[Application of three-dimensional ultrasound for diagnosis of congenital preauricular fistula].

Objective: To explore the application of real-time three-dimensional ultrasound in locating the course, the brand and the blind end of internal opening of congenital preauricular fistula. Methods: Congenital preauricular fistula patients from Changhai Hospital were studied. All the cases were evaluated using two-dimensional and three-dimensional ultrasound before surgeries. The surgery findings were utilized as the gold standard. The imaging features of 3D ultrasound were described to determine the accuracy of the blind end location, the course of the main fistula tract and the branch tracts. The diagnosis was compared with the surgery findings. Results: In 89 cases, among which there were 21 branch fistulae. There were 68 bend fistulae without branch. The diagnostic accuracy of both two-dimensional ultrasound and three-dimensional ultrasound was 100%. The accuracy in locating the blind end of internal opening, the course of the branch tracts with 3D ultrasound was 92.1%(82/89), 85.7%(18/21) , compared to 80.9%(72/89), 57.1%(12/21) with 2D ultrasound. It was obvious that 3D ultrasound had more advantages. These differences were statistically significant (χ(2)=4.8, P<0.05; χ(2)=4.2, P<0.05). Conclusions: Compared with 2D ultrasound, 3D ultrasound can accurately locate the blind end of internal opening, the course, and the branch of preauricular fistula, clearly display the morphology and the spatial structure of preauricular fistulaand its surroundings. It has high clinical application value in preoperative imaging examination.

Extratemporal abnormalities of brain parenchyma in young adults with temporal lobe epilepsy: a diffusion tensor imaging study.

AIM: To examine extratemporal abnormalities of the cerebral parenchyma in young adult temporal lobe epilepsy (TLE) patients using diffusion tensor imaging (DTI). MATERIALS AND METHODS: The study comprised 20 adults with unilateral TLE and 20 controls. The fractional anisotropy (FA), apparent diffusion coefficient (ADC), parallel eigenvalue (λ∥), and perpendicular eigenvalue (λ⊥) were calculated in the regions of interest (ROIs) using a 3 T MRI system. ROIs included the anterior/posterior limb of the internal capsule (AIC/PIC), external capsule (EC), head of caudate nucleus (HCN), lenticular nucleus (LN), thalamus (TL), and genu/body/splenium of the corpus callosum (GCC/BCC/SCC). RESULTS: Compared to controls, TLE patients showed lower FA in all ROIs; higher ADC in bilateral ECs, HCNs, TLs, and BCC; lower λ∥ in the ipsilateral LN and bilateral AICs, TL, and GCC; and higher λ⊥ in all ROIs except the bilateral PICs. In TLE patients, the ipsilateral TL had decreased FA compared with the contralateral TL. Pearson correlation analysis revealed a negative correlation between the ADC of the GCC and the age at onset of epilepsy; the λ∥ of the ipsilateral PIC and age at onset of epilepsy; the λ⊥ of the contralateral AIC and duration of epilepsy, respectively; and a positive correlation between the ADC of the GCC and the duration of epilepsy and the λ⊥ of the GCC and the duration of epilepsy, respectively. CONCLUSION: The study revealed bilateral extratemporal abnormalities in young adult TLE patients compared with controls. In addition, TLE patients with younger age at onset or longer duration of epilepsy may have more serious extratemporal changes.

Diffusion tensor imaging and 1H-MRS study on radiation-induced brain injury after nasopharyngeal carcinoma radiotherapy.

AIM: To investigate the metabolic characteristics of the temporal lobes following radiation therapy for nasopharyngeal carcinoma using diffusion tensor imaging (DTI) and proton magnetic resonance spectroscopy ((1)H-MRS). MATERIALS AND METHODS: DTI and (1)H-MRS were performed in 48 patients after radiotherapy for nasopharyngeal carcinoma and in 24 healthy, age-matched controls. All patients and controls had normal findings on conventional MRI. Apparent diffusion coefficient (ADC), fractional anisotropy (FA), three eigenvalues λ1, λ2, λ3, N-acetylaspartic acid (NAA)/choline (Cho), NAA/creatinine (Cr), and Cho/Cr were measured in both temporal lobes. Patients were divided into three groups according to time after completion of radiotherapy: group 1, less than 6 months; group 2, 6-12 months; group 3, more than 12 months. Mean values for each parameter were compared using one-way analysis of variance (ANOVA). RESULTS: Mean FA in group 1 was significantly lower compared to group 3 and the control group (p < 0.05). Group-wise comparisons of apparent diffusion coefficient (ADC) values among all the groups were not significantly different. Eigenvalue λ1 was significantly lower in groups 1 and 3 compared to the control group (p < 0.05). NAA/Cho and NAA/Cr were significantly lower in each group compared to the control group (p < 0.01 for both). The decrease in NAA/Cho was greatest in group 1. There were no significant between-group differences regarding Cho/Cr. CONCLUSION: A combination of DTI and (1)H-MRS can be used to detect radiation-induced brain injury, in patients treated for nasopharyngeal carcinoma.