Diffusional kurtosis imaging in differentiating nonarteritic anterior ischemic optic neuropathy from acute optic neuritis.

PURPOSE: We aimed to determine the feasibility of using DKI to characterize pathological changes in nonarteritic anterior ischemic optic neuropathy (NAION) and to differentiate it from acute optic neuritis (ON). METHODS: Orbital DKI was performed with a 3.0 T scanner on 75 patients (51 with NAION and 24 with acute ON) and 15 healthy controls. NAION patients were further divided into early and late groups. The mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), mean diffusivity (MD), fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD) were calculated to perform quantitative analyses among groups; and receiver operating characteristic curve analyses were also performed to determine their effectiveness of differential diagnosis. In addition, correlation coefficients were calculated to explore the correlations of the DKI-derived data with duration of disease. RESULTS: The MK, RK, and AK in the affected nerves with NAION were significantly higher than those in the controls, while the trend of FA, RD, and AD was a decline; in acute ON patients, except for RD, which increased, all DKI-derived kurtosis and diffusion parameters were significantly lower than controls (all P < 0.008). Only AK and MD had statistical differences between the early and late groups. Except for MD (early group) and FA, all other DKI-derived parameters were higher in NAION than in acute ON; and parameters in the early group showed better diagnostic efficacy in differentiating NAION from acute ON. Correlation analysis showed that time was negatively correlated with MK, RK, AK, and FA and positively correlated with MD, RD, and AD (all P < 0.05). CONCLUSION: DKI is helpful for assessing the specific pathologic abnormalities resulting from ischemia in NAION by comparison with acute ON. Early DKI should be performed to aid in the diagnosis and evaluation of NAION.

Preoperative Transarterial Embolization of Advanced Juvenile Nasopharyngeal Angiofibroma Using n-Butyl Cyanoacrylate: Case-Control Comparison with Microspheres.

PURPOSE: To evaluate the efficacy and safety of transarterial embolization (TAE) with n-butyl cyanoacrylate (nBCA) for juvenile nasopharyngeal angiofibroma (JNA). MATERIALS AND METHODS: A retrospective review was performed on patients with JNA who underwent TAE and endoscopic resection between 2020 and 2022. Patients embolized with nBCA were identified, and those embolized with microspheres were set as the control group. Data on demographics, symptoms, tumor characteristics, blood loss, adverse events, residual disease, and recurrence were collected, and case-control analysis was performed for the 2 groups. Differences in characteristics between the groups were tested using the Fisher exact and Wilcoxon tests. A generalized linear model (GLM) was used to analyze the univariate and multivariate influences on blood loss. RESULTS: Twenty patients were included in this study: 13 in the microsphere group and 7 in the nBCA group. The median blood loss was 400 mL (interquartile range [IQR], 200-520 mL) in the nBCA group and 1,000 mL (IQR, 500-1,000 mL) in the microsphere group (P = .028). The GLM confirmed lower blood loss in the nBCA group (relative risk, 0.58 [0.41-0.83]; P = .01). A residual tumor was found in 1 patient in each group (7.7% vs 14.3%; P = 1.000). Recurrence was not observed in any patient. None of the patients experienced adverse events during embolization. CONCLUSIONS: TAE of advanced JNA with nBCA glue is safe and effective and can significantly reduce intraoperative blood loss compared with microspheres.

Whole-tumor histogram analysis of apparent diffusion coefficient maps with machine learning algorithms for predicting histologic grade of sinonasal squamous cell carcinoma: a preliminary study.

PURPOSE: Accurate histologic grade assessment is helpful for clinical decision making and prognostic assessment of sinonasal squamous cell carcinoma (SNSCC). This research aimed to explore whether whole-tumor histogram analysis of apparent diffusion coefficient (ADC) maps with machine learning algorithms can predict histologic grade of SNSCC. METHODS: One hundred and forty-seven patients with pathologically diagnosed SNSCC formed this retrospective study. Sixty-six patients were low-grade (grade I/II) and eighty-one patients were high-grade (grade III). Eighteen histogram features were obtained from quantitative ADC maps. Additionally, the mean ADC value and clinical features were analyzed for comparison with histogram features. Machine learning algorithms were applied to build the best diagnostic model for predicting histological grade. The receiver operating characteristic (ROC) curve was used to evaluate the performance of each model prediction, and the area under the ROC curve (AUC) were analyzed. RESULTS: The histogram model based on three features (10th Percentile, Mean, and 90th Percentile) with support vector machine (SVM) classifier demonstrated excellent diagnostic performance, with an AUC of 0.947 on the testing dataset. The AUC of the histogram model was similar to that of the mean ADC value model (0.947 vs 0.957; P = 0.7029). The poor diagnostic performance of the clinical model (AUC = 0.692) was improved by the combined model incorporating histogram features or mean ADC value (P < 0.05). CONCLUSION: ADC histogram analysis improved the projection of SNSCC histologic grade, compared with clinical model. The complex histogram model had comparable but not better performance than mean ADC value model.

Dual-energy CT in differentiating benign sinonasal lesions from malignant ones: comparison with simulated single-energy CT, conventional MRI, and DWI.

OBJECTIVES: To explore the value of dual-energy CT (DECT) for differentiating benign sinonasal lesions from malignant ones, and to compare this finding with simulated single-energy CT (SECT), conventional MRI (cMRI), and diffusion-weighted imaging (DWI). METHODS: Patients with sinonasal lesions (38 benign and 34 malignant) who were confirmed by histopathology underwent DECT, cMRI, and DWI. DECT-derived parameters (iodine concentration (IC), effective atomic number (Eff-Z), 40-180 keV (20-keV interval), virtual non-enhancement (VNC), slope (k), and linear-mixed 0.3 (Mix-0.3)), DECT morphological features, cMRI characteristics, and ADC value of benign and malignant tumors were compared using t test or chi-square test. Receiver operating characteristic (ROC) curve was performed to evaluate the diagnostic performance, and the area under the ROC curve (AUC) was compared using the Z test to select the optimal diagnostic approach. RESULTS: Significantly higher DECT-derived single parameters (IC, Eff-Z, 40 keV, 60 keV, 80 keV, slope (k), Mix-0.3) were found in malignant lesions than those of benign sinonasal lesions (all p < 0.004, Bonferroni correction). Combined quantitative parameters (IC, Eff-Z, 40 keV, 60 keV, 80 keV, slope (k)) can improve the diagnostic efficiency for discriminating these two entities. Combination of DECT quantitative parameters and morphological features can further improve the overall diagnostic performance, with AUC, sensitivity, specificity, and accuracy of 0.935, 96.67%, 90.00%, and 93.52%. Moreover, the AUC of DECT was higher than those of Mix-0.3 (simulated SECT), cMRI, DWI, and cMRI+DWI. CONCLUSIONS: Compared with simulated SECT, cMRI, and DWI, DECT appears to be a more accurate imaging technique for differentiating benign from malignant sinonasal lesions. KEY POINTS: • DE can differentiate benign sinonasal lesions from malignant ones based on DECT-derived qualitative parameters. • DECT appears to be more accurate in the diagnosis of sinonasal lesions when compared with simulated SECT, cMRI, and DWI.

Oculomotor Nerve Palsy Due to Unusual Causes.

BACKGROUND: An isolated oculomotor nerve (CN III) palsy is a diagnostic concern because of the potential for serious morbidity or life-threatening causes. We present 5 unusual causes of oculomotor nerve palsy that escaped initial diagnosis in order to raise awareness of their associated features that will facilitate correct diagnosis. METHODS: This study consisted of a retrospective analysis of clinical features and imaging of 5 patients who were referred for neuro-ophthalmologic evaluation with presumed diagnosis of oculomotor nerve palsy of unknown reasons. RESULTS: A complete CN III palsy and an inferior division CN III palsy were diagnosed with a schwannoma in the cavernous sinus and orbital apex portion, respectively; a middle-aged woman with aberrant regeneration was found to have a small meningioma; an adult man with ptosis was diagnosed with cyclic oculomotor paresis with spasms; and a patient after radiation was diagnosed with neuromyotonia. CONCLUSIONS: Localizing the lesion of oculomotor nerve palsy and careful examination of the imaging is crucial. Aberrant regeneration, cyclic pupil changes, and past medical history of amblyopia, strabismus, or radiation are also very helpful for diagnosis.

Changes of incudostapedial joint angle in stapedotomy: does it impact hearing outcomes?

PURPOSE: The aims of this article are: (1) is there an ideal incudostapedial joint (ISJ) angle after stapedotomy? (2) is there any difference between pre- and postoperative ISJ angle? and (3) what is the significance of the ISJ angle in postoperative hearing outcomes? METHODS: Forty six ears from 39 different adult patients (28 women and 11 men; 21 left and 25 right ears) with a mean age of 39 years with clinical otosclerosis who underwent stapedotomy between May 2017 and May 2019 were retrospectively registered, including seven bilateral surgery cases. ISJ angle and intravestibular depth of the stapes prosthesis were measured from multiple planar reconstruction-computed tomography images and the length of the prosthesis was measured during surgery. Relationships between the ISJ angle parameters and postoperative hearing outcomes and parameters of the prosthesis were analyzed. RESULTS: The mean ISJ angle was 93.3° ± 8.8° preoperatively and 101.9° ± 6.3° postoperatively, increasing by 8.6° during stapedotomy (p < 0.01). There were weak and negative correlations between ISJ angle changes and postoperative air conduction gains at frequencies ≤1 kHz and bone conduction gains at 0.5 kHz. When the postoperative ISJ angle changed more than 20°, the success rate of the procedure decreased to 0%. CONCLUSION: The stapedotomy operation increased the ISJ angle. The success of postoperative auditory outcomes had more to do with the ISJ angle change than the value of the angle itself, indicating there is no universal ideal ISJ angle that surgeons should aim for during stapedotomy.

Performance of TGSE BLADE DWI compared with RESOLVE DWI in the diagnosis of cholesteatoma.

BACKGROUND: Based on its high resolution in soft tissue, MRI, especially diffusion-weighted imaging (DWI), is increasingly important in the evaluation of cholesteatoma. The purpose of this study was to evaluate the role of the 2D turbo gradient- and spin-echo (TGSE) diffusion-weighted (DW) pulse sequence with the BLADE trajectory technique in the diagnosis of cholesteatoma at 3 T and to qualitatively and quantitatively compare image quality between the TGSE BLADE and RESOLVE methods. METHOD: A total of 42 patients (23 males, 19 females; age range, 7-65 years; mean, 40.1 years) with surgically confirmed cholesteatoma in the middle ear were enrolled in this study. All patients underwent DWI (both a prototype TGSE BLADE DWI sequence and the RESOLVE DWI sequence) using a 3-T scanner with a 64-channel brain coil. Qualitative imaging parameters (imaging sharpness, geometric distortion, ghosting artifacts, and overall imaging quality) and quantitative imaging parameters (apparent diffusion coefficient [ADC], signal-to-noise ratio [SNR], contrast, and contrast-to-noise ratio [CNR]) were assessed for the two diffusion acquisition techniques by two independent radiologists. RESULT: A comparison of qualitative scores indicated that TGSE BLADE DWI produced less geometric distortion, fewer ghosting artifacts (P < 0.001) and higher image quality (P < 0.001) than were observed for RESOLVE DWI. A comparison of the evaluated quantitative image parameters between TGSE and RESOLVE showed that TGSE BLADE DWI produced a significantly lower SNR (P < 0.001) and higher parameter values (both contrast and CNR (P < 0.001)) than were found for RESOLVE DWI. The ADC (P < 0.001) was significantly lower for TGSE BLADE DWI (0.763 × 10- 3 mm2/s) than RESOLVE DWI (0.928 × 10- 3 mm2/s). CONCLUSION: Compared with RESOLVE DWI, TGSE BLADE DWI significantly improved the image quality of cholesteatoma by reducing magnetic sensitive artifacts, distortion, and blurring. TGSE BLADE DWI is more valuable than RESOLVE DWI for the diagnosis of small-sized (2 mm) cholesteatoma lesions. However, TGSE BLADE DWI also has some disadvantages: the whole image intensity is slightly low, so that the anatomical details of the air-bone interface are not shown well, and this shortcoming should be improved in the future.

Comparison of Different Slice Thicknesses in Computed Tomography for Labyrinthine Fistula Evaluation.

OBJECTIVES: The aim of the present study is to assess the impact of different slice thicknesses in computed tomography for labyrinthine fistula evaluation and to determine the appropriate slice thickness. METHODS: A total of 258 patients who underwent mastoidectomy and tympanoplasty for chronic otitis media with cholesteatoma from 2010 to 2014 were reviewed. The radiological diagnoses were compared with intraoperative findings. Sensitivity and specificity of 2.0-, 1.5-, 1.0-, and 0.75-mm-thick computed tomographic (CT) images for the evaluation of labyrinthine fistulae were calculated. Cohen's κ coefficient was also calculated. RESULTS: The sensitivities of 2.0-, 1.5-, 1.0-, and 0.75-mm-thick CT images for the evaluation of labyrinthine fistulae were 76.9, 86.5, 90.4, and 93.3% (observer 1) and 67.3, 76.0, 79.8, and 87.5% (observer 2), respectively. The specificities of 2.0-, 1.5-, 1.0-, and 0.75-mm-thick CT images for labyrinthine fistula evaluation were 96.1, 94.8, 95.5, and 95.5% (observer 1) and 99.4, 97.4, 95.5, and 94.8% (observer 2), respectively. Cohen's κ coefficients were 0.790, 0.788, 0.876, and 0.911 in 2.0-, 1.5-, 1.0-, and 0.75-mm-thick CT images, respectively. CONCLUSIONS: The sensitivity of CT for labyrinthine fistula evaluation increases with decreasing slice thickness, while the specificity does not improve.

A Staged Procedure in the Treatment of Primary Lacrimal Sac Epithelial Malignancy: A Retrospective Cases Analysis.

PURPOSE: To determine the effect of a staged procedure in the treatment of primary lacrimal sac epithelial malignancy. METHODS: This is a retrospective case series of 18 consecutive patients with primary lacrimal sac epithelial malignancy treated at an orbital tumor referral center between 2002 and 2017. Study was conducted in compliance with the Declaration of Helsinki. All patients underwent biopsy of the mass to confirm the diagnosis pathologically. Chemotherapy concurrent with radiotherapy was delivered to the patients to reduce and concrete the tumor prior to surgery. En bloc resection of the lacrimal sac malignancy and nasolacrimal duct was followed. RESULTS: Eleven patients were male and 7 patients were female. The median follow-up time was 72.2 months. Nine patients had squamous cell carcinoma, 7 poorly differentiated carcinoma, 1 transitional cell carcinoma, and 1 adenoid cystic carcinoma. After chemotherapy and radiotherapy, the tumor volume was reduced significantly (p < 0.0001). En bloc resection of the lacrimal sac malignancy was performed in all patients with concurrent partial ethmoidectomy in 8 patients and medial maxillectomy in 5 patients. One patient (5.6%) suffered from adenoid cystic carcinoma died of metastatic disease. Two patients (11.1%) with local recurrence received reoperation, and 1 patient (5.6%) with pulmonary metastasis received gamma knife radiosurgery. These patients are alive with no evidence of tumor. Other patients are alive without evidence of disease at last follow up. No patient had new onset of lymph node enlargement during and after the treatment. CONCLUSIONS: The staged procedure is a promising method for the treatment of primary lacrimal sac epithelial malignancy with no postoperative lymph node metastasis.

Diffusion-weighted imaging using readout-segmented echo-planar imaging, parallel imaging, and two-dimensional navigator-based reacquisition in detecting acute optic neuritis.

PURPOSE: To evaluate the accuracy of diffusion-weighted imaging (DWI) in comparison to contrast-enhanced, fat-suppressed T1 -weighted imaging (CET1WI) in detecting acute optic neuritis (ON). MATERIALS AND METHODS: The clinical data and magnetic resonance imaging (MRI) findings of 42 patients who presented with decreased vision were retrospectively reviewed. Both 3.0T MRI DWI and CET1WI orbital imaging studies were performed. Two neuroradiologists independently evaluated the DWI and CET1WI. The sensitivity, specificity, and accuracy of the DWI and CET1WI were individually calculated using the clinical diagnosis as the reference standard. The interobserver and intraobserver reliability of DWI and CET1WI were assessed by using a weighted Cohen's kappa (κ) test; a value of P < 0.05 was set as the threshold for statistical significance. RESULTS: Of the 42 patients, 34 patients (41 nerves) had clinically confirmed acute ON, two had ischemic optic neuropathy, and three had chronic recurrent ON. The sensitivities of DWI and CET1WI for acute ON were 82.9-82.9% and 68.3-85.4%, respectively; the specificities were 81.4-83.7% and 79.1-93.0%, respectively; and the accuracies were 82.1-83.3% and 82.1-90.0%, respectively. The interobserver kappa values were 0.596-0.643 and 0.694-0.734 for DWI and CET1WI, respectively; the intraobserver kappa values were 0.809-0.905 and 0.834-0.924 for DWI and CET1WI, respectively (each P < 0.0001). CONCLUSION: Given that its sensitivity and specificity are similar to those of dedicated CET1WI for acute ON, DWI can play an important complementary role in detecting acute ON, especially in atypical ON cases, and can provide a quantitative modality that can be used to evaluate axonal damage in the optic nerves.

Using coronary computerized tomographic images to predict the bulging second genu of the facial nerve in mastoidectomy.

The aim of the present study is to determine whether coronary CT images of the temporal bone are useful to predict a bulging second genu of the facial nerve (SGFN) in mastoidectomy by measuring and comparing the heights of the SGFN above the prominence of the lateral semicircular canal (PLSC) in medial-to-lateral dimension on coronary CT images and in mastoidectomy. The relationship between the SGFN and the PLSC in medial-to-lateral dimension, which may have big variability, can be evaluated on the coronary CT images of the temporal bone. The heights of the SGFN above the PLSC in medial-to-lateral dimension were measured on coronary CT images and in mastoidectomy in 184 patients. If the SGFN is above the PLSC in medial-to-lateral dimension, we called the SGFN a bulging SGFN. The data measured on CT images and in surgery were described in histograms and compared. The sensitivity and the specificity in the diagnosis of a bulging SGFN on CT images were calculated by comparison with surgical measurement. Cohen's kappa coefficient was calculated. The heights of the SGFN above the PLSC measured in medial-to-lateral dimension varied from -2.9 to 2.9 mm on coronary CT images and varied from -3.0 to 3.0 mm in surgery. The data measured in surgery showed that the SGFN was above the PLSC in medial-to-lateral dimension in 27.7% (51/184) patients, at least 1 mm above the PLSC in 15.8% (29/184) patients and at least 2 mm above the PLSC in 6.0% (13/184) patients. The sensitivity and the specificity for CT diagnosis of a bulging SGFN were 100% (51/51) and 91.0% (121/133), respectively. Bulging SGFN can be predicted by measuring the height of the SGFN above the PLSC on coronary CT images of the temporal bone.

[Imaging evaluation of the cases with tympanicum and pulsatile tinnitus].

OBJECTIVE: To analyze the CT and MRI features of glomus tympanicum tumors accompanied with tympanitis and evaluate the diagnostic value of CT and MRI in order to improve the cognition for the disease. METHODS: The clinical materials and images of 8 patients with the symptoms of pulsatile tinnitus and hearing loss in whom glomus tympanicum tumors with tympanitis surgically and pathologically confirmed were retrospectively reviewed. The characteristics and diagnostic value of CT and MR imaging were summarized. RESULTS: By CT examination the lesions in middle ear and mastoid were preoperatively diagnosed as tympanitis in five cases and only in three cases the glomus tympanicum tumors were suspected. In six patients underwent MR examination the lesions were all preoperatively diagnosed as glomus tympanicum tumors accompanied with tympanitis. HRCT scanning of the temporal bone in all patients showed the soft tissue lesions in the tympanic cavity and mastoid, and the caritas tympanic were mostly (n = 3) or completely (n = 5) occupied by soft tissue lesions, but the auditory ossicles were all without destruction. Contrast-enhanced axial CT scanning performed in five cases showed less soft tissue mass on the cochlear promontory, and the size of mass was less than that observed in MR imaging. MR T(1)-weighted imaging showed the presence of isointense lesions in middle ear and isointense (n = 3) or hyperintense (n = 3) lesions in mastoid. On T(2)-weighted imaging the lesions with slight hyperintense were viewed in the middle ear and the lesions with hyperintense in mastoid. T(1)-weighted gadolinium-enhanced MRI showed the masses in tympanum were markedly increased enhancement, but the lesions in mastoid without enhancement. MRI and CT imaging revealed the masses in six cases of eight extending to the eustachian tube. CONCLUSION: When the glomus tympanicum tumor was accompanied with tympanitis the tumor could be misdiagnosed or missed only by CT examination. The patients with pulsatile tinnitus should be taken seriously. MRI with contrast-enhancement is superior to CT in the preoperative diagnosis and accurately evaluation for the glomus tympanicum tumors with tympanitis.

Preoperative Embolization of Primary Juvenile Nasopharyngeal Angiofibroma: Is Embolization of Internal Carotid Artery Branches Necessary?

PURPOSE: To determine the effects of blood supply from internal carotid artery (ICA) on the surgical outcomes of primary juvenile nasopharyngeal angiofibroma (JNA) after transarterial embolization (TAE). METHODS: A retrospective analysis was performed on primary JNA patients who underwent TAE and endoscopic resection in our hospital between December 2020 and June 2022. The angiography images of these patients were reviewed, and then they were divided into ICA + external carotid artery (ECA) feeding group and ECA feeding group according to whether the ICA branches were part of the feeding arteries. Tumors in ICA + ECA feeding group were fed by both ICA and ECA branches, while tumors in ECA feeding group were fed by ECA branches alone. All patients underwent tumor resection immediately after ECA feeding branches embolization. None of the patients underwent ICA feeding branches embolization. Data on demographics, tumor characteristics, blood loss, adverse events, residual and recurrence were collected, and case-control analysis was performed for the two groups. Differences in characteristics between the groups were tested using Fisher's exact and Wilcoxon tests. RESULTS: Eighteen patients were included in this study: nine in ICA + ECA feeding group and nine in ECA feeding group. The median blood loss was 700 mL (IQR 550-1000 mL) in ICA + ECA feeding group versus 300 mL (IQR 200-1000 mL) in ECA feeding group, with no significant statistical difference (P = 0.306). Residual tumor was found in one patient (11.1%) in both groups. Recurrence was not observed in any patient. There were no adverse events from embolization and resection in either group. CONCLUSION: The results of this small series suggest that the presence of blood supply from ICA branches in primary JNA has no significant effect on intraoperative blood loss, adverse event, residual and postoperative recurrence. Therefore, we do not recommend routine preoperative embolization of ICA branches. LEVEL OF EVIDENCE: Level 4, Case-control.

Dual-energy CT in predicting Ki-67 expression in laryngeal squamous cell carcinoma.

PURPOSE: To investigate whether multiple dual-energy computed tomography (DECT) parameters can noninvasively predict the Ki-67 expression (associated with survival and prognosis) in laryngeal squamous cell carcinoma (LSCC). METHODS: Eighty-eight patients with histologically proven LSCC were retrospectively reviewed. Multiple DECT-derived parameters were measured and correlated with Ki-67 expression by Spearman correlation analysis. Comparisons of the DECT-derived parameters between tumors with low- and high-level expression of Ki-67 were made with the t-tests. RESULTS: The iodine concentration (IC), normalized IC (NIC), effective atomic number (Zeff), 40-80 keV, and slope (k) values were positively correlated with Ki-67 expression (all p < 0.05, rho=0.367-0.548). Among all DECT-derived parameters, NIC value had the highest r value in correlation with Ki-67 expression. The IC, NIC, Zeff, 40-80 keV, and slope (k) values were significantly higher in LSCC with high Ki-67 expression than in those with low Ki-67 expression (all p < 0.05). CONCLUSIONS: Multiple DECT-derived parameters (IC, NIC, Zeff, 40-80 keV, and slope (k)) can be used as predictors of survival and prognosis in LSCC, among which the NIC value is the strongest.

[High-resolution CT with multi-planar reformation in diagnosis of stapedial otosclerosis].

OBJECTIVE: To evaluate the value of HRCT with multi-planar reformation (MPR) in the diagnosis of otosclerosis. METHODS: 138 ears in 129 patients with otosclerosis confirmed by surgery were evaluated retrospectively, using the MPR image along stapes as standard image, and 132 normal ears were collected as the control group. RESULTS: In the otosclerosis group, HRCT-MPR was positive in 108 ears, suspicious positive in 12 ears, and negative in 18 ears.In the control group, HRCT-MPR was positive in 4 ears, suspicious positive in 9 ears, and negative in 119 ears. The sensitivity for HRCT-MPR was 87.0% and the specificity was 90.2%. However, with 2 mm axial CT alone, the sensitivity was only 47.8%.The positive findings were mainly fenestral foci which related to stapes. CONCLUSIONS: HRCT-MPR showed high rate of sensitivity and specificity.We recommend the MPR image along stapes as standard image for otosclerosis diagnosis.

[CT multiplane reconstruction images of superior semicircular canal dehiscence syndrome].

OBJECTIVE: To evaluate the clinical application of multi-planar reformation (MPR) for the diagnosis of superior semicircular canal dehiscence syndrome. METHODS: A retrospective study was conducted on 9 patients who were diagnosed with SSCD syndrome in the Otology and Skull Base Surgery group of Fudan University. Three radiologists analyzed all the patients' 0.75 mm-collimated axial and coronal images and 0.75 mm-collimated MPR images, and they came up with the same results. RESULTS: There were 18 superior semicircular canal in the 9 patients, of whom 9 were intact and 9 were defective. All the defective superior semicircular displayed a definite dehiscence in all the MPR images, which indicated the sensitivity was 100%; however, 7 of the 9 defective superior semicircular canal were diagnosed as dehiscence in axial images, while 8 of the 9 were diagnosed in coronal images, but the sensitivities were 77.8% and 88.9% respectively. The results of the other 9 with intact superior semicircular canal displayed in the MPR, axial, and coronal images were also different. In the MPR images, they all displayed definite intact roof over the superior semicircular canal. There were 2 dehiscence in all axial and coronal images, and the specificities were 77.8%. CONCLUSION: The MPR image is more useful in diagnosis of superior semicircular canal dehiscence syndrome than that of the routine axial and coronal images.