Paranasal Computed Tomography Scans Research Articles

Relation between anterior ethmoidal artery course on computed tomography and supraorbital ethmoid cell and Keros classification.

The anterior ethmoidal artery (AEA) is an important risk area in endoscopic sinus surgery. This study aimed to evaluate the course of AEA according to the Keros classification and the presence of supraorbital ethmoid cell (SOEC) and to prevent possible complications by emphasizing the importance of preoperative paranasal computed tomography (CT) imaging. This approach will increase the effectiveness of endoscopic sinus surgery and improve patient safety. The paranasal CT scan images of patients aged > 18 years between October 2020 and November 2021 from our center were retrospectively analyzed. The images were primarily evaluated in the coronal plane, and the sagittal and axial planes were utilized to evaluate variations in AEA regarding the skull base. Furthermore, the relation of AEA course with Keros classification and SOEC was evaluated. The study included 1000 patients aged 18-80 years (right and left, a total of 2000 samples). Grade 3 AEA was the most common regarding the skull base. Keros Type 2 was the most common classification. Overall, 48.7% patients had SOEC. The incidence of Grade 3 AEA was higher among patients with SOEC and a higher Keros classification compared with those without SOEC and a lower Keros classification. Furthermore, Keros Type 3 was the most associated with SOEC presence. Consistent with the literature, the probability of Grade 3 AEA in patients with high Keros classification and SOEC was significantly higher in our study. Therefore, we consider that preoperative imaging according to Keros classification and SOEC presence can predict AEA course and guide surgery.

The Role of Serum Galactomannan Assay as a Potential Surrogate Biomarker for Fungal Microinvasion in Allergic Fungal Rhinosinusitis.

We conducted this study to determine if serum galactomannan (GM) can be used as a marker to implicate the invasiveness of allergic fungal rhinosinusitis (AFRS), and correlate this value with the aggressiveness of disease documented via computed tomography (CT). All paranasal CT scans done for AFRS patients prospectively over a five-year period (2015-2019) were included. An indigenous 20-point score was used to document the extent of bone erosion seen on CT, wherein a higher score meant a greater extent of bone erosion. It was then correlated with serum GM scores. The median CT scores of galactomannan-positive (GM+) patients were compared with the median CT scores of galactomannan-negative (GM-) patients 3 using Mann-Whitney U test. The patients were divided into five groups based on the extent of disease-No bone erosion, erosion of only sinus wall/orbit, 3 erosion of orbit and skull base, erosion of only skull base and lateral extension of disease into infratemporal fossa (ITF). Subgroup analysis was conducted over mean GM values in these groups using ANOVA test. p-value < 0.05 was considered significant. Statistical analysis was performed using SPSS version 25.0. A total of 92 patients were included (56 males, 36 females). No statistically significant difference was found (p-value = 0.42) between the CT scores of galactomannan-positive (GM+) group and galactomannan-negative (GM-) group. The mean GM scores amongst the five sub-groups did not show a statistically significant difference. Serum galactomannan values correlate poorly with aggressiveness of disease quantified on non-contrast CT of paranasal sinuses.

Postoperative Clinical and Radiological Analysis of Deviated Noses.

Anatomical deformities can greatly alter nasal function, which can be largely corrected during septoplasty and septorhinoplasty operations. In this study, we aimed to objectively measure the results of septoplasty surgeries of deviated noses with radiological analysis and compare the results with clinical evaluations. Forty patients who were undergoing septorhinoplasty were included in the study. Patients were evaluated with preoperative and postoperative paranasal computed tomography scan measurements and satisfaction surveys. Preoperative and postoperative mean ± SD septal deviation angle measurements were 11.9 ± 5.3 degrees and 6.5 ± 3.1 degrees, respectively. Preoperative and postoperative mean ± SD septal deviation distance measurements were 7.3 ± 4 and 3 ± 1.3 mm, respectively. Preoperative and postoperative mean ± SD oblique conchal measurement on the deviated side was 17.3 ± 3.2 and 13.4 ± 2.8, respectively. Preoperative and postoperative mean ± SD patient satisfaction survey scores were 17 ± 1.9 and 4.5 ± 1.9 points, respectively. To obtain a nose with a greatly improved functional gains, especially in heavy deviated noses, is an important goal in septorhinoplasty surgery. It is essential to apply the technique that will benefit the patient. The most important success criterion seems to be the regression of the clinical complaints of the patients, which can be proven objectively with computed tomography scan measurements.

Lamina papyracea position in patients with allergic nasal polypi

Objective: This study aimed to describe the variations of the position of lamina papyracea (LP) in patients with allergic nasal polyposis candidate for functional endoscopic sinus surgery (FESS), by computed tomography (CT) analysis. Méthod: Paranasal CT scan of patients diagnosed to have allergic nasal polypi were included in this study and positions of lamina papyracea were registered then analyzed in relation to allergic sinonasal polypi grading. Results: fifty subjects (100 nasal sides) were included in the current study. Grade of nasal polypi was not necessarily associated with certain grade of lamina payracea. Conclusion: This study improves surgeons’ awareness of LP position in different grades of allergic sinonasal polypi and highlights that meticulous preoperative reading of every CT is the key to avoid LP injury during FESS.

C61 MULTIDISCIPLINARY MANAGEMENT IN A CASE OF EOSINOPHILIC MYOCARDITIS WITH CHURG STRAUSS SYNDROME: FROM ECG TO ENDOMYOCARDIAL BIOPSY

Abstract Background Eosinophilic granulomatosis with polyangiitis (EGPA), previously known as Churg–Strauss, is a rare multisystem disorder characterized by chronic rhinosinusitis, asthma, and prominent peripheral blood eosinophilia (PE). Cardiac involvement may include eosinophilic myocarditis and it is a serious manifestation of EGPA. Case Presentation A 67–year–old woman presented to the emergency department with 2–weeks history of dyspnea, orthopnea and asthenia. She had history of asthma, PE, adjuvant radiotherapy after right mastectomy (July 2021). The patient was diagnosed with new onset atrial fibrillation in the previous month. At admission, the patient was hemodynamically stable and with signs of congestion. Complementary exams showed sinus rhythm and T–wave inversion on lateral leads; PE (2010/uL), elevated troponin and BNP values; and severe biventricular systolic dysfunction with diffuse hypokinesia and apical akinesia. The patient was admitted to the ICU and was treated with intravenous diuretics and levosimendan. Optimal HF therapy was introduced. Serial echocardiography revealed partial recovery of LVEF and blood analysis showed a decrease in troponin levels, with persistent eosinophilia (6330/uL). Computed tomography (CT) excluded significant coronary disease, and showed bilateral basal ground–glass opacities, areas of air–space consolidation and bilateral reticular–nodular pattern. Cardiac magnetic resonance revealed increased T2 values/signs of myocardial edema in anterior wall, interventricular septum and apex and no late gadolinium enhancement, compatible with myocarditis. An endomyocardial biopsy (EMB) was performed and confirmed the diagnosis of eosinophilic myocarditis. Oral corticosteroids were started. Paranasal CT scan showed signs of chronic sinusitis, without polyposis, and antineutrophil cytoplasmic antibodies were positive, making the diagnosis of EGPA, according to ACR criteria. Discussion In a patient presenting with new onset heart failure and with history of asthma and eosinophilia, it is important to suspect eosinophilic myocarditis, as this is a rare but reversible life–threatening condition. EMB plays an important role in the diagnosis and should be done promptly. Conclusion We described a multidisciplinary management of a case of a patient with eosinophilic myocarditis and EGPA, presenting with severe acute biventricular dysfunction.

Posterior ethmoid sinus: a computed tomography analysis and classification

BackgroundThe CT details of the dimensions of the posterior ethmoid sinus are not fully covered in the literature, so building up for a base for the CT measurements and description of that area is important. Preoperative details of the posterior ethmoid sinuses are mandatory before any approach or procedure involving this area.ObjectiveTo determine the different dimensions, measurements, and grading of the posterior ethmoid sinus by computed tomography (CT) that were not previously published.MethodsTwo hundred paranasal CT scans (400 sides) were included in the study. Axial images were acquired with multiplanar reformats to obtain delicate details in coronal and sagittal planes for all subjects.ResultsWithin 200 CTs (400 sides), the mean anteroposterior dimension of the posterior ethmoid was 13.62± 1.75 mm (range= 9.5–19.5), the mean posterior ethmoid transverse diameter was 12.15+1.6 mm (range= 8–16.2) and the mean posterior ethmoid height was 44.64±3.83 mm (range= 35.8–56) without reported significant differences between both sides in all posterior ethmoid dimensions. The mean width of the posterior ethmoid sinus and its height from the orbital roof and nasal floor was significantly more in males than in females. There was significantly lower fovea ethmoidalis in males than females as we go posterior.ConclusionThis study improves surgeons’ awareness and orientation of posterior ethmoid sinus variations in the endoscopic sinus surgery and can be of help to residents in training.

Analysis of the clinical features of Japanese patients with primary ciliary dyskinesia

ObjectivePrimary ciliary dyskinesia (PCD) is a rare hereditary disease. Most reports of PCD in Japan are case reports, and clinical analysis has not been performed. Differences in the causative genes might affect the clinical features in different ethnic groups. The purpose of this study was to clarify the clinical features of Japanese patients with PCD. MethodsWe performed a retrospective chart review of PCD patients seen at Mie University Hospital and patients whose blood samples were sent to us for genetic analysis from 2011 to 2020. Data on the following items were collected and analyzed: age at first visit to the hospital, age at diagnosis of PCD, process of referral to our facility, chief complaint, situs status, PrImary CiliARy DyskinesiA Rule (PICADAR) score, nasal nitric oxide concentration, otoscopic findings, rhinoscopic findings, and paranasal computed tomography scan findings. ResultsSixty-seven patients (24 male, 43 female) were diagnosed with PCD during the study period. Age at diagnosis ranged from 2 months to 69 years (median, 17 years). Respiratory symptoms (77%) were the most common complaint, followed by nasal (15%) and aural (8%) symptoms. Situs inversus was present in 17 (25%) cases. Only 2 cases had congenital cardiac anomalies. The mean PICADAR score was 7.3 (range, 3–14) points. Approximately 50% of tympanic membranes showed retraction, suggesting otitis media with effusion. The mean Lund-Mackay score was 12.8 (range, 7–17) points, suggesting that the radiographic findings were not always severe. There was no significant difference in the total Lund-Mackay score between patients with and without situs inversus (12.7 vs. 12.6, respectively). ConclusionSitus inversus was present in 25% of Japanese PCD patients, which is much lower than observed in other countries. This is a result of differences in the major disease-causing genes. The general rule that “situs inversus is observed in approximately 50% of PCD patients” cannot be applied, at least, in Japanese PCD patients.

Anatomical Variations Associated With Maxillary Sinus Fungal Ball.

We investigated the anatomical and dental factors associated with unilateral maxillary sinus fungal ball (MSFB). Also, we evaluated the effect of combinations of those factors on the incidence of MSFB. Three hundred patients were divided into MSFB, normal, and chronic rhinosinusitis (CRS) groups. We reviewed paranasal computed tomography scans for the presence of deviated nasal septum, concha bullosa (CB), Haller cells, and various dental factors. Also, we measured the ethmoid infundibulum, maxillary natural ostium, and CB. Maxillary sinus fungal ball showed a more significant association with CB compared to the other 2 groups (37%, P < .05). The MSFB group had a lower rate of Haller cells than the normal group (10% vs 22%, respectively; P < .05). Also, the MSFB group had a wider maxillary sinus ostium than the normal group (7.07 ± 1.8 vs 5.48 ± 1.3 mm; P < .01). Moreover, the combination of CB and Haller cells was significantly associated with a decreased rate of the fungal ball (P = .047, odds ratio = 0.694). The dental factors were more prevalent in the MSFB and CRS groups (73% and 75%, respectively) than in the normal group (32%, P < .001). Maxillary sinus fungal ball is significantly associated with CB, Haller cells, an increased maxillary sinus ostium size, and dental factors.

Gender-specific differences in feasibility of pre-lacrimal window approach

The feasibility and surgical effort of a pre-lacrimal window approach (PLWA) depends on the width of the bony window anterior to the nasolacrimal duct. This study aimed to investigate gender-specific differences in feasibility of PLWA. A consecutive series of paranasal computed tomography scans from 50 females (n = 100) and 50 males (n = 100) were retrospectively analyzed. The primary outcome measure was the antero-posterior length of the bony pre-lacrimal window (BPLWA). The secondary outcome measure was the distribution of Simmen’s PLWA feasibility types (major, moderate and minor surgical effort). On average, males had a 1.5 mm (95% CI 0.8–2.2) significantly higher BPLW length in comparison to females [t(198) = 4.4, p < 0.0001]. The requirement of major surgical effort occurred 29% more frequently in females [χ2(1) = 17.7, p < 0.0001], whereas the necessity of moderate surgical effort was 21% more prevalent in males [χ2(1) = 8.8, p = 0.003]. The need of only minor surgical effort was twice as high in males compared to females [χ2(1) = 3, p = 0.081]. Our data indicates that females require more significant surgical effort during a PLWA to gain access to the maxillary sinus. These results are highly informative as a high amount of bone removal and nasolacrimal duct dislocation are associated with a higher likelihood of complications.

The middle turbinate as an anatomical landmark for a safe maxillary antrostomy during endoscopic sinus surgery: A computed tomography study

The purpose of this study is to characterize the anatomical relationship of the middle turbinate to the lamina papyracea and nasolacrimal duct and to understand if the middle turbinate can be used to landmark a safe maxillary antrostomy. Axial and coronal paranasal computed tomography scans of 109 patients were analyzed. Using the Picture Archiving and Communication Software measurement tool on coronal view, distances were measured. In 99% of CT scans, a maxillary antrostomy could be created safely at a minimum of 16.4 mm posterior to the anterior border of middle turbinate without injury to the nasolacrimal duct. In 98.5% of CT scans, a maxillary antrostomy could be safely initiated at the inferior border of middle turbinate, without injury to the orbit. The middle turbinate may be used as an effective adjunctive anatomical landmark when creating a maxillary antrostomy.

Microbiology, Histopathology, and Radiographic Findings in Silent Sinus Syndrome.

The histopathology and microbiology associated with silent sinus syndrome (SSS) have not been well described. This study details the histopathological and microbiological characteristics in addition to radiographic findings of SSS in comparison to those of chronic maxillary sinusitis (CRS). 42 patients diagnosed with SSS at Mayo Clinic Hospital in Arizona were identified. Paranasal computed tomography scans of the 42 SSS patients as well as 42 matched CRS patients were analyzed in order to assess differences in the prevalence of septal spurs/deviation. 20 of the SSS patients and 19 of the matched CRS patients also had histopathology and microbiology reports, which were compiled and summarized. Additionally, 19 SSS and 19 matched CRS patients were contacted via phone survey for a more complete patient history regarding maxillary dental disease/surgery. SSS patients have a significantly higher prevalence of septal spurs/deviation than CRS patients. The microbiomes of SSS patients more closely resemble those of healthy controls than those of CRS patients. Analysis of the histopathology of SSS reveals chronic, non-specific inflammation similar to that seen in non-eosinophilic CRS without polyps. SSS patients were significantly more likely to have a history of maxillary dental disease requiring surgery. These data support the hypothesis that the pathogenesis of SSS is more likely due to anatomical/mechanical factors than inflammatory/microbiological factors.

Value of Hounsfield Units in the Evaluation of Isolated Sphenoid Sinus Lesions.

Radiologic findings of fungal sinus disease are generally opacification in paranasal computed tomography (CT) images. The Hounsfield unit (HU) is a standardized objective unit that is also suitable for measuring remodeling and opacifications on CT scans of bone sections of patients with chronic rhinosinusitis. We hypothesized that HU values could provide valuable information in isolated sphenoid sinus lesions before surgery. Between 2012 and 2019, 35 patients underwent functional endoscopic sinus surgery for sphenoid sinus lesions. Tissues obtained from the sphenoid sinus were divided into two groups, fungal and nonfungal, according to the findings of histopathologic examinations. HU values were measured in sphenoid sinus sections on paranasal CT scans of these two groups. Differences in mean and maximum HU values between the two groups were statistically significant (p < .05). The maximum HU values calculated from the sphenoid sinus were 435.08 and 196.23 (p ≤ .05) in the fungal group and nonfungal group, respectively. The mean HU values calculated from the sphenoid sinus were 64.31 and 29 (p ≤ .05) in the fungal and nonfungal groups, respectively. At the maximum cutoff value of 241, the sensitivity and specificity of the HU maximum were 84.6% and 77.3%, respectively. At the mean cutoff value of 41.5, the sensitivity and specificity of the HU mean were 76.9% and 86.4%, respectively. HU is an objective value used in radiographic density measurement. The HU values were higher in fungal lesions than in nonfungal inflammations, and they are useful in preoperative measurement.

Sinonasal anatomic variations and relationship with sinonasal inflammatory mucosal disease: a computed tomography study

Objective: To evaluate sinonasal anatomic variations on the paranasal computed tomography (CT) scans and to investigate association with sinonasal inflammatory mucosal disease.&#x0D; &#x0D; Materials and Methods: Between January 2019 and December 2019, paranasal CT scans of 279 adult patients were retrospectively analyzed. Patients data were obtained from medical and imaging records. On CT examinations, each anatomic variation was evaluated with respect to side and bilaterality. We investigated statistically coexistence between anatomic variations and presence of sinonasal inflammatory mucosal disease.&#x0D; &#x0D; Results: Our results showed high prevalence of sinonasal anatomic variations. The most common anatomic variation was nasal septal deviation (65.2 %), followed by concha bullosa (41.6 %)and septal spur (28.7 %). We found a statistically significant relationship between concha bullosa and sinonasal inflammatory mucosal disease (p=0.009) which was observed especially in bulbous (p=0.048) and extensive types(p=0.017). No significant association was noted with the other anatomic variations.&#x0D; &#x0D; Conclusion: &#x0D; Concha bullosa, particularly bulbous and extensive types have a tendency to cause sinonasal inflammatory mucosal disease. &#x0D; Key words: Sinonasal cavity, anatomic variation, computed tomography, mucosal disease, rhinosinusitis

Thyroid Cancer Risk in Patients Undergoing 64 Slice Brain and Paranasal Sinuses Computed Tomography

Purpose: Computed Tomography (CT) is a fundamental part of diagnosis of diseases. During CT examinations organs in and out of scanned volume are exposed to ionization radiation. The aim of this study was Estimation Thyroid cancer risk in Patients who Underwent 64 Slice brain and paranasal sinuses CT scan. Materials and Methods: with permission from the authors and editor, data related to thyroid dose of 40 patients in Mazyar et al.'s paper was used and by using Biological Effects of Ionizing Radiation (BEIR)VII model thyroid cancer risk was calculated for different ages at exposure in male and female. Results: In both brain and paranasal sinuses CT, ERR values in female patients were twice as many as those in male patients. At age range from 20 to 40 years, ERR was considerably more than at age range 40-60 years since young patients are more radiosensitive than old patients. Conclusion: The calculations of ERR indicate that PNS and brain CT increase the theoretical risk of thyroid cancer incidence. Although the ERR values are low, impacts on the thyroid cancer incidence should not be disregarded.

Is Nasal Septal Body Size Associated With Inferior Turbinate Hypertrophy and Allergic Rhinitis?

Nasal septal body is a thickened mucosal area of nasal septum with an unknown certain role. In this study, the authors aimed to investigate the association between the area, length, and width of the nasal septal body with inferior turbinate hypertrophy (ITH) and allergic rhinitis (AR). A total of 106 patients with ITH (54 with AR and 52 without AR), and 49 patients without ITH and AR (control group) were included in this study. Using axial and coronal paranasal computed tomography scans, the area, length, and width of nasal septal body were measured, and the mean values between the groups were compared. Mean area, length, and width of nasal septal body significantly differed among 3 groups (P < 0.001). Septal body area was significantly greater in ITH with AR group, compared to ITH without AR group (P < 0.001) and the control group (P < 0.001). Also, it was significantly greater in ITH without AR group compared to the control group (P < 0.001). Septal body width was significantly greater in ITH with AR group, compared to ITH without AR group (P < 0.001) and the control group (P < 0.001). Also, it was significantly greater in ITH without AR group compared to the control group (P < 0.001). Patients with ITH had a greater nasal septal body area, length, and width, compared to the patients without. Moreover, AR had an additional increasing effect on the area and width of the nasal septal body.

Anterior Ethmoidal Artery: A Computed Tomography Analysis and New Classifications.

Objective to determine the anterior ethmoidal artery (AEA) anatomy and variations by computed tomography (CT) in adult and their relations to and presents new AEA classifications. Methods One hundred and fifty paranasal CT scans (300 sides) were included. Axial images were acquired with multiplanar reformates to obtain delicate details in coronal and sagittal planes. Results One hundred and forty-four AEAs canal (48%), 293 AEAs foramen (97.7%), and 229 AEAs sulcus could be detected (76.3%). The mean AEA intranasal length was 6.7 ± 1.27 mm (range: 4.24-10.6 mm). The mean angle between AEA and lamina papyracea was 105.49 ± 9.28 degrees (range: 76.41-129.76 degrees). Of them, 95.8% AEAs had an angle with lamina >90 degrees, while 4.2% had angle <90 degrees. The mean angle between AEA and lateral lamella of cribriform plate was 103.95 ± 13.08 degrees (range: 65.57-141.36 degrees). Of them, 87.5% AEAs had an angle >90 degrees and 12.5% had an angle <90 degrees. The mean distance between AEA and skull base was 1.37 ± 1.98 mm (range: 0-8.35 mm). The AEA types in relation to skull base was type 1 (0-2 mm from skull base; 64.6%), type 2 (2-4 mm; 22.2%), type 3 (4-6 mm; 11.1%), and type 4 (>6 mm; 2.1%). The mean distance between the AEA and frontal sinus ostium was 9.17 ± 4.72 mm (range: 0-25.36 mm). AEA classification according to distance from AEA to frontal sinus ostium was 17.4% type 1 (<5 mm), 41.7% type 2 (5-10 mm), 31.9% type 3 (10-15 mm), and 9% type 4 (>15 mm). Conclusion Provided AEA details improve surgeons' awareness of AEA variations in the endoscopic field and can help residents in training.

Anatomic Variations of Paranasal Region in Migraine.

To assess the incidence of anatomical variations of the paranasal region on computed tomography in migraine patients compared with control subjects. Paranasal computed tomography scans of 2 groups consisting of 50 migraine patients and 50 control subjects were evaluated, retrospectively. The presence of anatomic variations and the unilateral or bilateral presence of these variations were noted. Appropriate statistical tests were performed to compare the migraine and control groups, using a threshold P value of 0.05 for statistical significance. The migraine group included 39 female and 11 male patients with mean age of 39.9 (range: 18-65) years. The control subject group included 29 female and 21 male patients with mean age of 41.9 (range: 18-73) years. Anatomic variations noted included nasal septal deviation and spur, paradoxical curvature of middle concha, agger nasi cell, infraorbital ethmoidal (Haller) cells, sphenoethmoidal (Onodi) cells, supraorbital ethmoidal air cells, concha bullosa, uncinate bulla, and pneumatized crista galli. Of these variations, only the presence of Haller cells was statistically significantly higher in the migraine group compared with controls (P = 0.007). The unilateral presence of Onodi (P < 0.001), unilateral presence of supraorbital ethmoidal air cells (P = 0.012), and bilateral presence of concha bullosa (P = 0.016) were statistically significantly higher in the migraine group. There was no statistically significant difference between the unilateral or bilateral presence of Haller cells in migraine patients compared with controls (P > 0.05). Radiographic assessment of the paranasal sinuses is useful to elucidate potential points of pathology in migraine patients. The specific contribution of Haller cells to migraine headache symptoms and safe methods for surgical decompression warrant further study.

Bilateral concha bullosa with right sided extensive rhinolith: a case report

&lt;p class="abstract"&gt;Anatomic variations of the paranasal sinuses can lead to various diseases per se. The paranasal sinus anatomy should be carefully examined prior to performing endoscopic sinus surgery in terms of both existent pathologies and anatomic variations. The anatomy of the paranasal sinuses and its variations have gained importance, along with advances in coronal paranasal sinus computed tomography and extensive use of endoscopic sinus surgery. Rhinolith is a mass resulting from calcification of an endogenous or exogenous nidus within the nasal cavity. It is an uncommon disease that may present asymptomatically or cause symptoms like headache and nasal obstruction. A 24 year old woman was admitted in ENT department of GGS Medical College and Hospital, Faridkot with complaints of nasal obstruction, anosmia and headache persisting for 5 years. Right sided rhinolith was detected on anterior rhinoscopy. Bilateral concha bullosa with right sided rhinolith was reported on preoperative paranasal computed tomography scan. It is known that the paranasal sinuses have a number of anatomical variations. Sometimes severe anatomic variations predispose to rhinosinusitis. Herein we report a rare case, along with a review of the literature, to emphasize that severe anatomical variations should not be ignored.&lt;/p&gt;

Imaging Evaluation of the Location and Fenestration of Sellar Floor During Endonasal Transsphenoidal Surgery in Patients with Pituitary Adenomas

To evaluate clinical value of three-dimensional (3D) computed tomography (CT) reconstruction of the sphenoid sinus separation in localizing sellar floor during endonasal transsphenoidal surgery and determine size and location of sellar floor fenestration. There were 51 patients eligible for study inclusion. Preoperative CT scan of the paranasal sinus and CT scan and magnetic resonance imaging of the pituitary gland were obtained. Sphenoid sinus separation was reconstructed using Mimics 15.0 software, and quantity, shape, and orientation were observed and compared with intraoperative data to guide the localization of sellar floor. Anatomic variation of the sphenoid sinus and adjacent structures, tumor and sella turcica morphology, minimal distance between the cavernous segment of the internal carotid artery bilaterally, and shortest distance from the midline were measured. Based on the shape of the sphenoid sinus separation, sellar floor was accurately localized in all cases. Intraoperative sphenoid sinus separation was consistent with preoperative three-dimensional CT reconstruction images. The sellar floor was extremely small in 2 patients, and insufficient fenestration of sellar floor negatively affected tumor resection. Preoperative three-dimensional CT reconstruction is helpful for accurate and rapid localization of sellar floor. Anatomic variation of sphenoid sinus and adjacent structures, characteristics of tumor and sella, minimum distance between bilateral cavernous segment of the internal carotid artery, and shortest distance from midline are helpful for establishment of individualized sellar floor fenestration.

Radioanatomic Study of the Greater Palatine Canal Relevant to Endoscopic Endonasal Surgical Landmarks.

Objective A radioanatomic study of surgically relevant variations in the greater palatine canal (GPC) on computed tomography (CT) was performed to determine susceptibility during endoscopic endonasal procedures. Study Design Blinded radioanatomic analysis. Setting Tertiary university hospital. Subjects and Methods Fifty consecutive paranasal CT scans (100 sides) were analyzed. Measurements were standardized to landmarks such as the inferior turbinate (IT) and floor of the nasal cavity (FNC) to assess variability and vulnerability of the nerve. Measurements included (1) incidence of maxillary sinus pneumatization posterior to the GPC, (2) distance from the posterior wall of the maxillary sinus to the GPC at the IT and FNC, (3) width of bone containing the GPC, (4) incidence of medial GPC dehiscence, and (5) angle of the GPC extending from the IT to FNC. Results Ninety-one percent of maxillary sinuses were pneumatized posterior to the GPC. The distance from the posterior wall of the maxillary sinus to the GPC was 2.8 ± 1.7 mm (range, -2.3 to 5.9) at the posterior attachment of the IT and 4.1 ± 3.1 mm (range, -6.3 to 11.9) at the FNC. The width of bone containing the GPC was 3.3 ± 1.3 mm (range, 1-8.9), and the medial bony GPC was dehiscent in 38% of cases. In the sagittal plane, the angle of the GPC between the IT and the FNC was 31.9 ± 6.9 degrees (range, 10.8-45). Conclusion The GPC has considerable anatomic variability relative to important surgical landmarks in endoscopic procedures. Preoperative review of CTs to assess vulnerability may prevent postoperative complications.