|Year : 2015 | Volume
| Issue : 4 | Page : 280-285
Correlation of high-resolution computed tomography temporal bone findings with intra-operative findings in patients with cholesteatoma
Sonika Kanotra1, Rohan Gupta1, Nitika Gupta1, Rashmi Sharma2, Saurabh Gupta2, Sunil Kotwal1
1 Department of ENT and Head and Neck Surgery, SMGS Hospital, Government Medical College, Jammu, Jammu and Kashmir, India
2 Department of Radiodiagnosis and Imaging, Government Medical College, Jammu, Jammu and Kashmir, India
|Date of Web Publication||16-Oct-2015|
Department of ENT and Head and Neck Surgery, SMGS Hospital, Government Medical College, Shalamar Road, Jammu - 180 001, Jammu and Kashmir
Source of Support: None, Conflict of Interest: None
Aim: To evaluate the role of high-resolution computed tomography (HRCT) temporal bone in patients with active squamosal chronic otitis media (COM). Materials and Methods: Totally, 47 patients with active squamosal COM underwent preoperative HRCT temporal bone followed by surgery. Their intra-operative findings were considered as the gold standard and were compared and correlated with the radiological findings, to calculate the sensitivity, specificity, positive and negative predictive value of HRCT temporal bone. Results: According to the present study, HRCT was highly sensitive for detecting mastoid pneumatization, soft tissue extension, ossicular erosion, tegmen and sigmoid sinus erosion, and less sensitive for fallopian canal erosion and lateral sinus fistula. It was specific for all these parameters. Conclusion: The present study concludes that HRCT can be recommended not only in cases suspected with potential complications but also in all cases of COM to know the extent of disease, varied pneumatization, and the presence of anatomical variations, which should alert the clinician and guide in surgical approach and treatment plan.
Keywords: Cholesteatoma, High-resolution computed tomography, Intra-operative, Temporal bone
|How to cite this article:|
Kanotra S, Gupta R, Gupta N, Sharma R, Gupta S, Kotwal S. Correlation of high-resolution computed tomography temporal bone findings with intra-operative findings in patients with cholesteatoma. Indian J Otol 2015;21:280-5
|How to cite this URL:|
Kanotra S, Gupta R, Gupta N, Sharma R, Gupta S, Kotwal S. Correlation of high-resolution computed tomography temporal bone findings with intra-operative findings in patients with cholesteatoma. Indian J Otol [serial online] 2015 [cited 2020 Feb 23];21:280-5. Available from: http://www.indianjotol.org/text.asp?2015/21/4/280/164550
| Introduction|| |
Cholesteatoma, an inflammatory disease of the temporal bone, generally develops in the middle ear  and is the result of the formation of keratinized squamous epithelium in the middle ear. The clinical manifestations of cholesteatoma are quite variable, ranging from an asymptomatic phase to life-threatening complications. The diagnosis of middle ear cholesteatoma can be made simply by an otoscopic examination, in addition to endoscopic and microscopic evaluation or even surgical exploration.
| Aim|| |
The aim of the present study was to evaluate the role of high resolution computed tomography (HRCT) temporal bone in patients with active squamosal chronic otitis media (COM), by comparing the preoperative HRCT temporal bone findings with the intra operative findings (gold standard).
Acquired cholesteatomas are classified into two types - pars flaccida and pars tensa, they are difficult to discriminate on computed tomography (CT), when involvement is extensive. The vast majority are attic cholesteatomas (82%) which arise in the Prussak's space and extend posteriorly through the posterolateral attic and into the aditus, antrum, and mastoid air cells. As the mass expands, in the epitympanum, the ossicular chain is displaced medially and in more severe cases, the ossicles may be completely eroded. In children, attic cholesteatomas can extend inferiorly into the mesotympanum or anteriorly into the protympanum, and in the protympanum, the anterior portion of the horizontal facial nerve canal, like the sinus tympani may also be the site of occult disease and source of recurrent cholesteatoma. This information is critical to surgical planning and approach. Pars tensa cholesteatomas arise from the sinus tympani or postero-superior retraction pockets, and as these are medial to the ossicular chain, the ossicles are displaced laterally.
Cholesteatomas have characteristics pattern of growth, migration, and osseous erosion and are locally destructive. The only treatment to avoid its complications and to restore the middle ear is its full surgical removal since there is no effective clinical treatment for eradication of the disease so far.
A major advance in imaging of the ear structures has occurred with the development of HRCT., By means of special algorithms, thin section HRCT allows imaging of osseous structures up to a spatial resolution of 0.45–0.65 mm.
HRCT findings suggesting cholesteatoma include outer attic wall (scutum) erosion, aditus ad antrum widening, dislocation of ossicular chain, erosion of ossicles, semi-circular canal fistula, facial nerve canal (fallopian canal) erosion, tegmen plate dehiscence, mastoid destruction (automastoidectomy), sigmoid plate dehiscence, and external auditory canal roof erosion and sagging.
An HRCT scan is useful for planning the surgical approach, determining the extension and site of cholesteatoma and its sac, assessing the ossicles, evaluating the facial nerve, tegmen and sinus plate, and determining dural, sigmoid sinus, and jugular bulb positions.
The use of CT in the preoperative evaluation of the patient with COM is still controversial nowadays. Some otologists use it regularly aiming to evaluate the extension of the disease, which helps to plan the surgical strategies and helps to reduce the postoperative risks. Others reserve its utilization for cases of suspicion of complication, recurrence or diagnostic doubt, using the surgical indication only for the clinical profile presented.
This study assesses the usefulness of a preoperative HRCT in depicting the status of middle ear structures in the presence of cholesteatoma. Its aim is to correlate the preoperative HRCT findings with the intra-operative findings and establish HRCT as an efficacious tool for diagnosis of the extent and involvement of adjacent structures by cholesteatoma.
| Materials and Methods|| |
The present study was conducted in the Department of Otorhinolaryngology and Head and Neck Surgery, SMGS Hospital, Government Medical College, Jammu for a period of 1-year from November 1, 2012 to October 31, 2013 in which 47 patients with active squamosal COM (choleastatoma), underwent HRCT temporal bone and subsequently, tympanomastoidectomy in our institution. All the patients diagnosed with active squamosal COM, on clinical examination with otoscope and oto-endoscope were included in the present study while those with active mucosal COM, inactive mucosal COM, inactive squamosal COM, revision surgery, congenital ear disease, suspicion of ear pathology to be malignant, history of fracture temporal bone, systemic disease which may affect the ear (e.g., collagen vascular or granulomatous diseases), and patients unfit for CT scanning and surgery (pregnancy, ischemic heart disease, etc.) were excluded.
A thorough history and clinical examination of ear, nose, and throat were carried out. Ear examination under microscope, tuning fork tests, pure tone audiometry, radiological test (X-ray mastoid, Towne's view), and laboratory investigation were also performed. HRCT scan of the temporal bone was performed before surgery in all the cases with 1 mm sections in both axial and coronal planes. Findings were recorded and tabulated.
After detailed discussion regarding the nature of the disease, its complications, the possible outcome of surgery, and improvement, informed consent was obtained from each patient.
All the patients underwent mastoidectomy via postaural route, under general anesthesia and intraoperative findings were noted by the operating surgeon. These intra-operative findings were considered as the gold standard and were compared and correlated with the radiological findings, to calculate the sensitivity, specificity, positive and negative predictive value of HRCT temporal bone.
The apparent differences between the findings of HRCT temporal bone and intra-operative findings were studied in numbers and proportions, and the apparent differences between these two categories were statistically tried using Chi-square test to find out any statistically significant difference. A value of <0.05 was taken to be statistically significant.
| Results|| |
Totally, 47 patients were included in the present study with 27 (57.44%) male and 20 (42.55%) female patients with age ranging from 16 to 59 years and the mean age being 36.38 years.
Comparison of preoperative HRCT findings with intra-operative findings:
Pneumatization of the mastoid – Mastoid was sclerotic on CT in all the 47 (100%) patients and was similar to the intra-operative findings. Therefore, when statistically tried, the results of the 2 categories were at par with no difference. Sensitivity and positive predictive value of HRCT = 100% [Table 1].
On HRCT temporal bone, the soft tissue density (cholesteatoma) involved middle ear and attic in five patients while in the remaining 42 patients, it extended to the mastoid. Similar findings were reported by the surgeon intra-operatively. On statistical analysis, no difference was found between the two categories with the results being at par. HRCT, sensitivity = 100%, specificity = 100%, positive predictive value = 100%, and negative predictive value = 100% [Table 2].
Erosion of tegmen plate was reported in five patients on HRCT temporal bone while intra-operatively, it was present in three patients. On statistical analysis, Chi-square with Yates correction = 0.14 (degree of freedom = 1) and P = 0.7116. Therefore, HRCT sensitivity = 100%, specificity = 95.45%, positive predictive value = 60%, and negative predictive value = 95.23% [Table 3] and [Figure 1].
|Figure 1: High-resolution computed tomography temporal bone (a) coronal section and (b) axial section both showing erosion of tegmen tympanum of left side with soft tissue density in left middle ear|
Click here to view
Sigmoid sinus plate erosion was seen in five patients on HRCT temporal bone, and the same results were found intra-operatively. Therefore, the statistical analysis showed at par results with no difference, the sensitivity, specificity, positive and negative predictive value of HRCT = 100% [Table 4].
HRCT temporal bone reported the erosion of lateral semi-circular canal in two patients; while intra-operatively, it was present in three patients. On statistical analysis, Chi-square with Yates correction = 0.00 (degree of freedom = 1) and P = 1.00. Sensitivity of HRCT = 66.66%, specificity = 95.74%, positive predictive value = 100%, and negative predictive value = 97.77% [Table 5].
On HRCT temporal bone, 19 cases were reported to have an intact malleus and 28 cases with eroded malleus, while intra-operatively, it was found to be intact in 16 patients and was eroded in 31 patients. Statistical analysis, Chi-square = 0.41 and P = 0.522. HRCT, sensitivity = 90%, specificity = 100%, positive predictive value = 100%, and negative predictive value = 84.21%.
HRCT reported incus to be intact in two cases and eroded in 45 cases, while intra-operatively, it was found to be eroded in all the cases. Statistical analysis, Chi-square with Yates correction = 0.51 and P = 0.4747. HRCT, sensitivity = 95.74%, and positive predictive value = 100%.
Stapes superstructure was reported to be eroded in nine patients and intact in 38 patients on HRCT temporal bone, while intra-operatively, it was found to be eroded in 10 patients and intact in rest of the 37 patients. Statistical analysis, Chi-square = 0.07 and P = 0.7973. HRCT, sensitivity = 90%, specificity = 100%, positive predictive value = 100%, and negative predictive value = 97.36% [Table 6] and [Figure 2].
|Figure 2: High-resolution computed tomography temporal bone, both axial sections of the same patient at different levels showing soft tissue density replacement of middle ear air, with ossicular chain disruption in right ear whereas we can appreciate the normal ossicular anatomy of left ear with air surrounding them|
Click here to view
HRCT reported dehiscent fallopian canal in two patients whereas it was detected in four more patients intra-operatively. On statistical analysis, Chi-square with Yates correction = 1.23 and P = 0.2674. HRCT, sensitivity = 33.33%, specificity = 100%, positive predictive value = 100%, and negative predictive value = 91.11% [Table 7] and [Figure 3].
|Figure 3: High-resolution computed tomography temporal bone in a patient of cholesteatoma formation, showing erosion of bony canal of horizontal part of facial nerve (fallopian canal) in the medial wall of middle ear with soft tissue density (cholesteatomatous tissue) seen adjacent to the erosion|
Click here to view
| Discussion|| |
HRCT temporal bone plays an important role in the assessment of patients with suppurative COM and cholesteatoma by giving preoperative information of the closed spaces of the middle ear.
Pneumatization of mastoid
In the present study, the sensitivity and positive predictive value of HRCT were 100% in predicting the pneumatization of mastoid when compared with the intra-operative results. Similar results were reported by Jackler et al., Vlastarakos et al., Rai  and Datta et al., who also found a strong agreement between HRCT and intra-operative findings in case of mastoid air cell complex.
Extension of soft tissue
HRCT had sensitivity = 100%, specificity = 100%, positive predictive value = 100%, and negative predictive value = 100% in predicting the extension of soft tissue mass. This finding is in agreement with that of Walshe et al. and Sirigiri and Dwaraknath  who reported a sensitivity of 90% and 87.5%, respectively.
On comparing the HRCT findings with Intra-operative findings in the present study, the sensitivity = 100%, specificity = 95.45%, positive predictive value = 60%, and negative predictive value = 95.23%, P = 0.7116 (insignificant) thereby implying that there was no statistically significant difference between the HRCT report when it was compared to the gold standard (intra-operative findings). A similar specificity rate of 95% was reported by Gerami et al., and a specificity rate of 91.93% and negative predictive value of 100% were also reported by Prata et al. and Datta et al. A similar value of 100% sensitivity, of HRCT, was also reported by Rocher et al., Zhang et al., Alzoubi et al., and Datta et al. Gerami et al. reported the sensitivity, positive and negative predictive value to be 6%, 50%, and 60%, respectively, quite low as compared to the present study. A poor sensitivity rate of HRCT to detect tegmen tympani erosion was also reported by Jackler et al. and O'Reilly et al., while a moderate association was seen by Vlastarakos et al. and Chee and Tan.
Sigmoid sinus plate erosions
The present study reported the sensitivity, specificity, positive and negative predictive value to be 100%. Datta et al. reported results similar to that documented by the present study while Rai  intra-operatively found sigmoid sinus plate erosion in eight patients whereas it was reported by HRCT in only six patients.
Lateral semicircular canal fistula
Sensitivity = 66.66%, specificity = 95.74%, positive predictive value = 100%, negative predictive value = 97.77%, and P = 1.0 were reported in the present study in detecting lateral semicircular canal fistula, thereby pointing out an insignificant statistical difference between the HRCT temporal bone and intra-operative findings (gold standard). Datta et al. reported 100% sensitivity, specificity, positive and negative predictive value, values much higher than the present study. Alzoubi et al., Chee and Tan, Mafee et al., and Rocher et al. also reported HRCT to be 100% sensitive in predicting lateral semi-circular canal fistulas while Rai  reported it to be only 25% sensitive. Gerami et al. reported a weak correlation between HRCT temporal bone and intra-operative findings.
Malleus was reported to be eroded in 28 patients by HRCT, while intra-operatively, it was eroded in three more patients, making the HRCT, sensitivity = 90%, specificity = 100%, positive predictive value = 100%, and negative predictive value = 84.21% in the present study. A specificity rate of 100% was also reported by Rai, Rocher et al., and Zhang et al., however, they all reported HRCT to be 100% sensitive, which was higher as compared to the present study. The sensitivity, specificity, and positive predictive value of the present study were comparable to the study conducted by Datta et al., whereas the negative predictive value of the present study was higher 84.21% as compared to 66.66% reported by Datta et al. According to a study conducted by Rogha et al., there is a good radiosurgical correlation for malleus while Chee and Tan  reported an excellent correlation.
Incus was observed to be eroded in 45 cases on HRCT, while intra-operatively, it was found to be eroded in all the 47 cases, therefore, HRCT was found to be 95.74% sensitive with 100% positive predictive value and P = 0.4747, implying an insignificant difference between HRCT and intra-operative findings. Datta et al. and Rai  also observed a positive predictive value of 100%, but the sensitivity was slightly low (87% and 85%, respectively) as compared to the present study. Results comparable to the present study were also reported by Zhang et al. whereas Tok et al. reported a sensitivity rate of 84.6% and a positive predictive value of 97.1%. A good radio-surgical correlation was reported by Rogha et al. and Chee and Tan  for incus.
Stapes superstructure erosion was reported by HRCT in nine patients, while intra-operatively, it was found in one more patient, making HRCT, sensitivity = 90%, specificity = 100%, positive predictive value = 100%, and negative predictive value = 97.36%. Rai  reported HRCT to be 100% specific but less sensitive (75%) as compared to the present study, and a similar observation was made by O Donoghue. Tok et al. reported a sensitivity of 71.2%, specificity = 100%, positive predictive value = 100%, and negative predictive value = 76.2%. Chee and Tan  have reported a good radiosurgical correlation for stapes while Zhang et al. and Datta et al. have reported HRCT to be poor in detecting stapes.
Dehiscent fallopian canal
The present study reported 33.33% sensitivity, 100% specificity and positive predictive value, and 91.11% negative predictive value with a P = 0.267, the value being statistically insignificant (no statistically significant difference between HRCT and intra-operative findings). In the present study, HRCT reported 4 false-negative cases for facial canal dehiscence, making it 33.33% sensitive but 100% specific. Similar results were also observed by Alzoubi et al. and Rai, but poor and insignificant correlation between the two was reported by Jackler et al., O'Reilly, Rocher et al., Chee and Tan, Zhang et al., Gerami et al. and Rogha et al. Mafee et al., however, reported HRCT to be 100% accurate. Datta et al. reported the specificity, positive and negative predictive value to be comparable to the present study but a higher sensitivity of 75%, while Magliulo et al. in their study, observed a sensitivity and specificity of 69% and 87%, respectively.
| Conclusion|| |
The CT scan is the standard imaging technique for the temporal bone. In the present study, HRCT has high reliability for the parameters such as mastoid pneumatization, cholesteatoma extension in the middle ear and mastoid, and the presence of complications such as sigmoid sinus plate erosion and tegmen mastoideum erosion.
Therefore, it is concluded that CT despite its pitfalls such as more radiation exposure and higher cost delineates the location and extent of the disease and provides information on anatomical variations and complications. It serves as a roadmap to assist the surgeon during surgery.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Sengupta A, Anwar T, Ghosh D, Basak B. A study of surgical management of chronic suppurative otitis media with cholesteatoma and its outcome. Indian J Otolaryngol Head Neck Surg 2010;62:171-6.
Tos M, editor. Manuel of Middle Ear Surgery. New York: Thieme Press; 1995.
Lan MY, Lien CF, Liao WH. Using high resolution computed tomography to evaluate middle ear cleft aeration of postoperative cholesteatoma ears. J Chin Med Assoc 2003;66:217-23.
Jang CH, Wang PC. Preoperative evaluation of bone destruction using three-dimensional computed tomography in cholesteatoma. J Laryngol Otol 2004;118:827-9.
Valvassori GE, Potter GD, Hanafee WN, Carter BL, Buckingham RA. Radiology of the Ear, Nose and Throat. Philadelphia: WB Saunders; 1984. p. 222-8.
Virapongse C, Rothman SL, Kier EL, Sarwar M. Computed tomographic anatomy of the temporal bone. AJR Am J Roentgenol 1982;139:739-49.
Mohammadi G, Naderpour M, Mousaviagdas M. Ossicular erosion in patients requiring surgery for cholesteatoma. Iran J Otorhinolaryngol 2012;24:125-8.
O'Donoghue GM, Bates GJ, Anslow P, Rothera MP. The predictive value of high resolution computerized tomography in chronic suppurative ear disease. Clin Otolaryngol Allied Sci 1987;12:89-96.
Banerjee A, Flood LM, Yates P, Clifford K. Computed tomography in suppurative ear disease: does it influence management? J Laryngol Otol 2003;117:454-8.
Jackler RK, Dillon WP, Schindler RA. Computed tomography in suppurative ear disease: A correlation of surgical and radiographic findings. Laryngoscope 1984;94:746-52.
Vlastarakos PV, Kiprouli C, Pappas S, Xenelis J, Maragoudakis P, Troupis G, et al.
CT scan versus surgery: How reliable is the preoperative radiological assessment in patients with chronic otitis media? Eur Arch Otorhinolaryngol 2012;269:81-6.
Rai T. Radiological study of the temporal bone in chronic otitis media: Prospective study of 50 cases. Indian J Otol 2014;20:48-55.
Datta G, Mohan C, Mahajan M, Mendiratta V. Correlation of preoperative HRCT findings with surgical findings in Unsafe CSOM. J Dent Med Sci 2014;13:120-5.
Walshe P, McConn Walsh R, Brennan P, Walsh M. The role of computerized tomography in the preoperative assessment of chronic suppurative otitis media. Clin Otolaryngol Allied Sci 2002;27:95-7.
Sirigiri RR, Dwaraknath K. Correlative study of HRCT in attico-antral disease. Indian J Otolaryngol Head Neck Surg 2011;63:155-8.
Gerami H, Naghavi E, Wahabi-Moghadam M, Forghanparast K, Akbar MH. Comparison of preoperative computerized tomography scan imaging of temporal bone with the intra-operative findings in patients undergoing mastoidectomy. Saudi Med J 2009;30:104-8.
Prata AA, Antunes ML, Abreu CE, Frazatto R, Lima BT. Comparative study between radiological and surgical findings of chronic otitis media. Int Arch Otolaryngol 2011;15:72-8.
Rocher P, Carlier R, Attal P, Doyon D, Bobin S. Contribution and role of the scanner in the preoperative evaluation of chronic otitis. Radiosurgical correlation apropos of 85 cases. Ann Otolaryngol Chir Cervicofac 1995;112:317-23.
Zhang X, Chen Y, Liu Q, Han Z, Li X. The role of high-resolution CT in the preoperative assessment of chronic otitis media. Lin Chuang Er Bi Yan Hou Ke Za Zhi 2004;18:396-8.
Alzoubi FQ, Odat HA, Al-Balas HA, Saeed SR. The role of preoperative CT scan in patients with chronic otitis media. Eur Arch Otorhinolaryngol 2009;266:807-9.
O'Reilly BJ, Chevretton EB, Wylie I, Thakkar C, Butler P, Sathanathan N, et al.
The value of CT scanning in chronic suppurative otitis media. J Laryngol Otol 1991;105:990-4.
Chee NW, Tan TY. The value of pre-operative high resolution CT scans in cholesteatoma surgery. Singapore Med J 2001;42:155-9.
Mafee MF, Levin BC, Applebaum EL, Campos M, James CF. Cholesteatoma of the middle ear and mastoid. A comparison of CT scan and operative findings. Otolaryngol Clin North Am 1988;21:265-93.
Rogha M, Hashemi SM, Mokhtarinejad F, Eshaghian A, Dadgostar A. Comparison of preoperative temporal bone CT with Intraoperative findings in patients with cholesteatoma. Iran J Otorhinolaryngol 2014;26:7-12.
Tok S, Adapinar B, Incesulu A, Gurbuz MK. The examination of middle ear ossicles with preoperative 64-detector computed tomography in cases with chronic otitis media and cholesteatoma and comparison of operation findings. Int Adv Otol 2013;9:349-52.
O'Donoghue GM. Cholesteatoma: Diagnosis and staging by CT scan. J Otolaryngol 1987;12:157-60.
Magliulo G, Colicchio MG, Appiani MC. Facial nerve dehiscence and cholesteatoma. Ann Otol Rhinol Laryngol 2011;120:261-7.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]