Correlation of endolymphatic hydrops and perilymphatic enhancement with the clinical features of Ménière's disease.

OBJECTIVES: To use three-dimensional real inversion recovery (3D-real IR) MRI to investigate correlations between endolymphatic hydrops (EH) grades or the degree of perilymphatic enhancement (PE) and clinical features of Ménière's disease (MD), as previous findings have been inconsistent. METHODS: A total of 273 consecutive patients with definite unilateral MD were retrospectively enrolled from September 2020 to October 2021. All patients underwent 3D-real IR and 3D-T2WI 6 h after intravenous gadolinium injection. MD-related symptom duration and vertigo frequency were recorded. EH grades were evaluated, the signal intensity ratio (SIR) was measured, and correlations between clinical features and EH, PE were assessed respectively. RESULTS: The study included 123 males and 150 females, with a mean age of 53.0 years. A longer duration of vertigo was associated with higher cochlear EH grades, whereas the opposite was true for the duration of aural fullness. A longer time since vertigo onset was associated with higher vestibular EH grades; the opposite was true for the duration of individual vertigo attacks. The multiple regression analysis revealed that age, tinnitus duration, and vestibular EH were risk factors for SIR. Furthermore, the low-frequency hearing threshold (HT) was a risk factor for cochlear and vestibular EH, and the SIR. CONCLUSION: The EH grade and SIR (an indicator for the quantitative evaluation of PE) were correlated with clinical features and HT of MD; thus, imaging can be a valuable tool in planning individualised treatment. CLINICAL RELEVANCE STATEMENT: This study revealed that the grade of endolymphatic hydrops and degree of perilymphatic enhancement positively correlates with the length of time since onset of clinical symptoms and hearing thresholds in patients with Ménière's disease, facilitating the tailored treatment. KEY POINTS: • Relationships between 3-dimensional real inversion recovery features and clinical symptoms in Ménière's disease are unknown. • Symptom duration and hearing thresholds correlated with endolymphatic hydrops grades and degree of perilymphatic enhancement. • MRI features correlate with MD severity; thus, imaging is valuable for planning tailored treatment.

MRI can help differentiate Ménière's disease from other menieriform diseases.

It is difficult to distinguish other pathologies mimicking Ménière's disease (MD) clinically. This study aims to investigate the differences of imaging findings and features between MD and other menieriform diseases via intravenous gadolinium-enhanced magnetic resonance imaging (MRI). 426 patients with menieriform symptoms, including MD, vestibular migraine (VM), and vestibular schwannoma (VS), underwent 3D-FLAIR and 3D-T2WI MRI 6 h after the intravenous gadolinium injection. MR images were analyzed for inner ear morphology, perilymphatic enhancement (PE), EH and other abnormalities. EH was observed at a higher rate in MD patients (85.71%) than patients with other menieriform diseases (VM group = 14.75%, VS group = 37.50%). The prevalence of unilateral EH as well as both cochlear and vestibular EH showed significant differences between MD and VM groups. The prevalence of cochlear EH (I and II) and vestibular EH (II and III) was different between MD and VM groups. The prevalence of PE was higher in MD than VM group. The degrees of cochlear and vestibular hydrops were higher in the definite than probable MD group (P < 0.05). Using these imaging features, MRI can be used to help differentiate MD from other menieriform diseases.

Improving diagnostic accuracy for probable and definite Ménière's disease using magnetic resonance imaging.

PURPOSE: To determine whether magnetic resonance imaging (MRI) can improve diagnostic accuracy for definite and probable Ménière's disease (MD) based on perilymphatic enhancement (PE) and endolymphatic hydrops (EH). METHODS: 363 patients with unilateral MD (probable MD, n = 75 and definite MD, n = 288) were recruited. A three-dimensional zoomed imaging technique with parallel transmission SPACE real inversion recovery was performed 6 h after intravenous gadolinium injection to investigate the presence of PE and to evaluate the grading and location of EH. PE and EH characteristics were analyzed and compared between the probable and definite MD groups. RESULTS: The cochlear and vestibular EH grading on the affected side was more severe in the definite MD group than that in the probable MD group (P < 0.001). The EH locations within the inner ear on the affected side also differed between the two groups (χ2 = 81.15, P < 0.001). The signal intensity ratio (SIR) on the affected side was significantly higher in the definite MD group than in the probable MD group (t = 2.18, P < 0.05). The assessment of the combination of PE and EH parameters within the inner ear revealed a higher area under the curve (AUC) in the definite MD group (0.82) compared with the AUCs of the parameters assessed alone. CONCLUSION: The assessment of a combination of PE and EH parameters improved the diagnostic accuracy for probable and definite MD, suggesting that MRI findings may be clinically useful in the diagnosis of MD.

Longitudinal variation of endolymphatic hydrops in patients with Ménière's disease.

Background: The relationships of endolymphatic hydrops (EH) and perilymphatic enhancement (PE) with Ménière's disease (MD) remains unclear. This study aimed to describe the dynamic variation of EH and PE for MD patients over 2 hospitalizations by applying magnetic resonance imaging (MRI) to further clarify the relationships of EH and PE with MD. Methods: A total of 77 MD patients who underwent inner ear MRI after intravenous administration of gadolinium and pure-tone average (PTA) testing during a first and second hospitalization were included. The degree of EH and PE were evaluated via MRI, and the duration and frequency of vertigo attacks and PTA were collected and recorded. The PTA, EH, and PE for the 2 hospitalizations were compared, and the relationships of EH and cochlear PE with the MD stage were investigated. Results: There was no difference between the 2 hospitalizations for duration of vertigo attacks or frequency of vertigo attacks. However, there were significant differences in PTA (Z=-3.02, P=0.003). Additionally, the cochlear and vestibular EH in the asymptomatic ear at the second hospitalization was significantly worse than that of the first hospitalization (Z=-2.33 and -2.49, P=0.020 and 0.013, respectively), while there were no differences in EH and PE in the affected ear (all P>0.05). Moreover, the degree of cochlear and vestibular EH was correlated with MD stage (both P<0.01). Conclusions: Although EH and PE in the affected ear were unchanged over 2 hospitalizations, an underlying EH in the asymptomatic ear and hearing loss in the affected ear for MD patients developed longitudinally with the duration of disease, and EH varied with the natural course of MD whereas PE did not. Therefore, EH instead of PE is necessary but insufficient to cause the clinical symptoms of MD.

Hepatic steatosis with mass effect: A case report.

BACKGROUND: Hepatic steatosis is a common radiologic finding. Some imaging inklings are the absence of a mass effect, and there is currently no report of hepatic steatosis with mass effect. CASE SUMMARY: A 23-year-old female was admitted due to a liver mass for half a month. No obvious abnormalities were found in physical and laboratory examinations. Ultrasound, computed tomography, and magnetic resonance imaging showed a huge mass between the liver and stomach with a significant mass effect, and the caudate lobe and left lobe of the liver were involved. The signal on T2- and T1- weighted fat-saturated images of the mass was significantly reduced, and the enhanced scan showed inhomogeneous enhancement. Surgical and pathological findings indicated the diagnosis of hepatic steatosis. The operation and re-review of the patient's images showed that the lesion was supplied by the branch of the hepatic artery. The signal on T1-weighted out-of-phase images of the lesion was lower than on in-phase images, and there was no black rim cancellation artifact around the hepatic steatosis area on T1-weighted out-of-phase images. The dynamic enhancement pattern of the lesion was similar to that of the adjacent normal liver parenchyma. The above characteristics suggested that the lesion was hepatic steatosis. However, in this case, the lesion showed exogenous growth and was mass-like, with an obvious mass effect, which has not been reported previously. CONCLUSION: Hepatic steatosis could grow exogenously and has an obvious mass effect. It needs to be distinguished from fat-rich tumors. The T1-weighted in- and out-of-phase images and dynamic enhanced scanning are valuable for differential diagnosis of this lesion.

Eustachian tube teratoma: A case report.

BACKGROUND: Mature teratoma composed of all three basic germ cell layers of the head and neck is a rare disease. Teratomas involving the temporal bone are particularly scarce. CASE SUMMARY: A 48-year-old male patient with a history of chronic otitis of the left ear from infancy, for which he had been operated on twice, was referred to our hospital for chronic otitis, cholesteatoma and a middle ear mass. Computed tomography (CT) scan and magnetic resonance imaging (MRI) revealed a eustachian tube teratoma, in which the anterior lower part and posterior upper part were connected by a thin membranaceous tissue. The mass was removed completely under general anesthesia by mastoidectomy. As of last follow-up (2 years post-surgery), the disease had not relapsed. CONCLUSION: Pre-operative CT and MRI are necessary for eustachian tube teratoma. Complete surgical resection provided excellent prognosis.

Revision surgery after triple semicircular canal plugging and morphologic changes of vestibular organ.

This study aims to investigate the causes of vertigo relapse in patients with Meniere's disease (MD) who had undergone triple semicircular canal plugging (TSCP) and explore the morphologic changes of vestibular organ through revision surgery. Eleven intractable MD patients who underwent TSCP initially and experienced episodic vertigo recurrence later, were enrolled. All patients accepted revision surgery, including seven cases who underwent labyrinthectomy and four cases who underwent repeat TSCP. Pure tone test, caloric test and video-head impulse test (v-HIT) were used to evaluate audiological and vestibular functions. Specimens of canal plugging materials and vestibular end organs were collected from patients who underwent labyrinthectomy during revision surgery. Mineralization and other histological characteristics of canal plugging materials were evaluated by von Kossa staining. Incomplete occlusion or ossification was observed in the semicircular canals (SCs) of all eleven patients, with all three SCs affected in three, the superior SC in five patients, the horizontal SC in two and the posterior SC in one. The results of v-HIT were in accordance with findings discovered intraoperatively. Few mineralized nodules and multiple cavities were found in the von Kossa-stained canal plugging materials. Incomplete occlusion or ossification of SCs was the principal cause of vertigo recurrence in MD patients who underwent TSCP. v-HIT was helpful in determining the responsible SCs.

CTA/V detection of bilateral sigmoid sinus dehiscence and suspected idiopathic intracranial hypertension in unilateral pulsatile tinnitus.

PURPOSE: This aimed to evaluate the prevalence and extent of bilateral sigmoid sinus dehiscence (SSD) and to explore the presence of idiopathic intracranial hypertension (IIH) in patients with unilateral pulsatile tinnitus (PT) with CTA/V. METHODS: Sixty PT patients (52 females; 40.4 ± 11.6 years [20-72]) who underwent CTA/V and 30 non-PT patients (27 females; 38.4 ± 14.7 years [12-62]) were enrolled in this study. The primary outcome measure was the radiographic presence of SSD. The index of transverse sinus stenosis (ITSS) was obtained by multiplying the stenosis scale values for each transverse sinus, and once was ≥ 4, the presence of IIH was suspected. RESULTS: The prevalence and extent of SSD on symptomatic side (78%; maximum transverse diameter, MTD 0.49 ± 0.23; maximum vertical diameter, MVD 0.50 ± 0.26 cm) were significantly higher and larger than those on asymptomatic side (50%, P < 0.001; MTD 0.35 ± 0.18, P = 0.006; MVD 0.30 ± 0.15 cm, P < 0.001) in the study group and those (20%, P < 0.001; MTD 0.36 ± 0.18, P = 0.073; MVD 0.30 ± 0.22 cm, P < 0.048) in the control group. The presence of SSD showed significant correlation with both PT (logistic regression analysis, OR 4.167 [1.450-11.97]; P = 0.008) and suspected IIH (OR 16.25 [1.893-139.5]; P = 0.011). CONCLUSION: In PT patients, SSD has a significant correlation with PT and a potential correlation with IIH.

Evaluation of vertebral artery anomaly in basilar invagination and prevention of vascular injury during surgical intervention: CTA features and analysis.

OBJECTIVE: To evaluate vertebral artery anomaly at the craniovertebral junction (CVJ) in patients with basilar invagination (BI) by computed tomographic angiography (CTA), and to discuss the prevention strategy of vascular injury. METHODS: The primary axial, multiple planar reconstruction and volume-rendering cervicocranial CTA images of 39 BI patients were analysed to evaluate vertebral artery anomaly at the CVJ: persistent first intersegmental artery (PFIA), fenestrated vertebral artery (FEN), and extracranial C1/2 origin of posterior inferior cerebellar artery (PICA), high-riding vertebral artery, side-to-side asymmetry and irregular midline carotid artery loop was determined by subjective vision. 100 patients who underwent CTA for reasons other than CVJ deformity were enrolled as normal controls to evaluate the prevalence of vertebral artery anomaly in a normal population. Chi-square test was utilized for comparing the prevalence of vertebral artery anomaly between these two groups. RESULTS: The incidence of PFIA was 25.6% (10/39), FEN was 7.7% (3/39), PICA was 5.1% (2/39), and the total incidence of extraosseous anomalous course of vertebral artery was 38.5% (15/39), significantly higher than that of control group, 7.0% (7/100) (P < 0.01). The incidence of high-riding vertebral artery and side-to-side asymmetry were 61.5% (24/39) and 30.8% (12/39), respectively. An irregular midline carotid artery loop was observed in five patients (12.8%). CONCLUSION: Vertebral artery anomaly, which can be clearly depicted by CTA, is more frequent in BI patients. Preoperative CTA should be performed for this patient population to prevent vascular injury. These slides can be retrieved under Electronic Supplementary Material.

Clivodens Angle: A New Diagnostic Method for Basilar Invagination at Computed Tomography.

STUDY DESIGN: Retrospective study. OBJECTIVE: To investigate whether clivodens angle (CDA) could diagnose basilar invagination (BI) at computed tomography (CT). SUMMARY OF BACKGROUND DATA: Over the years, multiple craniometric methods such as Chamberlain line, McGregor line, McRae line, Wackenheim clivus baseline, and Welcher basal angle have been described for evaluation of craniovertebral junction anomalies, initially with radiography and later with CT. However, such a variety of measurements in turn reflects the difficulty in making a definite diagnosis of BI and there is a certain disadvantage in all of these criteria because the anatomic landmarks vary within a normal range. METHODS: CDA, described an angle formed at the intersetion of a line that runs along the long axis of the clivus and one that runs along the long axis of the dens, was measured on mid-sagittal reconstructed CT images from 63 BI patients and 100 control participants to compare the two groups by using independent-sample t test. Interobserver reliability was evaluated with Kendall correlation coefficient. For evaluating the diagnostic performance and determining the cutoff value of CDA, receiver operating characteristic curve was utilized. RESULTS: The measurement of CDA showed good interobserver agreement (KCC = 0.891). Compared with control participants whose mean value was 135.8 degrees ±â€Š9.2 (range, 118-156°), BI patients had a significantly smaller one (P < 0.001), 110.4 degrees ±â€Š15.8 (range, 55-140°). The area under receiver operating characteristic curve was 0.937 (95% confidence interval: 0.901, 0.973), and the cutoff value of 125 degrees had the largest Youden index (J), 0.715. CONCLUSION: Having a better diagnostic performance than clivoaxial angle, CDA can be utilized for diagnosing BI. LEVEL OF EVIDENCE: 3.

HRCT and MRI findings in X-linked non-syndromic deafness patients with a POU3F4 mutation.

OBJECTIVE: The aim of this study was to analyze HRCT and MRI findings in patients with X-linked non-syndromic deafness and a POU3f4 mutation. METHODS: HRCT and MRI data of four patients (males, 2-19 years old) with a POU3f4 mutation were collected and a retrospective review was performed. Cochlea, internal auditory canal (IAC), vestibule, semicircular canals, vestibular aqueduct, nerve canals in the IAC fundus, stapes and cochlear nerve were evaluated on 2D images (multi-planner reformation, MPR) and cochlear foramen on 3D images (CT virtual endoscopy, CTVE). Ten cases with normal hearing subjected to CT and MR exams served as controls. RESULTS: Inner ear malformations were bilateral and symmetrical. Cochlear malformation was shown to consist of as a relatively normal outer coat shape, absence of a cochlear modilous, and a direct intercommunication between the IAC and cochlear inner cavity. The lateral portion of the IAC was dilated. A spiral cochlear inner cavity was observed with CTVE images versus a helical cochlear nerve foramen as seen in controls. The labyrinthine facial nerve canal and superior vestibular nerve canal were enlarged. The Bill's bar was hypertrophic and partially pneumatized. A thickened stapes footplate was present and a fissura ante fenestram was absent in seven ears examined. A column shaped stapes was observed in one ear. CONCLUSIONS: The absence of a cochlear modilous with a dilated lateral IAC and thickened stapes footplate were the remarkable features observed with imaging these in X-linked non-syndromic deafness patients with a POU3F4 mutation. Preoperative recognition of the image features in these patients is important because it precludes stapedectomy and indicates the risks in the surgery of cochlear implantation including CSF gusher and electrode insertion into IAC.

A retrospective study of laparoscopic unilateral adrenalectomy for primary hyperaldosteronism caused by unilateral adrenal hyperplasia.

OBJECTIVE: To evaluated the long-term outcomes of laparoscopic unilateral adrenalectomy for primary aldosteronism (PA) caused by unilateral adrenal hyperplasia (UAH). METHODS: One hundred and sixty-four patients who underwent laparoscopic unilateral adrenalectomy for UAH from January 2004 to December 2011 were entered in this retrospective analysis. Patients demographics, perioperative parameters, and follow-up results were recorded and analyzed statistically. RESULTS: All 164 cases suffered hypertension with biochemical evidence of hyperaldosteronism prior to operation. Hypokalemia was observed in 52/164 (37.14%) patients. UAH was proved by multi-slice computed tomography (MSCT). All operations were completed successfully without any conversions or complications. Postoperative pathology confirmed that 164 cases were cortical nodular hyperplasia, of which 4 cases coexist with medullary hyperplasia and 7 with micro-adenoma. At the median follow-up of 48 months, hypertension was cured in 88 (53.7%) patients, improved in 71 (43.3%) patients, and refractory in 5 (3.05%) patients. Hypokalemia and hyperaldosteronism were cured in all patients except re-elevation of blood pressure and plasma aldosterone in two patients 1 month after adrenalectomy. CONCLUSIONS: As an underestimated subtype of PA, UAH is accepted gradually. Laparoscopic unilateral adrenalectomy is nowadays the preferred approach to treat patients with PA caused by UAH. When adrenal venous sampling is not allowed, high-resolution MSCT is a reliable test for lateralization of aldosterone hypersecretion in carefully selected patients and 97% had either cure or improvement in blood pressure control.

Detection of hypoplasia of bony cochlear nerve canal by the opening threshold of virtual endoscopy: a pilot study.

BACKGROUND: Dimensions of the bony cochlear nerve canal (BCNC) have been proposed as a potential diagnostic standard for BCNC hypoplasia, but the standard remains inconsistent. Some studies have revealed that computed tomography virtual endoscopy (CTVE) with variation of reconstruction threshold is good at identifying labyrinthine fistulas or semi-circular canal dehiscence. PURPOSE: To examine diagnostic accuracy of VE in the evaluation of BCNC hypoplasia on basis of opening threshold. MATERIAL AND METHODS: Twenty ears diagnosed with BCNC hypoplasia were included in this study. One hundred ears served as controls. The opening thresholds were measured by two reviewers. Intraclass correlation coefficients (ICC) were reported. The width of BCNC was obtained on transverse CT images. Association between the width of BCNC and opening threshold was assessed by using Spearman correlation coefficients. ROC curves were applied to assess the best cut-off value of opening threshold. RESULTS: The opening threshold of BCNC was significantly higher in diseased ears (926 ± 308 Hounsfield units [HU]) than that in control ears (287 ± 72 HU). Inter-observer agreement was very good. The mean width of BCNC for diseased ears and control ears were 0.83 ± 0.36 mm and 2.21 ± 0.35 mm, respectively. Significant negative linear correlation was found between opening thresholds and width of BCNC (Spearman coefficient, -0.768; P < 0.001). The area under the ROC curve was 0.981. The cut-off opening thresholds of 408 for differentiation between the two groups provided the best combination of sensitivity (85%) and specificity (94%). CONCLUSION: The VE with opening threshold may be an effective optional tool for prediction of hypoplasia of BCNC.

Enlarged geniculate ganglion fossa: CT sign of facial nerve canal fracture.

RATIONALE AND OBJECTIVES: The aim of this study was to preliminarily investigate whether an enlarged geniculate ganglion fossa (GGF) on temporal bone computed tomography can diagnose GGF fracture in patients with traumatic facial paralysis by evaluating the diameter of the GGF. MATERIALS AND METHODS: Thirty-six patients who underwent computed tomography before confirmation of GGF fracture on otologic surgery were recruited into a study group. Additionally, a cohort of 107 patients with no histories of head trauma, no structural abnormalities of inner ear, and no clinical symptoms of facial nerve disability who underwent computed tomography for other reasons were selected as a control group. The diameters of the GGFs of the study group were evaluated by two observers and compared retrospectively with those of the control group. Wilcoxon's test was used to compare discrepancies of both sides, and intraclass correlation coefficients were used to evaluate intraobserver and interobserver reliability. RESULTS: The measurement of diameters showed good interobserver and intraobserver consistency. The discrepancy in the measurement of transdiameter between both sides of the GGF on reformatted transverse images of the study group was significantly different from that of the control group (Wilcoxon's test, P < .001). Discrepancy in the GGF on transverse images of the study group was larger than that of the control group. A significant difference existed in the discrepancy in vertical diameter between the study and control groups (Wilcoxon's test, P < .001) as well. CONCLUSIONS: An enlarged GGF on temporal bone computed tomography offers an additional sign for the diagnosis of GGF fracture in patients with traumatic facial paralysis.

[On the clinical application of spiral CT three-dimensional reconstruction of middle ear ossicles].

OBJECTIVE: To investigate the CT virtual endoscopy (CTVE) shows the display method of the normal structure of the middle ear, and evaluation of middle ear disease, particularly in the value and significance of the connection status of the ossicular chain, established display ossicular chain and middle ear structure methods. METHOD: Volume scanning with a spiral CT unit was performed in forty normal cases and thirty patients with suspected lesions of middle ear. Respectively, with Germany's Siemens (Siemens SOMATOM Sensation 16) spiral CT the Inner Ear scanner patients with axial scanning, reconstruction of the original image, the software selected Fly-through A, B, C the point approach CTVE imaging studies. Focus ossicular chain connection status, and chronic otitis media shown the results of surgery in exploratory image control. RESULT: Normal group CTVE in the hammer bone, incus promontory, facial nerve, the lateral semicircular canal display rate was 100%; stapes, the two arch of the display rate in three display levels, respectively, to 57.5%, 70.0%, 97.5%; round window, oval window was 90.0%, 93.0%, 97.5%. Ossicular injury, displacement, interruption, deletion, deformity in cases of otitis media, trauma, temporal bone malformations. CONCLUSION: CTVE link relations between the three ossicles (such as interrupt, etc.) have a certain advantage. By choosing the appropriate approach, CTVE has a considerable advantage in the ossicles and their connections, relations as well as pathological state. By comparing CTVE in three different display levels,the technique of CTVE is considered to be an advantageous supplement of tomography.

[Removable appliance and closed of central incisors: report of 48 cases].

PURPOSE: To evaluate the treatment effect of orthodontic traction on embedded and inverted maxillary bending central incisors. METHODS: Fifty-two embedded and inverted maxillary central incisors without-eruption ability in 48 cases were treated by combined orthodontic traction with surgical treatment after spiral CT positioning and expanding the space, the eruption situation, gingival-breaking time and teeth pulp vitality after treatment were recorded, and the treatment effect was evaluated. RESULTS: Forty-eight cases with 52 impacted upper central incisors were treated with surgical and closed orthodontic traction, successful results were achieved in 36 cases, accounting for 69.23%; 15 cases had improvement, accounting for 28.85%; 1 case failed, accounting for 1.9%. Pulp vitality tests were all normal and there was no root absorption and ankylosis. CONCLUSIONS: Selecting appropriate cases, precise positioning with spiral CT, proper space expanding and rational application of removable traction appliance are the keys to successful treatment of impacted and inverted maxillary bending central incisors of children in mixed dentition.

Diagnostic value of bent-lever planes in detecting abnormality of the malleus-incus complex.

OBJECTIVE: To retrospectively investigate the diagnostic value of the bent-lever planes in detecting abnormality of the malleus-incus complex. STUDY DESIGN: Diagnostic test assessment. SETTING: The study was conducted at the Shandong Medical Imaging Research Institute, Shandong University, Jinan, People's Republic of China. SUBJECTS: Eighty-five ears in 74 patients with surgically proved abnormality of the malleus-incus complex. MATERIALS AND METHODS: The bent-lever planes and direct axial images were reviewed by 2 radiologists. The radiologists assigned a value of abnormality or continuity to different parts of the malleus-incus complex. Differences in categorical data were evaluated with the McNemar test. The sensitivity, specificity, Youden index, and interobserver agreement were calculated. RESULTS: There was no significant difference between bent-lever planes and direct axial images in identifying abnormality of the malleus-incus complex. The sensitivity ranged from 71.4% to 97.1%, and specificity ranged from 89.5% to 100.0%. The Youden index ranged from 0.609 to 0.971. The radiologists had almost perfect or substantial agreement in identifying the abnormality of different parts of the malleus-incus complex. CONCLUSION: The bent-lever planes do not add additional diagnostic value for experienced observers.

Detection of hypoplasia of bony cochlear nerve canal by virtual endoscopy: a pilot study.

BACKGROUND: Dimensions of the bony cochlear nerve canal (BCNC) have been proposed as a potential diagnostic standard for hypoplasia of BCNC, but the standard remains inconsistent. We have previously found that a helix-like shape appears in normal BCNCs at VE images, whereas, the sign does not appear in some hypoplastic BCNCs. PURPOSE: To retrospectively examine the feasibility of computed tomographic (CT) virtual endoscopy (VE) in the evaluation of hypoplasia of BCNC on the basis of absence of a helix-like shape. MATERIAL AND METHODS: Twenty ears in 14 consecutive patients (mean age 5.5 years, range 1-15 years, 6 boys, 8 girls) diagnosed with hypoplasia of BCNC were included in this work. One hundred ears in 50 gender- and age-matched individuals (mean age 6.6 years, range 1-15 years, 29 boys, 21 girls) without inner ear disease and internal auditory canal (IAC) malformations served as controls. The presence or absence of a helix-like shape was evaluated by two independent reviewers. The value of VE for the diagnosis of hypoplasia of BCNC was assessed with clinical results and routine radiologic evaluation as the reference standard. Inter-observer agreement was calculated. Sensitivity, specificity, and accuracy were selected to test the diagnostic ability of the VE. RESULTS: Absence of a helix-like shape was found in the cochlear area of 17 of 20 ears in patients with hypoplasia of BCNC but in none of the control subjects. Inter-observer agreement was substantial (к = 0.773). The diagnostic rates of absence of a helix-like shape for hypoplasia of BCNC in terms of sensitivity, specificity, and accuracy were 85%, 100%, and 98%, respectively. There were significant differences between the two groups with respect to VE findings for absence of a helix-like shape (P < 0.001). CONCLUSION: The absence of a helix-like shape at VE images may be used as a potentially useful sign in the diagnosis of hypoplasia of BCNC.

[Observation of foramina hypoplasia within internal auditory canal fundus with CT virtual endoscopy].

OBJECTIVE: To observe normal and abnormal findings of foramina within internal auditory canal (IAC) fundus with Virtual Endoscopy of multisection helical Computed Tomography. METHOD: CT scanning of temporal bone was undergone in 25 volunteers (50 ears) in the normal group, in 8 cases (13 ears) with foramina hypoplasia within IAC fundus which were shown on CT and MRI images. CT virtual endoscopy (CTVE) findings were observed in the normal and abnormal groups. The lower threshold value was 900-1200 HU, the upper value was 3,071 HU in CTVE definitions. RESULT: The shape and position of foramina within IAC fundus were shown on the CTVE image, 50 foramina within IAC fundus were shown in all normal cases. In abnormal group, 9 ears were shown as IAC fundus disorder and foramina absent, only 1 foramina was shown in 1 ear, 2 foramen in 4 ears, 3 foramen in 2 ears, 4 foramen in 2 ears; Abnormal shape of cochlear nerve foramina was seen in 4 ears. Other malformations were also shown, including IAC malformations in 3 ears and inner ear malformations in 8 ears. CONCLUSION: CTVE is useful to show the shape and position of normal foramina and pathological changes in the patients with foramina hypoplasia within IAC fundus.