Two Cases of Atraumatic Laryngeal Fractures

INTRODUCTION AND AIM

Atraumatic laryngeal fractures are extremely rare and are most commonly provoked by sneezing or coughing. Only seven cases have been described in medical literature, and only one case described a fracture after swallowing. We present two cases of atraumatic laryngeal fracture after swallowing.

CASE REPORT

A 37-year-old male presented to the outpatient ENT clinic with severe dysphonia and odynophagia. He reported feeling a crack in the throat after swallowing with a flexed head. The patient's physical examination showed diffuse swelling and tenderness over the thyroid cartilage without subcutaneous emphysema. Flexible nasolaryngoscopy showed a large right true vocal fold hematoma with normal vocal fold movement. Computed tomography (CT) showed a fracture of the thyroid. Treatment consisted of corticosteroids and pantoprazole. Two years later he presented again at the emergency department with extreme odynophagia after suffering a knee punch on the larynx. CT showed a new fracture line, slightly off midline to the left in the thyroid cartilage. A 42-year-old male presented at the emergency department with odynophagia, dysphonia, and fever after feeling a crack in the throat during forceful swallowing in an extended neck position. Physical examination demonstrated a painful thyroid cartilage with subcutaneous emphysema. Flexible nasolaryngoscopy was normal but CT scan showed a slightly displaced fracture line of the median thyroid cartilage. Complaints gradually disappeared with conservative treatment with corticosteroids and antibiotics.

CONCLUSION

Congenital anomalies by abnormal mineralization and ossification could lead to focal weakness of the thyroid cartilage and thus predispose to non-traumatic fractures. The double triad of odynophagia, dysphagia, and dysphonia after sneezing, coughing or swallowing should raise the physician's attention to the possibility of thyroid cartilage fracture, especially after feeling or hearing a crack. Further investigation is obligatory with high-resolution CT of the neck and examination by an ENT specialist.

Guidelines for magnetic resonance imaging in pediatric head and neck pathologies: a multicentre international consensus paper

The use of standardized imaging protocols is paramount in order to facilitate comparable, reproducible images and, consequently, to optimize patient care. Standardized MR protocols are lacking when studying head and neck pathologies in the pediatric population. We propose an international, multicenter consensus paper focused on providing the best combination of acquisition time/technical requirements and image quality. Distinct protocols for different regions of the head and neck and, in some cases, for specific pathologies or clinical indications are recommended. This white paper is endorsed by several international scientific societies and it is the result of discussion, in consensus, among experts in pediatric head and neck imaging.

Diagnosis of Menière's disease on MRI: feasibility at 1.5 Tesla

BACKGROUND

Menière's disease (MD) is clinically characterized by the triad sensorineural hearing loss, tinnitus and/or aural fullness, and vertigo. Endolymphatic hydrops (EH) is the histopathological basis associated with MD, which can be demonstrated on magnetic resonance imaging (MRI). Currently, most studies are done on a 3-T MRI scanner and to date it is believed that EH can only be demonstrated on a 3-T magnet. We report the feasibility of demonstrating EH on a 1.5-T scanner using the standard 20-channel head and neck coil and the current standard 4-h delayed intravenous gadolinium-enhanced three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequence.

PURPOSE

To investigate whether current standard 4-h delayed intravenous gadolinium-enhanced 3D-FLAIR imaging can demonstrate endolymphatic hydrops on a 1.5-T MRI scanner.

MATERIAL AND METHODS

The 3D-FLAIR sequence was taken from a 3-T MRI protocol and tested on a volunteer patient with clinically "definite" MD, after 4-h delayed intravenous contrast injection. Good image quality was obtained after reducing both the matrix and the bandwidth, with clear demonstration of EH. Subsequently, eight more patients with unilateral disease were imaged. Five patients had "definite" MD and four had "probable" MD.

RESULTS

We imaged nine patients with unilateral disease and detected EH in eight of nine ears. One patient with "probable" MD did not show any abnormality, but the images were degraded by motion artifacts.

CONCLUSION

At a cost of 2 min extra scanning time compared to a 3-T scanner, EH can be confidently demonstrated with the current standard 3D-FLAIR sequence on a 1.5-T magnet.

Radiological Follow-up After the Bony Obliteration Tympanoplasty in Detecting Residual Cholesteatoma: Towards an Optimal Postoperative MR Imaging Protocol

INTRODUCTION AND AIM

There is no consensus in literature on the most optimal follow-up imaging protocol for non-echoplanar diffusion-weighted magnetic resonance imaging (non-EP DW MRI) after the canal wall-up bony obliteration tympanoplasty. Clearly, no residual cholesteatoma should be missed but on the other hand, unnecessary MR controls should be avoided. The aim of this study is to evaluate the postoperative results of non-EP DW MRI after canal wall-up bony obliteration tympanoplasty surgery at our Institute and to propose an optimal postoperative MR imaging scheme based on our data.

MATERIAL AND METHODS

Retrospective cohort study; all 271 patients who underwent the bony obliteration tympanoplasty between January 2010 and January 2016 with follow-up at our Institute were included. A postoperative MR imaging was systematically performed at 1 year after surgery and repeated at either 5 or both 3 and 5 years after surgery, based on the preferences of the surgeon. Variables of interest were retrieved from electronic patient records.

RESULTS

The median follow-up time was 60 months (inter-quartile range 56-62 mo). Two hundred seventy-one patients (100%) received a 1-year MRI, 107 (39%) a 3-year MRI, and 216 (79.7%%) a 5-year MRI. Residual cholesteatoma was found in nine cases (3.3%), corresponding with an estimated residual rate at 5 years follow-up of 3.7% when using Kaplan-Meier analysis. Of these nine cases, six cases of residual cholesteatoma (66.7%) were detected at the 1-year MRI (12-14 mo postsurgery), two cases (22.2%) at the 3-year MRI (35-39 mo postsurgery), and one case (11.1%) at the 5-year MRI (51 mo postsurgery, in this patient no 3-year MRI was performed). An uncertain MRI result was found in 15 cases, presenting as relatively hyperintense lesions. However, subsequent follow-up scans did not show persistent evidence for residual disease in 14 of these 15 cases.

CONCLUSIONS

A postoperative MRI scan after 1 and 5 years is essential to detect early and late residual cholesteatoma. In our cohort, 22.2% of residual cases were detected at the 3-year MRI. However, this percentage could potentially have been higher when all patients would have received a 3-year MRI. Therefore, in order to detect residual disease as soon as possible, we propose to perform an MRI scan at 1, 3, and 5 years after the bony obliteration tympanoplasty. In cases with an unclear MR result, we suggest a repeat MRI after 12 months.

The Sensitivity of the cVEMP Test in Detecting A Superior Semicircular Canal Dehiscence and the Influence of a Coexisting Incudal Lysis: A Case Report

In this case report, the air-conducted cervical vestibular evoked myogenic potentials (AC cVEMP) test was only sensitive for the left superior semicircular canal dehiscence (SCD), even though the contralateral SCD was of equal length (2.5 mm). Furthermore, a lysis of the processus lenticularis incudis caused a real conductive hearing loss in the left ear. A diminished left AC cVEMP was thus expected, but the opposite was shown (increased corrected amplitude, lowered detection threshold). The patient only experienced hearing loss, so middle ear surgery was performed to repair the lysis. The postoperative AC cVEMP showed a further "uncovering" of the SCD with increased corrected amplitude on the left but no vestibular symptoms. The significance of an SCD should be interpreted with caution, even when the AC cVEMP and the imaging are significant. Furthermore, AC cVEMPs should not be considered as evidence for the absence or presence of conductive hearing loss.

Synchrotron radiation X-ray microtomography for the visualization of intra-cochlear anatomy in human temporal bones implanted with a perimodiolar cochlear implant electrode array

Recently, synchrotron radiation computed microtomography (SRµCT) has emerged as a promising tool for non-destructive, in situ visualization of cochlear implant electrode arrays inserted into a human cochlea. Histological techniques have been the `gold standard' technique for accurate localization of cochlear implant electrodes but are suboptimal for precise three-dimensional measurements. Here, an SRµCT experimental setup is proposed that offers the benefit of a high spatial and contrast resolution (isotropic voxel size = 4.95 µm and propagation-based phase-contrast imaging), while visualizing the soft-tissue structures and electrode array of the cochlear implant simultaneously. In this work, perimodiolar electrode arrays have been tested, which incorporate thick and closely spaced platinum-iridium contacts and wiring. These data can assist cochlear implant and hearing research, can be used to verify electrode segmentation techniques for clinical computed tomography or could be utilized to evaluate cochlear implant electrode array designs.

Imaging Anatomy of the Jaw and Dentition with Cone Beam Computed Tomography

Knowledge of dental, maxillary, and mandibular anatomy and the use of correct nomenclature is critical in the evaluation of a mandibulofacial and/or maxillofacial imaging data set. The use of the correct diagnostic imaging tool tailored to the patient's needs is of equal importance. This article highlights imaging anatomy and cross-sectional imaging modalities mainly focusing on cone beam computed tomography of the mandibulofacial and maxillofacial region.

Facial and Dental Trauma

Dental and facial trauma are very common in a daily routine radiology practice. Knowledge of the functional anatomy of the mandibulofacial and maxillofacial regions forms the cornerstone of a thorough full radiologic evaluation of the patient with a dental and/or facial trauma. Cone beam computed tomography and multidetector computed tomography are currently considered the imaging modalities of choice. There are several patterns and classification systems for the various subtypes of mandibulofacial and maxillofacial fractures. They are discussed separately in this article with special attention to the types of dental trauma and orbital trauma.

Intratemporal facial nerve schwannomas: multicenter experience of 80 cases

PURPOSE

To provide more data on the clinical presentation and natural evolution of facial nerve schwannomas and to provide guidance for therapeutic decision making.

METHODS

A retrospective case review of eighty patients diagnosed with a facial nerve schwannoma between 1990 and 2018 in ten tertiary referral centers in Europe was performed. Patients' demographics, symptomatology, audiometry, anatomical site (segments involved), size and whenever possible volume measurement were registered.

RESULTS

At presentation, transient or persistent facial palsy was the most common symptom, followed by hearing loss. The schwannoma involved more than one segment in the majority of the patients with the geniculate ganglion being most commonly involved. Initial treatment consisted of a wait and scan approach in 67.5%, surgery in 30% and radiation therapy in 2.5% of the patients. Tympanic segment schwannomas caused mainly conductive hearing loss and were more prone to develop facial palsy at follow-up. Internal auditory canal or cerebellopontine angle schwannomas presented with significantly more sensorineural hearing loss.

CONCLUSIONS

Although modern imaging has improved diagnosis of this tumor, choosing the best treatment modality remains a real challenge. Based on the literature review and current findings, more insights into the clinical course and the management of facial nerve schwannomas are provided.

Cochlear Erosion due to a Facial Nerve Schwannoma

Facial nerve schwannomas are rare benign neoplasms. We report a case of a 60-year-old woman who initially presented with vestibular complaints. Magnetic resonance imaging (MRI) revealed a facial nerve schwannoma centered on the right geniculate ganglion extending in the labyrinthine segment. The patient consulted again after 2 months because she developed a sudden and severe right-sided sensorineural hearing loss. MRI showed no progression or pathological enhancement in the membranous labyrinth. A cone beam computed tomography (CT) of the temporal bone was performed and revealed a large erosion at the region of the geniculate ganglion in open communication with the middle turn of the cochlea. This case report demonstrates the importance of CT in facial nerve schwannomas for evaluating the impact on the surrounding structures.

Imaging of Ménière Disease

Visualization of the morphologic substrate of Ménière disease, the endolymphatic hydrops, can be performed using noncontrast or contrast-enhanced MR imaging techniques. Noncontrast MR imaging uses a heavily T2-weighted sequence; however, its reproducibility remains to be confirmed. Contrast-enhanced MR imaging techniques mainly use a 3-dimensional fluid-attenuated inversion recovery sequence after intratympanic gadolinium administration or after a 4-hour delayed intravenous gadolinium administration. The latter technique is most frequently used and is able to detect and grade Ménière disease. It is a reliable technique with a high diagnostic accuracy, enabling visualization of endolymphatic hydrops.

Results, Hearing Rehabilitation, and Follow-up with Magnetic Resonance Imaging after Tympanomastoid Exenteration, Obliteration, and External Canal Overclosure for Severe Chronic Otitis Media

Objectives:

We sought to evaluate the results, auditory rehabilitation, and follow-up with magnetic resonance imaging (MRI) after tympanomastoid exenteration with obliteration of the mastoid cavity and overclosure of the external ear canal in patients with severe chronic otitis media that was resistant to medical therapy and conventional surgery and was associated with a profound sensorineural or severe conductive hearing loss.

Methods:

Twenty-nine patients were analyzed and underwent this surgical technique. Twelve patients had, during the same or later stage, either cochlear implantation, fixture implantation for a bone-anchored hearing aid, or middle ear implantation. For follow-up control of the obliterated cavity, delayed gadolinium-enhanced, T1-weighted MRI in combination with non-echo planar imaging diffusion weighted sequences were used.

Results:

No patient had recurrent otorrhea after an average follow-up period of 4.75 years. One patient had a residual cholesteatoma as shown by new MRI techniques, and this was successfully resected. One patient developed complications 6 months after 1-stage tympanomastoid exenteration and cochlear implantation.

Conclusions:

This technique is very useful in selected patients with severe chronic otitis media that is resistant to medical therapy and surgery and is associated with a profound sensorineural or severe conductive hearing loss. New sequences in MRI are used for postoperative follow-up of these obliterated cavities and seem reliable for the detection of residual or recurrent cholesteatoma. Middle ear implantation and cochlear implantation can be relatively safely performed in these patients in a second stage.

Aberrant internal carotid artery presenting as a retrotympanic vascular mass

We report a case of a young woman with an aberrant right internal carotid artery (ICA) presenting as a retrotympanic reddish mass. This variant of the ICA represents the collateral pathway that is formed as a result of an embryological agenesis of the cervical segment of the ICA. The embryonic inferior tympanic artery is recruited to bypass the absent carotid segment. This hypertrophied vessel may be seen otoscopically and wrongfully considered to be a vascular middle ear tumor. Informing the otorhinolaryngologist of this important vascular variant not only obviates biopsy but also helps in careful preoperative planning of eventual middle ear procedures.

A case of a temporal bone meningioma presenting as a serous otitis media

We report the imaging features of a case of a temporal bone meningioma extending into the middle ear cavity and clinically presenting as a serous otitis media. Temporal bone meningioma extending in the mastoid or the middle ear cavity, however, is very rare. In case of unexplained or therapy-resistant serous otitis media and a nasopharyngeal tumor being ruled out, a temporal bone computed tomography (CT) should be performed. If CT findings are suggestive of a temporal bone meningioma, a magnetic resonance imaging (MRI) examination with gadolinium will confirm diagnosis and show the exact extension of the lesion.

Handling an Isolated Malleus Handle Fracture

Background:

An isolated malleus handle fracture is rare and presents with vague otological symptoms. Diagnosis depends on careful history taking and otoscopic examination. Different treatment options are available. Reconstruction with hydroxyapatite bone cement is a relatively new technique.

Objective:

The aim of this article is to review the current diagnostic work-up and treatment options and to demonstrate our method of treatment with hydroxyapatite bone cement.

Methods:

Three cases, repaired with hydroxyapatite bone cement in a tertiary referral otologic center, were retrospectively analyzed. A review of the literature on diagnosis and treatment procedures was performed.

Results:

One fracture occurred by withdrawing a finger from the external auditory canal and 2 occurred without clear prior trauma. Our 3 cases were successfully repaired with hydroxyapatite bone cement.

Conclusion:

Diagnosis of an isolated malleus handle fracture still depends on careful clinical examination. In addition to pure tone audiometry, both low and higher frequency tympanometry may be useful. High resolution computed tomography with reformatting through the malleus handle is the most accurate imaging modality. Reconstruction with hydroxyapatite bone cement is reliable by restoring the original situation with only minimal manipulation and without additional ossicular interruption.

Apparent diffusion coefficient measurements as very early predictive markers of response to chemotherapy in hepatic metastasis: a preliminary investigation of reproducibility and diagnostic value

PURPOSE

To evaluate the reproducibility and diagnostic value of apparent diffusion coefficient (ADC) as an early predictor of response to chemotherapy of liver metastasis in routine clinical practice.

MATERIALS AND METHODS

A prospective study of 20 patients with histologically proven primary tumors with liver metastases was undertaken. Diffusion weighted MRI was performed twice before and 12-14 days after the start of treatment. Absolute and liver normalized ADC values were calculated. Bland Altman statistics were used to assess the reproducibility of ADC change for predicting lesion response as measured by RECIST.

RESULTS

Nineteen of 31 metastases responded. Significant increases in absolute and normalized ADC values were found in responding (mean +208.7 × 10(-6) m(2)/s and +18% respectively, both P < 0.001) compared with nonresponding lesions (mean +98.6 × 10(-6) m(2)/s and 2%, respectively, P = 0.09 and 0.519). Reproducibility was better using normalized ADC compared with absolute ADC values (within patient coefficient of variability 8.0% and 10.1%, respectively). Using the repeatability threshold of ±22.3% for normalized ADC, only 8 of 19 responding and all but one nonresponding lesions could be prospectively detected.

CONCLUSION

Increases in ADC values in responding liver metastases occurred within days after the start of chemotherapy but were of smaller magnitude than the variability of ADC measurement. These preliminary data suggest that the presently used technique is not reliable enough to predict final response at such an early time point in individual lesions.

Diagnosis of liver metastases: can diffusion-weighted imaging (DWI) be used as a stand alone sequence?

OBJECTIVES

To evaluate if diffusion-weighted MRI (DWI) can replace gadolinium-enhanced MRI (Gd-MRI) for diagnosing liver metastases. The diagnostic accuracy of both techniques alone and in combination are compared.

MATERIALS AND METHODS

Sixty-eight patients with histologically proven primary extrahepatic tumors were included in this retrospective study. Lesions included 62 metastases and 130 benign lesions. Three image sets (unenhanced T1 and T2/gadolinium enhanced T1 (Gd-MRI), DWI and combination of both) were reviewed independently by 3 observers. The areas under the receiver operating characteristic curves (A(z)), sensitivity and specificity for the 3 image sets were compared. The standard of reference was either histopathology or multi-modality and clinical follow-up.

RESULTS

Pooled data showed higher diagnostic accuracy for the combined set (A(z)=0.93) compared to Gd-MRI (p=0.001) and DWI (p<0.0001). No difference was found between the performance of Gd-MRI and DWI (p=0.09). Sensitivity for the combined set was higher than Gd-MRI (p=0.0003) and DWI (p=0.0034). Specificity for DWI was lower than Gd-MRI (p<0.0001) and the combined set (p<0.0001).

CONCLUSION

The diagnostic performance of DWI is equal to that of Gd-MRI. DWI alone can be used in patients where gadolinium contrast administration is not allowed. Combination of Gd-MRI and DWI significantly increases diagnostic accuracy.

Middle ear cholesteatoma: non-echo-planar diffusion-weighted MR imaging versus delayed gadolinium-enhanced T1-weighted MR imaging--value in detection

PURPOSE

To retrospectively compare non-echo-planar (non-EP) diffusion-weighted (DW) imaging, delayed gadolinium-enhanced T1-weighted magnetic resonance (MR) imaging, and the combination of both techniques in the evaluation of patients with cholesteatoma.

MATERIALS AND METHODS

This institutional review board-approved study, for which the need to obtain informed consent was waived, included 57 patients clinically suspected of having a middle ear cholesteatoma without a history of surgery and 63 patients imaged before "second-look" surgery. Four blinded radiologists evaluated three sets of MR images: a set of delayed gadolinium-enhanced T1-weighted images, a set of non-EP DW images, and a set of both kinds of images. Overall sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV), as well as intra- and interobserver agreement, were assessed and compared among methods. To correct for the correlation between different readings, a generalized estimating equations logistic regression model was fitted. Results were compared with surgical results, which were regarded as the standard of reference.

RESULTS

Sensitivity, specificity, NPV, and PPV were significantly different between the three methods (P < .005). Sensitivity and specificity, respectively, were 56.7% and 67.6% with the delayed gadolinium-enhanced T1-weighted images and 82.6% and 87.2% with the non-EP DW images. Sensitivity for the combination of both kinds of images was 84.2%, while specificity was 88.2%. The overall PPV was 88.0% for delayed gadolinium-enhanced T1-weighted images, 96.0% for non-EP DW images, and 96.3%for the combination of both kinds of images. The overall NPV was 27.0% for delayed gadolinium-enhanced T1-weighted images, 56.5% for non-EP DW images, and 59.6% for the combination of both kinds of images.

CONCLUSION

MR imaging for detection of middle ear cholesteatoma can be performed by using non-EP DW imaging sequences alone. Use of the non-EP DW imaging sequence combined with a delayed gadolinium-enhanced T1-weighted sequence yielded no significant increases in sensitivity, specificity, NPV, or PPV over the use of the non-EP DW imaging sequence alone.

Subarcuate Supralabyrinthine Approach for Supralabyrinthine Petrosal Cholesteatoma

Congenital cholesteatomas of the petrosal apex account for 1% to 3% of all cholesteatomas and often present an important surgical challenge. This report describes an exceptional case of a “nondestructive” translabyrinthine surgical approach to a large congenital petrosal cholesteatoma that threatened the vestibulum, superior semicircular canal, facial nerve, and internal auditory canal. We applied a nonconventional transmastoid subarcuate supralabyrinthine approach in a 20-year-old patient by accessing the lesion through the center of the superior semicircular arch without damaging the integrity of the canal. This led to a complete removal of the petrosal cholesteatoma with preservation of hearing and vestibular function. Follow-up imaging performed 1 and 2 years after operation by means of non—echo-planar diffusion-weighted imaging did not show residual cholesteatoma. This report describes the first successful use of a subarcuate supralabyrinthine approach through the arches of the superior semicircular canal in a case of petrosal cholesteatoma.

Imaging of inflammatory and infectious diseases in the temporal bone

Inflammatory and infectious diseases of the temporal bone are a major indication to perform high-resolution CT and MR imaging studies. Such studies allow one to evaluate the extent of the disease in the soft tissues and in the bony structures of the temporal bone. On these same imaging studies the possible extension of the infection to surrounding regions is visualized. In this article a segmental approach is used, focusing on four structures in the temporal bone: the external ear, the otomastoid and petrous apex, the inner ear, and the facial nerve. For each of the four sections imaging findings are described and illustrated, and if relevant a differential diagnostic approach is highlighted.

The value of single-shot turbo spin-echo diffusion-weighted MR imaging in the detection of middle ear cholesteatoma

INTRODUCTION

Single-shot (SS) turbo spin-echo (TSE) diffusion-weighted (DW) magnetic resonance imaging (MRI) is a non echo-planar imaging (EPI) technique recently reported for the evaluation of middle ear cholesteatoma. We prospectively evaluated a SS TSE DW sequence in detecting congenital or acquired middle ear cholesteatoma and evaluated the size of middle ear cholesteatoma detectable with this sequence. The aim of this study was not to differentiate between inflammatory tissue and cholesteatoma using SS TSE DW imaging.

METHODS

A group of 21 patients strongly suspected clinically and/or otoscopically of having a middle ear cholesteatoma without any history of prior surgery were evaluated with late post-gadolinium MRI including this SS TSE DW sequence.

RESULTS

A total of 21 middle ear cholesteatomas (5 congenital and 16 acquired) were found at surgery with a size varying between 2 and 19 mm. Hyperintense signal on SS TSE DW imaging compatible with cholesteatoma was found in 19 patients. One patient showed no hyperintensity due to autoevacuation of the cholesteatoma sac into the external auditory canal. Another patient showed no hyperintensity because of motion artifacts.

CONCLUSION

This study shows the high sensitivity of this SS TSE DW sequence in detecting small middle ear cholesteatomas, with a size limit as small as 2 mm.

Value of high-resolution computed tomography and magnetic resonance imaging in the detection of residual cholesteatomas in primary bony obliterated mastoids

PURPOSE

The objective of this study was to assess the value of high-resolution computed tomography (HRCT) and that of magnetic resonance imaging (MRI), including postcontrast T(1)-weighted images and echo-planar diffusion-weighted (EP-DW) images, in the detection of residual cholesteatomas after primary bony obliteration of the mastoid.

PATIENTS AND METHODS

Twenty-three patients underwent a second-look surgery 8 to 18 months after they underwent a primary bony obliteration technique. All patients were evaluated by HRCT and MRI before their second-look surgery. A retrospective analysis was performed.

RESULTS

A residual cholesteatoma was found in 2 of the 23 patients; both cases of cholesteatoma had a diameter less than 4 mm. In these 2 patients, residual cholesteatoma was found in the middle ear cavity and not in the obliterated mastoid. In all cases, HRCT showed a homogeneous obliteration of the mastoid cavity. On MRI, only one cholesteatoma pearl was detected using contrast-enhanced T(1)-weighted imaging. Findings from the EP-DW imaging were negative for all cases.

CONCLUSION

This study demonstrates that HRCT is still the imaging technique of choice for the evaluation of bony obliterated mastoids. It shows the low sensitivity and specificity of HRCT for the characterization of an associated opacified middle ear and those of contrast-enhanced T(1)-weighted imaging and EP-DW imaging for the detection of small residual cholesteatomas after primary bony obliteration.

The value of diffusion-weighted MR imaging in the diagnosis of primary acquired and residual cholesteatoma: a surgical verified study of 100 patients

Our goal was to determine the value of echo-planar diffusion-weighted MR imaging in detecting the presence of primary acquired and residual cholesteatoma. One hundred patients were evaluated by preoperative magnetic resonance (MR) imaging with diffusion-weighted MR imaging. The patient population consisted of a first group of 55 patients evaluated in order to detect the presence of a primary acquired cholesteatoma. In the second group, 45 patients were evaluated for the presence of a residual cholesteatoma 8-18 months after cholesteatoma surgery, prior to second-look surgery. Surgical findings were compared with preoperative findings on diffusion-weighted imaging (DWI). The sensitivity, specificity, positive and negative predictive values of both groups was assessed. In the group of primary surgery patients, hyperintense signal compatible with cholesteatoma was found in 89% of cases with a sensitivity, specificity, positive and negative predictive value for DWI of 81, 100, 100 and 40%, respectively. In the group of second-look surgery patients, only one of seven surgically verified residual cases was correctly diagnosed using DWI, with a sensitivity, specificity, positive and negative predictive values of 12.5, 100, 100 and 72%, respectively. These results confirm the value of DWI in detecting primary cholesteatoma, but show the poor capability of DWI in detecting small residual cholesteatoma.

Estimation of thyroid gland volume by spiral computed tomography

The objective of this study was to test the accuracy of CT for the estimation of the volume of enlarged thyroid glands. An unenhanced spiral CT scan of neck and upper mediastinum was obtained in 36 patients with an enlarged thyroid gland. By manual segmentation the surface of the thyroid gland on 5-mm-thick slices was calculated; these surfaces were multiplied by the slice interval (10 mm) and summated to obtain the volume of the gland. All patients underwent a total or subtotal thyroidectomy. 1 cm3 of thyroid gland tissue was considered to weigh 1 g. A good correlation was found between the volume estimated by CT and the weight at pathological examination of the resected gland (r = 0.98, p < 0.001), with a mean difference of + 12 % (range: + 57.3 to -13.9 %). The volume calculation is reproducible among different observers (r = 0.99, p < 0.01). Computed tomography allows an easy, reliable and reproducible volume determination of enlarged thyroid glands.