Growth and microanatomy of the paranasal sinuses in two species of New World monkeys

Paranasal sinuses of living apes and humans grow with positive allometry, suggesting a novel mechanism for bone enlargement. Here, we examine the paranasal sinuses of the owl monkey (Aotus spp.) and a tamarin (Saguinus midas) across postnatal development. The prediction that paranasal sinuses grow disproportionately faster than the main nasal chamber is tested. We used diffusible iodine-based contrast-enhanced computed tomography and histology to study sinuses in eight Aotus and three tamarins ranging from newborn to adult ages. Sinuses were segmented at the mucosa-air cavity interface and measured in volume. All sinuses were lined by a ciliated respiratory epithelium, except for the ethmoid air cells in Aotus, which are lined in part by olfactory epithelium. An age comparison indicates that only the maxillary sinus and ethmoid air cells are present in newborns, and two additional sinuses (invading the orbitosphenoid and the frontal bone), do not appear until late infancy or later. Comparing newborns and adults, the main nasal airway is 10 times larger in the adult Aotus and ~ 6.5 times larger in adult Saguinus. In contrast, the maxillary sinus far exceeds this magnitude of difference: 24 times larger in the adult Aotus and 46 times larger in adult Saguinus. The frontal sinuses add significantly to total paranasal space volume in both species, but this growth is likely delayed until juvenile age. Results suggest ethmoid air cells expand the least. These results support our prediction that most paranasal sinuses have a distinctly higher growth rate compared to the main nasal chamber.

Dupilumab reduces opacification across all sinuses and related symptoms in patients with CRSwNP

BACKGROUND

Chronic rhinosinusitis with nasal polyposis (CRSwNP) is associated with substantial sinus opacification. In a phase 2a study (NCT01920893), dupilumab, a fully human anti-IL-4Rα monoclonal antibody, improved outcomes in CRSwNP refractory to intranasal corticosteroids. We evaluated dupilumab’s effect on sinus opacification in relation to effects on nasal polyp burden, symptoms, and health-related quality of life (HRQoL) in patients with CRSwNP.

METHODOLOGY

16-week randomized, double-blind, placebo-controlled, parallel-group study in 60 adults with CRSwNP. Patients received weekly subcutaneous dupilumab 300-mg or placebo and daily mometasone furoate nasal spray. Sinus opacification was assessed using standard and Zinreich-modified Lundâ€"Mackay (zLMK) scoring. Correlation was assessed between zLMK score and CRSwNP endpoints, including nasal polyp score (NPS), SNOT-22, daily symptom scores, and UPSIT smell-test score.

RESULTS

Baseline characteristics were similar across treatment groups. Mean plus/minus SD baseline LMK scores of 18.7 plus/minus 5.5 (placebo) and 18.6 plus/minus 5.0 (dupilumab) indicated severe disease with extensive opacification involving all sinuses. Baseline LMK and LMK scores correlated with NPS severity and loss of sense of smell (daily symptoms; SNOT-22 smell/taste; loss of sense of smell [UPSIT]). At Week 16, dupilumab-treated patients had significantly improved sinus opacification measured by LMK in all individual sinuses vs placebo. Dupilumab also showed similar efficacy with zLMK, with only small differences from LMK, and correlated with SNOT22 smell/taste. The most common adverse events were nasopharyngitis, injection-site reactions, and headache.

CONCLUSIONS

In patients with CRSwNP, baseline LMK showed extensive sinus opacification and correlated with symptoms, HRQoL, and hyposmia. Dupilumab treatment reduces opacification across all sinuses and related symptoms in patients with CRSwNP.

The Ponticulus Ethmoidalis: A Newly Appreciated Anatomic Landmark in Endoscopic Sinus Surgery

INTRODUCTION

Ethmoid sinus anatomy is so variable it has been referred to as a "labyrinth." Accordingly, this provides a challenge for surgeons performing ethmoidectomy. Identifying consistent anatomic features or landmarks within the ethmoid sinus can aid surgeons performing sinus surgery. The goal of this investigation was to determine if subtle anatomic features are consistently present within the retrobullar recess and could potentially serve as a reliable landmark for surgeons performing ethmoid surgery.

MATERIALS AND METHODS

Ethmoid sinus anatomy was studied in 60 sinonasal complexes through several methods including gross anatomic dissection, endoscopic dissection and 3-D CT stereoscopic imaging.

RESULTS

Review of gross sagittal sinonasal specimens revealed that the retrobullar recess was present in all specimens and a tissue bridge was noted emanating from the basal lamella deep within the retrobullar recess in 23/24 gross sagittal specimens; in 1/24 specimens it was quite small or difficult to appreciate. In the radiographic analysis, the tissue bridge was noted in 17/18, in 1/18 it was not appreciated. In the endoscopic dissections it was noted in 17/18, in 1/18 it was small or not appreciated.

CONCLUSION

The small tissue bridge, or ponticulus within the retrobulbar recess was seen in nearly all ethmoid sinuses studied leading us to venture that could be used in surgery to orient surgical dissection through the basal lamella into the posterior ethmoid region.

The Atelectatic Maxillary Sinus

The atelectatic maxillary sinus is a distinct anatomic variant. It may be identified in a symptomatic patient complaining of recurrent acute or chronic sinusitis or may be found incidentally, presenting as an asymptomatic opacified sinus. Recognition of the disorder is important. Lateral displacement of the posterior fontanelle may lead to the erroneous radiographic diagnosis of an air fluid level. At surgery, the infundibular atelectasis associated with the disorder may give rise to inadvertent orbital entry as the uncinate process is incised. Surgery may be further complicated by lateral displacement of the medial maxillary sinus wall, reducing access to the sinus by the transnasal approach. Although the atelectatic sinus may be identified at any age, its occurrence in childhood and the typical concurrence of sinus hypoplasia suggests sinus hypoventilation from an early age. The characteristic findings of the atelectatic maxillary sinus are presented and its surgery discussed.

Computed Tomography (CT) Scan Findings of the Paranasal Sinuses in Cystic Fibrosis

Nearly all patients with cystic fibrosis (CF) have abnormal findings on plain paranasal sinus radiographs. To establish this relationship more accurately, 58 CF patients with nasal symptoms were evaluated with paranasal sinus computed tomography (CT). Bilateral medial displacement of the lateral nasal wall in the middle meatus and uncinate process demineralization were seen in 43 patients (74%). Three patients (5%) had unilateral displacement and uncinate demineralization. Ten patients had maxillary sinus opacification, two patients (3.5%) had unremarkable paranasal sinuses on CT, and another patient (2%) had normal findings on one side. Although the vast majority of CF patients do have paranasal sinus abnormalities, we found on CT scan a progression of abnormalities that range from normal sinuses to pansinus disease, and in 74%, bilateral medial displacement of the lateral nasal wall and uncinate process demineralization.

The Functional Endoscopic Approach to Inflammatory Sinus Disease: Current Perspectives and Technique Modifications

Endoscopic examination and pleuridirectional polytomography provided some important insights into the pathogenesis of inflammatory sinus disease. These insights have been further refined by the increasing utilization of endoscopy in medical therapy and surgical follow-up, and by the use of computed tomography for diagnosis. The aim of this paper is to review the current status of the diagnosis of chronic inflammatory sinus disease and of functional endoscopic surgical techniques. The impact of this approach on previously held theoretical and diagnostic concepts is evaluated. Technical modifications made since the surgery was first introduced in the United States and the lessons learned from close postsurgical endoscopic examination are presented.

The Internal Carotid Artery as it Relates to Endonasal Sphenoethmoidectomy

A better understanding of the pathogenesis of chronic sinus disease has led to an increased performance of endonasal sphenoethmoid surgery. Approaching the sphenoid sinus via this route mandates that the surgeon be aware of the anomalies which may be encountered in this region, if injury to the related neurovascular structures is to be avoided. This study was therefore undertaken to evaluate a critical anatomic variation, the incidence of bony dehiscence over the carotid artery. Following cadaver sphenoethmoidectomy, the lateral wall of the sphenoid sinus was examined endoscopically and gently palpated in 188 sphenoid sinuses. An apparent dehiscence of bone was found over the carotid artery in 41 sinuses (22%), a significantly higher incidence than reported in other studies. In 3 specimens the carotid artery was exposed in the posterior ethmoid sinus. The study highlights the importance of considering this anatomic variation and of careful evaluation of the patient's computed tomographic scan, before this kind of surgery is attempted. Management of injury to the internal carotid artery in this area is also discussed.

3D cinematic rendering of the calvarium, maxillofacial structures, and skull base: preliminary observations

Three-dimensional (3D) visualizations of volumetric data from CT have gained widespread clinical acceptance and are an important method for evaluating complex anatomy and pathology. Recently, cinematic rendering (CR), a new 3D visualization methodology, has become available. CR utilizes a lighting model that allows for the production of photorealistic images from isotropic voxel data. Given how new this technique is, studies to evaluate its clinical utility and any potential advantages or disadvantages relative to other 3D methods such as volume rendering have yet to be published. In this pictorial review, we provide examples of normal calvarial, maxillofacial, and skull base anatomy and pathological conditions that highlight the potential for CR images to aid in patient evaluation and treatment planning. The highly detailed images and nuanced shadowing that are intrinsic to CR are well suited to the display of the complex anatomy in this region of the body. We look forward to studies with CR that will ascertain the ultimate value of this methodology to evaluate calvarium, maxillofacial, and skull base morphology as well as other complex anatomic structures.

Xenon-enhanced computed tomography quantifies normal maxillary sinus ventilation

OBJECTIVE

The purpose of this study was to determine the applicability, safety, and normal parameters of a xenon-enhanced CT technique to quantify maxillary sinus ventilation.

PATIENTS AND METHODS

Nine healthy subjects inhaled a xenon-oxygen-air mixture through their noses while repeated CT scans were performed through the same section of their sinuses. Images were obtained every 1 to 3 minutes and analyzed to measure the density of the gas in the maxillary sinus as a function of time.

RESULTS

Individual nasal cavity time constants ranged from 0.5 to 18 minutes. Studies performed after decongestion showed poorer sinus ventilation.

CONCLUSIONS

The xenon-CT washin/washout technique is safe, effective, and gives representative data.

Imaging of the Paranasal Sinuses: Mitigation, Identification, and Workup of Functional Endoscopic Surgery Complications

The purpose of this article is to identify and define the appropriate imaging techniques in the evaluation of post-functional endoscopic surgery (FESS) complications. Although most complications encountered during FESS are identified readily during surgery, some are less conspicuous and require postoperative imaging. As illustrated in this article, these include cerebrospinal fluid leak, vascular injury, brain injury, orbital injury, and infectious complications of the brain and meninges. Some of the common anatomic variants of the paranasal sinuses are identified, and how these may predispose to surgical complications is discussed.

Ask the Experts: An Endoscopic Potpourri

Program Description:

Rhinologic diagnostic and treatment problems commonly create dilemmas in practice. This miniseminar provides for interactive discussion of the management options and the decision rationale involved in difficult sinus diagnostic and treatment situations. A case presentation format is used with case presentations from each of the panelists emphasizing questions with regard to differential diagnosis, evaluation, imaging, and treatment. Cases are representative of those encountered by either a general otolaryngologist or a subspecialty rhinologist but have critical decision points for discussion. The session focuses on the decision-making process, frontal sinus disease, revision surgery, and fungal sinusitis, as well as common tumors.

Educational Objectives:

(1) Review the surgical decision-making process in chronic sinus disease. (2) Implement different imaging modalities and improved quality of interpretation for both computed tomography and magnetic resonance images. (3) Improve the management of difficult-to-treat chronic rhinosinusitis.

Ask the Experts: An Endoscopic Potpourri

Program Description:

Rhinologic diagnostic and treatment problems commonly create dilemmas in practice. This miniseminar provides for interactive discussion of the management options and the decision rationale involved in difficult sinus diagnostic and treatment situations. A case presentation format is used with case presentations from each of the panelists, emphasizing questions with regard to differential diagnosis, evaluation, imagining, and treatment. Cases are representative of those encountered by either a general otolaryngologist or a subspecialty rhinologist, but have critical decision points for discussion. The session focuses on the decision making process, frontal sinus disease, revision surgery, and fungal sinusitis, as well as common tumors.

Educational Objectives:

1) Review the surgical decision making process in chronic sinus disease. 2) Implement different imaging modalities and improved quality of interpretation for both CT and MRI images. 3) Improve the management of difficult to treat chronic rhinosinusitis.

Rhinology/Allergy

Program Description: The miniseminar provides an open forum for interactive discussion of management options and the decision rationale involved in sinus and skull base cases of varying complexity. A case presentation format is utilized with case presentations from each of the panelists. Questions regarding differential diagnosis, evaluation, imaging, and treatment are posed to the audience in multiple choice format. The responses provided by the audience response system are then discussed and expanded upon by the panelists in an interactive discussion. In general, cases are selected that might be encountered by either a general otolaryngologist or a subspecialty rhinologist, but which have important decision and management dilemmas. Each panelist has been chosen because of their depth of knowledge in the field and because of the clarity of their presentations. Particular emphasis is placed on the decision making process and on frontal sinus disease, revision surgery, and fungal sinusitis, as well as the management of more common tumors. The rationale behind each recommendation will be carefully elucidated. Discussion from the floor is encouraged and the use of a touch pad audience response system creates audience participation as an integral aspect of the case discussions.

Educational Objectives: 1) Improve knowledge of the surgical decision making process in chronic sinus disease. 2) Learn different imaging modalities and improve quality of interpretation for both CT and MRI images. 3) Improve understanding of the management of difficult to treat chronic rhinosinusitis.

Imaging of the paranasal sinuses and in-office CT

Since the introduction of functional endoscopic sinus surgery (FESS) in the United States in 1985, the information gained from imaging has proved imperative in understanding regional morphology and guidance of surgical procedures. More than 20 years later, the importance of imaging continues to be the anatomic detail afforded by this technology, the roadmap it provides in planning the surgery, and the morphologic detail it provides in recurrent disease. The latest development in CT technology, cone beam CT instrumentation, may change the way imaging of the nasal cavity and paranasal sinuses is performed in the future. These topics are discussed in this article.

Image overlay for CT-guided needle insertions

OBJECTIVE

We present a 2D image overlay device to assist needle placement on computed tomography (CT) scanners.

MATERIALS AND METHODS

The system consists of a flat display and a semitransparent mirror mounted on the gantry. When the physician looks at the patient through the mirror, the CT image appears to be floating inside the body with correct size and position as if the physician had 2D 'X-ray vision'. The physician draws the optimal path on the CT image. The composite image is rendered on the display and thus reflected in the mirror. The reflected image is used to guide the physician in the procedure. In this article, we describe the design and various embodiments of the 2D image overlay system, followed by the results of phantom and cadaver experiments in multiple clinical applications.

RESULTS

Multiple skeletal targets were successfully accessed with one insertion attempt. Generally, successful access was recorded on liver targets when a clear path opened, but the number of attempts and accuracy showed variability because of occasional lack of access. Soft tissue deformation further reduced the accuracy and consistency in comparison to skeletal targets.

CONCLUSION

The system demonstrated strong potential for reducing faulty needle insertion attempts, thereby reducing X-ray dose and patient discomfort.

MRI image overlay: Application to arthrography needle insertion

Magnetic Resonance Imaging (MRI) offers great potential for planning, guiding, monitoring and controlling interventions. MR arthrography (MRAr) is the imaging gold standard for assessing small ligament and fibrocartilage injury in joints. In contemporary practice, MRAr consists of two consecutive sessions: (1) an interventional session where a needle is driven to the joint space and MR contrast is injected under fluoroscopy or CT guidance; and (2) a diagnostic MRI imaging session to visualize the distribution of contrast inside the joint space and evaluate the condition of the joint. Our approach to MRAr is to eliminate the separate radiologically guided needle insertion and contrast injection procedure by performing those tasks on conventional high-field closed MRI scanners. We propose a 2D augmented reality image overlay device to guide needle insertion procedures. This approach makes diagnostic high-field magnets available for interventions without a complex and expensive engineering entourage. In preclinical trials, needle insertions have been performed in the joints of porcine and human cadavers using MR image overlay guidance; in all cases, insertions successfully reached the joint space on the first attempt.

Criteria to screen for chronic sinonasal disease

BACKGROUND

Sinusitis and rhinitis are associated with uncontrolled asthma. There are no simple, validated tools to screen for these diseases. The objective of this study was to assess instruments to assist in the diagnosis of chronic sinonasal disease.

METHODS

Participants without acute sinonasal symptoms underwent an extensive evaluation. The results were submitted to an expert panel that used the Delphi method to achieve consensus. Using the consensus diagnosis of the panel, we determined the sensitivity and specificity of test procedures to diagnose chronic sinonasal disease. We determined the reproducibility of the most sensitive and specific instrument in a separate cohort.

RESULTS

Fifty-nine participants were evaluated, and the expert panel reached consensus for all (42 participants with chronic sinonasal disease, 17 participants without chronic sinonasal disease). A six-item questionnaire based on the frequency of nasal symptoms was the most sensitive tool used to diagnose sinonasal disease (minimum specificity, 0.90). Reproducibility testing in a separate cohort of 63 participants (41 chronic sinonasal disease with asthma, 22 chronic sinonasal disease without asthma) showed a concordance correlation coefficient of 0.91 (95% CI, 0.85 to 0.94) when this questionnaire was limited to five items (ie, excluding a question on smell). This five-item questionnaire had a sensitivity of 0.90 (95% CI, 0.77 to 0.97), a specificity of 0.94 (95% CI, 0.71 to 1.00), and an area under the receiver operating characteristic curve of 0.97 (95% CI, 0.93 to 1.0). Sinus CT scans and nasal endoscopy lacked sensitivity for use in the diagnosis of chronic sinonasal disease.

CONCLUSIONS

We have developed a sensitive, specific, and reproducible instrument to screen for chronic sinonasal disease. Validation studies of this five-item questionnaire are needed, including in patients with asthma.

Intraosseous lipoma of the left frontoethmoidal sinuses and nasal cavity

Intraosseous lipomas are very rare slow-growing benign tumors that may appear as congenital lesions or may be acquired (metaplasia from a pre-existing lipoma). Only a handful of head and neck cases have been reported in the literature. We present the first reported case of a solitary osteolipoma involving the sinonasal tract in a 66-year-old man with sinonasal symptoms. CT showed a lesion involving the left frontal sinus, extending into the ethmoid sinus with insinuation along the left middle turbinate. It appeared to be an atypical mass with areas of high attenuation (calcification) within.

Progress in sinonasal imaging

Imaging of sinonasal structures has evolved from standard radiographs to the much more complicated and informative techniques used today. The plain radiograph was useful when the surgical techniques practiced were primarily aimed at the maxillary and frontal sinuses. With a better understanding of the mucociliary clearance of the nasal cavity and the paranasal sinuses, the surgical technique was shifted to the ethmoid sinuses and became more focal, thus needing a better understanding and display of the intricate morphology of the nasal cavity and paranasal sinuses. Polytomography was a step above plain radiographs and was first used in the display of the regional anatomy for the development of functional endoscopic sinus surgery. Polytomography was quickly replaced by computed tomography, as this imaging technique provides a much more detailed view of the sinonasal architecture than does polytomography. Magnetic resonance imaging has also shown usefulness in imaging this morphological area, as it provides better soft tissue resolution, but it does not allow good visualization of bony structures. Newer computer systems with software capable of reconstructing the digitized information into a 3-dimensional display further enhance our understanding of the regional morphology and afford an improved means of correlating the imaging and endoscopic information. Furthermore, stereotactic navigation systems allow surgeons the ability to visualize the endoscope-instrument tip position, as instruments are actively being used during surgery, on the computed tomographic and/or magnetic resonance images. There is a persistent trend toward reducing the size of the imaging equipment to render it more mobile (computed tomography) and adapt it for operating room use.

Imaging for functional endoscopic sinus surgery

Radiologic imaging is an essential part of the presurgical evaluation of patients with sinusitis and of the monitoring of difficult-to-treat,recurrent, and postsurgical disease. In patients with noninflammatory sinus pathology and those who "baffle" clinical diagnosis, ima-ging is extremely helpful in differentiating the various pathological entities and determining the extent of disease. Computerized tomography (CT), when deemed clinically necessary, is the current modality of choice to evaluate sinusitis. CT's ability to display bone,mucosa, and air makes it a perfect tool for imaging of the paranasal sinuses. The fine bony architecture of the nasal cavity and the para-nasal sinus drainage pathways are depicted accurately with CT examination.

Head and Neck Imaging at 3T

For the theoretic advantages of 3T units to translate to improved diagnostic quality, careful attention must be paid to optimization of pulse sequences and development of clinically feasible imaging protocols. RARE sequences continue to be the choice for routine clinical imaging of the head and neck; although exquisite T2W images are afforded, T1W imaging is problematic. Short ETLT1W RARE imaging seems to be a good compromise.

Treatment of chronic rhinosinusitis with high-dose oral terbinafine: a double blind, placebo-controlled study

OBJECTIVES

To evaluate antifungal terbinafine in patients with chronic rhinosinusitis.

STUDY DESIGN

Randomized, double-blind, placebo-controlled multicenter pilot study.

METHODS

Fifty-three adults with chronic rhinosinusitis received terbinafine 625 mg/day (n = 25) or placebo (n = 28) once daily for 6 weeks. Sinus secretions were collected at screening for mycology. Computed tomography was graded for extent of opacification at baseline and at week 6 using a modification of the Lund-Mackay scoring system. Patients recorded rhinosinusitis symptoms on a visual analogue scale and completed the Rhinosinusitis Disability Index.

RESULTS

Positive fungal cultures were found in 41 of 53 patients (17 terbinafine, 24 placebo). (Two subjects from the Terbinafine group and one subject from the control group had no week 6 data). The mean opacification scores pre- and posttreatment for the entire study group improved from 24.2 to 22.5 in placebo (n = 26) and from 26.3 to 24.2 in terbinafine group (n = 23). The least squares means for percent change from baseline (SE) were -6.0 (8.7) for placebo compared with -7.2 (8.1) for terbinafine; 95% confidence interval for treatment difference (-18.9, 21.1); P = .91. Results were similar when only patients with positive fungal cultures were evaluated in the efficacy analysis. Investigator therapeutic evaluations and sinus symptom scores were not significantly different between the two groups at baseline or at treatment completion.

CONCLUSION

Treatment with terbinafine failed to improve the symptoms or radiographic appearance of chronic rhinosinusitis even when nasal irrigation samples were positive for fungus on culture. One consideration is that the fungi isolated were not a major pathologic factor in this cohort. It is also possible that, even at high dose, terbinafine may not have maintained therapeutic levels in the nasal secretions.

MRI image overlay: applications to arthrography needle insertion

Magnetic Resonance Imaging (MRI) has unmatched potential for planning, guiding, monitoring and controlling interventions. MR arthrography (MRA) is the imaging gold standard to assess small ligament and fibrocartilage injury in joints. In contemporary practice, MRA consists of two consecutive sessions: 1) an interventional session where a needle is driven to the joint space and gadolinium contrast is injected under fluoroscopy or CT guidance. 2) A diagnostic MRI imaging session to visualize the distribution of contrast inside the joint space and evaluate the condition of the joint. Our approach to MRA is to eliminate the separate radiologically guided needle insertion and contrast injection procedure by performing those tasks on conventional high-field closed MRI scanners. We propose a 2D augmented reality image overlay device to guide needle insertion procedures. This approach makes diagnostic high-field magnets available for interventions without a complex and expensive engineering entourage.

Silent sinus syndrome: an acquired condition

We present the case of a 30-year-old man with silent sinus syndrome. A CT scan obtained 10 years earlier showed completely normal maxillary sinuses. This case illustrates the acquired nature of this disorder.

Advances in imaging of the paranasal sinuses

Significant changes in surgical technique, surgical instrumentation, and imaging technology have occurred during the past 20 years. These changes have largely resulted from a better understanding of the pathophysiology ofa specific pathologic process, the inflammation of paranasal sinus mucosa. As surgical techniques were adapted to address clinical issues, new instrumentation was developed. Changes in imaging technology were also a result of these and similar issues pressing from other similar medical/surgical fields. The obsolescence of plain-film imaging is being addressed by miniaturization of large and bulky cross-sectional imaging equipment that will gradually become available and embraced by the clinical practice. These changes will bring about greater responsibilities, the foremost of which is vigilance in reducing radiation dose to the patient.

Image Overlay Guidance for Needle Insertion in CT Scanner

We present an image overlay system to aid needle insertion procedures in computed tomography (CT) scanners. The device consists of a display and a semitransparent mirror that is mounted on the gantry. Looking at the patient through the mirror, the CT image appears to be floating inside the patient with correct size and position, thereby providing the physician with two-dimensional (2-D) "X-ray vision" to guide needle insertions. The physician inserts the needle following the optimal path identified in the CT image rendered on the display and, thus, reflected in the mirror. The system promises to reduce X-ray dose, patient discomfort, and procedure time by significantly reducing faulty insertion attempts. It may also increase needle placement accuracy. We report the design and implementation of the image overlay system followed by the results of phantom and cadaver experiments in several clinical applications.

Rhinosinusitis: establishing definitions for clinical research and patient care

Background

There is a need for more research on all forms of rhinosinusitis. Progress in this area has been hampered by a lack of consensus definitions and the limited number of published clinical trials.

Objectives

To develop consensus definitions for rhinosinusitis and outline strategies useful in clinical trials.

Methods

Five national societies, The American Academy of Allergy, Asthma and Immunology; The American Academy of Otolaryngic Allergy; The American Academy of Otolaryngology Head and Neck Surgery; The American College of Allergy, Asthma and Immunology; and the American Rhinologic Society formed an expert panel from multiple disciplines. Over two days, the panel developed definitions for rhinosinusitis and outlined strategies for design of clinical trials.

Results

Committee members agreed to adopt the term “rhinosinusitis” and reached consensus on definitions and strategies for clinical research on acute presumed bacterial rhinosinusitis, chronic rhinosinusitis without polyposis, chronic rhinosinusitis with polyposis, and classic allergic fungal rhinosinusitis. Symptom and objective criteria, measures for monitoring research progress, and use of symptom scoring tools, quality-of-life instruments, radiologic studies, and rhinoscopic assessment were outlined for each condition.

Conclusion

The recommendations from this conference should improve accuracy of clinical diagnosis and serve as a starting point for design of rhinosinusitis clinical trials.

Rhinosinusitis: Establishing definitions for clinical research and patient care

Background

There is a need for more research on all forms of rhinosinusitis. Progress in this area has been hampered by a lack of consensus definitions and the limited number of published clinical trials.

Objectives

To develop consensus definitions for rhinosinusitis and outline strategies useful in clinical trials.

Study design

Five national societies, The American Academy of Allergy, Asthma and Immunology; The American Academy of Otolaryngic Allergy; The American Academy of Otolaryngology Head and Neck Surgery; The American College of Allergy, Asthma and Immunology; and the American Rhinologic Society formed an expert panel from multiple disciplines. Over two days, the panel developed definitions for rhinosinusitis and outlined strategies for design of clinical trials.

Results

Committee members agreed to adopt the term “rhinosinusitis” and reached consensus on definitions and strategies for clinical research on acute presumed bacterial rhinosinusitis, chronic rhinosinusitis without polyposis, chronic rhinosinusitis with polyposis, and classic allergic fungal rhinosinusitis. Symptom and objective criteria, measures for monitoring research progress, and use of symptom scoring tools, quality-of-life instruments, radiologic studies, and rhinoscopic assessment were outlined for each condition.

Conclusions

The recommendations from this conference should improve accuracy of clinical diagnosis and serve as a starting point for design of rhinosinusitis clinical trials.

Imaging for staging of rhinosinusitis

Although clinical judgment is sufficient to diagnose rhinosinusitis in many cases, a number of patients with recurrent or complicated sinus disease require imaging studies. Advances in the field of diagnostic imaging techniques such as computed x-ray tomography (CT) and magnetic resonance imaging have enhanced our understanding and management of the disease. Magnetic resonance imaging excels in displaying soft tissue resolution and is superior in demonstrating the presence of neoplasia and fungal sinusitis. but has limited advantages over CT scanning in demonstrating the regional anatomy (bony structure) and in the diagnosis of chronic rhinosinusitis. Computed tomography provides greater detailed information about the paranasal sinuses than do plain radiographic films. Rhinosinusitis staging systems utilizing CT techniques are reviewed. Although results from the Lund-Mackay system appear to be easily reproducible. there are still clinical challenges not addressed by this method of classification. Considering the patency of specific ostiomeatal channels and quantifying the volume of disease may add to the clinical value of future classification systems.

Paranasal and orbital anatomy revisited: identification of the ethmoid arteries on coronal CT scans

OBJECTIVE

The aim of this study was to identify recognizable landmarks on coronal CT (CCT) scans for the localization of the anterior and posterior ethmoid arteries, which are important anatomic structures and surgical landmarks within the ethmoid sinuses.

MATERIALS AND METHODS

Four series of plastinated cadaver specimens and 80 CCT examinations were evaluated to identify the anatomical landmarks that define the course of the anterior and posterior ethmoid arteries within the ethmoid sinuses.

RESULTS

The following anatomic landmarks: the indentations into the medial orbital wall, the relationship between the superior oblique and medial rectus orbital muscles, and the lateral ethmoid fovea wall thinning proved to be useful CCT landmarks for the localization of the anterior and posterior ethmoid arteries.

CONCLUSION

The results of this study suggest that familiarity with the above-mentioned landmarks on routine CCT images facilitates the localization of the anterior and posterior ethmoid arteries as they enter the ethmoid sinus.

High-resolution CT findings suggest a developmental abnormality underlying superior canal dehiscence syndrome

OBJECTIVE

Patients with superior canal dehiscence (SCD) syndrome experience vertigo and oscillopsia with loud sounds and/or stimuli that result in changes in middle ear or intracranial pressure. Findings on temporal bone CT were analyzed to determine if a developmental abnormality is associated with the syndrome.

MATERIAL AND METHODS

Temporal bone CT scans [0.5 mm collimation and projections into the superior semicircular canal (SC) plane] were used to compare the bone overlying the SC in patients with SCD syndrome (20 unilateral, 7 bilateral) and in 88 patients without SCD syndrome who had undergone temporal bone CT for evaluation of other otologic disorders (controls).

RESULTS

The thickness of bone overlying the SC in the controls measured 0.67 +/- 0.38 mm (mean +/- SD). For individual control subjects. the thickness of bone on one side was correlated with that on the other side (r = 0.43; p < 0.0001). The thickness of bone overlying the SC on the intact side in patients with unilateral dehiscence measured 0.31 +/- 0.23 mm, and was thinner than that noted in the controls (p < 0.0001).

CONCLUSION

These findings support the notion that there is a developmental abnormality underlying SCD syndrome. When dehiscence is found on one side, the contralateral side is likely to be thin.

Evaluation of registration methods used in frameless stereotactic surgery for the lumbar and cervical regions of the spine

Computer-assisted pedicle screw insertion is feasible but has proved to be problematic. The purpose of this study was to detail the accuracy of registration techniques and pedicle screw insertion using a frameless stereotactic system. Two registration techniques were evaluated on a model spine. The frameless stereotactic system was then used to insert 26 pedicle and 8 lateral mass screws in human cadavers. For posterior vertebral elements, trajectory accuracy was 2.5 +/- 1.0 mm between T12 and L5 and 2.2 +/- 0.9 mm between C2 and T1. Registration of the anterior elements, however, was less accurate. Despite this flaw, all screws were inserted without penetrating the cortex. Screw trajectory was accurate to 2 degrees. The main limitation of frameless stereotactic surgery in the spine stems from the fact that only the posterior vertebral elements are used during registration. Despite this flaw, the system placed all screws correctly. Given these limitations, we believe that this system is most useful for locating the screw insertion point and providing a trajectory in the pedicle.

CT evaluation of bone dehiscence of the superior semicircular canal as a cause of sound- and/or pressure-induced vertigo

PURPOSE

To describe the computed tomographic (CT) findings at different collimation widths associated with superior semicircular canal (SSC) dehiscence syndrome and to determine the frequency of these findings in a control population.

MATERIALS AND METHODS

Temporal bone CT scans with 1.0-mm and/or 0.5-mm collimation were obtained in 50 patients with sound- and/or pressure-induced vestibular symptoms. The control population consisted of 50 patients undergoing CT at 1.0-mm collimation and 57 patients undergoing CT at 0.5-mm collimation for other reasons.

RESULTS

SSC dehiscence was documented on CT scans in all 36 patients with the clinical syndrome, with bilateral findings in six patients. Six other patients without specific clinical signs appeared to have dehiscence on 1.0-mm-collimated scans. Intact bone overlaying the SSC was subsequently identified with 0.5-mm-collimated CT in each case. On the 1.0-mm-collimated scans in 50 control patients, an area judged as possible or definite dehiscence was identified in 18 of 100 ears. The bone overlaying the SSC was intact in each of the 114 control ears evaluated with 0.5-mm-collimated CT. CT findings from the patients with vestibular symptoms combined with those in the control population indicated that the positive predictive value of an apparent dehiscence in the diagnosis of SSC dehiscence syndrome improved from 50% with 1.0-mm-collimated CT with transverse and coronal images to 93% with 0.5-mm-collimated CT with reformation in the plane of the SSC.

CONCLUSION

The positive predictive value of CT in identification of SSC dehiscence syndrome improves with 0.5-mm-collimated helical CT and reformation in the SSC plane.

Effective dose range of mometasone furoate nasal spray in the treatment of acute rhinosinusitis

BACKGROUND

Mometasone furoate nasal spray (MFNS) 400 microg, twice daily, as adjunctive treatment with oral antibiotic significantly improved symptoms of recurrent rhinosinusitis.

OBJECTIVE

To evaluate the effectiveness and safety of MFNS 200 microg, twice daily, and 400 microg, twice daily, compared with placebo as adjunctive treatment with oral antibiotic for acute rhinosinusitis.

METHODS

In this multicenter, double-blind, placebo-controlled study, 967 outpatients with computed tomographic scan-confirmed moderate to severe rhinosinusitis received amoxicillin/clavulanate potassium (Augmentin, GlaxoSmithKline, Research Triangle Park, NC) 875 mg, twice daily, for 21 days with adjunctive twice daily MFNS 200 microg, MFNS 400 microg, or placebo nasal spray. Patients recorded scores of six rhinosinusitis symptoms and any adverse events twice daily. Pre- and postcosyntropin-stimulation plasma cortisol levels were measured in a subset of patients at selected study sites.

RESULTS

Treatment with MFNS 200 microg or 400 microg, twice daily, produced significantly greater improvements in total symptoms score (primary efficacy variable) day 1 to day 15 average (50% and 51%, respectively) than placebo (44%, P < or = 0.017). Both doses of MFNS produced significant total symptoms score improvement over placebo by day 4, and maintained efficacy over the entire 21-day study. Relief of individual symptoms showed a similar pattern. Both doses of MFNS were well tolerated, and adverse events were similar to that of placebo. Cosyntropin stimulation showed no evidence of hypothalamic-pituitary-adrenal axis suppression.

CONCLUSIONS

As adjunctive therapy to oral antibiotic treatment, MFNS at doses of 200 microg or 400 microg, twice daily, was well tolerated and significantly more effective in reducing the symptoms of rhinosinusitis than antibiotic therapy alone.

Imaging in laryngeal cancer: computed tomography, magnetic resonance imaging, positron emission tomography

Imaging modalities have become increasingly significant in the treatment of laryngeal cancer. The ability of CT and MR imaging to reveal pathologic conditions that are undetectable by palpation or endoscopy has led to the development of several imaging-based systems of anatomic classification and tumor staging. This article provides an up-to-date review of the radiographic evaluation of the normal neck and information for both the radiologist and clinician treating the patient with laryngeal cancer. Technical considerations, imaging-based staging systems, and the radiographic characteristics of laryngeal cancer in various regions of the neck are discussed.

Holoprosencephaly in children: diffusion tensor MR imaging of white matter tracts of the brainstem--initial experience

PURPOSE

To evaluate the dimensions of specific white matter tracts in the brainstems (region of brain thought to be least affected) of children with holoprosencephaly by using diffusion tensor magnetic resonance (MR) imaging and to correlate these abnormalities with forebrain malformation severity and neurologic deficit severity.

MATERIALS AND METHODS

Thirteen patients with holoprosencephaly underwent diffusion tensor MR imaging, with which white matter color maps were generated. Type of holoprosencephaly was correlated with presence or absence of specific brainstem white matter tracts. Furthermore, patient rank based on cortico-ponto-spinal tract (CPST) and middle cerebellar peduncle (MCP) dimensions was correlated with holoprosencephaly type and neurodevelopmental score by using Spearman rank correlation analysis.

RESULTS

Two patients had alobar holoprosencephaly, five had the semilobar type, one had the lobar type, and one had the middle-hemisphere-variant type. Four patients were excluded from analysis. In the two patients with alobar holoprosencephaly, the CPSTs were absent bilaterally. In all of the remaining patients except one, who had semilobar holoprosencephaly in which the CPSTs could not be identified at the level of the medulla oblongata, all tracts were present bilaterally. Holoprosencephaly type and neurodevelopmental score correlated strongly with CPST and MCP dimensions (P <.01) over and above the effect of age.

CONCLUSION

In vivo identification of brainstem white matter tract abnormalities in patients with holoprosencephaly can be achieved by performing diffusion tensor MR imaging.

Dynamic assessment of paranasal sinus ventilation using xenon-enhanced computed tomography

Disease of the paranasal sinuses is a common and costly condition. Evaluation of the efficacy of either medical or surgical methods of treatment is limited by the lack of quantitative methods to characterize sinus ventilation, which may be an important determinant of the baseline physiological state of the sinuses. Xenon-enhanced computed tomography (Xe-CT) measurement of sinus ventilation provides a noninvasive method of quantifying maxillary sinus ventilation using the nonradioactive, radiodense gas Xe as a tracer. Study subjects breathed a mixture of Xe gas and oxygen through a close-fitting nasal mask during serial CT imaging of a single radiographic plane through the maxillary sinuses--a generally well-tolerated protocol. Analysis of the sinus density-time curves allowed calculation of first-order exponential time constants from which specific ventilation rates could be determined for individual sinuses. Previously developed data analysis techniques were used to assess the statistical significance of the data and determine confidence intervals, allowing examination of the effects of noise in the data, and to demonstrate areas for further study protocol refinement. We conclude that Xe-CT measurement of sinus ventilation is a potentially valuable noninvasive technique for the diagnostic imaging of the human maxillary sinus.

T2 relaxation measurements in X-linked adrenoleukodystrophy performed using dual-echo fast fluid-attenuated inversion recovery MR imaging

SUMMARY

The purpose of this study was to determine whether dual-echo fast fluid-attenuated inversion recovery MR imaging and corresponding T2 brain maps can show different zones in the affected white matter of patients with cerebral X-linked adrenoleukodystrophy. Ten male patients with cerebral X-linked adrenoleukodystrophy underwent imaging performed using dual-echo fast fluid-attenuated inversion recovery and dual-echo conventional spin-echo MR sequences. Corresponding T2 relaxation maps of the brain were generated. On the basis of dual-echo fast fluid-attenuated inversion recovery images and T2 maps, the affected white matter could be divided into two distinct zones in four patients with cerebral X-linked adrenoleukodystrophy.

The cerebral angiographic findings in Cogan syndrome

SUMMARY

Cogan syndrome is an uncommon disorder of unknown etiology characterized by vestibuloauditory dysfunction and nonsyphilitic interstitial keratitis. To our knowledge, the case herein is the first report to demonstrate the cerebral angiographic findings of a patient with this syndrome.