Temporal Bone Pneumatization Research Articles

CT characteristics of dehiscent sigmoid plates presenting as pulsatile tinnitus: a study of 23 patients.

Although some features of dehiscent sigmoid plates as a cause of pulsatile tinnitus (PT) have been reported, detailed imaging findings have not been evaluated. To retrospectively evaluate the computed tomography (CT) features of dehiscent sigmoid plates associated with PT. The CT images of 23 PT patients were assessed to evaluate the features of the dehiscent sigmoid plates, lateral sinuses, and temporal bone pneumatization. A total of 31 defects were found on the PT side. Twenty-five defects involved the superior curve or the descending segment, four involved above both sites, and only two involved the inferior curve. Twenty-six defects involved the anterior border or the anterolateral border, and only five involved the lateral border of the sigmoid sinus. The dehiscent sigmoid plate was on the dominant side in all 18 patients with a unilateral dominant lateral sinus, and on the right side in two patients and on the left side in three patients with co-dominant lateral sinuses. Fourteen patients had hyperpneumatization and nine had good pneumatization of temporal bone. Fifteen of the 17 patients with resolution of PT after surgery had a single defect. Four of the six patients with persistence of PT after surgery had more than one defect. Sigmoid plate dehiscence often involves the anterior or anterolateral border of the superior curve or the descending segment of the sigmoid sinus on the side of the dominant lateral sinus, which often coexists with extensive pneumatization of the temporal bone.

Pneumatization of Mastoid Air Cells, Temporal Bone, Ethmoid and Sphenoid Sinuses. Any Correlation?

The aim of this study is to assess the pneumatization of the paranasal sinuses (PNS) and other parts of temporal bone such as mastoid air cells and to investigate if there was any association between the aeration of these structures among the three major ethnic groups in Malaysia (Malay, Chinese, Indian) as this would be representative of Asia. A retrospective review of 150 computed tomography (CT) scans of PNS and temporal bones was done and analysed. The pneumatization of each area was obtained and compared using statistical analysis. Patients with a history of previous medical or surgical problems in the intended areas were excluded from the study. The pneumatization of the mastoid air cells and other temporal bone parts were noted to be symmetrical in more than 75%. There was a positive correlation between the pneumatization of mastoid air cells and that of the sphenoid sinus. The prevalence of Agger nasi, Haller's and Onodi cells was observed to be significantly higher in the Chinese group. Preoperative assessment of the temporal bone and PNS with CT scan may be helpful in the evaluation of their anatomical landmark and decrease the possibility of surgical complications related to 3D structures.

Trans-mastoid Repair of Superior Semicircular Canal Dehiscence

Objective: Superior semicircular canal (Sup SC) dehiscence syndrome is a rare condition, causing a variety of auditory and vestibular symptoms. The traditional surgical management is a middle cranial fossa, extradural approach to resurface the superior semicircular canal. Recently, a transmastoid approach for plugging of the superior semicircular canal has been developed. We present further data supporting the use of the transmastoid approach in preference to the middle fossa approach. Study Design: Retrospective multiinstitutional case series. Material and Methods: Overall 10 patients were included in this case series from two tertiary otology institutions. Sup SC dehiscence was confirmed by correlation of clinical symptoms with positive audiometric, c-VEMP and CT findings. A transmastoid approach was used for plugging of the Sup SC canal. Either a single fenestration was created at the site of dehiscence, or separate fenestrations sited ampullopetal and ampullofugal to the dehiscence. Results: All patients who underwent this procedure had good symptom control and hearing preservation postoperatively. Conclusions: In patients with adequate temporal bone pneumatization, the transmastoid approach provides a safe and effective alternative to the middle cranial fossa approach. This series has demonstrated excellent symptom control and preservation of hearing with the transmastoid approach.

Clinical analysis of secondary acquired cholesteatoma

ObjectiveThis study aimed to analyze the clinical features of patients who underwent surgery for secondary acquired cholesteatoma (SAC). Materials and methodsThe subjects were 30 patients who underwent surgery for SAC in 30 ears. We investigated the age distribution, sex, tympanic membrane (TM) findings, temporal bone pneumatization, morphology of TM epidermis invasion, extent of cholesteatoma invasion, ossicular erosion, surgical methods and surgical results. ResultsThere were 10 males (33.3%) and 20 females (66.6%), with a mean age 54.9years. The TM perforation was medium-sized or larger in 27 ears (90%). Temporal bone pneumatization was poor or bad in 90% (18/20) of the evaluated ears. The cholesteatoma invaded from the malleus manubrium to the promontory in 23 ears (76.7%). There were no patients in whom the cholesteatoma invaded the antrum or mastoid. The ossicles were affected in 19 ears (63.3%). Ossiculoplasty with a columella on the stapes was the most frequent procedure, performed for 16 ears (53.3%). There were no hearing results with a postoperative air-bone gap of more than 31dB. ConclusionsAlthough SAC is rare, it is important for the clinician to keep this type of cholesteatoma in mind.

Interspecific comparison of ontegenetic change in temporal bone pneumatization (918.22)

Comparative studies of temporal bone pneumatization in adult chimpanzees and modern humans have shown that human temporal bones have reduced pneumatization compared to chimpanzee temporal bones, following the general trend towards reduction in pneumatization over the course of hominid evolution. Although the adult pattern of pneumatization in chimpanzees is well studied, extensive quantitative comparisons of the ontogenetic change in pneumatization of the temporal bone in chimpanzees and modern humans have not been completed. The purpose of this study is to compare patterns of ontogenetic change in temporal bone pneumatization in humans and chimpanzees.High resolution computed tomography scans were acquired from cross‐sectional ontogenetic series of human (n=29) and chimpanzee (n =30) temporal bones. The sample included individuals ranging in age from neonate to adult for both species. Surface areas and volumes of the temporal bone air cell tracts were calculated using Amira for both species.Results indicate that, from an early age, chimpanzees show larger surface areas and volumes of the temporal bone air cell tracts compared to modern humans. Although there are some differences in timing of pneumatization in the two species, these differences in size may result from the progression of the air cells from both the mastoid and squamous antrums in chimpanzees. This study highlights the early establishment of adult size differences in pneumatization.

Temporal bone pneumatization in cystic fibrosis: A correlation with genotype?

Paranasal sinus pneumatization in patients with cystic fibrosis (CF) is less extensive compared to the general population and seems to be correlated to CF genotype. Interestingly, in CF patients temporal bone pneumatization (TBP) is more extensive compared to the general population, and middle ear pathology is generally uncommon in CF. It is debated whether TBP is influenced environmentally or genetically. The aim of the present study was to investigate pneumatization of the temporal bone in patients with CF and to correlate this with genotype and paranasal sinus volume. Prospective collection of data. In 104 adult CF patients, computed tomography of the temporal bone and the paranasal sinuses was performed. TBP was graded using a validated scoring system. Patients were divided into two groups, mild and severe CF, based on their mutations in the CF transmembrane conductance regulator gene. Of the 31 patients with mild CF, 71% had extensive TBP, and of the 73 patients with severe CF, 82% had extensive pneumatization of the temporal bone. TBP did not differ significantly for CF genotype, and TBP was not correlated to paranasal sinus volume. Whereas paranasal sinus pneumatization in CF patients seems to be related to CF genotype among other influencing factors, this study showed no correlation between TBP and CF genotype. TBP was not correlated to paranasal sinus volume. Hypothetically, in CF, pneumatization of the temporal bone is under a different influence than paranasal sinus pneumatization. 4.

CT analysis of dehiscent sigmoid plate presenting as pulsatile tinnitus

To evaluate the CT the characteristics of dehiscent sigmoid plate accompanied with pulsatile tinnitus (PT). Dual phase contrast enhancement CT data of 15 PT patients were analyzed retrospectively. Dehiscent sigmoid plate was located on the same side of PT in all patients. Thirteen defects had been showed in both CT images and surgery. Among of them, eight defects located on the descending segment, 3 on the superior curve, and the other 2 defects involved the superior curve and descending segment of sigmoid sinus simultaneously. The maximum anteroposterior and vertical diameters of defect measured in CT images were significant larger than that measured during surgery. There were still 5 defects showed in CT images, which did not been found during surgery. Among 9 patients with unilateral dominant brain venous systems, all the dehiscent sigmoid plates were seen on the dominant side. The other 2 patients showed co-dominant brain venous systems, whose the dehiscent sigmoid plates were on the left side. In addition, extensive pneumatized temporal bone filled with air was found in all patients. Dehiscent sigmoid plate commonly located on the anterior, lateral, or anterolateral wall of the superior curve or descending segment of the sigmoid plate, which usually coexist with the strong unilateral dominant brain venous system and extensive temporal bone pneumatization.

Classification and volumetric analysis of temporal bone pneumatization using cone beam computed tomography

This study performed volumetric analysis and classified different repeated patterns of temporal bone pneumatization in adults using cone beam computed tomography (CBCT) scans. A total of 155 temporal bones were retrospectively evaluated from 78 patients with no radiographic evidence of pathology. Two reference structures were used to classify temporal bone pneumatization into 3 groups. Volumetric analysis of the pneumatization was performed using a window thresholding procedure on multiplanar CBCT images. Correlation between direct communication of peritubal cells with the eustachian tube and the degree of pneumatization was also assessed. Using 2 reference structures, pneumatization pattern in the temporal bone can be classified into 3 groups. Statistically significant differences were present in their mean volumes between 3 groups. Statistically significant correlation was found between degree of pneumatization and presence of peritubal cells associated with ET. This study showed that CBCT can be effectively used for imaging temporal bone air cavities and for volumetric assessment.

Temporal bone pneumatisation: A computed tomography study of pneumatized articular tubercle

To determine the prevalence and characteristics of pneumatized articular tubercle (PAT) at computed tomography (CT), and to determine whether the presence of PAT is a predictor of larger pneumatized spaces of temporal bone. A retrospective study was performed using axial, sagittal and coronal CT images of 225 patients who attended a private medical imaging centre. Age and gender were recorded for all patients and, for cases of PAT, laterality and types were also recorded. Temporal bone pneumatization was recorded based on three reference structures on axial images. The Chi-square and Mann-Whitney U-tests were used. Of the 225 patients, 43 (9.55%) had PAT, of whom 24 were female and 19 were male. This difference was not statistically significant (p > 0.05). The age range of the patients with PAT was 8-67 years. Of the 43 patients, 24 had unilateral and 19 had bilateral PAT. Fifteen cases of PAT were unilocular and 28 were multilocular. Cases of PAT showed larger pneumatized spaces of other parts of the temporal bone (p = 0.0001). It is possible that PAT is a more frequent condition than is commonly perceived. The degree of pneumatization of temporal bone can be estimated by the evaluation of the air cells around the articular tubercle. CT is highly recommended in patients with PAT undergoing surgical treatment to determine the exact size and relationship of PAT to other parts of temporal bone.

The clinical and radiological status of contralateral ears in unilateral cholesteatoma patients

To evaluate the clinical and radiological features and the risk of middle ear disease in the contralateral ears of unilateral cholesteatoma with clinical and radiological assessment. Fifty-two patients with unilateral cholesteatoma and 30 control subjects underwent otoscopic and audiologic examination. Temporal bone computed tomography was performed to evaluate the pneumatization of the temporal bones, the status of anterior epitympanic space and eustachian tube. Then, the parameters of the temporal bone pneumatization were calculated. 28% of the contralateral ears in the cholesteatoma patients showed abnormal tympanic membrane findings. In the audiologic examination, 10% of the contralateral ears showed moderate hearing loss and 3% showed severe hearing loss. Aeration areas were 1.81 ± 1.01, 2.50 ± 1.31 and 4.49 ± 1.45 cm(2), aeration ratios were 24, 28 and 42%, in cholesteatoma, contralateral and control ears, respectively. Development of the anterior epitympanic space and eustachian tube patency was reduced in contralateral ears relative to control ears. The degree of temporal bone pneumatization, eustachian tube function, and development of the anterior epitympanic space are significantly decreased in the contralateral ears of unilateral cholesteatoma patients, and there is an increased risk of middle ear diseases. Continuous monitoring of the contralateral ear is crucial for early detection and optimal treatment of middle ear disease.

Sigmoid sinus diverticulum and pulsatile tinnitus: analysis of CT scans from 15 cases

Although the imaging features of sigmoid sinus diverticulum induced pulsatile tinnitus (PT) have been presented in some extent, detailed imaging findings still have not been systematically evaluated and precise diagnostic radiographic criteria has not been established. To examine the computed tomography (CT) characteristics of sigmoid sinus diverticulum accompanied with PT. Fifteen PT patients with sigmoid sinus diverticula proven by surgery were recruited after consenting. CT images of 15 patients were obtained and analyzed, including features of diverticula, brain venous systems, integrity of the sigmoid plate, and the degree of temporal bone pneumatization. Sigmoid sinus diverticulum was located on the same side of PT in 15 patients. Diverticula originated at the superior curve of the sigmoid sinus in 11 patients and the descending segment of the sigmoid sinus in four patients. Sigmoid sinus diverticula focally eroded into the adjacent mastoid air cells in 12 patients and mastoid cortex in three patients. Among eight patients with unilateral dominant brain venous systems, the diverticula were seen on the dominant side in seven patients and non-dominant side in one patient. In contrast, the other seven patients showed co-dominant brain venous systems, with three presenting diverticula on the right side and four on the left. More notably, dehiscent sigmoid plate on the PT side was demonstrated in all patients. In addition, temporal bone hyper-pneumatization was found in nine patients, good and moderate pneumatization in three patients, respectively. Dehiscent sigmoid plate and extensive temporal bone pneumatization are two important imaging characteristics of the PT induced by sigmoid sinus diverticulum.

Accuracy of digital panoramic radiography in the diagnosis of temporal bone pneumatization: A study in vivo using cone-beam-computed tomography

PurposeThe objective of the study was to determine the diagnostic accuracy of panoramic radiographs in the evaluation of pneumatization of the temporal bone, with confirmation of the diagnosis by cone-beam-computed tomography (CBCT) images. MethodsImages of 200 patients' digital panoramic radiographies and CBCT were examined by three evaluators regarding the presence or absence of pneumatization on temporomandibular joint (TMJ) fossa and/or articular eminence. When present, the defect was classified as uni- or multilocular, and as unilateral or bilateral. Areas under the ROC curve were compared to assess the accuracy of panoramic radiograph. ResultsThe values obtained in the comparisons ranged from Az = 0.67 to 0.55 (Az = area under the ROC curve). ConclusionsThe panoramic radiograph, is not the exam of choice for detecting the presence of these air cells based on its medium to low accuracy for diagnosis of pneumatized articular eminence and TMJ fossa when compared to CBCT.

Can Myringoplasty Close the Air-Bone Gap?

The aim of this study is to evaluate whether closure of a tympanic membrane perforation with an intact ossicular chain results in a closure of the air-bone gap. Prospectively collected data from 154 patients undergoing temporalis fascia myringoplasty for chronic otitis media simplex were identified. Tertiary referral center. Between 2001 and 2009, overall, 106 patients with a central tympanic membrane perforation and, an intact ossicular chain were further analyzed. All patients underwent myringoplasty using temporalis fascia in an underlay technique. Comparison of the preoperative and postoperative hearing results in patients undergoing myringoplasty for chronic otitis media simplex. The mean postoperative air-bone gap (ABG) was 8.2 dB for the frequencies 0.5 to 4 kHz. Eighty-three patients (78%) showed postoperatively a mean ABG of 10 dB or lower. The ABG difference (improvement) was statistically significant for each single frequency (0.5, 1, 2, 3, and 4 kHz) (p < 0.0001). There is a linear correlation between the preoperative tympanic membrane perforation size and the postoperative ABG (p = 0.0017) for the frequencies 0.5 to 4 kHz. No statistical significant correlation was seen between the state of the middle-ear mucosa, temporal bone pneumatization, tympanometric middle-ear/mastoid volume, and the postoperative ABG. Complete ABG closure by myringoplasty could be achieved in only approximately 20% of the cases. 80% respectively presented with a mean residual ABG of 8 dB. We found a significant linear correlation between the preoperative size of the tympanic membrane perforation and the postoperative ABG, whereas mastoid volume, temporal bone pneumatization, and the condition of the mucosa did not affect the outcome.

307 Kidney transplantation after lung transplantation in cystic fibrosis patients

Objectives: Long term survival after lung transplantation has significantly improved during the last 10 years. On the other hand, complications have increased. Renal diseases, most probably related to the immunosuppression therapy and cystic fibrosis therapy such as antibiotic threrapy, are important complications during the followup. Methods: During the period November 1996 up to now 84 lung transplantation recipients with with cystic fibrosis (40 males) followed in our center according to a pre-established follow-up protocol for Tx patients: During the follow-up period all patients developed renal complications. The mean time of occurrence after lung transplantation was 12 months. All patients have reduced immunosuppression therapy during the follow-up period (in 10 patient Tacrolimus was changed to Rapamycin) Three patients (2 females) developed severe renal complications after 8, 10, 13 years after lung transplantation, and underwent kidney transplantation. Two pts are alive after 4 and 1 year after renal transplantation with good pulmonary function (FEV1 65% and 85% predicted) normal creatinine serum level and good creatinine clereance. One pt (female) died after 1 year after renal transplantation due to bronchiolitis obliterans syndrome. Conclusion: Renal diseases after lung transplantation are an important complication; A multidisciplinary approach is needed since the beginning of the followup, in order to obtain precocious diagnosis and establish an adequate therapy. Kidney transplantation for our opinion is a good opportunity in pts with severe renal complication. 308 Temporal bone pneumatization in adult patients with cystic fibrosis M.C. Berkhout1, C.J. van Rooden2, R.C. Aalbers3, E. Rijntjes3, L.H. el Bouazzaoui1, H.G.M. Heijerman1. 1Haga Teaching Hospital, Pulmonary Diseases, The Hague, Netherlands; 2Haga Teaching Hospital, Radiology, The Hague, Netherlands; 3Haga Teaching Hospital, Otorhinolaryngology, The Hague, Netherlands

308 Temporal bone pneumatization in adult patients with cystic fibrosis

Objectives: Long term survival after lung transplantation has significantly improved during the last 10 years. On the other hand, complications have increased. Renal diseases, most probably related to the immunosuppression therapy and cystic fibrosis therapy such as antibiotic threrapy, are important complications during the followup. Methods: During the period November 1996 up to now 84 lung transplantation recipients with with cystic fibrosis (40 males) followed in our center according to a pre-established follow-up protocol for Tx patients: During the follow-up period all patients developed renal complications. The mean time of occurrence after lung transplantation was 12 months. All patients have reduced immunosuppression therapy during the follow-up period (in 10 patient Tacrolimus was changed to Rapamycin) Three patients (2 females) developed severe renal complications after 8, 10, 13 years after lung transplantation, and underwent kidney transplantation. Two pts are alive after 4 and 1 year after renal transplantation with good pulmonary function (FEV1 65% and 85% predicted) normal creatinine serum level and good creatinine clereance. One pt (female) died after 1 year after renal transplantation due to bronchiolitis obliterans syndrome. Conclusion: Renal diseases after lung transplantation are an important complication; A multidisciplinary approach is needed since the beginning of the followup, in order to obtain precocious diagnosis and establish an adequate therapy. Kidney transplantation for our opinion is a good opportunity in pts with severe renal complication. 308 Temporal bone pneumatization in adult patients with cystic fibrosis M.C. Berkhout1, C.J. van Rooden2, R.C. Aalbers3, E. Rijntjes3, L.H. el Bouazzaoui1, H.G.M. Heijerman1. 1Haga Teaching Hospital, Pulmonary Diseases, The Hague, Netherlands; 2Haga Teaching Hospital, Radiology, The Hague, Netherlands; 3Haga Teaching Hospital, Otorhinolaryngology, The Hague, Netherlands

Transmastoid Repair of Superior Semicircular Canal Dehiscence

Objective/Hypothesis Superior semicircular canal (Sup SC) dehiscence syndrome is a rare condition, causing a variety of auditory and vestibular symptoms. The traditional surgical management is a middle cranial fossa, extradural approach to resurface the Sup SC. Recently, a transmastoid approach for plugging of the Sup SC has been developed. We present further data supporting the use of the transmastoid approach in preference to the middle fossa approach. Design This is a retrospective multi-institutional case series. Method We included 10 patients in this case series from two tertiary otology institutions. Sup SC dehiscence was confirmed by correlation of clinical symptoms with positive audiometric, vestibular evoked myogenic potential, and computed tomography findings. A transmastoid approach was used for plugging of the Sup SC. Either a single fenestration was created at the site of dehiscence or separate fenestrations sited ampullopetal and ampullofugal to the dehiscence. Results All patients who underwent this procedure had good symptom control and hearing preservation postoperatively. Conclusion In patients with adequate temporal bone pneumatization, the transmastoid approach provides a safe and effective alternative to the middle cranial fossa approach. This series has demonstrated excellent symptom control and preservation of hearing with the transmastoid approach.

Zygomatic air cell defect

Zygomatic air cell defect is extension of pneumatization of temporal bones anteriorly into the articular tubercle. These are variations of normal structures which can be detected on the simplest imaging modality, the panoramic radiograph. A literature search, electronic as well as manual, was done using the keywords zygomatic air cell defect, pneumatized articular eminence and pneumatized articular tubercle. The search yielded considerable literature on the topic, which was analyzed thoroughly for its contents and this paper reviews this normal variant from the time of its recognition to the present day updates. It can be concluded that the zygomatic air cell defect has a low prevalence in general population and can be mistaken for a pathologic process. Further, if not recognized in subjects undergoing surgical procedures may lead to inadvertent complications such as leakage of cerebrospinal fluid.

Ontogenetic Change in Temporal Bone Pneumatization in Humans

Pneumatization of the temporal bone is often included in descriptions of fossils and as a phylogenetic marker, but a number of questions about the evolution, growth, and development of the trait remain. Many studies have analyzed temporal bone pneumatization from a clinical perspective, but a systematic quantification of normal development of pneumatized spaces has not been conducted. In this study, ontogenetic change in the size and organization of temporal bone pneumatization is analyzed in a cross-sectional sample of humans. High resolution computed tomography scans of the temporal bone were acquired from a cross-sectional sample of humans (N = 28). Bone volume fractions, anisotropy, trabecular number, trabecular thickness, surface area, and volume were analyzed to provide information about the organization and size of pneumatized spaces across ontogeny. The results indicate that there are general and region-specific patterns of ontogenetic changes in the organization of pneumatized spaces. These changes reflect the transition from nonpneumatized bone to pneumatized bone. It also demonstrates that those regions that are pneumatized early in ontogeny (such as the mastoid antrum) continue to remodel after the initial period of pneumatization. The dynamic nature of temporal bone pneumatization over ontogeny suggests that this character requires careful consideration when used as a character for phylogenetic analyses. These results demonstrate the importance of comparing individuals from similar developmental stages, especially when completing quantitative analyses of the extent of pneumatization or organization of the spaces.

Computed Tomographic Analysis of Outer Calvarial Thickness for Osseointegrated Bone-Anchored Hearing System Insertion

Osseointegrated bone-anchored hearing systems (BAHSs) are a useful tool in auditory rehabilitation for single-sided deafness and conductive/mixed hearing loss. They rely on adequate osseointegration of titanium implants, which can be limited by calvarial thickness. This study examines adult computed tomographic (CT) temporal bone normative data for calvarial thickness in the areas commonly recommended for BAHS insertion and identifies hazards that may compromise the osseointegration process. Prospective analysis of 100 consecutive adult helical CT scans. Calvarial thickness was measured in axial and coronal planes 5.5 cm posterior to the superior external auditory canal at 6 vertical points (EAC, +1 cm, +2 cm, +3 cm, +4 cm, and +5 cm). Other parameters measured include temporal bone pneumatization and the presence of suture lines, bone marrow, and vascular structures. A total of 195 temporal bones were examined in 100 patients. Mean patient age was 60.9 years, of whom 54.4% were men and 45.6% were women. Mean calvarial thickness was greatest at +1 cm above the EAC level (6.3 mm) and thinnest at +4 cm (5.1 mm). Of temporal bones, 55% had at least 1 site thinner than 4 mm and 21% had at least 1 site thinner than 3 mm. Air cells and suture lines were more likely to be encountered within 2 cm above the EAC level, and marrow space is more likely to be encountered 3 to 4 cm above the EAC level. Selecting a position 3 to 4 cm above the level of the EAC is more likely to result in dural exposure for a 3-mm BAHS abutment, especially in men. Selecting a position near the level of the EAC provides thicker bone, but the surgeon is more likely to encounter suture line or enter mastoid air cells. Preoperative CT imaging may be a useful tool in evaluating calvarial thickness and hazards when planning BAHS insertion in the adult population.

Double‐barrel stenting in infracochlear approach for drainage of petroux apex cholesterol granulomas

Double‐barrel stenting in infracochlear approach for drainage of petroux apex cholesterol granulomas