non-EPI DWI Research Articles

ESR Essentials: imaging of middle ear cholesteatoma-practice recommendations by the European Society of Head and Neck Radiology.

Although non-malignant,middle ear cholesteatoma can result in significant complications due to local bone erosion and infection. The treatment of cholesteatoma is surgical, but residual disease is common and may be clinically occult, particularly when the canal wall is preserved or reconstructive techniques are employed. Imaging plays a pivotal role in the management of patients with middle ear cholesteatoma-aiding clinical diagnosis, identifying complications, planning surgery, and detecting residual disease at follow-up. Computed tomography is the primary imaging tool in the preoperative setting since it canprovide botha surgical roadmap and detect erosive complications of cholesteatoma. The ability of magnetic resonance imaging with non-echoplanar diffusion-weighted sequences to accurately detect residual disease has led to a shift in the diagnostic paradigm for post-surgical follow-up of cholesteatoma, such that routine "second-look" surgery is no longer required. The following practice recommendations are aimed athelping the radiologist choose appropriate imaging approaches and understand the key diagnostic considerations for the evaluation of pre- and post-surgical middle ear cholesteatoma. KEY POINTS: In the preoperative setting, CT is the first-line imaging modality and MRI is reserved for rare clinical scenarios (low evidence). Non-echoplanar imaging (EPI) DWI is the optimal MRI sequence for the detection of residual cholesteatoma (moderate evidence). Non-EPI DWI plays an important role in the postoperative surveillance of cholesteatoma (moderate evidence).

Post-operative MRI detection of residual cholesteatoma in pediatric patients - The yield of serial scans over a long follow-up

ObjectivesNon-echo-planar diffusion weighted magnetic resonance imaging (Non-EPI DWI MRI) is commonly used for follow-up after cholesteatoma surgery. MRI has a critical role in the evaluation of residual disease, where physical examination will commonly demonstrate an intact tympanic membrane. The aim of our study was to assess the timing of residual cholesteatoma identification on serial MRI scans and the yield of MRI follow up after canal wall up tympano-mastoidectomy. MethodsA retrospective chart review of children that underwent canal wall up tympano-mastoidectomy due to cholesteatoma in Schneider Children's Medical Center during 2004–2016, and were followed up both clinically and with MRI. ResultsSeventy-seven children (89 ears) were included, who altogether underwent 166 surgeries (77 revisions). Average follow-up was 66 ± 34.4 months. During follow up, 244 scans were performed; 19 cases of residual disease were diagnosed by MRI and confirmed in surgery. The mean time from surgery and an MRI positive for residual disease was 29.7 ± 16 months (range: 10–66). In 9/19 cases (47%), at least one negative MRI preceded the scan positive for residual disease, and in 4 cases at least two initial scans were negative. ConclusionsMRI plays an important role in the diagnosis of residual disease after cholesteatoma surgery. In our cohort. Almost half of the cases diagnosed with residual disease had at least one negative scan prior to the positive one, emphasizing the importance of close radiological follow-up with serial scans after surgery.

The Role of Fusion Technique of Computed Tomography and Non-echo-planar Diffusion-weighted Imaging in the Evaluation of Surgical Cholesteatoma Localization.

Objective:In recent years, the fusion of computed tomography (CT) and non-echo-planar diffusion-weighted magnetic resonance imaging (non- EPI DWI) has been preferred in cholesteatoma localizations. This study aimed to investigate the role of CT and non-EPI DWI fusion imaging in cholesteatoma localizations.Methods:This retrospective study included 39 patients who underwent chronic otitis media operation [mean age of 35.10±15.33 years (18-67 years), 64.1% female, and 35.9% male] and had preoperative high-resolution temporal bone CT and non-EPI DWI examinations. Images were sent to the Advantage Workstation VolumeShare 7 for fusion. These selected images were fused on the workstation and were manually corrected by the radiologist. The sensitivity, specificity, positive and negative predictive values, and diagnostic accuracies of fused images of CT and non-EPI DWI were evaluated according to anatomic cholesteatoma localizations based on surgical data.Results:The sensitivity, specificity, positive and negative predictive values, and diagnostic accuracies of non-EPI DWI for detecting cholesteatomas were 97.14%, 75.00%, 97.14%, 75.00%, and 94.87%, respectively. Three true-negative, one false-positive, and one false-negative case were observed according to surgical results in detecting the presence of a cholesteatoma with non-EPI DWI. Moderate agreement was determined between the surgical and radiological results in detecting the presence of a cholesteatoma (k=0.721). Detecting the lesion of localization on the fused images compared to surgical found an almost perfect agreement in the mastoid antrum (k=0.948), strong agreement in the hypotympanum and mastoid cells (k=0.894), moderate agreement in the epitympanum (k=0.653), and weak agreement in those in the mesotympanum (k=0.540).Conclusions:The surgeons’ determinations are supported by the guidance of temporal CT and non-EPI DWI fused images. Therefore, preferring the fusion imaging technique could increase the quality of life by reducing unnecessary operations.

The Use of Serial Non EPI DWI MRI Scans to Determine the Growth of Cholesteatoma

Introduction It is an established practice to use non-EPI DWI MRI scans to detect the presence of cholesteatoma post operatively. In the present era of Covid-19 where routine surgery to remove cholesteatoma has been suspended resulting in potentially unprecedented demands on the service, a review of serial MRI scans performed over a 7 year period was undertaken to determine the rate of growth of cholesteatoma. Materials and Methods A retrospective longitudinal study identified 24 middle ear cholesteatomas in 17 patients with serial non-EPI DWI MRI scans (having excluded those having surgical intervention between scans) for a median period of 33 months (range of 6-91 months). Cholesteatomas were measured by the first author and by the consultant radiologist. Results Of 24 cholesteatomas, 1 resolved completely, 5 reduced, 6 stayed the same size, 4 grew slowly and 8 grew significantly. Conclusion Non-EPI DWI MRI scans to determine cholesteatoma growth in asymptomatic ears is useful in triaging patients in the Covid-19 era.

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

ObjectivesA 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. MethodsPatients 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). ResultsA 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. ConclusionsThe 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.

Non-EPI versus Multishot EPI DWI in Cholesteatoma Detection: Correlation with Operative Findings.

Although multishot EPI (readout-segmented EPI) has been touted as a robust DWI sequence for cholesteatoma evaluation, its efficacy in disease detection compared with a non-EPI (eg, HASTE) technique is unknown. This study sought to compare the accuracy of readout-segmented EPI with that of HASTE DWI in cholesteatoma detection. A retrospective review was completed of consecutive patients who underwent MR imaging for the evaluation of suspected primary or recurrent/residual cholesteatomas. Included patients had MR imaging examinations that included both HASTE and readout-segmented EPI sequences and confirmed cholesteatomas on a subsequent operation. Two neuroradiologist reviewers assessed all images, with discrepancies resolved by consensus. The ratio of signal intensity between the cerebellum and any observed lesion was noted. Of 23 included patients, 12 (52.2%) were women (average age, 47.8 [SD, 25.2] years). All patients had surgically confirmed cholesteatomas: Six (26.1%) were primary and 17 (73.9%) were recidivistic. HASTE images correctly identified cholesteatomas in 100.0% of patients. On readout-segmented EPI sequences, 16 (69.6%) were positive, 5 (21.7%) were equivocal, and 2 (8.7%) were falsely negative. Excellent interobserver agreement was noted between reviews on both HASTE (κ = 1.0) and readout-segmented EPI (κ = 0.9) sequences. The average signal intensity ratio was significantly higher on HASTE than in readout-segmented EPI, facilitating enhanced detection (mean difference 0.5; 95% CI, 0.3-0.8; P = .003). HASTE outperforms readout-segmented EPI in the detection of primary cholesteatoma and disease recidivism.

Apparent diffusion coefficients for predicting primary cholesteatoma risk of recurrence after surgical clearance

PurposeBeside the well-known accuracy of non-EPI DWI techniques and relative ADC maps in detecting cholesteatomatous tissue, ADC can also represent a useful tool for stratifying cholesteatoma risk of recurrence. Aim of this study is to test the role of ADC in determining risk of recurrence for primary middle ear cholesteatoma, proposing stratification based on pre-operative mean (mADC) and normalized (nADC) ADC values. MethodsIn this prospective study, 60 patients with primary unilateral middle ear cholesteatoma underwent a three-years-long follow-up to assess the presence of recurrent disease after macroscopically complete excisional surgery. Baseline MRI examination mADC and nADC values in the group with early evidence of recurrent cholesteatoma were compared to the group with no evidence of recurrence by using T statistics. ResultsADC values on pre-operative MRI examination were lower in cholesteatomas with early evidence of recurrence, and statistical significance was slightly higher for nADC compared to mADC measurements. We also determined a cut-off between the two groups, proposing stratification in high-risk of recurrence cholesteatomas (mADC≤ 1000 or nADC< 1.3) and low-risk cholesteatomas (mADC>1000 or nADC≥1.3). ConclusionsADC values resulted discriminating in identifying cholesteatomas with higher risk of early recurrence, both for mean and normalized ADC, with optimized tissue characterization and outcome prediction.

Diagnostic imaging in chronic otitis media: does CT and MRI fusion aid therapeutic decision making? - a pilot study.

Despite the recent advances in otosurgery diagnosis of cholesteatoma and qualification for surgery remains an issue in contemporary laryngology. In cases of cholesteatoma recidivism, it is of utmost importance to properly locate the pathology in the middle ear to plan surgical approach. Magnetic Resonance imaging in diffusion-weighted non-echoplanar sequences (non-EPI DWI) enables cholesteatoma detection as small as 2 mm and could potentially prevent unnecessary second-look surgery. Computed Tomography of the temporal bone allows precise visualization of bony structures and topographical landmarks of the middle ear. A fusion of both imaging modalities combines the advantages of these techniques. Five patients treated in the Department of Otolaryngology, the Medical University of Lodz for probable cholesteatoma recidivism were included in this study. A high-resolution CT scan of the temporal bone and an MRI scan including non-EPI sequences was obtained in all patients. A fusion of CT and MRI studies was conducted using OsirixMD software. Fist, CT studies were fused with MRI BFFE sequences, then non-EPI sequences were added. Finally, if the patient qualified for surgical treatment histopathological diagnosis was compared with MRI results. CT scans were analyzed to establish the extent of previous surgical interventions and anatomical landmarks preservation. In all cases, MRI results were suspicious of cholesteatoma recidivism. Four cases were confirmed in postoperative histopathological evaluation, there was one false positive case when intraoperatively scar tissue was identified, which was later confirmed as connective tissue upon histopathological evaluation. CT and MRI fusion provides a helpful diagnostic tool in preparation for surgery in patients with suspected cholesteatoma recidivism.

Turbo spin non echo-planar diffusion weighted MRI for cholesteatoma in revision mastoidectomy: a prospective study of diagnostic accuracy and clinical impact

Background: Non-echo planar diffusion weighted MRI (NEDWI MRI) is accurate in detecting cholesteatoma in the post-operative ear but the effect on surgical decision-making in the setting of revision mastoid surgery using surgical histopathology as the gold standard has not been investigated. Methods: A blinded diagnostic accuracy study of pre-operative NEDWI MRI was conducted for consecutive patients requiring revision mastoid surgery. The operating surgeon completed a pre-operative survey without knowledge of the MRI results and post-operative survey after knowledge of the MRI results to determine impact on clinical decision making. Results: Non-EPI DWI MRI demonstrated overall sensitivity of 45.45% (95% CI: 16.75–76.62), specificity of 88.24% (95% CI: 63.56–98.54%), in detecting recurrent cholesteatoma in 28 operations. In 65.22% of cases the operating surgeon would have proceeded with second look surgery regardless of the MRI result. Conclusions: Negative NEDWI has the potential to reduce unnecessary surgery in patients who have no indication for surgery other than disease surveillance.

The results of surgical ablation of parathympanic spaces in the patients presenting with cholesteatoma

On the one hand, open-type surgical modalities have the advantage of the low frequency of relapses; on the other hand, they lead to the undesirable changes in the anatomical and physiological characteristics of the ear that in the long run create serious problems for both the doctor and the patient. In contrast, the closed-type surgical interventions are associated with a more favourable hygienic status and functional outcome but create a high risk of development of recurrent and residual cholesteatomas. The disadvantages of both types of cholesteatoma surgery motivated the surgeons for the development of the 'hybrid' approaches combining the advantages of open and closed strategies. The obliteration of the paratympanic spaces is one of them. The objective of the present study was to evaluate the results of the surgical treatment of recurrent and residual cholesteatomas and to optimize the algorithm of the postoperative control with the use of MRI in the non-EPI DWI regime. The retrospective analysis of the available clinical materials covering the period from 2009 to 2014 included the results of the surgical treatment of the patients suffering from chronic otitis media and cholesteatoma with the use of the method for the obliteration of the paratympanic spaces. A total of 179 patients were operated using the obliteration technique. The patients were under observation for 34 months on the average. We used the otomicroscopy and MRI in the non-EPI DWI regime to examine the patients within 1, 2, and 3 years after surgery. The residual cholesteatoma was discovered in 15 (8.4%) patients out of the total 179 ones. The cases of recurrence of the cholesteatomas were not observed. The diagnostic effectiveness of MRI in the non-EPI DWI regime was estimated for the purpose of the postoperative control. Sensitivity of the method was 93.3%, specificity - 97.1%.

Recidivous cholesteatoma: DWI MR after canal wall up and canal wall down mastoidectomy.

To investigate the correlation between preoperative non-echo planar diffusion-weighted (non-EPI DWI) MR imaging with surgical findings of recidivous middle ear cholesteatoma after canal wall up (CWU) and canal wall down (CWD) mastoidectomy. The detection of recidive cholesteatoma after CWU and after CWD procedures, when the trepanation cavity is spontaneously closed by soft tissue, is possible by second-look and revision surgery. However, many cases prove to be negative of the disease. To avoid unnecessary operational risks we adopted a novel imaging method to evaluate its potential in the detection of recidivous cholesteatoma. The prospective study included 27 cases. Fifteen cases were revised after CWD and 12 cases were second-look surgeries after CWU procedures. All patients underwent the MR protocol: T2-weighted, T1-weighted and non-EPI DWI. The finding on MR correlated with peroperative presence of cholesteatoma. Non-EPI DWI sequence showed an increased signal intensity in 16/27 (59 %) cases. This correlated with surgical findings in all 7 patients after CWU and in 8 patients after CWD. The overall sensitivity, specificity, positive and negative predictive values of non-EPI DWI were 83.3 %, 88.8 %, 93.8 % and 72.7 %, respectively. DWI presented a sensitivity of 100 % and specificity of 85.7 % in the subgroup of patients after CWD mastoidectomy. Residual and/or recurrent cholesteatoma can be accurately detected by DWI MR. It can be used as a screening method to select patients, who are indicated to second-look or revision surgery after CWU and CWD mastoidectomy (Tab. 1, Fig. 3, Ref. 49).

Non-EPI DWI と MR cisternography の fusion 画像による真珠腫の進展度診断

Non-EPI DWI と MR cisternography の fusion 画像による真珠腫の進展度診断

The current standard treatment of chronic otitic media with cholecteatoma

BACKGROUND: Currently there are two main techniques for cholesteatoma surgery: the closed technique (wall up) and the open technique (wall down). The canal wall down mastoidectomy in cholesteatoma can secure a good operation field and easy removal of the lesion. However, there are some problems: the lifelong care of the cavity, dizziness due to the exposed semicircular canal, difficulty with the fitting of a hearing aid as well as poor cosmetics. The canal wall up technique has a better hygienic status and better functional outcome. This technique is associated with a higher rate of residual disease and a higher rate of recurrent disease. To prevent both residual and recurrent cholesteatoma, we performed canal wall down technique with the obliteration of paratympanic spaces for patients with acquired cholesteatoma. MATERIAL AND METHODS: This paper studies the long-term outcomes of surgical treatment of chronic suppurative otitis media with cholesteatoma to prevent residual disease and its relapses. The results of the postoperative observation of 189 patients during the period from 2009 till 2014 are presented. All patients underwent sanation surgery with the obliteration of paratympanic spaces followed by the restoration of the posterior wall of the external auditory meatus and simultaneous tympanoplasty (closed-type surgery). The patients were examined one year after the treatment with the use of the MRI technology using the non-EPI DWI regime to monitor the residual and recurrence cholesteatoma. RESULTS: We analyzed the postoperative results from 189 patients. The follow-up observation revealed 11cases of residual cholesteatoma. Recurrent cholesteatoma was not observed during the follow-up periods. CONCLUSION: Long-term follow up indicated that the canal wall down technique with bony obliteration is a safe method with which to treat primary cases and to reconstruct unstable cavities. The MRI technology in the non-EPI DWI regime was successful in differentiating soft tissues and enabling the detection of residual or recurrent cholesteatoma after a canal wall down bony obliteration technique procedure.

The Efficacy of Color-Mapped Diffusion-Weighted Images Combined With CT in the Diagnosis and Treatment of Cholesteatoma Using Transcanal Endoscopic Ear Surgery.

To assess the efficacy of a color-mapped diffusion-weighted image combined with a computed tomography scan (CMDWI-CT) in preoperatively evaluating the anatomical location of cholesteatomas and determining whether a patient is indicated for transcanal endoscopic ear surgery (TEES) to reduce intraoperative switching to microscopic ear surgery (MES). Prospective case study. A single university hospital. Fifty-five patients scheduled for middle ear cholesteatoma surgery. The CMDWI-CT is produced in a multistep process. A color-mapped fusion image (CMFI) is created by performing MR cisternography on a 1-mm thin-slice nonecho planar diffusion-weighted imaging (non-EPI DWI) and then by performing color mapping on the resulting image to enhance cholesteatoma visualization. False positives are reduced by taking a T1-weighted image (T1WI), whereas false negatives are further reduced by preoperative endoscopic examination. As cholesteatomas are difficult to locate on a CMFI in the temporal bone region, we stripped out the MR cisternography data from the CMFI and then fused the CMFI to the initial computer tomography (CT) scan to create a CMDWI-CT. This CMDWI-CT better clarifies the cholesteatoma position within temporal bone. CMDWI-CT preoperative findings were compared with intraoperative findings. The positive predictive value and negative predictive value were also evaluated depending on the cholesteatoma location. CMDWI-CT facilitated accurate detection of the cholesteatoma anatomical location in the temporal bone region which was reflected in positive predictive and negative predictive values of over 90% for all areas of the middle ear. CMDWI-CT is a reliable diagnostic modality for evaluating the anatomical location of cholesteatomas that seem as high-signal regions on a CMFI and for determining whether TEES is indicated for treatment in such patients.

Non-EPI DW MRI in Planning the Surgical Approach to Primary and Recurrent Cholesteatoma

To investigate a correlation between preoperative non-echo planar diffusion-weighted magnetic resonance imaging (non-EPI DW MRI) with surgical findings of localization and extension of cholesteatoma and to develop criteria for surgical planning. Preoperative non-EPI DWMRI was available and positive for cholesteatoma in 27 patients with primary and 23 with residual/recurrent lesions. Patients with cholesteatoma limited to the middle ear and its extensions were managed with a transcanal endoscopic approach. Patients with extension of the cholesteatoma posteriorly to the lateral semicircular canal underwent retroauricular mastoidectomy combined with an endoscopic approach. Comparison of preoperative radiologic to surgical findings. DWI showed isolated tympanic and attic extension in 33 cases and attico-antral and mastoid extension in 17 cases. MRI findings correlated with surgical findings in all patients with primary cholesteatoma, 19 of whom were managed with a transcanal endoscopic approach and 8 with endoscope-assisted ear surgery. The transcanal endoscopic approach was applied in 14 of the patients with residual/recurrent cholesteatoma, and the other 9 residual/recurrent lesions were eradicated using endoscope-assisted mastoidectomy. DWI overestimated cholesteatoma sites in 1 patient with residual lesion. The smallest cholesteatoma detected on DWI was a 3-mm lesion in the middle ear over the facial nerve. Primary and residual/recurrent cholesteatoma was accurately detected on non-EPI DWI with 98% clinical and radiologic concordance. Lesions less than 8 mm confined to the middle ear and its extensions can be eradicated with a minimally invasive endoscopic transcanal technique, whereas endoscope-assisted retroauricular mastoidectomy is preferred for larger lesions.

The modern approaches to the treatment of chronic suppurative otitis with cholesteatoma

The objective of the present study was to evaluate the long-term outcomes of the surgical treatment of chronic suppurative otitis with cholesteatoma in terms of prevention of a residual disease and its relapses. The results of the postoperative observation of 149 patients during the period from 2009 till 2013 are presented. All the patients underwent sanation surgery with the obliteration of paratympanic spaces followed by the restoration of the posterior wall of the external auditory meatus and simultaneous tympanoplasty (closed-type surgery). The patients were examined one year after the treatment with the use of the MRI technology in the non-EPI DWI regime for the purpose of monitoring the residual disorders and relapses of cholesteatoma. The follow-up observation revealed 9 cases of residual cholesteatoma, no relapse of chronic suppurative otitis was documented.

Mucous retention cyst of temporal bone: a mimic of cholesteatoma on DW-MRI

Non-EPI DW imaging is increasingly being used as a sensitive sequence in detecting cholesteatomas especially if CT findings are not confirmatory. Cholesteatoma appears as a hyperintense focus on DWI. We present two cases of mucous retention cysts in the mastoid temporal bone/middle ear cavity, which present as hyperintense on non-EPI DWI and potentially may mimic cholesteatomas. Differentiating between the two conditions is important, as surgery can be avoided in mucous retention cysts. We have also discussed ways to differentiate between these two conditions on MRI. To our knowledge, this entity is not reported previously.

The Diagnostic Accuracy of Non-Echo-Planar Diffusion-Weighted Imaging in the Detection of Residual and/or Recurrent Cholesteatoma of the Temporal Bone

Non-EPI DWI is a promising alternative to second-look surgery for the detection of residual and/or recurrent cholesteatoma. We evaluated the diagnostic accuracy, expressed as a positive predictive value, of MR imaging for the detection of residual and/or recurrent cholesteatoma in our hospital. Fifty-six MR imaging studies were performed from 2005 to 2010 in patients having previously undergone surgery for cholesteatoma. Pre- and postgadolinium T1-weighted, T2-weighted, and non-EPI DWI sequences were performed and correlated with clinical and intraoperative findings. Twenty-seven patients underwent second-look surgery; 7 were under close clinical follow-up. Twenty-two patients without evidence of cholesteatoma were under regular follow-up (range, 14-44 months). Non-EPI DWI sequences showed increased DW signal intensity in 36 patients. Of those, 27 had second-look surgery, confirming cholesteatoma in 25 patients; in 1 patient, an empyema was diagnosed, and in the other patient, no cholesteatoma was found at surgery. In 2 patients who had not undergone surgery, increased DW signal intensity was accompanied by hyperintense signal intensity on T1-weighted images, consistent with transplanted fat in the postoperative cavity. The positive predictive value for detection of cholesteatoma was 93% (25/27). Residual and/or recurrent cholesteatomas after primary cholesteatoma surgery can be accurately detected by increased DW signal intensity on non-EPI DWI. However, DWI without conventional sequences increased the risk of misdiagnosis in our patient setting because transplanted fat within the postoperative cavity may show increased DW signal intensity.

Predictive validity of MRI in detecting and following cholesteatoma

High recurrence rate of the middle ear cholesteatoma requires regular postoperative follow-up. This study evaluated data from the patients investigated with DW MRI to ascertain (1) the strength of the technique in detecting primary, and residual recurrent cholesteatoma, and (2) its accuracy in differentiating cholesteatoma from postoperative tissue changes. The diagnostic accuracy of two different DW imaging (EPI and non-EPI) techniques was evaluated. The data have been collected prospectively from 33 consecutive patients with either primary cholesteatoma, or with suspicious symptoms for potential cholesteatoma recurrence. The findings from non-EPI (HASTE) DW MR and EPI DW MR images were blindly compared with those obtained during a primary or secondary surgery. Preoperative non-EPI (HASTE) DWI pointed to a cholesteatoma in 25 out of 33 patients. In this subgroup, cholesteatoma were confirmed also by the surgery. In five cases, the non-EPI (HASTE) DWI did not show a cholesteatoma in the temporal bone, which agreed with the surgical findings. Three misclassifications were made by non-EPI (HASTE) DWI, all in the subgroup of patients indicated for primary surgery. The resulting pooled sensitivity of non-EPI (HASTE) DW imaging for diagnosing cholesteatoma in our study amounted to 96.15% (95% confidence interval (CI) 80.36-99.9), specificity was 71.43% (95% CI 29.04-96.33). Positive predictive value was 92.59% (95% CI 75.71-99.09) and negative predictive value 83.33% (95% CI 35.88-99.58). In conclusion, we recommend the non-EPI (HASTE) DW MRI as a valid method for diagnosing cholesteatoma and follow-up after cholesteatoma surgery.