With the development of various imaging equipments and technologies,the manifestation capability of disease raised, and the application fields extended.Imaging examinations including CT and MRI should play a more marked role in the diagnosis and definition of treatment plans in ophthalmic diseases.(Ophthalmol CHN,2007,16:289-290)

Objective To measure the size and area of the vestibule of normal inner ear to provide basic data for further study of the vestibule-related diseases.Methods Two hundred forty patients (480 ears) who underwent temporal bone 64 slices CT scans were enrolled in this study from April 2011 to July 2012.These patients were divided into 4 groups,including Child group (＜ 18 years),Youth group (18-44 years),Adult group (45-59 years),and Elder group (≥ 60 years).The size and area of the vestibules were measured on the multiplanar reformatted images in post-processing workstation.Results There were no statistically significant differences in the size and area of vestibules in sides,genders and among the different groups (P ＞ 0.05),while there were statistically significant differences of those in different positions (P ＜ 0.05).Conclusion The measurements in different planes were as follow:1) In axial plane,the length of vestibule and its 95％ confidence interval were (5.89 ± 0.34),5.22-6.56 mm,respectively; the width (2.47 ± 0.36),1.76-3.18 mm; the area(13.97 ± 1.71) 10.62-17.32 mm2 2) in coronal plane,the length of vestibule and its 95％ confidence interval were (5.10 ± 0.32),4.47-5.73 mm,respectively; the width (2.42 ± 0.21),2.01-2.83 mm; the area (11.30 ± 1.33),8.69-13.91 mm2 ;3)in sagittal plane,the length of vestibule and its 95 ％ confidence interval were(5.27 ± 0.33),(4..62-5.92) mm,respectively; the width (3.72 ± O.35),(3.03--4.41) mm; the area (13.77 ± 1.55),(10.73-16.81)mm2.The volume CT combined with post-processing technology can accurately measure the size and area of the vestibules.The data can provide quantitative basis for diagnosis of the vestibule-related diseases.

Functional imaging is a newly arisen interdisciplinary subject compared with the routine radiology displaying anatomy and morphology of lesions. It can exhibit the function-changed information, such as blood flow and metabolism of organs and tissues as visual images or data to provide organizational functions and metabolic information, which makes early diagnosis, more accurate orientation, qualitative definition, and also the prognosis judgment. The ophthalmologists should pay more attention to the functional imaging applications in the field of neuro-ophthalmology.

The function of the retina is sensitive to oxygen tension, and any changes in oxygen perfusion associated with retinal vessel diseases, such as diabetic retinopathy could affect inner retinal oxygen responses (ΔPO_2). However, the application of currently available techniques in measurements of the retinal oxygenation is limited. Recently, with the development of MRI, it is possible to detect ΔPO_2 noninvasively, and the effects are satisfactory. The application of MR based measurements of ΔPO_2 following the shift from breathing room air were reviewed in this article.

With the rapid development of modem medical imaging technology,imaging examination especially CT and MRI plays an increasingly important role in the quantitative analysis of ophthalmic diseases,including the measurement of orbital volume with CT, the morphological changes of extraocular muscles in different eye positions,changes of oxygen pressure of the retina and the breakdown of blood-retinal barrier,the quantitative analysis of fiber bundles of visual pathway and so on.In this paper,a brief review was made about the application of imaging measurement with CT and MRI in ophthalmic diseases.

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 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 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 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 assess the value and limitation of the ultrasonography in diagnosis of vocal cord paralysis(VCP).METHODS We analyzed the ultrasound images of 33 patients with VCP,which were confirmed by laryngoscope.RESULTS Among the 33 cases,30 with unilateral VCPs were shown with ultrasound,having the vocal cords with distortion(n=18)and reduced movement or immobilization(n=27),enlarged fissure of the glottis(n=19),arytenoid cartilage with reduced movement or immobilization(n=30),distended piriform sinus(n=25),and posterior cricoarytenoid muscle with increased echogenicity and decreased thickness(n=10);3 with bilateral VCPs were diagnosed in ultrasound examination,all of which had distortion of vocal cord,enlarged fissure of glottis,and reduced movement of arytenoid cartilages.Ultrasonographic appearances were correlated with laryngoscope findings,with consistency rates of 93.9% for VCPs.CONCLUSION Ultrasonography,in particular observing movement of arytenoid cartilages,could be a non-invasive and effective alternative method in diagnosis of VCP.