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 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 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 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 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.

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 study the CT and MRI findings of schwannoma in tIle sinonasal region and evaluate their clinical application.Methods All 12 cases of schwannoma locating in the sinonasal region were verified by pathology.r111e CT images in all 12 cases and MRI findings in 10 cases were analyzed retrospectively.Results Of the 12 cases of schwannoma in the sinonasal cavity.11 were benign and l was malignant.The tumors located in the nasoethmoid region in 4 cases.in the maxillary sinus in 3 cases and in the maxillary.ethmoid and sphenoid sinuses in 2 cases.The lesion of the remaining 3 cases involved maxillary sinus and hasal cavity,sphenoid sinus and choana respectively.The lesions with well-defined margin showed elliptic shape in 4 cases,irregular shape in 8 cases.On CT,the lesion resulted in dilatation of the affected sinonasal cavity with remodeling,thinning and displacement of the bony wall.In addition.local bony absorption was detected in 8 cases and bony destruction was found in 1 case.The lesions revealed homogeneous density in 10 cases and inhomogeneous in 2 on precontrast CT.Two cases showed heterogeneous enhancement on postcontrast CT. On MR T1WI,schwannoma in the sinonasal region demonstrated isointense signal compared to brain in 10 cases with patchy and nodular low signal intensity in 3 cases and patchy hish signal intensity in 2 cases.On T2 WI.the lesion showed heterogeneous isointense singal in 7 cases and slightly hyperintense signal in 3 cases.Stippled and patchy hyperintense signal was seen in 9 cases and well-defined and regular nedular high intense signal in 6 cases.Patchy low signal intensity was found in 2 cases corresponding to the high signal intensity on MR Tl WI.In addition,liquid-iquid level was identified in one case.The lesion displayed rooderate to marked inhomogeneous enhancement on contrast-enhanced MR images in 9 cases and marked homogeneous enhancement in one case.The time.intensity curve of dynamic contrast enhancement of MRI showed plateau type in 2 cases.In this group,the lesions were complicated with obstructive parasinusitis in 6 cases.which showed hypointense signal on MR T1 WI,hyperintense signal on T,WI and peripheral enhancement on postcontrast MRI.MRI showed the extent and other associated changes of the lesions more clearly compared to CT Conclusions Bone remodeling.thinning and absorption on CT and Patchy and noduhr high signal intensity on MR T2WI without postcontrast enhancement were typical manifestations of schwannoma in the sinonasal region.Combined findings of CT and MRI call provide more comprehensive information for the diagnosis and therapy.

Objective To study the CT and MR characteristic features of the respiratory epithelial adenomatoid hamartoma of olfactory clefts. Methods (1)The CT and MRI findings of 29 patients with histologically proved respiratory epithelial adenomatoid hamartoma in the olfactory clefts were retrospectively reviewed.All patients underwent CT and 8 of them underwent MRI. Location, CT and MRI features, and associated findings of the disease were reviewed;(2)The CT findings, olfactory clefts width, total nasal distance, and the ratio of OC to the total nasal distance of the case patients (29 cases) and the control patients (33 patients with sinusitis) were compared to investigate the correlation of the olfactory clefts distance and the incidence of respiratory epithelial adenomatoid hamartoma in olfactory clefts. Results All patients were associated with sinusitis, and 23 had sinonasal polyps, 1 had papilloma. On nonenhanced CT, the OC lesions with the OC widening were isodense to gray matter in all cases, and the lesions caused the adjacent bony expansion and absorption rather than erosion; 15 cases were bilateral diseases and 14 were unilateral;The olfactory clefts width of the case patients and the control patients were (1.03±0.24) cm, (0.71± 0.17) cm, respectively. There was statistically significant difference (t=4.963, P<0.01) for the olfactory clefts width between the case patients and the control patients, and there was no significant difference (t=1.640, P>0.05) for the total nasal distance, and was significant difference(t=6.029,P<0.01)in the ratio of OC to the total nasal distance between the two groups. On T1WI, the disease appeared isointense in 6 patients and slightly hypointense in 2 patients compared with gray matter. On T2WI, the lesions revealed heterogeneous isointense in all patients. Regular cribriform pattern was found on MR T2WI and enhanced TlWI. Conclusions The unilateral or bilateral olfactory cleft opacification in chronic sinusitis patients with or without sinonasal polyposis, with involved OC widening and the adjacent bony walls compressed and remodeled may highly suggests the presence of REAH in the OC. The lesions showed inhomogeneous isointense signal on T2WI images, regular cribriform pattern enhancement are typical imaging feature of this entity.

Objective To investigate the MRI findings of perihip heterotopic ossification (HO) in the early, mid and late stages. Meth-ods The MRI of 44 inpatients with HO from February, 2011 to September, 2013 were reviewed, in which 20 cases (28 joints) were in early stage, 18 cases (24 joints) in mid stage and 6 cases (8 joints) in late stage. For the enhanced T1WI, 9 cases (11 joints) were in early stage, 6 cases (7 joints) in mid stage, and 3 cases (4 joints) in late stage. Theχ2 trend test was used to evaluate the MRI signal change with the HO maturity. Results With the maturity of hip HO, the signal intensity of T2WI reduced (χ2=16.773, P<0.001), fat signal on T1WI increased, the enhancement reduced (χ2=16.048, P=0.007). Conclusion The MRI findings of perihip HO are characteristic in MRI in all the stages. MRI is useful for the diagnosis of perihip HO, especially for the early HO.