Objective To investigate the value of perfusion MR imaging in differential diagnosis between primary central nervous system lymphomas(PCNSL)and high grade astrocytomas.Methods Twelve patients with PCNSL and 23 patients with high grade astrocytomas were preoperatively examined using a 1.5T MR unit.Routine MR sequences were performed followed by dynamic susceptibility contrastenhanced MR perfusion imaging.The perfusion color images and the time-signal intensity curves of the two tumor groups were compared.The relative cerebral blood volume(rCBV)within the tumor parenchyma was measured and the data were analyzed with unpaired Student's t-test.Results The rCBVs within the tumor parenchyma of the PCNSL and high grade astrocytomas were 1.78±0.5 1 and 3.87±0.87 respectively.The rCBV in the PCNSL was significantly lower than that of the high grade astrocytoma(P＜0.05).When the time-signal intensity curves were compared,the PCNSL showed a trend towards the baseline after the first pass and the curves even overshot above the baseline in 7 out of 12 cases,whereas the high grade astrocytoma showed a trend to be close to the baseline but couldn't return to the baseline completely.Conclusion The MR perfusion imaging can be very useful in distinguishing the PCNSL from high grade astrocytomas.

Objective To investigate the CT and MR] features of basal cell adenoma of the parotid gland. Methods CT and MRI features of 9 basal cell adenoma cases (4 men and 5 women, median age 58) confirmed by operation and pathology were reviewed retrospectively. All CT and MR images were retrospectively evaluated with respect to location, size, morphology, margin, CT density/MR] signal intensity and enhancement behavior. Results Each of the 9 patients had only 1 tumor. Eight lesions were located in the superficial lobe and 1 in the deep lobe. Seven tumors were round without lobular appearance, and 2 tumors were elliptic with small lobular appearance. All the 9 lesions were well circumscribed with smooth contours. A capsule-like rim with low intensity on MR[ was observed in 2 lesions, and a rim with high intensity on T1 WI and T2 WI was detected in another lesion. These 3 lesions showed low intensity on T1 WI and T2 WI with heterogeneously strong enhancement and delayed enhancement. Four lesions showed cystic areas in the center with mural nodules on CT, which were moderately or obviously enhanced (the mean increase of CT values: 65.5 H U ), and 2 lesions showed homogeneous enhancement. Conclusion Basal cell adenoma of parotid gland should be first considered when the old women had single round lesion located in the superficial lobe with smooth contour and low intensity on T2WI, especially when cystic areas were observed in the center with mural nodules on CT/MR.

OBJECTIVE: To explore the value of high-resolution temporal bone CT (HRCT) multi-planar reconstruction (MPR) technique for measuring cochlear morpholog in the preoperative evaluation of cochlear implant. METHOD: We retrospectively analyzed the clinical data of 80 cochlear implant recipients. The groups were investigated in our research according to the patient's sex, age and whether the inner ear is malformed or not. Temporal bone HRCT MPR was applied to analyze the measurement parameter in the standard orientation of the cochlea image: the largest distance from the round window to the lateral wall (distance A), the perpendicular distance (B) and angle of the basal turn of the cochlea relative to the midsagittal plane (γ). Reproducibility of the measured data was evaluated and the results between the different groups were compared. RESULT: Measurement of parameter values between the intraobserver and interobserver showed good reproducibility. In normal group, distance A [(8.79±0.34) mm] and perpendicular distance B [(6.58±0.28) mm] of males' cochleae were significantly larger than A [(8.53±0.47) mm] and B [(6.22±0.43) mm] of females' (P<0.05), but the angle γ was not significantly different between the two groups (P>0.05). The A and B values didn't change with age (P>0.05), but the angle γ tended to decrease with increasing age (r=-0.25, P<0.05). In the malformation group, the value B was significantly smaller than that of the normal group (P<0.01), but for value A and angle γ, there was no significant difference between the two groups (P>0.05). CONCLUSION HRCT MPR technique is simple and reliable in measurement of cochlear morphology. It can be used to guide the surgery and provide an objective basis for designing the personalized electrode. More clinical application of this technology is recommended.
Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Cochlea ; diagnostic imaging ; Cochlear Implantation ; Female ; Humans ; Infant ; Male ; Middle Aged ; Retrospective Studies ; Temporal Bone ; diagnostic imaging ; Tomography, X-Ray Computed ; Young Adult

Objective To investigate the image features of congenital pyriform sinus fistula (CPSF). Methods We retrospectively analyzed the clinical features and preoperative images of 80 patients with confirmed diagnosis of CPSF by surgical and pathological outcome in Guangdong general hospital from January 2007 to December 2014. At least one of the following imaging examinations were performed for all the patients, including Barium swallow X-ray (BSX), CT and MRI. Among them, 63 patients were examined with BSX, while 42 patients underwent plain and enhanced CT scans, wherein 40 of them were exanimated shortly after BSX. Thirty-two patients underwent plain and enhanced MRI scans. Patients were divided into two groups according to their age, young age group (≤14 years old) and older age group (>14 years old). Furthermore, they were also grouped based on inflammatory or quiescent stage clinically. The images of BSX, CT, and MRI from the patients were analyzed and the positive diagnostic rates (PDR) between groups were compared by using χ2 tests. Results For the patients examined with BSX, sinuses in 35 of 63 were depicted from pyriform and fistulas in 9 of 63 were depicted from the pyriform. The overall PDR of BSX was 74.6%(47/63),wherein 46.2%(12/26)in young age group , 94.6%(35/37)in older age group, 52.9%(9/17) in inflammatory stage group ,and 82.6%(38/46)in quiescent stage group. The inter-group differences were statistically significant (χ2 were 18.911 and 5.766,both P<0.05). The PDR of CPSF with CT was 85.7%(36/42), MRI was 84.4%(27/32), BSX+CT was 87.5%(35/40). The courses of fistula or sinus were showed on CT and MRI. The presence of air bubbles at the inferomedial edge of cricothyroid joints or around the upper lobe of the thyroid gland, the changes of the morphology of thyroid grand as well as the inflammatory change along the fistula region were detected much clearly on CT and MRI. There was no statistical difference between CT and MRI groups(P>0.05).Conclusions BSX could be a screening method for suspected cases of CPSF in quiescent stage. However, the PDR could be affected by many factors (age and inflammation). CT and MRI could provide valuable information for diagnosis. An examination combined BSX and CT is preferred to improve the positive detective rate of CPSF.

Objective: To investigate the feasibility and significance of modified Killian(MK) method in the clinical diagnosis of congenital pyriform sinus fistula(CPSF) by electronic laryngoscopy. Methods: The following examinations were performed for 30 suspected cases of CPSF, including the traditional electronic laryngoscopy, MK examination(modified Killian position+ head rotation+ the Valsalva maneuver), barium swallow X-ray(BSX) and CT , and a prospective comparison among them were done. Patients were divided into two groups according to their age: young age group(≤14 years old) and older age group (>14 years old). The results of MK examination from the patients were analyzed and the positive diagnostic rates (PDR) between groups were compared by using χ² tests. Results: Sinuses in 20 of 30 patients were depicted from pyriform sinus in BSX, and the PDR was 66.7%(20/30). The PRD of CT was 83.3%(25/30). The presence of air bubbles around the upper lobe of the thyroid gland or at the inferomedial edge of cricothyroid joints, morphological changes of thyroid grand as well as pseudo-fistula formation on lower neck were detected clearly on CT. Comparing to the traditional electronic laryngoscopy, the effect of exposing piriform fossa fistula by MK examination is significant(χ²=17.05, P<0.05), with the PDR of 13.3%(4/30) and 76.7%(23/30) respectively. Nevertheless, comparing to BSX and CT, there were no statistically significant differences in the effect to diagnose CPSF (χ²=0.31, χ²=0.10 respectively, P>0.05). The PDR of MK in older group is significantly higher than younger group(χ²=6.68, P<0.05). Conclusions MK examination can clearly reveal the hypopharyngeal anatomical structure and detect the sinus of CPSF .It could be a safe, feasible, convenient and economical method as an application in preoperative diagnosis and follow-up examination of clinical suspected CPSF.