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Can You Get an Mri if You Have a Stapedectomy

Written By Sunday, 20 February 2022 Add Comment Edit

i Introduction

Otodystrophy of the otic capsule or what is known as otosclerosis (Bone) is seen located in the majority of patients in the anterior attribute of the oval window or what is known as the fissula dues fenestrum. 1 Patients usually present between the ages of 10 and twoscore with hearing loss whether conductive, sensorineural or mixed hearing loss; depending on the type of otosclerosis. 2 There are 2 types of otosclerosis; fenestral and retrofenestral. The classical clinical findings are an intact tympanic membrane with no signs of middle ear inflammation, progressive conductive hearing loss (CHL) and absent stapedial reflexes. 3–7

Usually, clinicians do non continue to imaging those patients with the typical clinical picture. A Stapedectomy with stapes prosthesis is the treatment of selection for fenestral otosclerosis. 3–seven

Since its introduction into otology, the computed tomographic (CT) scan has been shown to exist a useful instrument for diagnosis of otosclerosis. 3 Many studies plant a reliability of more than than 90% in the diagnosis of otosclerosis. iii

The temporal bone is fully imaged with no demand for intravenous dissimilarity textile. Centric images best demonstrate the lucent spongiotic fenestral otosclerotic foci considering of the location of the footplate of stapes too as that of the oval window. 2

Stapedectomy unremarkably involves stapes prosthesis insertion in an aim to improve hearing by removing the stock-still stapes bone and replacing information technology with a microprosthesis. Prosthesis insertion may exist linked to a few congenital-in problems such as outward displacement or inwards protrusion of the prosthesis into the vestibule, granuloma development to the more serious complications as labyrinthitis or perilymphatic fistulas. HRCT is the modality of choice as it accurately shows the position of the prosthesis and helps to exclude other complications mentioned higher up. Because of the hyperdensity of the prosthesis, information technology can be hands identified on HRCT. Nonetheless, MRI may be needed as a supplementary study to exclude labyrinthitis or fibrotic changes within the labyrinth. 4,v,8–10

Aim of this written report is to assess the importance and utility of both CT and MRI in the evaluation of poststapedectomy complications and to properly select the right imaging modality according to the suspected clinical postoperative complication.

2 Materials and methods

two.one Patients

From September 2022 to July 2016, we evaluated xx patients; including 12 females and 8 males, aged 31–64 years sometime, with a mean age of 47.five. They were all referred from the ENT surgical section. All are known cases of otosclerosis with history of stapedectomy, ranging from 4 weeks to 2 years ago. Their clinical presentation included hearing loss (viii cases), vertigo (seven cases) and routine follow up (5 cases). Onset of symptoms ranged from iv weeks post-obit the operation to upwards to 2 years later.

CT was done for all the twenty patients followed past an MRI report for only two patients where CT showed no well-defined cause and labyrinthitis was suspected. CT/MR diagnosis was correlated with the clinical diagnosis and the operative findings as the standard of reference. The study was supported by the ethical board of our establishment.

2.ii Imaging technique

MDCT examinations were performed with Siemens Somatom Definition Wink, 128 slice combined with Advantage Workstation GE; parameters consisted of a voltage of 120 kV, a electric current of 240 mA, FOV 16cm, pitch/speed 1, and a rotation time ane, no gantry tilt: 0, slice thickness 0.4 mm at 0.4 mm interval, patient position: supine. No intravenous dissimilarity was given to the patients in the routine study. Conquering of ultra-thin centric cuts was done using a multidetector CT machine, with reformats taken in both coronal and sagittal planes with respect to the lateral semicircular canal. MRI was washed for only 2 patients around v–7 days after CT imaging. Stapedectomy is non a contraindication for doing an MRI. MRI was performed on a 3 T unit. The conventional T1 and T2 weighted sequences were done with a slice thickness of 2 mm. Both centric likewise as coronal planes were taken, for improve spatial assignment. T1- weighted sequence following Iv contrast administration was also caused. A 3D high resolution heavily T2 weighted submillimetre was then followed to allow evaluation of the facial vestibulo-cochlear nerve complex and for detection of alterations in the labyrinth.

2.3 Images interpretation

All images were reviewed and analyzed by two radiologists. CT interpretation included a comment on the position of the stapes prosthesis for either migration or protrusion, exclusion of perilymphatic fistula and labyrinthitis ossificans every bit well as heart ear assessment for any soft tissue lesions. MRI interpretation included evaluation of T1 and T2 signal intensity as well equally postcontrast enhancement of the membranous labyrinth.

3 Results

A full of 20 symptomatic patients poststapedectomy were submitted for Multidetector CT examination with 2 of the cases followed by an MRI study. Seven (35%) patients showed medial migration of the prosthesis into the vestibule (Fig. 1). Six (xxx%) patients were diagnosed every bit outward protrusion of the prosthesis (Fig. 2). Two patients (ten%) showed a perilymphatic fistula (Fig. iii). Three patients (15%) had a lesion in the oval window region (Fig. 4). Two patients (10%) showed signs of labyrinthitis diagnosed on MRI (Fig. 5). The radiological results were in concordance with the intraoperative findings.

Fig. ane Two different patients with vertigo and dizziness postoperative to stapes surgery. (A) Coronal CT reformatted and (B) axial CT images showed intravestibular protrusion of the prosthesis superior to 2 mm (arrows).

Fig. ii 55 years old male person presented with CHF half dozen months afterwards stapes surgery. Coronal reformatted CT images showed outward and inferior displacement of the stapes prosthesis seen betwixt the oval window and prosthesis (arrow).

Fig. 3 Postoperative vertigo and sensory neural hearing loss in a 52 year old female patient post-obit stapedectomy. (A) Centric CT and (B) coronal MPR CT reformatted images showed deep intravestibular protrusion of the prosthesis with prove of pneumolabyrinth (arrows).

Fig. iv Dizziness and vertigo in a 35 yr-erstwhile the female afterwards stapes surgery. (A) Coronal CT reformatted and (B) centric reformatted CT images showed a nonspecific soft tissue mass around the tip of the prosthesis and in the oval window niche suggestive of an intravestibular granuloma (arrows).

Fig. 5 Patient presented with intermittent tinnitus and vertigo 2 weeks mail stapedectomy. (A) coronal reformatted pre-contrast T1 WI and (B) coronal reformatted post dissimilarity T1 WI showed bilateral intense postal service contrast enhancement in the lesion of both oval window and lobby on the left side; suggestive of early labyrinthitis (arrows). Incidentally noted bilateral middle ear effusion.

4 Discussion

Otosclerosis is a disease resulting in various foci of bone resorption involving the otic capsule region and is characterized by the presence of demineralization in the active stage followed by sclerosis in remission. eleven–thirteen The recommended surgical procedures for otosclerosis are Stapedotomy or stapedotomy. 17

Stapedectomy involves the insertion of a stapes prosthesis aiming to restore ossicular chain linkage. A variety of dissimilar stapes prosthesis are available, with different materials used as Teflon, stainless steel and platinum; all of which are of variable hyperdensities on CT. 15 80% of the causes for surgical revision are due to surgical failure, which is why imaging following the operation is extremely essential in the therapeutic determination. Least encountered complications are the labyrinthine complications reaching to less than twenty%. Primary complications following surgery are: prosthesis displacement, fibrosis of the oval window, incudo-mallear dislocation, and obliterative otosclerosis. i

Temporal bone CT examination can place many complications of stapes surgery; especially prosthesis dislocation and graft retraction. Postoperative otitis media and injury of the tympanic membrane are ofttimes seen with few cases of cholesteatoma formation being reported as a complication following Stapedectomy. 15

MR examination, on the other hand, may reveal inner ear complications every bit an intralabyrinthine hemorrhage, intravestibular extension of a granuloma or inflammatory labyrinthitis. 15 Our study showed more than prevalent complications among females, which is in agreement with Maria et al. 17

Position of the prosthesis; whether intravestibular bulging or outward protrusion has been reported as the well-nigh common complexity. CT tin easily diagnose intravestibular protrusion of the prosthesis- a bulge of the tip of prosthesis more than ii mm into the lobby is highly diagnostic. 4 In our report, 55% of the cases were due to prosthesis displacement- 30% of them had medial migration of the prosthesis into the entrance hall whereas 25% had outward protrusion into the center ear cavity. Our findings are in agreement with Feldman et al. xviii and Han et al. nineteen The incidence of occurrence of perilymphatic fistula following Stapedectomy is quite rare, ranging from iii to ten%. 20

Air bubbles seen within the vestibule or fifty-fifty a few bubbles seen adjacent to the prosthesis (pneumolabyrinth) is highly suspicious, peculiarly if associated with a fluid-filled middle ear crenel. 21 In our study, we encountered only 2 cases out of the 20 (10%) which showed few air bubbles adjacent to the prosthesis particularly the tip on CT. Findings were confirmed on surgery.

Granulation tissue formation may result in recurrent CHL and if visualized at the oval window niche is known equally a reparative or postoperative granuloma. Granulation tissue is seen as soft tissue attenuation; notwithstanding small size, suboptimal technique, and/or movement may limit visualization. 3 of our cases showed a small-scale well-defined round lesion within the oval window by CT; i of which showed suspected intravestibular extension besides. One of the severely encountered complications of stapedectomy is suppurative labyrinthitis, as infection could spread intracranially resulting in serious complications equally meningitis. 22

2 of our cases showed no well-defined cause past CT inspite of persistent SNHL. MRI was thus followed and they were diagnosed equally early labyrinthitis past the presence of enhancement of the membranous labyrinth on the postcontrast sequence. Labyrinthitis may be suggested belatedly in the course of the disease if CT shows increased density within the labyrinth, irregularity or obliteration of the labyrinth. 22 There were no suspected cases of postoperative cholestaetomas in our study.

Fortunately, complications of stapedectomy are non commonly seen, reaching upward to just 1%. 10

CT is the well-nigh important imaging modality to be washed following operation equally almost of the complications are diagnosed past CT. The sparse cuts taken allows accurate and clear identification of all the middle ear complications encountered postoperatively as prosthesis location and presence or absence of a reparative granuloma. Even progression of the otosclerosis can be diagnosed by CT alone.

On the other mitt, MRI is rarely performed and used for only those cases where labyrinthine complications are suspected and which usually occur secondary to intravestibular migration of the prosthesis, labyrinthitis or intravestibular hemorrhage. Another complication diagnosed by CT but which can be confirmed by MRI is the presence of a perilymphatic fistula.

SNHL may appear immediately post-obit surgery or over years later; with vertigo being the master complaint in patients with profound SNHL. Revision Stapedectomy is required in these cases. 20 In those patient's with deteriorated cochlear function post-obit stapes surgery, many studies stressed the need for emergency surgical revision to avoid permanent deafness. 20

In our study, CT and in few of the cases MRI, were of great help to the surgeons and helped determine the cause of failure of the stapedectomy process; allowing farther management and intervention. We had some limitations in our written report, which included the limited number of the written report population and lack of long-term follow upward afterwards diagnosis and surgical revision.

five Conclusion

Complications following stapedectomy are uncommon, just crave urgent management in some cases. CT is the primary imaging modality for evaluating those patients with clinical complaints poststapedectomy and who may crave revision surgery. MRI may be further on needed if CT was inconclusive.

Conflict of interest

The authors declared that there is no conflict of interest.

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Source: https://www.tandfonline.com/doi/full/10.1016/j.ajme.2017.07.001

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