Post-treatment magnetic resonance imaging predicts outcomes of maxillary sinus cancer treatment using super-selective intra-arterial infusion of high-dose cisplatin with concomitant radiotherapy (RADPLAT).

OBJECTIVES: This study aimed to evaluate the prognostic value of magnetic resonance imaging (MRI) findings in predicting local recurrence in patients with maxillary sinus cancer treated with super-selective intra-arterial infusion of high-dose cisplatin with concomitant radiotherapy (RADPLAT). METHODS: This single-center retrospective study included consecutive patients with maxillary sinus squamous cell carcinoma, who underwent RADPLAT between October 2016 and September 2021. MRI was performed before (within 2 weeks) and 1 month after (post-treatment MRI) the start of treatment. Tumor reduction rates and pre-treatment cross-sectional areas were calculated from the maximum cross-sectional areas on pre- and post-treatment MRI T2-weighted axial images. Statistical analyses, including receiver operating characteristic analysis, were performed to assess the predictive value of the tumor reduction rates. RESULTS: Twenty-four patients were included in this study. Recurrence occurred in seven patients with a median time of 213 days. The tumor reduction rates were significantly higher in the benign post-treatment changes group compared to the recurrence group (median, 0.814 vs. 0.174; p < 0.001). The cut-off value for the reduction rate between the groups was 0.3578. No significant difference was observed in the maximum pre-treatment cross-sectional area between the groups (p = 0.664). The inter-observer agreement for the tumor areas was excellent. CONCLUSIONS: The tumor reduction rate calculated from MRI T2-weighted images may be a predictor of local recurrence in patients with maxillary sinus cancer treated with RADPLAT. Patients with lower reduction rates may benefit from early salvage surgeries.

Radiological features of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma: case series and systematic review.

PURPOSE: To comprehensively summarize the clinical data and CT/MRI characteristics of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma (TL-LGNPPA). METHODS: Twenty-seven lesions from 25 study articles identified through a systematic review and three lesions from our institution associated with TL-LGNPPA were evaluated. RESULTS: The mean age of the patients at diagnosis was 35.7 years, and the male-to-female ratio was nearly half. The chief complaint was nasal obstruction, followed by epistaxis. All patients underwent excision. None of the patients had neck nodes or distant metastases. All patients survived with no locoregional/distant recurrence during 3-93 months of follow-up. All lesions were located at the posterior edge of the nasal septum, attached to the nasopharyngeal parietal wall, and showed no laterality. The mean lesion diameter was 1.7 cm. The margins of lesions were well-defined and lobulated, followed by well-defined smooth margins. None of lesions were associated with parapharyngeal space or skull base destruction. All lesions were iso- and low-density on non-contrast CT. Adjacent skull base sclerosis was detected in 63.6% of lesions. High signal intensity on T2-weighted imaging and mostly iso-signal intensity on T1-weighted imaging compared to muscle tissue. Most lesions were heterogeneous and exhibited moderate contrast enhancement. Relatively large lesions (≥1.4 cm) tended to be more lobulated than smooth margins compared to relatively small lesions (<1.4 cm) (p = 0.016). CONCLUSION: We summarized the clinical and radiological features of TL-LGNPPA to facilitate accurate diagnosis and appropriate management.

A rare case of epithelial-myoepithelial carcinoma ex pleomorphic adenoma of the parotid gland: Radiologic-pathologic correlation.

Carcinoma ex pleomorphic adenoma is a carcinoma that arises from a primary or recurrent benign pleomorphic adenoma. The prevalence of epithelial-myoepithelial carcinoma is low, and this histological type accounting for only 1% of all salivary gland tumors. Here, we report a rare case of Epithelial-Myoepithelial Carcinoma ex pleomorphic adenoma of the parotid gland with a radiologic-pathologic correlation.

Radiological features of human papillomavirus-related multiphenotypic sinonasal carcinoma: systematic review and case series.

PURPOSE: To comprehensively summarize the radiological characteristics of human papillomavirus (HPV)-related multiphenotypic sinonasal carcinomas (HMSCs). METHODS: We reviewed the findings for patients with HMSCs who underwent computed tomography (CT) and/or magnetic resonance imaging (MRI) and included nine cases from nine publications that were identified through a systematic review and three cases from our institution. Two board-certified radiologists reviewed and evaluated the radiological images. RESULTS: The locations in almost all cases included the nasal cavity (11/12, 91.7%). The involved paranasal sinuses included the ethmoid sinus (6/12, 50.0%) and maxillary sinus (3/12, 25.0%). The mean long diameter of the tumors was 46.3 mm. The margins in 91.7% (11/12) of the cases were well-defined and smooth. Heterogeneous enhancement on contrast-enhanced CT, heterogeneous high signal intensities on T2-weighted images and heterogeneous enhancement on gadolinium-enhanced T1-weighted images were noted in 2/2, 5/5, and 8/8 cases, respectively. Mean apparent diffusion coefficient values in two cases of our institution were 1.17 and 1.09 × 10-3 mm2/s. Compressive changes in the surrounding structures were common (75%, 9/12). Few cases showed intraorbital or intracranial extension. None of the cases showed a perineural spread, neck lymph node metastasis, or remote lesions. CONCLUSIONS: We summarized the CT and MRI findings of HMSCs. Knowledge of such characteristics is expected to facilitate prompt diagnosis and appropriate management.

Comparative evaluation of temporal subtraction computed tomography and non-echoplanar diffusion-weighted imaging for the mastoid extension of middle ear cholesteatoma.

OBJECTIVE: Preoperative imaging assessment influences the decision to perform mastoidectomy for the mastoid extension of middle ear cholesteatoma. This study compared the performance of temporal subtraction CT (TSCT) and non-echoplanar diffusion-weighted imaging (non-EP DWI) in evaluating such mastoid extensions. METHODS: We retrospectively evaluated 239 consecutive patients with surgically proven middle ear cholesteatoma between April 2016 and April 2021. The diagnostic performance of TSCT, wherein the presence of black color indicated progressive bone erosion, and non-EP DWI, wherein high signal intensity in the mastoid region suggested mastoid extension, was compared using Fisher's exact test. RESULTS: In 34 patients with evaluable TSCT images, black color was significantly more common in patients with mastoid extension than in those without; the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of TSCT were 1.00, 0.95, 0.94, 1.00, and 0.97, respectively. In 90 patients with evaluable non-EP DWI, high signal intensity was significantly more common in patients with mastoid extension than in those without; the sensitivity, specificity, PPV, NPV, and accuracy of non-EP DWI were 0.88, 0.85, 0.91, 0.81, and 0.87, respectively. In 16 patients with both evaluable TSCT and non-EP DWI, the diagnostic performance of the TSCT was slightly superior to that of the non-EP DWI for predicting mastoid extension, although the difference was not significant. CONCLUSIONS: TSCT images generated using consecutively acquired preoperative high-resolution CT images are useful for predicting mastoid extension of middle ear cholesteatoma, and the diagnostic performance of TSCT is non-inferior to that of non-EP DWI.

Comprehensive radiological features of laryngeal sarcoidosis: cases series and systematic review.

PURPOSE: To comprehensively summarize the characteristic radiological findings of laryngeal sarcoidosis. METHODS: We reviewed patients with laryngeal sarcoidosis who underwent computed tomography (CT) and/or magnetic resonance imaging (MRI) and included 8 cases from 8 publications that were found through a systematic review and 6 cases from our institutions. Two board-certified radiologists reviewed and evaluated the radiological images. RESULTS: Almost all cases exhibited supraglottic lesions 13/14 (92.9%) and most of them involved aryepiglottic folds (12/13, 92.3%), epiglottis (11/14, 78.6%), and arytenoid region (10/14, 71.4%). Most lesions were bilateral (12/14, 85.7%). All cases showed well-defined margins and a diffuse swelling appearance (14/14, 100%). Non-contrast CT revealed a low density (4/5, 80%). The contrast-enhanced CT showed a slight patchy enhancement predominantly at the margin of the lesion in most cases (12/13, 92.3%). In one case, T2-weighted images showed high signal intensity peripherally and low signal intensity centrally (1/1, 100%). Gadolinium-enhanced MRI showed moderate heterogeneous enhancement predominantly at the margin of the lesion (2/2, 100%). In one case, diffusion-weighted imaging showed intermediate signal intensity; the apparent diffusion coefficient value was 2.4 × 10-3 mm2/s. The larynx was the only region affected by sarcoidosis in 57.1% (8/14) of the cases. Involvement of the neck lymph nodes and distant organs was observed in 4/14 (28.6%) patients, respectively. CONCLUSION: We summarized the CT and MRI findings of patients with laryngeal sarcoidosis. Knowledge of these characteristics is expected to facilitate prompt diagnosis and appropriate management.

Preoperative prediction for mastoid extension of middle ear cholesteatoma using temporal subtraction serial HRCT studies.

OBJECTIVES: This study investigated the utility of temporal subtraction computed tomography (TSCT) obtained with temporal bone high-resolution computed tomography (HRCT) for the preoperative prediction of mastoid extension of middle ear cholesteatomas. METHODS: Twenty-eight consecutive patients with surgically proven middle ear cholesteatomas were retrospectively evaluated. The presence of black color in the mastoid region on TSCT suggested progressive changes caused by bone erosion. Enlarged width of the anterior part of mastoid on HRCT was interpreted as suggestive of mastoid extension. Fisher's exact test was used to compare the widths and black color on TSCT for cases with and without mastoid extension. The diagnostic accuracy of TSCT and HRCT for detecting mastoid extension and interobserver agreement during the evaluation of black color on TSCT were calculated. RESULTS: There were 15 cases of surgically proven mastoid extension and 13 cases without mastoid extension. Patients with black color on TSCT were significantly more likely to have a mastoid extension (p < 0.001). The sensitivity and specificity of TSCT were 0.93 and 1.00, respectively. Patients in whom the width of the anterior part of the mastoid was enlarged were significantly more likely to have a mastoid extension (p = 0.007). The sensitivity and specificity of HRCT to detect the width of the anterior part of the mastoid were 0.80 and 0.77, respectively. Interobserver agreement during the evaluation of TSCT findings was good (k = 0.71). CONCLUSIONS: This novel TSCT technique and preoperative evaluations are useful for assessing mastoid extension of middle ear cholesteatomas and making treatment decisions. KEY POINTS: •TSCT shows a clear black color in the mastoid region when the middle ear cholesteatoma is accompanied by mastoid extension. •TSCT obtained with preoperative serial HRCT of the temporal bone is useful for assessing mastoid extension of middle ear cholesteatomas.

A rare case of positional changes of carotid artery depicted within a single MR study and a wandering carotid artery depicted on a serial MR studies.

The retropharyngeal carotid artery (RCA) is a relatively rare anatomical malposition, and positional changes in the RCA is also extremely rare. In addition, there are some reports of "wandering carotid artery" which means that the carotid artery reciprocate positional changes (wandering) between its normal position and retropharyngeal regions, during follow-up evaluations. A male patient in his 50s with a chief complaint of globus pharyngeus. A pulsatile swelling of the posterior pharyngeal wall of the right side was found on clinical examination. In this case, the right carotid artery showed the clinical course of a wandering carotid artery, which reciprocated between its normal position and the retropharyngeal space during three serial MR investigations. Interestingly, both the most recent MR study and the MR study performed 4 years ago showed that the carotid artery at the level of the hyoid bone moved laterally (positional normalization) during the single MR investigation. This is a first case which showed a rare clinical course of a wandering carotid artery on serial follow-up MR studies and positional changes of carotid artery within a single MR study. It is important for clinicians to be aware of these phenomena, in order to avoid fatal and unexpected complications during clinical procedures.

Improved assessment of middle ear recurrent/residual cholesteatomas using temporal subtraction CT.

PURPOSE: The purpose of this study was to investigate the usefulness of temporal subtraction CT (TSCT) of temporal bone CT for the detection of postoperative recurrent/residual cholesteatoma of the middle ear. METHODS: Thirty-two consecutive patients with surgically proven postoperative recurrent/residual cholesteatoma and 14 consecutive patients without recurrent/residual lesion matched the selection criteria and were retrospectively evaluated. TSCT imaging was generated with the use of serial postoperative CT. Two experienced radiologists and two residents evaluated the presence of bone erosive change by comparison serial CT studies, and CT and TSCT. The detection rate of bone erosive change, sensitivity and specificity of the recurrence/residual lesions, and reading time for each reader were evaluated. RESULTS: TSCT + CT significantly improved the detection of bone erosive changes compared to CT-only evaluation (17.4-41.3% vs. 37.0-58.7%, p = 0.008-0.046). The mean sensitivity and specificity of TSCT + CT for experienced radiologists were 0.77 and 1.00, and 0.52 and 0.97 without TSCT. The mean sensitivity and specificity of TSCT + CT for residents were 0.64 and 1.00, and 0.41 and 1.00 without TSCT. Sensitivity showed an increase in all readers. The use of TSCT significantly reduced the reading time per case in all readers (p < 0.001). CONCLUSION: TSCT improves the depiction of newly occurring progressive bone erosive changes, and detection sensitivity and reading time in postoperative recurrence/residual cholesteatoma of middle ear.

CT and MR imaging of laryngeal metastasis from renal cell carcinoma: A case report.

Laryngeal metastasis is an extremely rare condition. To the best of our knowledge, there has been no previous report on a laryngeal metastasis from renal cell carcinoma, which describes on details of the CT and MR imaging findings. A male patient in his 80s. Laryngoscopy revealed reddish-colored masses in the right false vocal cord and in the subglottic larynx. CT and MR imaging of this case showed multiple hypervascularized lesions with a wash-out effect in the supra and subglottis of the larynx and in the right intervertebral foramen of the cervical spine. Angiography revealed a hypervascular tumor consistent with the subglottic lesion. The histopathology and immunohistochemistry findings were compatible with laryngeal metastasis from renal clear cell carcinoma. A history of postoperative renal clear cell carcinoma about 7 years ago was later confirmed, which was not stated at the time of the initial imaging evaluation. It is a possible differential diagnosis in cases of multiple hypervascular masses in the head and neck region with a history of renal carcinoma. In particular, if the contrast-enhancement pattern of the lesion on the dynamic CT is similar to that of renal cell carcinoma. It is also important to reconfirm the patient's medical history, including postoperative status.

Imaging predictor of ophthalmic involvement in maxillary sinus cancer during super selective intra-arterial cisplatin infusion and concomitant radiotherapy (RADPLAT).

OBJECTIVE: To investigate the predictability of ophthalmic artery involvement in maxillary sinus cancer using preprocedural contrast enhanced CT and MRI. METHODS: We analyzed advanced (T3, T4a, and T4b) primary maxillary sinus squamous cell carcinoma treated with super-selective intra-arterial cisplatin infusion and concomitant radiotherapy (RADPLAT) from Oct 2016 to Mar 2020. Two diagnostic radiologists evaluated the tumor invasion site around the maxillary sinus using preprocedural imaging. These results were compared with the angiographic involvement of the ophthalmic artery using statistical analyses. We also evaluated our RADPLAT quality using complication rate, response to treatment, local progressive free survival (LPFS), and overall survival (OS). RESULTS: Twenty patients were included in this study. There were ten cases of ophthalmic artery tumor stain and there was a correlation between ophthalmic artery involvement and invasion for ethmoid sinus with statistically significant differences. Other imaging findings were not associated with ophthalmic artery involvement. CONCLUSIONS: Ethmoid sinus invasion on preprocedural imaging could suggest ophthalmic artery involvement in maxillary sinus cancer. It may be useful in predicting prognosis and treatment selection.

Assessment of squamous cell carcinoma of the floor of the mouth with magnetic resonance imaging.

PURPOSE: We aimed to use magnetic resonance imaging (MRI) to determine the relationship between the pathological depth of invasion (DOI), undetectability, and tumor thickness of squamous cell carcinoma of the floor of the mouth. MATERIALS AND METHODS: We retrospectively evaluated the relationship between pathological DOI and MRI detectability, as well as the relationship between pathological DOI and tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging or coronal T2-weighted imaging. RESULTS: We analyzed 30 patients with squamous cell carcinoma of the floor of the mouth; MRI revealed that the pathological DOI of the 11 undetectable lesions (median 2 mm) was smaller than that of the 19 detectable lesions (median 14 mm) (p < 0.001), and the cut-off value was 3 mm (sensitivity, 0.84; specificity, 0.91; area under the curve, 0.89). Tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging was assessed in all 19 detectable lesions; however, tumor thickness on coronal T2-weighted imaging could not be assessed in eight cases. Tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging was found to be significantly associated with the pathological DOI. CONCLUSIONS: Undetectability on MRI indicates superficial lesions with a pathological DOI value that is less than 3 mm. In detectable lesions, tumor thickness on coronal fat-suppressed contrast-enhanced T1-weighted imaging is associated with pathological DOI.

Radiological differences in computed tomography findings and texture analysis between cystic lymph node metastases of human papillomavirus-positive oropharyngeal cancer and second branchial cysts.

PURPOSE: The study aimed to analyse radiological differences in computed tomography (CT) findings and texture analysis between cystic lymph node metastases (CNM) in human papillomavirus (HPV)-positive oropharyngeal cancer (OPC) and second branchial cleft cysts (2nd BC). MATERIAL AND METHODS: Patients with pathological evidence of CNM-HPV-OPC and 2nd BC, who underwent contrast-enhanced CT, were retrospectively evaluated. The evaluated characteristics include age, sex, and CT findings. CT findings included the maximum and minimum transverse diameters, maximum caudal diameter, thickness of the peripheral wall, presence of internal septation, presence of surrounding fat stranding, location, and 40 texture parameters. RESULTS: A total of 13 patients had CNM-HPV-OPC (19 lesions), while 20 patients had 2nd BC (20 lesions). Patients with 2nd BC were significantly younger than those with CNM-HPV-OPC (p < 0.001). In terms of diameter, 2nd BC lesions were significantly larger than the CNM-HPV-OPC lesions (p < 0.001). CNM-HPV OPC lesions had significantly thicker walls than 2nd BC lesions (p < 0.001). CNM-HPV-OPC lesions had significantly higher association with internal septations than 2nd BC lesions (p < 0.001). Second BC lesions were significantly less common at level III than CNM-HPV-OPC lesions (p = 0.047). Among the 40 texture parameters measured, 8 had significant differences (p ≤ 0.001). CONCLUSIONS: There were significant differences in CT findings and textural parameters between CNM-HPV-OPC and 2nd BC lesions. These results may help in differentiating one from the other.

Non-echoplanar diffusion weighed imaging and T1-weighted imaging for cholesteatoma mastoid extension.

OBJECTIVES: A broad mastoid extension limits cholesteatoma resection via a transmeatal approach including endoscopic ear surgery. Therefore, a preoperative diagnosis of mastoid extension is a the most critical factor to determine whether to perform mastoidectomy. The purpose of this study was to assess the efficacy of non-echoplanar diffusion-weighted imaging (non-EPI DWI) and T1-weighted imaging in the evaluation of mastoid extension in cholesteatomas of the middle ear. METHODS: Patients who underwent magnetic resonance imaging (MRI) for pretreatment evaluation before primary surgery for pars flaccida or tensa cholesteatoma, which revealed a high-signal intensity in the mastoid on T2-weighed imaging were retrospectively evaluated. Two board-certified radiologists retrospectively evaluated the extent of cholesteatomas on MRI with non-EPI DWI, non-EPI DWI- and T1-weighted axial imaging. The presence of a high signal intensity on non-EPI DWI or low or high signal intensity on T1-weighted imaging in the mastoid was evaluated. All cases were subclassified as M+ (surgically mastoid extension-positive) or M- (surgically mastoid extension-negative). RESULTS: A total of 59 patients with middle ear cholesteatoma were evaluated. There were 37 M+ cases and 22 M- cases. High-signal intensity on non-EPI DWI exhibited a sensitivity of 0.89 and specificity of 0.82, whereas partial low-signal intensity on T1-weighted imaging exhibited a sensitivity of 0.84 and specificity of 0.91 for detecting mastoid involvement. Complete high-signal intensity on T1-weighted imaging exhibited a sensitivity of 0.73 and specificity of 0.89 for detecting non-involvement of the mastoid. The sensitivity (0.92) and specificity (0.96) of combined non-EPI DWI and T1-weighted imaging evaluation were higher than those of with non-EPI DWI or T1-weighted imaging alone. The interobserver agreement for the presence of high-signal intensity in the mastoid cavity on non-EPI DWI was very good at 0.82, that of a partial low-signal intensity area in the mastoid cavity lesions on T1-weighted imaging was good, at 0.76 and that of complete high-signal intensity in the mastoid cavity lesions on T1-weighted imaging was good, at 0.67. CONCLUSIONS: The signal intensity on non-EPI DWI and T1-weighted imaging of the mastoid could be used to accurately assess the extent of middle ear cholesteatoma, which could facilitate surgical treatment planning.

Correlation between the magnetic resonance imaging features of squamous cell carcinoma of the buccal mucosa and pathologic depth of invasion.

OBJECTIVE: The objective of this study was to determine correlations between magnetic resonance imaging (MRI) features including radiologic depth of invasion (r-DOI) and pathologic DOI (p-DOI) of squamous cell carcinoma of the buccal mucosa. STUDY DESIGN: In total, 31 lesions were retrospectively evaluated. MRI findings included detectability, buccinator muscle invasion (positive: BMI+, negative: BMI-), buccal fat pad invasion (positive: BFPI+, negative: BFPI-), and r-DOI measured on T2-weighted images (T2-DOI) and contrast-enhanced T1-weighted images (CET1-DOI). These findings were compared to the p-DOI of the tumors. RESULTS: The p-DOI values of undetectable lesions were smaller than those of detectable lesions (P < .001), and the cutoff value was 1 mm. BMI+ and BFPI+ lesions had significantly larger p-DOI values than the corresponding BMI- and BFPI- lesions (P < .001), with cutoff values of 5 and 6 mm, respectively. The correlation coefficient between CET1-DOI and p-DOI was 0.68 (P < .001). CET1-DOI values were larger than p-DOI (P < .001) and the average difference between them was 3.4 mm. T2-DOI was inconclusive in 50% of cases. Interobserver agreements of MRI evaluation were good to very good. CONCLUSION: MRI-derived parameters were useful in estimating p-DOI and may be helpful in predicting the depth of invasion of tumors and the risk of lymph node metastasis.

Pre-treatment MRI predictor of high-grade malignant parotid gland cancer.

OBJECTIVES: We aimed to evaluate pre-treatment MRI predictors of high-grade malignant parotid gland cancer by comparing MRI findings and texture parameters between high-grade and intermediate/low-grade parotid gland cancers. METHODS: Patients underwent a pre-treatment MRI and had a parotid gland cancer resection with pathological evaluation. Evaluation objectives included attributive factors such as age and gender, several MRI findings of T1- and T2-weighted images, post-contrast fat suppression T1-weighted images, ADC value and 40 texture parameters calculated from T2-weighted axial images. Such objects were compared between high-grade and intermediate/low-grade lesions. RESULTS: Of the parotid gland cancers surveyed, 39 were included for analysis. Of these, 18 were high-grade lesions, 2 were intermediate-grade lesions, and 19 were low-grade lesions. The high-grade group was significantly older than the low- and intermediate-grade groups (p = 0.01). There were more males in the high-grade group than in the low- and intermediate-grade groups (p = 0.01). There were also significantly more MRI findings of neck lymph node metastases in the high-grade group than in the low- and intermediate-grade groups (p < 0.001). Other MRI findings and texture parameters did not show significant differences between the two groups (p = 0.07-1.00). CONCLUSIONS: Morphological assessment on MRI and texture parameters alone is not sufficient to estimate the grade of parotid cancer. MRI findings of neck lymph node metastases, as well as patient characteristics such as age (older patients) and gender (male) can be suggestive of high-grade parotid gland cancer in pre-treatment evaluation.

Preoperative predictive criteria for mastoid extension in pars flaccida cholesteatoma in assessments using temporal bone high-resolution computed tomography.

OBJECTIVES: We aimed to clarify the usefulness of high-resolution computed tomography (HRCT) and establish HRCT criteria for presurgical assessment of the mastoid extension in pars flaccida cholesteatomas of the middle ear. METHODS: Retrospective observational study. Patients who underwent primary surgery for pars flaccida cholesteatoma and those who underwent temporal bone HRCT for pretreatment evaluation were reviewed. The distance in the anterior-most portion of the mastoid sinus on HRCT was measured, and the presence of surgically verified mastoid extension of cholesteatoma was evaluated. All cases were subclassified as M+ (surgically mastoid extension-positive) or M- (surgically mastoid extension-negative). RESULTS: A total of 107 patients with pars flaccida cholesteatoma were included. The distance in the M+ cases was significantly longer than that in the M- cases, and the cutoff value was 3.6 mm. The difference between the ipsilateral/diseased-side distance and the contralateral/evaluable side (difference value) in M+ cases was larger than that in M- cases, with a cutoff value of 0.6 mm. The inter-rater reliability of this distance measurement was excellent, regardless of imaging experience. CONCLUSIONS: The cutoff values of the distance and the difference value can be used for pretreatment HRCT evaluation of mastoid extension in middle ear cholesteatoma with relatively high accuracy, regardless of the experience and skill levels of the evaluator.

Imaging Analysis for Cholesteatoma Extension to the Perilymphatic Space in Labyrinth Fistulae.

OBJECTIVES/HYPOTHESIS: Disturbed perilymph behind a labyrinth fistula can lead to hearing deterioration; thus, delicate manipulation is required during surgery for cholesteatomatous fistulae with matrix extension to the perilymphatic space (EPS). However, it remains challenging to identify the EPS preoperatively. This study aimed to evaluate the diagnostic value of computed tomography (CT) for preoperative prediction of the EPS of cholesteatomatous fistulae. STUDY DESIGN: Retrospective study. METHODS: We included serial high-resolution CT images showing a cholesteatomatous bone defect in the lateral semicircular canal (LSC) requiring mastoidectomy. CT and intraoperative findings were analyzed retrospectively. Using axial CT planes, we evaluated the length and angle between the margins of bone defects. Receiver operating characteristic (ROC) curves were constructed to determine the cutoff points. RESULTS: We extracted data from 30 bone defects, of which six (20.0%) showed EPS intraoperatively. Bone defects with EPS (n = 6) had significantly greater length and angle values than those without EPS (n = 24) (P < .001 for both, Wilcoxon rank sum test). For length and angle, the area under the curve was 0.944 (95% confidence interval [CI]: 0.858-1.000) and 0.951 (95% CI: 0.875-1.000), respectively, according to the ROC analysis, and the optimal cutoff values were 3.65 mm and 71.6°, respectively, with 100% sensitivity and 91.67% specificity for both. CONCLUSIONS: Results demonstrated that a length >3.65 mm and an angle >71.6° for LSC bone defects on axial CT images are reliable diagnostic markers of EPS. Preoperative high-resolution CT analysis can provide surgeons with a more conscientious preparation for handling deeper labyrinth fistulae. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1301-E1307, 2021.