Objective To observe the morphological features of the incisive canal in normal anatomy and abnormalities with multi-slice spiral CT (MSCT). Methods MSCT findings of 108 normal subjects and 65 patients with abnormalities involving incisive canal were retrospectively analyzed. Results The normal incisive canal were classified into 3 types according to the morphology of the nasal opening:two openings, short bony crest and one opening (37.04%, 33.33% and 29.63%, respectively), as well as cylinder, Y-shaped and pyramidal (59.26%, 37.04% and 3.70%) in coronal images, and cylinder, pyramidal and fusiform (84.26%, 14.81% and 0.93%) in sagittal images. The maximum diameter of the nasal and palatal opening was (4.67±1.31) mm and (3.51±0.88) mm (P<0.05). The length of the incisive canal was (10.71±1.95) mm, (11.51±1.97) mm in male and (9.91±1.58) mm in female respectively, and gender difference was found (P<0.05). The angle between the posterior wall and the hard palate was (118.51±9.44)°. The upper and lower length from the anterior wall of the incisive canal to the cortical palate was (9.29±1.26) mm and (7.12±1.21) mm, respectively (P<0.05). The manifestations of abnormalities involving incisive canal including enlargement (47.69%), narrowing (46.15%), shortening (3.08%) and interruption (3.08%) were observed. Conclusion The morphology of the incisive canal can be clearly delineated with MSCT and post processing techniques. It is extremely valuable for avoiding potential complications during surgical procedures such as implant placement and helpful to the diagnosis and treatment of abnormalities involving maxillary incisive canal.

Objective To study the CT and MR imaging feature of adult sphenoid spontaneous cerebrospinal fluid (CSF) rhinorrhea and accompanying intracranial hypertension. Methods Thirty consecutive patients including 11 males and 19 females with mean age of (50 ± 8) years (range, 31 to 64 years) were retrospectively reviewed. Imaging findings in 30 patients with adult sphenoid spontaneous CSF rhinorrhea (CT in 26 patients, MR in 29 patients, and both CT and MR in 25 patients) were analyzed. The MR imaging and CT features were evaluated by two experienced head and neck radiologists. The CT and MR imaging parameters of 30 fistulas were evaluated, including side, location, size, amount, bony change, and the adjacent structures change. Results Of the 30 patients of adult sphenoid spontaneous CSF rhinorrhea lesions, the site of the CSF fistula confirmed by endoscopy surgery was at the junction of the roof of the inferolateral recess and the floor of the middle cranial in 25 (83%, 25/30) patients, the roof of the inferolateral recess in 3 (10%,3/30) patients, and the lateral wall of the sphenoid sinus in 2 (7%,2/30). CT images revealed the osseous defects of the sphenoid sinus walls in 21 patients (80.7%, 21/26) patients, excessive pneumatization of the inferolateral recess of the sphenoid sinuses in 25 cases (96.1%, 25/26). MRI demonstrated the linear hyperintensity communicating subarachnoid space and sphenoid cavity, accompanying meningoencephalocele in 26 (89.6%, 26/29) patients, sphenoid sinus filled with CSF in 24 (82.7%,24/29) patients and air-fluid level in the sphenoid sinus in 8 cases (27.6%, 8/29), excessive expansion of adjoining lateral fissure cistern in 22 cases (75.9%,22/29), adjoining sulcus in one case (3.4%, 1/29), adjoining lateral ventricle in one case (3.4%,1/29). The imaging feature of accompanying intracranial hypertension included empty sella in 29 cases (100%, 29/29), augmentation of the complex of the optic sheath in 27 cases (93.1%, 27/29), the arachnoid pits in the middle cranial fossa in 30 cases (100%). Conclusions The spontaneous CSF fistula coexists with intracranial hypertension. The combined application of CT and MRI can accurately identify the fistula with accompanying symptom and the intracranial hypertension.

Objective To investigate 16-slice spiral CT findings of bony canals of the internal auditory canal ( IAC ) fundus withmultiplanar reformation (MPR) and provide evidence for dignosis of lesions in the IAC fundus and surgery.Methods CT scan of thetemporal bone was performed in 30 volunteers. Bony canals of the IAC fundus were measured in images acquired with MPR.Results The mean?SD measurements (in mm) of the anteroposterior diameter and superoinferior diameter of fundus of the IAC was (4.07?0.97) mm and (3.24?0.88) mm respectively. The mean?SD measurements (in mm) of the length and width of bony canal for the labyrinthinesegment of the facial nerve was (3.04?0.52) mm and (0.96?0.31) mm, respectively. The mean?SD measurements (in mm) of the length and width of bony canal of the superior vestibular nerve was (2.52?0.48) mm and (0.83?0.30) mm respectively. The mean?SD measurements (in mm) of the length and width of bony canal of the cochlear nerve was (0.89?0.19) mm and (2.05?0.39) mm respectively. The mean?SD measurements ( in mm ) of the length and width of bony canal of the inferior vertibular nerve was ( 1.07?0.23 ) mm and (0.73?0.21) mm respectively. The mean?SD measurements ( in mm ) of the length and width of singular canal was (3.56?0.68) mm and (0.56?0.11) mm respectively . Conclusion MPR with 16-slice spiral CT can demonstrate the shape and measurements of the IAC fundus,which would contribute in dignosis of lesions in the IAC fundus and surgery.

Objective To investigate diagnostic value of CTA for traumatic pseudoaneurysms (TPA) in the cavernous segment of the internal carotid artery (ICA) when they rupture into the sphenoid sinus. Methods CTA of 7 patients with TPA in the cavernous segments of ICA verified by DSA were retrospectively analyzed. All the patients were performed CTA scanning. The post-processing techniques included VR,MIP,MPR, and CPR. Results All the CTA images of 7 patients showed irregular mass in the sphenoid sinus with obviously enhancement in the same phase to ICA, which communicating with ICA in wide base. The peripheral area of the mass showed no enhancement. The size varied from 3 mm × 2 mm × 1 mm to 33 mm × 30 mm × 27 mm. The adjacent lateral wall of sphenoid sinus showed fractures in all cases. TPA located at anterior-knee segments of cavernous ICA in 6 cases, and cavernous free segment in 1 case. All the disruptions were found at medial or anterior medial wall of ICA. Conclusions Cranial CTA is the effective non-invasive method for diagnosing TPA in the cavernous segment of ICA when they rupture into sphenoid sinus. Combined using of VR, MIP, MPR, and CPR can delineate the location and size of the sphenoid wall fracture and the ICA rupture, which help to clarify the anatomical relationship between them.

Objective To study the MRI features of nasopharyngeal carcinoma (NPC) in patients who presented with ocular abnormalities. Methods The clinical signs and MRI features of Ⅲ, Ⅳ and/or Ⅵ cranial nerve involvement in 22 cases of histologically proved nasopharyngeal carcinoma were retrospectively analyzed. Results All 22 cases showed perineural tumor spread along the course of Ⅲ, Ⅳ and Ⅵ cranial nerve. Diplopia was the most common sign, occurred in 14/22 patients. The incidence of incomplete palsy of Ⅲ, Ⅳ and Ⅵ cranial nerve were 16/44, 7/44 and 4/44, respectively. There were four types of abnormal MRI findings: cavernous sinus thickening (10/44) and mass ( 16/44), superior orbital fissure enlargement (4/44) and abnormal signals (9/44), thickened oculomotor muscles with obscured adjacent fatty space and abnormal enhancement (10/44). The dynamic contrast enhancement patterns of the masses in cavernous sinus and orbital were the same as that of nasopharynx lesions; all appeared as rapid initial enhancement followed by a plateau phase. Conclusion Oculomotor nerve involvement can be the first clinical signs of NPC, and MRI can show the perineural extension along the Ⅲ, Ⅳ and Ⅵ cranial nerve in NPC.

Objective To investigate the value of CT and MRI in diagnosing nasopharyngeal angiofibromas.Methods 18 cases of nasopharyngeal angiofibromas were retrospectively analyzed including the location, density ,signal intensity, extension of tumors and changes of surrounding bones.Results 16 cases located in the area around sphenopalatine foramen. 6 cases exhibited homogeneous density on CT scans(6/11 cases) and 12 cases displayed inhomogeneous signal intensity on MR scans(12/14 cases). All the Fourteen MRI examinations revealed vice signal by vessels, inhomogeneous enhancement and extensive invasion along the foramina or fissures.Conclusion MRI not only determines the location and traces out the extension of nasopharyngeal angiofibroma more exactly, but also displayes its diagnostic signal fashion. Namely MRI has greater value in diagnosing this tumor than CT.

Objective To analyse the imaging characteristics of the complications after nasal endoscopy.Methods The imaging findings of complications after nasal endoscopy were analyzed in comparison with clinic retrospectively.Results Among 18 patients,there were 15 cases with orbital bone defect (14 cases were at the medial wall),split of medial straight muscle in 1 case,6 cases with orbital inflammation, tortuous and grown optic nerve with indefinite margin in 5 cases,7 cases with local cranial base defect(the ethmoid plate in 5 and the superior wall of sphenoidal sinus in 2),2 cases with meningoencephalocele at defective ethmoid plate ,2 cases with cerebral spinal fluid nasal leak at defective right ethmoid plate and the superior wall of sphenoidal sinus in one respectively and 1 case with left nasolacrimal duct injury.Conclusion CT can definite the location and extent of the complications after nasal endoscopy,while MRI can be used in the diagnosis of the more complex complications of which.

Objective To analyze the MRI findings of the optic chiasmal lesions, and to evaluate the value of MRI in demonstrating the optic chiasmal lesions. Methods MRI findings in 117 cases of optic chiasmal lesions confirmed by clinical data or pathology were analyzed retrospectively. There were 54 males and 63 females, with the age from 9 months to 67 years, mean 37.4 years. Results There were 24 (20.5%) cases with direct involvement of the optic chiasms. 11 of them were gliomas of the optic chiasm which showed enlargement or mass of the optic chiasms with involvement of optic nerves and/or optic tracts. Diffuse enlargement of optic chiasm with inflammation of adjacent structures, particularly meninges, was found in 5 cases of inflammation. Metastases were found in 5 cases, of which optic chiasm involved by retinoblastoma spreading along optic nerves were found in 4 cases, and linear enhancement of optic chiasm was found in 1 case. Circumscribed enhancement of the optic chiasm with mass of optic nerve was found in 1 meningioma. Abnormal shape of optic chiasm with encephalomalacia of the frontal lobe was found in 1 case of trauma. Irregular enlargement of the optic chiasm showing short T 1 and long T 2 signal was found in 1 case of intrachiasmal hemorrhage. The displacement of the optic chiasms compressed by the lesions arising from adjacent structures was revealed on MRI in 93 (79.5%) cases. Of which superior displacement of the optic chiasms was found in 51 patients, anterior displacement in 2 cases, inferior displacement in 10 cases, and posterior displacement in 1 patient. Only one aspect of the optic chiasms was compressed by the lesions in 13 cases, and the optic chiasms were poorly defined in 16 patients. Conclusion MRI could accurately show the optic chiasmal lesions, which could contribute to clinical diagnosis and treatment.

Objective To investigate the imaging manifestations of metastasis in the nasal cavity and paranasal sinuses. Methods Twelve lesions of 10 patients with pathologically proved metastasis were retrospectively reviewed, including 6 renal clear cell carcinoma, 2 pulmonary adenocarcinoma, 1 colorectal carcinoma and 1 hepatic carcinoma. All the patients underwent CT and MRI scan.Among them,9 patients had contrast enhanced MRI scan and 5 patients had dynamic contrast-enhenced MRI as well. The location, bone changes, shape,margin,density,signal intensity, and enhancement characteristics of the lesions were observed. Results The metastasis involved spheno-ethmoid area(n=3), ethmoid sinus (n=2), maxillary sinus (n=2), nasal cavity(n=2), fronto-ethmoid area(n=2) and sphenoid sinus (n=1). All 12 metastatic lesions demonstrated bone destruction with tumor bone formation in 1 lesion. The CT displayed 10 metastases showed equal density, one mixed density was high, another form of low-density mixed. MR imaging showed equal signal in 9 lesions, while low-mixed signal in 3 lesions on T1WI compared with grey matter were found. On T2WI, 11 lesions showed high mixed signal and homogeneous low signal in 1 lesion. All 12 lesions demonstrated markedly heterogenous enhancement after intravenous administration of contrast media. Of 5 cases with dynamic contrast-enhanced MRI scanning, 4 lesions demonstrated wash-out time-signal intensity curve (TIC) pattern and 1 lesion demonstrated plateau pattern. Conclusions Renal carcinoma is the most common primary tumor for nasal cavity and paranasal sinuses metastasis. A typical imaging finding is located in the ethmoid sinuses, the soft tissue mass surrounded with rich blood supply multiple sinuses and significant bone destruction.

Objective To investigate the diagnostic value of apparent diffusion coefficient in the evaluation of sinonasal masses.Methods Sixty-seven sinonasal solid masses over 1 cm in diameter confirmed by pathology were retrospectively analyzed,all patients underwent preoperative routine MRI with DWI,the ADC values were measured in ROI within the solid mass.The patients were divided into benign and malignant groups by the histopathology,according to pathological findings,the patients were further divided into the hematolymphoid tumors,the malignancy of epithelium and mesenchymal tissue,the benign tumors of epithelial and mesenchymal tissue,and vasogenic masses.ANOVA test and t test were used to compare the ADC values of different groups.The receiver operating characteristic curve (ROC) was constructed using various cut points of ADC for different parameters to confirm the diagnostic threshold value and evaluate the diagnostic efficacy.Results All lesions were solitary.There were 22 malignant tumors,of which 6 lesions were hematolymphoid tumors and 16 lesions malignancy from epithelium and mesenchymal tissue.There were 45 benign tumors,of which 22 lesions were benign tumors from epithelium and mesenchymal tissue and 23 lesions vasogenic masses.The mean ADC value of malignant and benign masses was(0.88 ± 0.26) × 10-3 mm2/s and (1.54 ± 0.41) × 10-3 mm2/s respectively.There was statistically significant differences between them (t =6.897,P ＜ 0.01).The mean ADC value was(0.63 ± 0.10) × 10-3 mm2/s in hematolymphoid tumors,(0.97 ±0.24) × 10 3 mm2/s in malignancy from epithelium and mesenchymal tissue,(1.38 ± 0.23) × 10-3 mm2/s in benign tumors from epithelium and mesenchymal tissue,(1.68 ± 0.49) × 10-3 mm2/s in vasogenic masses respectively.There was statistically significant difference among all 4 groups(F =22.788,P ＜ 0.01),and the differences between any 2 groups were still statistically significant(P ＜ 0.05).The area under the ROC calculated was 0.945.Using an ADC value of 1.08 × 10-3 mm2/s as the threshold value for differentiating malignant from benign lesions,the best result obtained had a sensitivity of 81.8％ (18/22),specificity of 97.8％ (44/45),accuracy of 92.5 ％ (62/67).Conclusion The ADC value is a valuable tool in differentiating benign from malignant masses and different kinds of masses in sinus and nasal cavity.