Magnetic resonance imaging and high-resolution computed tomography in the otospongiotic phase of otosclerosis

Combining CT Images and Clinical Features of Four Periods to Predict Whether Patients Have Rectal Cancer

In this paper, we mainly use random forest and broad learning system (BLS) to predict rectal cancer. A total of 246 participants with computed tomography (CT) image records were enrolled. The total model in the training set (combined with imaging and clinical indicators) has the best prediction result, with the area under the curve (AUC) of 0.999 (95% confidence internal (CI): 0.996-1.000) and the accuracy of 0.990 (95%CI: 0.976-1.000). Model 3, the general model in the test set, has the best prediction result, with the AUC of 0.962 (95%CI: 0.915-1.000) and the accuracy of 0.920 (95%CI: 0.845-0.995). The results of the model using random forest prediction are compared with those using BLS prediction. It can be found that there is no statistical difference between the two results. Our prediction model combined with image features has a good prediction result, and this image feature is the most important among all features. Consequently, we can successfully predict rectal cancer through a combination of the clinical indicators and the comprehensive indicators of CT image characteristics in four different periods (plain scan, vein, artery, and excretion).

Role of MRI as first-line modality in the detection of previously undiagnosed otosclerosis: a single tertiary institute experience

Background

Otosclerosis causes conductive, sensorineural and mixed hearing loss (CHL, SNHL, MHL) and tinnitus in young adults. It is best diagnosed on high-resolution CT (HRCT). Occasionally, patients presenting with SNHL and/or tinnitus may undergo temporal bone MRI as the first investigation. In this study, we have described the role of MRI as the first-line modality in the detection of previously undiagnosed otosclerosis.

Using search words ‘MRI otosclerosis’ we found 15 cases in the PACS of our institute, (University Hospitals, KU Leuven, Belgium) from 2003 to 2018. Of these, 2 were known cases of otosclerosis, hence excluded from the study. The remaining 13 patients underwent MRI as first-line investigation for unilateral SNHL (8/13), bilateral SNHL (3/13), unilateral MHL (1/13) and bilateral pulsatile tinnitus (1/13). All MRI studies were reported by the same senior radiologist.

Results

Of these 13 cases, 12 were reported as showing MRI features suspicious for otosclerosis. The typical positive findings in these cases were intermediate T1 signal and post-contrast enhancement in the perilabyrinthine/pericochlear regions. Out of 13 patients, 9 underwent subsequent HRCT, confirming otosclerosis in all. The single MRI which was reported as normal initially showed otosclerosis on HRCT. Retrospective evaluation of this MRI study showed subtle positive findings of otosclerosis.

Conclusion

The end point of this study was to validate the subtle findings of otosclerosis on MRI, by comparison to the gold-standard modality HRCT. Our hypothesis is that in the appropriate clinical setting, familiarity with MRI features of otosclerosis would increase the diagnostic ‘catch’ in the first ‘net’ itself i.e. first-line MRI.

3D-Flair sequence at 3T in cochlear otosclerosis

PURPOSE

To assess the capability of three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequences in detecting signal alterations of the endolabyrinthine fluid in patients with otosclerosis.

MATERIALS AND METHODS

3D-FLAIR before and after (-/+) gadolinium (Gd) administration was added to the standard MR protocol and acquired in 13 patients with a clinical/audiological diagnosis of severe/profound hearing loss in otosclerosis who were candidates for cochlear implantation and in 11 control subjects using 3-T magnetic resonance imaging (MRI) equipment. The MRI signal of the fluid-filled cochlea was assessed both visually and calculating the signal intensity ratio (SIR = signal intensity cochlea/brainstem).

RESULTS

We revealed no endocochlear signal abnormalities on T1-weighted -/+ Gd images for either group, while on 3D-FLAIR we found bilateral hyperintensity with enhancement after Gd administration in eight patients and bilateral hyperintensity without enhancement in one patient. No endocochlear signal abnormalities were detected in other patients or the control group.

CONCLUSION

Using 3-T MRI equipment, the 3D-FLAIR -/+ Gd sequence is able to detect the blood-labyrinth barrier (BLB) breakdown responsible for alterations of the endolabyrinthine fluid in patients with cochlear otosclerosis. We believe that 3D-FLAIR +/- Gd is an excellent imaging modality to assess the intra-cochlear damage in otosclerosis patients.

KEY POINTS

• Gd-enhanced T1-weighted MRI has limited application to detect intra-cochlear damage. • 3D-FLAIR is less sensitive to flux artefacts and allows multiplanar reconstruction. • Post-Gd 3D-FLAIR is advantageous as it may highlight the BLB breakdown. • Using 3D-FLAIR -/+ Gd, we were able to identify intra-cochlear signal hyperintensities. • 3D-FLAIR might be applied for monitoring disease progression and treatment response.

Magnetic resonance imaging in the evaluation of clinical treatment of otospongiosis: a pilot study

OBJECTIVES

To evaluate the applicability of magnetic resonance imaging (MRI) as a method for monitoring the activity of otospongiotic lesions before and after clinical treatment.

STUDY DESIGN

Prospective, randomized, controlled, double-blind study.

SETTING

One single tertiary care institution in a large, cosmopolitan city.

METHODS

Twenty-six patients (n = 42 ears) with clinical, audiometric, and tomographic diagnosis of otosclerosis were enrolled. If computed tomography (CT) demonstrated active lesions, these patients underwent MRI to detect otospongiotic foci, seen as areas of gadolinium enhancement. Patients were divided into 3 groups and received treatment with placebo, sodium alendronate, or sodium fluoride for 6 months. After this period, clinical and audiometric evaluations and a second MRI were performed. Each MRI was evaluated by both a neuroradiologist and an otolaryngologist in a subjective (visual) and objective (using specific eFilm Workstation software) manner.

RESULTS

Otospongiosis was most predominantly identified in the region anterior to the oval window, and this site was reliable for comparing pre- and posttreatment scans. The patients in the alendronate and sodium fluoride groups had MRI findings that suggested a decrease in activity of otospongiotic lesions, more relevant in the alendronate group. These findings were statistically significant for both subjective and objective MRI evaluations.

CONCLUSIONS

MRI shows higher sensitivity than clinical or audiometric assessment for detecting reduction in activity of otospongiosis. The objective MRI evaluation based on software analysis was the most accurate method of monitoring clinical treatment response in otospongiosis.

[Otosclerosis: retrospective study of 36 cases]

L'objectif de l’étude est de rapporter notre expérience concernant la prise en charge de l'otospongiose et comparer nos résultats avec ceux de la littérature. Nous rapportons une étude rétrospective concernant 36 cas d'otospongiose colligés au service d'Oto-rhino-laryngologie de l'hôpital militaire Avicenne de Marrakech, entre Janvier 2009 et Décembre 2012. L’âge moyen des patients était de 38 ans avec une nette prédominance masculine (77%). Notre étude a révélé un retard diagnostique (stades audiométriques II et III). Ce diagnostic est le plus souvent simple, très fortement suspecté dès la première consultation devant l'existence d'une surdité de transmission ou mixte à tympan normal qui constitue le signe de découverte le plus prépondérant et constant dans notre série (100%), accompagnée parfois d'acouphènes (41%). L'existence d'antécédents familiaux de la maladie a été retenue chez 33,33%. L'audiométrie tonale liminaire et la tympanométrie ont été réalisées chez tous nos patients (100%) évoquant le diagnostic dans la majorité des cas. La tomodensitométrie, non obligatoire, reste indispensable pour le diagnostic différentiel et surtout permet de prévoir les difficultés opératoires ainsi que les éventuelles associations pathologiques. Tous les patients ont subit une intervention chirurgicale comportant soit une platinectomie partielle ou totale(83%) ou une platinotomie. L’évolution et les résultats ont été généralement satisfaisants, par ailleurs nous avons constaté la survenue d'un cas de fistule périlymphatique, la persistance des acouphènes chez six patients et une surdité de transmission chez trois patients.

Imaging Evaluation in Otosclerosis: Single Photon Emission Computed Tomography and Computed Tomography

Objectives:

The aim of our study was to demonstrate the utility of diphosphonate bone single photon emission computed tomography (SPECT) in diagnosing otosclerosis and to correlate the findings from SPECT with age, gender, and sensorineural hearing loss. We also evaluated the ability of high-resolution computed tomography (HR-CT) in detecting otospongiotic and otosclerotic foci and correlated the HR-CT findings with the SPECT results.

Methods:

Seventy-three subjects with surgically confirmed otosclerosis underwent SPECT, and 45 of the 73 patients also underwent HR-CT of the petrous bones.

Results:

In the patient sample examined in this study, SPECT demonstrated a sensitivity of 95.2% and a specificity of about 96.7%. By correlating the SPECT findings, we found an inverse relationship between bone radioactivity and age (ie, greater disease activity in younger patients) and a direct relationship between bone radioactivity and the severity of sensorineural impairment in younger patients. In the 45 patients who also underwent HR-CT, the sensitivity of HR-CT (58%) was lower than that of SPECT, and the comparison between SPECT activity and the HR-CT findings (fenestral or retrofenestral type) demonstrated a statistically significant correlation between the morphological finding of bone demineralization (pericochlear foci) and a high uptake index.

Conclusions:

The use of SPECT seems to be highly effective in differentiating normal from pathological petrous bone. It also provides a quantitative evaluation of disease activity and shows a significant correlation with bone demineralization revealed by HR-CT.

Otosclerosis: mid-term results of cochlear implantation

INTRODUCTION

Constant histological changes in otosclerosis lead to progressive hearing loss which may end up in a profound hearing loss and then be treated by means of cochlear implants. These progressive changes could be followed by changes in cochlear implants fitting and speech discrimination results over the years.

OBJECTIVES

The aim of the study is to correlate the progressive histological changes to the cochlear implant clinical outcomes (fitting and speech discrimination results). Also main complications (facial nerve stimulation and difficulties at insertion) and new complications will be discussed.

DESIGN

A 5-year prospective case-control study was performed in order to compare cochlear implant results in otosclerosis patients to those in a matched-pair control group.

MATERIALS AND METHODS

Fifteen otosclerosis patients were followed throughout the study. Preoperatively temporal bone high-resolution computed tomography, electrically evoked auditory brainstem responses and speech discrimination tests were performed in order to select the patients to be implanted.

RESULTS

Not only difficulties with electrode guide insertion were reported, but also difficulties with fitting over the years, due to increasing difficulties to spread the electrical stimuli, which provokes increasing thresholds, maximum comfort levels and charges needed to stimulate hearing cells in basal and medial turn electrodes (p < 0.05), which required deactivating some basal and medial turn electrodes in order to improve cochlear implant effectiveness. The results demonstrated no statistical differences in speech discrimination in otosclerosis patients compared to the control group (p > 0.05). Several complications were reported: facial nerve stimulation (7.14%) and sudden episodes of tinnitus and headaches (14.28%).

CONCLUSIONS

Although progressive histological changes in otosclerosis lead to increasing thresholds, maximum comfort levels and charges needed to stimulate hearing cells, speech discrimination results support the cochlear implantation in otosclerosis.

Relationship between CT densitometry with a slice thickness of 0.5 mm and audiometry in otosclerosis

The appropriate cutoff Hounsfield unit (HU) value for the diagnosis of otosclerosis was determined and the correlation between the bone conduction threshold and the findings of computed tomography (CT) densitometry investigated. CT images, 0.5-mm thick, were evaluated in 24 ears with otosclerosis and 19 control ears. Eight regions of interest were set around the otic capsule. The mean HU values in the area anterior to the oval window (A-OW) and anterior to the internal auditory canal (A-IAC) were significantly lower in otosclerosis than in controls. Based on receiver operating characteristic (ROC) analysis, the cutoff HU value in A-OW was determined to be 2,187.3 HU. The mean HU value in retrofenestral otosclerosis was significantly lower in the area A-OW, A-IAC and around the cochlea than in controls. Based on ROC analysis, the cutoff HU value in the latter was determined to be 2,045 HU. A statistically significant correlation was found between the density of the area A-OW and the hearing level at 500 and 1,000 Hz, and between the density of the area around the cochlea and the hearing level at most frequencies. These results suggest the semi-automated diagnosis of otosclerosis may be possible.

Otospongiose cochléaire et pseudo-quatrième tour de cochlée

OBJECTIVE

To describe different sequences on magnetic resonance imaging (MRI) in otosclerosis with peri-cochlear involvement.

METHOD

MRI T1 and T2 sequences with T1 gadolinium injection and computed tomography (CT) scans with millimetric slices on axial and coronal views were obtained. The diagnosis of bilateral otosclerosis was confirmed by surgical exploration.

RESULTS

On the CT scan, there was a fourth turn of the cochlea which appeared on the MRI T1 sequence with an intermediate signal and on the T2 sequences with a high intensity signal. After gadolinium injection, there was signal enhancement, suggestive of active otospongiosis. On the CT scan, there was another lesion in front of the cochlea with endosteal involvement. This was no however visible on the MRI, even after gadolinium infusion, in accordance with inactive otospongiosis.

DISCUSSION

We reviewed the literature concerning MRI and results in otosclerosis.

CONCLUSION

MRI of the labyrinth with T1 sequences and gadolinium injection can be contributive to the diagnosis of otosclerosis to differentiate inactive from inactive otospongiosis. However, prospective studies must be conducted to confirm this hypothesis.