Role of MR and CT in the paranasal sinuses

A Descriptive Analysis of Nasal Polyposis in HIV Positive Versus HIV Negative Patients

Nasal polyposis (NP) represents a benign proliferation of soft tissue tumors within the nasal cavity and paranasal sinuses, characterized by chronic inflammation of the sinonasal mucosa. This phenomenon, attributed to various environmental and physiological factors, presents clinically as semi-transparent masses with variable morphology, often obstructing nasal passages and causing respiratory compromise, olfactory dysfunction, and recurrent infections. Predominantly associated with chronic rhinosinusitis (CRS), NP poses significant challenges in diagnosis and management, particularly in the context of comorbid conditions such as human immunodeficiency virus (HIV) infection. HIV infection, known for its debilitating effects on the immune system, is theorized to exacerbate NP development and manifestation through mechanisms involving CD4 cell depletion and dysregulation of immune responses. Despite extensive research, elucidating potential pathways linking HIV infection to NP, comprehensive understanding remains elusive. This study aims to address this knowledge gap by conducting a retrospective chart review of patients presenting with NP at Charlotte Maxeke Johannesburg Academic Hospital between January 2016 and December 2020. The primary objective is to investigate the influence of HIV status on the clinical, radiological, and histological features of NP. Data collection, encompassing patient demographics, HIV status, clinical presentations, radiological findings, and histopathological characteristics, will be conducted between March 2021 and August 2022. Preliminary analysis of collected data reveals a cohort of 41 patients meeting inclusion criteria, with notable exclusions based on undisclosed HIV status and incomplete documentation. Initial findings suggest a nuanced interplay between genetic predisposition, environmental factors, and HIV status in NP pathogenesis, underscoring the need for further research to validate these observations. In conclusion, this study underscores the importance of elucidating the complex relationship between HIV infection and NP to optimize diagnostic and therapeutic approaches, particularly in regions with a high HIV prevalence such as South Africa. By comprehensively assessing the clinical, radiological, and histological features of NP in HIV-positive and HIV-negative populations, this research endeavours to enhance our understanding of NP pathophysiology and improve patient outcomes.

Review of olfactory cleft roof anatomy

Progress in skull-base endoscopic surgery has improved our knowledge of olfactory cleft (OC) anatomy. This article presents a review of current knowledge concerning the OC roof: descriptive anatomy, radiological exploration, and endoscopic observation. The OC is a narrow area in the most superior part of the nasal cavity. Its roof is the thinnest structure separating the nasal cavities from the brain; it comprises three superimposed tissues: nasal mucosa, ethmoid cribriform plate (ECP), and dura mater. The ECP comprises the anterior ECP containing the ethmoidal slit (ES) medially and the cribroethmoidal foramen (CEF) laterally; and the posterior ECP, comprising the olfactory foramina. The OC roof is bordered anteriorly by the nasal bone roof, laterally by the lateral ethmoid masses, and posteriorly by the jugum and anterior wall of the sphenoid sinuses. Imaging is crucial for analyzing this wall, providing precise detailed information on conformation and anatomic relations with adjacent structures such as the anterior ethmoidal artery. Understanding OC roof anatomy and correct interpretation of imaging are essential for safety in present-day functional endoscopic sinus surgery and anterior skull-base oncologic surgery.

Comparison of Diagnostic Accuracy of Panoramic Radiography to CBCT in Maxillary Sinus Diseases

We aimed to compare the effectiveness of panoramic radiography (PR) and cone beam computed tomography (CBCT) in radiographic diagnosis of maxillary sinus (MS) diseases. MS diseases (mucosal thickening, mucus retention cyst, polyp sinusitis, mucocele and tumoral formations) was carried out on both PR and CBCT images belonging to 625 patients. Analyzes were performed separately for right and left maxillary sinus, and total of 1250 PR and CBCT images. While a diagnosis of disease was made in 42.96% of a total of 1250 MS according to CBCT. According to PR, diagnosis was made in 58.72%. The 537 diagnoses where lesion presence was determined on CBCT in our study were compared over PR, and it was observed that, there was the right diagnosis (true positive) in 106 (19.73%) of these including respectively mucus retention cyst (n = 88), polyp (n = 16), 1 sinusitis and 1 tumor, and there was an incorrect diagnosis (false positive) in 221 (41.15%). In 42.92% of the MS that were identified as healthy based on CBCT, the correct diagnosis was also made on PR (true negative). The use of CBCT instead of PR in the diagnosis of pathological or inflammatory diseases contributes to a more accurate radiographic differential diagnosis.

CT anatomy of the head in the Ile de France sheep

Background

CT scan images provide accurate anatomical data from different areas of the body that can be used to diagnose diseases.

Objectives

The present work aimed to describe the normal anatomical structures of the Ile de France sheep head and its morphometric and volumetric properties using computed tomography (CT) and stereological methods.

Methods

Five adult Ile de France sheep heads, which were of mature age (above 10 months), were included in this study. The different cavities of the head, including the nasal cavity, paranasal sinuses, oral cavity, orbital cavity and vestibulocochlear system, were evaluated using CT scans, cross, sagittal and coronal sections.

Results

The mean length, height and width of the skull were 25.3 ± 1.02, 9.8 ± 0.93 and 12.3 ± 0.91 cm, respectively. The results showed that the nasal cavity is divided into three regions. Vestibular, respiratory and olfactory regions. The paranasal sinuses are composed of maxillary, frontal, palatine, sphenoid, lacrimal and ethmoidal that were identified and named in the CT scan images and their corresponding anatomical cross‐sections. The total volume of the head, nasal cavity and oral cavity was estimated to be 2998 ± 202.00, 303 ± 31.33 and 229.3 ± 10.61 cm³, respectively.

Conclusions

The frontal sinus in the Ile de France sheep was limited to the frontal bone without extending into the parietal, temporal, or occipital bones, similar to Saanen goat. This study provided a comprehensive atlas of Ile de France sheep anatomy to internal medicine veterinarians and surgeons.

LOW-DOSE COMPUTED TOMOGRAPHY OF THE PARANASAL SINUSES: PERFORMANCE OF TWO DIFFERENT ITERATIVE RECONSTRUCTION ALGORITHMS

To evaluate the performance of two iterative reconstruction algorithms in low-dose paranasal sinus computed tomography (CT). Sinus CT scans were reconstructed using Adaptive Iterative Dose Reduction 3D (AIDR 3D, n = 36 patients) or Sinogram Affirmed Iterative Reconstruction (SAFIRE, n = 32 patients). Reconstructed images were evaluated regarding subjective image quality, depiction of anatomic landmarks and noise (HU). Dose-length product (DLP), calculated effective dose (ED) and CT dose index (CTDIvol) were documented for each scan. Images were not significantly different in subjective image quality (p = 0.09) and conspicuity of anatomic landmarks (p = 0.28). Noise was significantly lower in images reconstructed with AIDR 3D (p = 0.012). DLP, ED and CTDIvol were significantly lower in the SAFIRE datasets (each p < 0.001). The results indicate that iterative reconstruction, independent of the manufacturer, enables for imaging the paranasal sinuses with an ED below 0.1 mSv while ensuring diagnostic image quality.

Surgical anatomy of the nasal and paranasal sinuses in Egyptian native sheep (Ovis aries) using computed tomography and cross sectioning

The present work aimed to describe the normal computed tomography (CT) and cross-sectional anatomy of the nasal and paranasal sinuses in sheep and to correlate these features with the relevant clinical practices. Twenty apparent healthy heads of Egyptian native breed of sheep (Baladi sheep) of both sexes were used for studying these sinuses. CT images and their closely identical cross sections of the same head were selected and serially labelled in a progression from the rostral nasal region to the caudal aspect of the head using cheek teeth as landmarks. The current investigation reported seven sinuses in sheep, including maxillary, frontal, lacrimal and sphenoidal as paranasal, as well as dorsal and middle conchal and ethmoidal as nasal with unnoticeable palatine and ventral nasal conchal sinuses. The boundaries, extension, structure and communications of these sinuses were fully described. The current study provided anatomical guidelines for surgical interference in the frontal and maxillary sinuses during trephination, dehorning and sinuscopy. Also, an acceptable anatomical explanation was reported in this study for the high incidence of maxillary sinusitis than other sinuses. CT and cross-sectional anatomy could be used as helpful database for diagnosis and clinical interference of the nasal and paranasal sinuses in sheep.

PET/MR Imaging in Head and Neck Cancer: Current Applications and Future Directions

Clinical PET/MR imaging is being implemented at institutions worldwide as part of the standard-of-care imaging for select oncology patients. This article focuses on oncologic applications of PET/MR imaging in cancers of the head and neck. Although current published literature is relatively sparse, the potential benefits of a hybrid modality of PET/MR imaging are discussed along with several possible areas of research. With the increasing number of PET/MR imaging scanners in clinical use and ongoing research, the role of PET/MR imaging in the management of head and neck cancer is likely to become more evident in the near future.

Giant Antrochoanal Polyp-A Rare Presentation

Antrochoanal polyp (ACP), also called as Killian polyp, is an infrequent, benign lesion of maxillary origin in non-atopic patients. The antrochoanal polyp is shaped according to the anatomical constraints of the lateral nasal wall, particularly the middle meatus and antrum, resembling typically a dumbbell. Here presenting a common problem with unusual presentation.

Evaluation and treatment of isolated sphenoid sinus diseases

PURPOSE OF REVIEW

To review cause, clinical evaluation, medical and surgical management of isolated sphenoid sinus diseases.

RECENT FINDINGS

Early diagnosis of isolated sphenoid sinus diseases requires a high index of clinical suspicion and appropriate radiological imaging. Sphenoid sinus can be approached endoscopically via a few different surgical techniques.

SUMMARY

Isolated sphenoid sinus diseases are uncommon, with nonspecific clinical presentation. Early diagnosis requires a high index of clinical suspicion, proper endoscopic nasal examination, and appropriate radiological imaging. Surgical intervention is the primary treatment modality for most of the isolated sphenoid sinus diseases. Endoscopic endonasal approach to sphenoid sinus is the technique of choice. The location of sphenoid sinus disease, the extent of the surgery, and anatomic configuration of the sphenoid sinus are the main factors that help to decide the most suitable surgical approach to the sphenoid sinus.

Reducing the dose of CT of the paranasal sinuses: potential of an iterative reconstruction algorithm

OBJECTIVE

To evaluate the feasibility and image quality of low-dose CT of the paranasal sinuses using iterative reconstruction with adaptive-iterative dose reduction in three dimensions (AIDR 3D) in comparison with conventional image protocols of older scanner generations.

METHODS

Sinus CT scans of 136 patients were assessed retrospectively. Patients underwent CT either with low-dose settings (Protocol A: 80 kV, 30 mA s; Protocol B: 120 kV, 15 mA s or C: 80 kV, 90 mA s) reconstructed using AIDR 3D (Protocols A and B) or filtered back projection (FBP) (Protocol C) or with standard dose (Protocol D: 120 kV, 80 mA s) and FBP. Image quality was assessed in consensus by two blinded readers scoring the diagnostic image quality (from 1 = excellent to 5 = non-diagnostic) and conspicuity of important anatomic landmarks (from 0 = not visible to 2 = completely visible; maximum score of 16 points) as well as osseous structures (maximum score of 12 points). Dose-length product, effective dose (ED), CT dose index and scan length were retrieved for each scan and compared.

RESULTS

Mean ED could be lowered by 82% when using Protocol A. The best image quality was found using Protocol B (mean score = 2.1 ± 0.51). Conspicuity of relevant anatomic landmarks was best with Protocol A (mean score = 11.97 ± 1.88). Protocol B provided the highest conspicuity of osseous structures (mean score = 8.27 ± 1.58). Image noise was highest in images obtained using Protocol A.

CONCLUSIONS

AIDR 3D allows a significant dose reduction while maintaining a good diagnostic image quality and conspicuity of relevant anatomic structures.

Uncinate Process Variations and Their Relationship with Ostiomeatal Complex: A Pictorial Essay of Multidedector Computed Tomography (MDCT) Findings

The ostiomeatal complex (OMC) is a key area for the drainage and ventilation of the paranasal sinuses. Stenosis created by inflammation and anatomic variations in this region causes an ideal ground for parasanal sinus infections, by preventing the drainage and ventilation of the sinuses. In today’s diagnostics of paranasal sinus infections, the role of evaluation of OMC anatomical variations and soft tissue pathology has increased.. Knowing the anatomical details is important in terms of directing both medical and surgical treatment. The uncinate process (UP) constitutes the most important structure of the ostiomeatal complex, playing a role in mucociliary activity. UP variations can cause mucociliary drainage and ventilation problems, causing complications during surgery. Therefore, knowing and identifying their appearances in multidetector computed tomography (MDCT), the most frequently used radiological imaging method for these variations, becomes a very important consideration.

Imaging Characteristics of Olfactory Neuroblastoma (Esthesioneuroblastoma)

This presentation outlines the clinical and imaging characteristics of esthesioneuroblastoma.

Cysts of the maxillary sinus: a literature review

BACKGROUND

Patients with isolated mucosal cysts of the maxillary sinus (MMC) often undergo surgical treatment despite the absence of relevant symptoms. Some physicians believe that MMC might increase in size and cause complications in the future. The anticipated value of this study is to consolidate and improve the understanding of MMC based on published data and to contribute to avoiding unnecessary interventions.

METHODS

We performed a comprehensive review of the literature regarding definition, etiology, epidemiology, natural course, and best treatment of MMC.

RESULTS

Among the 988 papers found in the literature search, 33 studies were selected to be relevant. Among those studies, there are only a few prospective controlled studies. Their prevalence rates range broadly from 3.6% to 35.6% according to different diagnostic methods as well as different indications for imaging. Recent prospective studies showed no correlation of MMC with sinonasal complaints or Lund-Mackay computed tomography (CT) score. The natural course is characterized by a decrease in size of MMC in 30% of the cases, an unchanged status in 50% to 60%, and an increase in 8% to 20% of the cases.

CONCLUSION

MMC are harmless, mostly asymptomatic lesions that usually do not need surgical treatment. If surgery is indicated, endonasal endoscopic techniques should be the gold-standard approach.

Diagnosis of chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a rather common disease in children, but its symptoms are often subtle and non-specific and this may result in overlooking a correct diagnosis. In turn, a missed diagnosis of CRS prevents a correct management to be performed and is associated with uneffective investigations and improper treatments. Actually, when CRS symptoms, which are mainly nasal congestion and obstruction, nasal discharge, facial pain, cough, and halitosis, are correctly assessed, the clinical diagnosis of CRS may be achieved, and confirmation may be obtained by imaging criteria or nasal fibroendoscopy. In imaging, computed tomography (CT) is the first choice technique for the evaluation of CRS and is able to provide an anatomic road map when surgery is required. Magnetic resonance imaging (MRI) of the sinuses, orbits, and brain should be performed whenever extensive or multiple complications of sinusitis are suspected. Also for middle ear disorders, CT is the first choice because it detects opacification of the middle ear cavity and mastoid cells, presence of fluids or debris, and allows the ossicular chain and the cortical bone of the mastoid to be evaluated. Another important diagnostic issue is the need to look for disorders that are frequently associated with CRS, such as obstructive sleep apnea syndrome (OSAS), that has some recognized risk factors in adenotonsillar hypertrophy, craniofacial anomalies, obesity, and neuromuscular disorders. Other associated disorders requiring investigation are recurrent or persistent otitis media and difficult asthma.

Relationship between clinical sinusitis symptoms and sinus CT severity in pediatric post bone marrow transplant and immunocompetent patients

Since typical inflammatory responses may be diminished in children following bone marrow transplant (BMT), computed tomography (CT) imaging of the sinuses has been increasingly ordered to diagnose sinusitis in this group. The objective of this study was to determine the association between clinical sinusitis symptoms and sinus opacification on CT scans in post BMT versus immunocompetent children. Our sample was comprised of 64 post BMT and 86 immunocompetent children with sinus CT scans. CT sinus opacification was scored using the modified Lund-Mackay staging system. The relationship between clinical sinusitis symptoms (rhinorrhea, nasal congestion, cough, headache, and facial pain) and opacification was compared for the two groups. The severity of sinus opacification in the BMT group was significantly higher compared to the immunocompetent group. In combined patient groups the odds ratio (OR) for moderate/severe sinusitis was significantly elevated for rhinorrhea (OR = 3.00; 95% confidence interval [CI], 1.27-7.12), cough (OR = 2.80; 95% CI, 1.22-6.42), and having either rhinorrhea, nasal congestion, or cough (OR = 4.76; 95% CI, 1.71-13.24). While the immunocompetent group had a greater number of sinusitis symptoms compared to the post BMT group, both groups had a significant increase in the severity on CT with increasing number of symptoms.

CONCLUSION

In post BMT patients, our data demonstrated higher odds of moderate/severe sinusitis on CT scans associated with rhinorrhea, cough or nasal congestion. These finding suggest that in post BMT children, detailed sinus history may still play a vital role in the diagnosis of sinusitis.

Mucosal cysts in the paranasal sinuses: long-term follow-up and clinical implications

BACKGROUND

Although mucosal cysts in the paranasal sinuses (PSMCs) are commonly detected, the long-term follow-up studies of PSMCs are sparse. This study evaluated the natural course of PSMCs and identified risk factors for the disease progression.

METHODS

A total of 133 subjects with PSMCs who underwent health checkup including brain magnetic resonance imaging more than two times with an interval of ≥24 months between January 2000 and December 2009 were included. The characteristics of PSMCs were analyzed on the initial and follow-up images. Nasal symptoms, smoking status, and comorbid medical conditions were evaluated using structured questionnaires and medical records.

RESULTS

The mean follow-up duration was 40.38 months (range, 24.0-109.8 months). The mean size of PSMCs decreased from 15.07 to 12.73 mm. Only 8.3% of subjects showed an increase in size, whereas the size of cysts was decreased or unchanged in the remaining 91.7% of subjects. Six (4.5%) subjects complained of nasal symptoms during follow-up and subsequent sinusitis was developed in 3% of subjects. An increase in cyst size was associated with development of sinusitis (odds ratio = 45.375). Initial size of cysts >20 mm and bilateral location were significant risk factors for progression (p = 0.019 and p = 0.039, respectively).

CONCLUSION

The majority of PSMCs in this follow-up study were decreased or unchanged and most subjects were asymptomatic. Just observation is enough for most PSMCs. However, those who have a large cyst (>20 mm) or bilateral cysts at initial diagnosis were at risk for disease progression and should be regularly followed.

Perioperative and intraoperative maneuvers to optimize surgical outcomes in skull base surgery

There are many approaches to obtaining a workable endoscopic surgical field in sinus surgery. With extended sinus and transdural endoscopic surgery, a more rigid approach must be taken. There are 3 main factors that invariably lead to poor surgical outcomes in endoscopic sinus and skull base surgery: bleeding, inadequate access, and unidentified anatomic anomalies. Bleeding is arguably the most common reason for incomplete resection. An understanding of microvascular and macrovascular bleeding allows a more structured approach to improve the surgical field in extended endoscopic surgery. The endoscopic surgeon should always be comfortable in performing the same procedure as an open operation. However, converting or abandoning an endoscopic procedure should rarely occur because much of this decision making should take place preoperatively. Along with poor hemostasis, inadequate access is an important cause of poor outcome. Evaluation of the anatomy involved by pathology but also the anatomy that must be removed to allow adequate exposure is important. This article reviews the current techniques used to ensure optimal surgical conditions and outcomes.

Assessment of nasal and paranasal sinus masses by diffusion-weighted MR imaging

PURPOSE

To assess nasal and paranasal sinus masses by diffusion-weighted echoplanar magnetic resonance imaging (MRI).

PATIENTS AND METHODS

This prospective study included 55 consecutive patients (34 males, 21 females; aged 14-64 years, mean 39 years) with nasal and paranasal sinus masses. All underwent diffusion-weighted MRI using single-shot echoplanar imaging (EPI) with a b factor of 0.500 and 1000 s/mm2. Apparent diffusion coefficient (ADC) maps were constructed, allowing ADC values of the mass to be calculated and correlated with histopathological findings.

RESULTS

The mean ADC value of nasal and paranasal sinus malignant lesions (1.10+/-0.25x10(-3) mm2/s) was significantly different (P=0.001) from that of benign lesions (1.78+/-0.41x10(-3) mm2/s). Also, there was a significant ADC difference between carcinoma and sarcoma (P=0.01) as well as between well differentiated and poorly differentiated malignancies (P=0.005). Using an ADC value of 1.53x10(-3) mm2/s as the threshold value for differentiating malignant from benign lesions, the best result obtained had an accuracy of 93%, sensitivity of 94%, specificity of 92%, a positive predictive value of 92% and negative predictive value of 94%. However, the use of 0.97x10(-3) mm2/s and 1.16x10(-3) mm2/s as threshold values to differentiate carcinomas from sarcomas and poorly differentiated malignancy, respectively, gave the best results.

CONCLUSION

The ADC value is a non-invasive imaging parameter that can be used to assess nasal and paranasal sinus masses, as it can help in the differentiation of malignant tumors from benign lesions, and in the characterization and grading of malignancies.

Diagnostic and Staging Accuracy of Magnetic Resonance Imaging for the Assessment of Sinonasal Disease

Background

Concerns over radiation exposure with paranasal sinus computed tomography (CT) have recently evolved. Magnetic resonance imaging (MRI) may be more advantageous in this regard, but the diagnostic assessment of MRI in chronic rhinosinusitis (CRS) has not been reported. The purpose of this study was to determine the correlation between CT- and MRI-based staging and diagnosis of CRS.

Methods

Paired CT and MRI scans of 89 adult patients who were imaged by both modalities within a 3-month time period for evaluation of pituitary disease were scored for sinus disease using the Lund-Mackay system in a randomized and blinded fashion. The Lund scores were compared for similarity, correlation, and diagnostic classification between modalities.

Results

The mean Lund scores were 2.3 ± 0.6 (95% CI) for CT-based staging and 2.1 ± 0.5 for MRI-based staging with a median time interval between scans of 3 days. The difference means was not statistically significant (p = 0.444, paired t-test). Correlation analysis revealed a significant association between CT- and MRI-based scores (Pearson's r = 0.837, p < 0.001). Disease classification agreement analysis using published Lund score cutoffs (3 versus 4) for the likelihood of true sinus disease revealed that CT- and MRI-based scoring agreed on 76 cases (85.4%). Disagreement occurred in 13 cases (kappa: 0.557, p < 0.001). Sensitivity, specificity, positive predictive value, and negative predictive value were 66.7, 90.1, 63.2, and 91.4%, respectively.

Conclusion

Lund-Mackay staging of sinus disease by MRI is closely correlated to corresponding staging based on CT. MRI does not significantly overstage or overclassify patients with sinus disease.

Radiologic Appearances in Fungal Rhinosinusitis

Radiological diagnosis forms an important tool in the armamentarium to diagnose and classify fungal rhinosinusitis. However, many times, the appearances may be deceptive; while on one hand in Allergic Fungal Rhinosinusitis the appearance is classical and considered one of the clinchers in the diagnosis of the condition, in invasive fungal rhinosinusitis (especially in the early phases), the appearances may range from a nonspecific sinusitis to even a ‘apparently normal’ scan! CT scan as well as MRI may at times complement each other, in order to aid the clinician arrive at a diagnosis. Nevertheless, despite the best radiologic modalities, a clinicoradiological correlation is a must to accurately diagnose this often deceptive condition called fungal rhinosinusitis.

Association of magnetic resonance imaging findings and histologic diagnosis in dogs with nasal disease: 78 cases (2001-2004)

OBJECTIVE-To determine whether magnetic resonance imaging (MRI) features correlated with histologic diagnosis in dogs with nasal disease. DESIGN-Retrospective case series. ANIMALS-78 Dogs undergoing MRI for evaluation of nasal disease. PROCEDURES-Medical records and MRI reports of dogs were reviewed to identify MRI features associated with histologic diagnosis. Features evaluated were presence of a mass effect, frontal sinus involvement, sphenoid sinus involvement, maxillary recess involvement, nasopharyngeal infiltration by soft tissue, nasal turbinate destruction, vomer bone lysis, paranasal bone destruction, cribriform plate erosion, and lesion extent (ie, unilateral vs bilateral). RESULTS-33 Dogs had neoplastic disease, 38 had inflammatory rhinitis, and 7 had fungal rhinitis. Lesion extent was not significantly associated with histologic diagnosis. Absence of a mass effect was significantly associated with inflammatory disease. However, presence of a mass was not specific for neoplasia. In dogs with evidence of a mass on magnetic resonance (MR) images, nasal turbinate destruction, frontal sinus invasion, and maxillary recess invasion were not useful in distinguishing neoplastic from nonneoplastic disease, but cribriform plate erosion, vomer bone lysis, paranasal bone destruction, sphenoid sinus invasion, and nasopharyngeal invasion were. CONCLUSIONS AND CLINICAL RELEVANCE-Results suggested that in dogs with nasal disease, the lack of a mass effect on MR images was significantly associated with inflammatory disease. In dogs with a mass effect on MR images, vomer bone lysis, cribriform plate erosion, paranasal bone destruction, sphenoid sinus invasion by a mass, and nasopharyngeal invasion by a mass were significantly associated with a diagnosis of neoplasia.

CT versus MR: still a tough decision

CT and MRI are the two most widely used imaging modalities for evaluating head and neck pathology. There is continued controversy in the literature about which modality is superior for imaging different areas of the head and neck. This article summarizes the literature supporting the use of CT, MRI, or both for specific clinical scenarios in otolaryngology. Familiarity with the benefits and potential pitfalls of each modality allows referring physicians and radiologists to tailor imaging regimens to the needs of individual patients.

Isolated sphenoid sinus pathology: spectrum of diagnostic and treatment modalities

OBJECTIVE

Isolated sphenoid sinus pathology is a relatively uncommon entity. The present study is a retrospective review of 40 patients with isolated sphenoid sinus pathology who were treated at the Department of Otorhinolaryngology, Alexandria University between July 2002 and December 2005. Special emphasis will be given to the role of various endoscopic approaches in the surgical management of isolated sphenoid sinus pathology. Factors that govern the selection of each approach will be discussed.

METHODS

Extracted data included patient demographics, clinical presentation, imaging studies, treatment modalities and complications. Sphenoid sinus was approached through one of the following three approaches: (1) endoscopic transnasal approach, (2) endoscopic transseptal approach and (3) endoscopic transpterygoid approach. Outcome measures were based on assessment of patients' symptoms and confirmation of a patent sphenoid sinus by office endoscopy.

RESULTS

The pathology spectrum was rather wide and included 26 (65%) inflammatory conditions (acute/chronic sphenoiditis, mucoceles, and fungal sinusitis), 7 (17.5%) neoplasms and 7 (17.5%) miscellaneous conditions (cerebrospinal fluid (CSF) rhinorrhea, sphenochoanal polyp, and fibrous dysplasia). The most common initial symptom was headache (50%) followed by ophthalmological symptoms (22.5%). Other presenting symptoms included CSF leak in five patients, epistaxis in four patients and nasal obstruction and/or rhinorrhea in two patients. Radiological workup included computed tomography (CT) scan of the paranasal sinuses in all patients. Magnetic resonance imaging (MRI) was performed in 21 patients (52.5%). The most common indication was a sphenoid mass based on endoscopic and CT findings. Four patients with acute/chronic sphenoiditis were successfully treated with medical therapy. One patient with fibrous dysplasia did not require any definitive treatment. Thirty-five patients underwent endoscopic surgery under general anaesthesia. An adjuvant radiotherapy with or without chemotherapy was utilized in two patients.

CONCLUSIONS

A high index of clinical suspicion, routine office nasal endoscopy and radiological imaging are central to making an accurate and timely diagnosis of isolated sphenoid sinus pathology. Surgical treatment of sphenoid pathology can be safely and successfully performed through a variety of endoscopic approaches. Selection of the most appropriate endoscopic approach is governed by the nature and location of sphenoid pathology as well as the anatomical configuration of the sphenoid sinus.

Cancer of the paranasal sinuses

Carcinoma of the paranasal sinuses is a heterogeneous disease that is frequently locally advanced at presentation. Treatment commonly includes radical surgery followed by adjuvant therapy. Despite such aggressive therapy, the likelihood of locoregional failure is significant, resulting in poor survival, particularly with advanced tumors. In this paper, we review the recent literature in search of advances in treatment optimization. These advances include conformal radiotherapy techniques, chemotherapy, image-guided and endoscopic surgery, and surgical approaches for orbital preservation, all of which have a potential to improve the oncologic outcome as well as cosmetic and functional results. We also outline our approach in using these advances in the management of patients with these cancers.

Advances in imaging of the paranasal sinuses

Imaging technology has played a significant role in the diagnosis and management of sinonasal disorders. Plain sinus films are almost exclusively replaced by CT in the work-up for inflammatory sinus disease. MRI provides complementary information to CT in cases of sinonasal and skull-base neoplasms. The evolution of endoscopic surgical techniques for the paranasal sinuses and skull base is made possible by the parallel advancement of imaging technologies. Recent advances that are currently in clinical use have included multidetector row CT scanners and computer image-guidance systems for surgery. Three-dimensional CT angiography, image-guided CT-MR fusion, and intraoperative image-guidance are new techniques that are currently being evaluated. As imaging technology continues to advance, so does the capability to treat diseases beyond the sinuses and skull base with minimally invasive, endoscopic approaches.