To improve the teaching effect of head and neck imaging and to further train most high quality talents majoring in head and neck imaging,some teaching experiences were summarized in this article. First,the‘step teaching method’was put forward for students to master the head and neck imag-ing anatomy. Second,students were taught to familiarize the imaging modalities of head and neck and to know the optimal imaging pathway and protocol of this region. Last, students were taught to develop good ideas for analyzing imaging of head and neck disease including localization diagnosis and characteri-zation diagnosis. Additionally,teaching supervision system,including taking notes,attending morning shifts,following up patients and reading literatures,was established for students.

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 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.

Objective To explore the MRI features of solitary fibrous tumor(SFT)in the orbit.Methods The MRI findings of 7 patients with SFT in the orbit confirmed by histopathology were analyzed retrospectively.Re sults Of the 7 lesions,5 occurred in the right orbit and 2 in the left orbit.Six lesions were located in the extraconal space near the lacrimal gland fossa,including 5 in the superomedial region and 1 in the inferolateral region.The other one was located in the retrobulbar intraconal space.The lesions with well-defined margin showed elliptic shape in 6 cases and lobulated configuration in 1.The maximum diameter of the lesions ranged from 18 to 40 mm(mean,31 mm).The lesions showed homogeneous isointense relative to gray matter on T1-weighted images in 6 patients.On T2-weighted images,the lesions showed heterogeneous hypointense in 5 patients,isointense and hyperintense in one patient respectively.SFT demonstrated markedly homogeneous enhancement in 6 patients and inhomogeneous enhancement in one patient The time-intensity curves(TIC)of 7 patients exhibited a rapidly enhancing and rapid washout pattern on dynamic contrast-enhanced(DCE)MRI.Conclusion Hypointense signal on T2WI,marked enhancement on contrast-enhanced T1 WI,and a rapidly enhancing and rapid washout pattern TIC on DCE MRI are the typical MRI features of orbital SFT.

Objective:To evaluate the value of CT in the diagnosis of skeletal metastases from hepatoma.Methods:27 patients proved by clinical or pathological materials were analysed retrospectively.Results:All the lesion were osteolytic on CT scans.The most frequently involved areas were spine(26%),ribs(22%),pelvis(19%)and femur(11%).Conclusion:CT scan is superior to X-ray plain flims in showing the lesions.Most foci can be diagnosed accurately.

Objective To investigate the imaging findings of early heterotopic ossification. Methods The imaging findings of 30 rehabilitation patients with heterotopic ossification were analyzed. Results The early heterotopic ossification performance of X-ray and CT showed articular soft tissue edema, and higher density. MR images showed different signal characteristics at different stages of heterotopic ossification. Immature bone performance the same or long T1 and T2 signal, enhanced scan showed the edge of the lace-like "strengthen". Conclusion Heterotopic ossification at different stages shows different imaging features. Magnetic resonance imaging is the best effective methods for the diagnosis of early ectopic ossification, X-ray and CT can be used for review.

Objective To characterize the regular and the dynamic contrast enhancement MR imaging in choroidal hemangioma.Methods MR imaging findings of 30 cases (31eyes, 32 lesions) with choroidal hemangioma confirmed by follow-up results were retrospectively analyzed.Among them, postcontrasted T1-weighted imaging was performed in 30 patients and dynamic contrast enhancement scanning was performed in 26 cases.MRI findings and the time-intensity curve of dynamic contrast enhancement were analyzed.Results Among the 32 choroidal hemangiomas, 26 of them were at the temporal side of optic disc and 28 lesions were fusiform.Before enhancement, 23 lesions showed isointense T1-weighted signal and 31 lesions were isointense on T2-weighted imaging.All the lesions showed strong enhancement on postcontrast T1-weighted imaging, including 31 homogenously enhanced lesions and one heterogeneously enhanced lesion.Retinal detachments were found in 18 eyes.Fill-in sign were observed in 12 lesions during dynamic contrast enhancement.The time-intensity curve of dynamic contrast enhancement in 28 lesions suggested a pattern with rapid enhancement and slow washout, time to peak (91.00±25.27) s, slope ratio 3.03±1.13, the median of washout ratio 17.06%, enhancement ratio 2.87±0.79.Conclusion MRI showed a few features of the location, shape, signal characteristics, and enhancement pattern in choroidal hemangioma, which may contribut to diagnosis and treatment plan of this disease.

Objective To determine the CT and MRI features of the sinonasal cavity. Methods The CT and MRI of nine patients with histologically proved hemangiopericytoma in the sinonasal cavity were retrospectively reviewed. All nine patients underwent CT and seven of them underwent MRI. In addition, the time-intensity curve (TIC) of dynamic contrast-enhanced (DCE) MRI were analyzed in three patients. Results The lesions were from the nasal cavity in 5 cases, the maxillary sinus in 3 cases, and the sphenoid sinus in one case. The lesions appeared spindle in 4 cases, oval in 3, and irregular in 2. The mean maximum diameter of the lesions was 31 mm (range, 15 to 52 mm). Seven hemangiopericytomas had welldefined margins and 2 had ill-defined margins. On plain CT, the lesions were isodense to gray matter in six (66. 7% ) and slightly hyperdense in three (33. 3% ) patients. Only two patients had post-contrast CT and the tumors showed marked enhancement. The lesions caused adjacent bony compression and absorption in 7 cases and bony destruction in 2. On MR T1WI, hemangiopericytomas appeared hypointense in 3 (42. 8% ) patients and isointense in 4 (57. 2% ) patients. On T2WI, the lesions appeared hyperintense in three (42.8%) patients and isointense in four (57.2%) patients. On T1WI, all the lesions showed relatively homogeneous signal, while 2 lesions revealed heterogeneous signal on T2WI. Hemangiopericytomas showed marked homogeneous contrast enhancement in 4 cases and heterogeneous contrast enhancement in 3.TIC showed a steady enhancement pattern in 3 patients. The lesions involved the orbit in 2 cases and,cavernous sinus, anterior skull base meninge, pterygopalatine fossa and infratemporal fossa in one case. Five patients underwent follow-up for two to eight years after surgery. Two patients were found to have recurrence.Conclusions Marked enhancement and steady enhancement pattern of TIC on MRI are typical manifestations of hemangiopericytoma of the sinonasal cavity. Bone changes may help to identify the nature of the lesion. Imaging can accurately detect the scope of hemangiopericytoma in this region.

ObjectiveTo investigate the MRI appearance of malignant melanoma in the sinonasal tract and nasopharynx.MethodsMRI Findings and clinical data from 8 patients with biopsy or operation proved malignant melanoma were retrospectively reviewed.Gadolinium-enhanced imaging and dynamic contrast enhancement scanning were performed in all cases.ResultsThe majority of lesions were located in the nasopharynx (n =2),middle turbinate (n =1 ),or a combination of the nasal cavity,ethmoidal sinus,and maxillary sinus ( n =5 ).The aggressive nature of the tumors was demonstrated by bone destruction ( n =5 ) and invasion of adjacent structures,involving anterior fossa (n =2 ),orbits (n =4 ),infratemporal fossa ( n =2 ),pterygopalatine fossa ( n =3 ),and parapharyngeal space ( n =1 ).The MRI appearance included two patterns.In the first pattern,the tumors were round and small (smaller than 2 cm in maximum dimension in three patients).MR signal intensity of the lesions was hyperintense to gray matter on T1 WI and hypointense on T2.In the second pattern,the lesions were irregular and large ( larger than 3 cm in maximum dimension in five patients).They showed heterogeneous low-signal on T1 WI.On T2WI,one lesion showed isointensity or little hypo-intensity,and four lesions showed hyperintense.They demonstrated mild heterogeneous enhancement on gadolinium-enhanced images.Four patients demonstrated as plateau type time-signal intensity curve (TIC) pattern,and another four patients demonstrated as wash-out type TIC pattern.ConclusionsThe MR signal characteristic of the malignant melanoma in the sinonasal tract and nasopharynx were related with the tumor size.When the lesion was small,the MR signal intensity was more typical.When the lesion was large,they had mixed signal intensity as other malignant tumors,and specific mild heterogeneous enhancement.

Objective To explore the features of inflammatory pseudotumor in the maxillary sinus on CT and MRI.Methods The CT and MRI data of 8 patients with histology-proven inflammatory pseudotumor in the maxillary sinus were retrospectively analyzed.All 8 patients underwent CT scans and 7 of them also underwent MRI examinations.In addition, the time-intensity curve (TIC) of dynamic contrast-enhanced (DCE)MR imaging were analyzed in 3 patients.Results Two cases had lesions in the left maxillary sinus, while the others showed lesions in the right maxillary sinus.All the lesions showed irregular shape with well-defined margins in 5 cases and hazy margins in 3 cases.The mean maximum diameter of the lesions was 51 mm (ranged from 29 mm to72 mm).On non-enhanced CT, the lesions were isodense to gray matter in 6 and slightly hypodense in 1 patients.Only 2 patients had post-contrast CT with moderate enhancement of their lesions.The lesions caused adjacent bony absorption and destruction with residual bony sclerosis.On MR T_1 WI, inflammatory pseudotumor showed hypointense in 2 patients and isointense in 5 cases in relative to gray matter.On T_2 WI, the lesions revealed inhomogeneous hypointense in 6 patients and isointense in 1 patients.Inflammatory pseudotumor showed heterogeneously slight contrast enhancement in 2 cases and moderate enhancement in 5 cases.The TIC showed a steady enhancement pattern in 3 patients.The lesions extended to nasal cavity in 6 cases, pterygopalatine fossa and infratemporal fossa in 4, orbit in 4, and cheek in 3 cases.Six patients underwent follow-up for 2-5 years after surgery and 2 of them were found to have recurrence.In comparison to CT, MRI was proved to show the extent of the lesions more clearly.Conclusions Bony destruction with sclerosis and hypointense signal on MR T_2 WI are typical manifestations of inflammatory pseudotumor in the maxillary sinus.Combined CT and MRI can provide clinicians with more comprehensive information for the diagnosis, therapy, and follow-up of these lesions.