=0.784, 0.653, 0.757, P=0.007, 0.041, 0.030). TΔT1 1/2 showed a significant positive correlation with ICG-R15 (r=0.685, P=0.029). Tmaxshowed a significant positive correlation with ICG-R15 (r=0.532, P=0.019). Conclusions ΔT1 in the late hepatobiliary phase and T ΔT1 1/2 exhibited moderate correlations with liver function. The longer time period of Gd-EOB-DTPA-enhanced T1 mapping scanning, as well as DCE and multiple hepatobiliary phases, may be of some value for estimating liver function in rats with liver fibrosis.

Patient-adapted respiratory training: Effect on navigator-triggered 3D MRCP in painful pancreatobiliary disorders.

PURPOSE: To compare the image quality of navigator-triggered (NT) 3D MR cholangiopancreatography (MRCP) with and without a patient-adapted respiratory training, in clinical patients with painful pancreatobiliary disorders. MATERIALS AND METHODS: With institutional review board approval, hospitalized patients with painful pancreatobiliary disorders who were scheduled for MRCP study were prospectively enrolled. The numerical rating scale (NRS) of abdominal pain during the examination was recorded. Special patient-adapted respiratory training was conducted before the examination. A control group of patients was enrolled with the same criteria, who received ordinary instructions only (n=60 for each group). A subgroup of patients (n=10) underwent MRCP studies with ordinary instructions first and with patient-adapted training later. Acquisition time was recorded. General image quality, degree of artifacts and visualization of 12 segments of the pancreatobiliary tree were rated on a five-point scale and compared between the groups. RESULT: Both groups had similar NRS of pain. There was a significant improvement in image quality (p<0.01) as well as visualization of right posterior hepatic duct (p=0.045), left lateral hepatic duct (p=0.037), and pancreatic duct (p<0.01 for head, body and tail segments) in patients receiving respiratory training. The other segments showed no significant differences. The percentage of patients with severe and extensive imaging artifacts decreased from 18.3%(11/60) to 8.3%(5/60). The acquisition time was shorter (175±54s vs 249±67s, p<0.01) in patients with respiratory training. CONCLUSION: Patient-adapted respiratory training improves the image quality of NT-MRCP in patients with painful pancreatobiliary disorders.

Cortical representation of facial and tongue movements: a task functional magnetic resonance imaging study.

BACKGROUND: Functional magnetic resonance imaging (fMRI) mapping can present the activated cortical area during movement, while little is known about precise location in facial and tongue movements. OBJECTIVE: To investigate the representation of facial and tongue movements by task fMRI. METHODS: Twenty right-handed healthy subjects were underwent block design task fMRI examination. Task movements included lip pursing, cheek bulging, grinning and vertical tongue excursion. Statistical parametric mapping (SPM8) was applied to analysis the data. RESULTS: One-sample t-test was used to calculate the common activation area between facial and tongue movements. Also, paired t-test was used to test for areas of over- or underactivation in tongue movement compared with each group of facial movements. CONCLUSIONS: The common areas within facial and tongue movements suggested the similar motor circuits of activation in both movements. Prior activation in tongue movement was situated laterally and inferiorly in sensorimotor area relative to facial movements. Prior activation of tongue movement was investigated in left superior parietal lobe relative to lip pursing. Also, prior activation in bilateral cuneus lobe in grinning compared with tongue movement was detected.

Time-course of Changes in Activation Among Facial Nerve Injury: A Functional Imaging Study.

Patients suffering different intervals of facial nerve injury were investigated by functional magnetic resonance imaging to study changes in activation within cortex.Forty-five patients were divided into 3 groups based on intervals of facial nerve injury. Another 16 age and sex-matched healthy participants were included as a control group. Patients and healthy participants underwent task functional magnetic resonance imaging (eye blinking and lip pursing) examination.Functional reorganization after facial nerve injury is dynamic and time-dependent. Correlation between activation in sensorimotor area and intervals of facial nerve injury was significant, with a Pearson correlation coefficient of -0.951 (P < 0.001) in the left sensorimotor area and a Pearson correlation coefficient of 0.333 (P = 0.025) in the right sensorimotor area.Increased activation in integration areas, such as supramarginal gyrus and precunes lobe, could be detected in the early-middle stage of facial dysfunction compared with normal individuals. Decreased activation in sensorimotor area contralateral to facial nerve injury could be found in late stage of facial dysfunction compared with normal individuals. Dysfunction in the facial nerve has devastating effects on the activity of sensorimotor areas, whereas enhanced intensity in the sensorimotor area ipsilateral to the facial nerve injury in middle stage of facial dysfunction suggests the possible involvement of interhemispheric reorganization. Behavioral or brain stimulation technique treatment in this stage could be applied to alter reorganization within sensorimotor area in the rehabilitation of facial function, monitoring of therapeutic efficacy, and improvement in therapeutic intervention along the course of recovery.

[Gamma event-related synchronization analysis: a new method for cortical function mapping].

OBJECTIVE: To localize the sensory motor cortex of human brain by analyzing the power change in Gamma band (> 60 Hz) of electrocorticography (ECoG) data. METHODS: Eight patients with intractable epilepsy underwent temporary placement of subdural electrodes. After surgery, sensory evoked potential (SEP), electrocortical stimulation (CES) and event-related synchronization analysis of Gamma band (Gamma ERS analysis) were performed to reduce the risk of complications. The results of Gamma ERS analysis were compared with those of SEP and CES. RESULTS: The results of Gamma ERS analysis had 80.7% electrodes fitting perfectly those of CES and SEP. And the percentage reached 92.3% if electrodes were superimposed or added adjacently. CONCLUSION: The Gamma ERS analysis is a new sensitive and precise method for cortical function mapping.