Radiographic techniques of the nasal cavity and sinuses

Diseases of the nasal cavity and sinuses can be frustrating problems for owners and veterinarians alike. Initial physical examination and routine blood work are often unrewarding in directing the clinician at a diagnosis. Diagnostic imaging can help characterize the disease process and direct treatment or further diagnostics. Radiographs of the skull are an excellent first-line diagnostic step in the analysis of nasal disease. The following article reviews basic techniques, positioning, and interpretation of radiographs of the nasal cavity and paranasal sinuses.     

Osteoma of paranasal sinuses of a horse

A 2-year-old Quarter Horse gelding was examined for torticollis, facial protuberances over the frontal and maxillary sinuses, and persistent nasal discharge unresponsive to antibiotics. Radiograph revealed an osseous mass in the right paranasal sinuses. Histologic examination of the biopsied mass led to a diagnosis of osteoma. The mass was removed surgically in sections from the right frontal and maxillary sinuses through separate bone flaps, and sinuses were irrigated with saline solution for 8 days after surgery. Two weeks after surgery, radiography revealed small osseous opacities in the right paranasal sinuses. These opacities remained unchanged in radiographs obtained up to 23 months after surgery.     

The diagnosis and successful treatment of Aspergillus fumigatus infection of the frontal sinuses and nasal chambers of the dog

Five cases of rhinitis and sinusitis in the dog are presented in which the invading organism was Aspergillus fumigatus . The diagnosis of the condition is described and the radiographic features emphasized. The surgical treatment, post-operative management and successful outcome of the five cases are reported.
Résumé. On présente cinq das de rhinite et de sinusite chez le chien, cas dans lesquels l'organ-isme était l'Aspergillus fumigatus. On décrit le diagnostic de la condition et on souligne les traits radiographiques caractéristiques. On rapporte le traitement chirurgique, la ligne de conduite postopératoire à suivre et la menée à bien des cinq cas.   Zusammenfassung.     

Bilateral congenital cysts in the frontal sinuses of a horse

Congenital frontal sinus cysts were found bilaterally in the frontal sinuses of a one-year-old miniature horse. Diagnosis was based on radiography of the head and cytologic examination of tissue aspirated from the frontal sinuses. The cysts were surgically removed, using a hinged bone flap technique bilaterally over the frontal sinuses.     

A new approach for the diagnosis of myiasis of animals: the example of horse nasal myiasis

The myiasis caused by larvae of Rhinoestrus purpureus and Rhinoestrus usbekistanicus (Diptera, Oestridae) are of importance in the horse medicine since it causes severe respiratory diseases. Therefore an accurate diagnosis of rhinoestrosis is central to its epidemiology and control. This paper describes concisely a molecular diagnostic tool that overcomes the current inherent diagnostic constraints and, therefore, is of importance to understand the actual incidence and epidemiology of this myiasis in live horses.     

Pasteurella haemolytica serotype 1 colonization of the nasal passages of virus-infected calves

Nasal passages of calves with a virus-induced respiratory tract disease became colonized by Pasteurella haemolytica serotype 1 after they were inoculated intranasally with P haemolytica. Inoculation with infectious bovine rhinotracheitis virus caused a more severe clinical illness and resulted in a greater degree of colonization with P haemolytica than developed after inoculation with parainfluenza-3 virus. Nasal passages of parainfluenza-3 virus-inoculated calves were colonized to a greater degree with P haemolytica than were those of healthy, nonstressed calves. Calves were susceptible to P haemolytica colonization during or shortly after virus-induced illness, even though they had been previously exposed to P haemolytica and had serum antibody and nasal secretion antibody to P haemolytica.     

Early diagnosis may hold the key to the successful treatment of nasal and paranasal sinus neoplasia in the horse

Intrasinus neoplasia remains a rare but difficult condition to diagnose and treat in the horse, comprising approximately 8–19% of sinonasal disorders. There are, however, only a few case series upon which to base an approach to diagnosis and management ( Cotchin 1967, 1977 ; Madewell et al. 1976 ; Stunzi and Hauser 1976 ; Sundberg et al. 1977 ; Priester and McKay 1980 ; Boulton 1985 ; Hilbert et al. 1988 ; Dixon and Head 1999 ; Head and Dixon 1999 ; Tremaine and Dixon 2001a,b ). Squamous cell carcinoma (SCC) is the most common neoplasm observed in the equine paranasal sinuses. Evidence from other species would indicate that early recognition of SCC is crucial to the success of treatment and the ideal treatment remains complete excision with margins. Sinus involvement generally precludes this and we must often settle for surgical debulking, with or without adjunctive radio‐ or chemotherapy. In horses, as in other species, early recognition is difficult because clinical signs are nonspecific. Treatment is, therefore, often not attempted due to the extensive nature of lesions at presentation and the limited surgical access. The accompanying article by Kowalczyk et al. (2011 ) showed how 3‐dimensional (3D) imaging can identify the hallmark changes associated with aggressive neoplasia in the equine sinuses ( Kowalczyk et al. 2011 ). The value of computed tomography (CT) and magnetic resonance imaging (MRI) lies in noninvasive early diagnosis as well as lesion monitoring post intervention. Where CT can be performed with the horse in the standing position, avoidance of general anaesthesia offers further value, especially as standing surgical techniques now allow thorough, minimally invasive evaluation and biopsy of the equine sinuses. In combination, standing CT and minimally invasive sinus surgery allow accurate and early diagnosis and monitoring of disease progression, opening the door for advances in surgical and adjunctive treatments for this complex condition.     

Osteoma of paranasal sinuses in a horse with inspiratory dyspnoea

We describe a case of osteoma in the frontal and maxillary sinuses of a 3-year-old Arabian mare, presented due to an inspiratory dyspnoea. The mare underwent two surgical procedures in order to excise the tumour. Twelve months after admission the mare was healthy with no signs of respiratory abnormalities. Sinus radiographs and endoscopy repeated at that time revealed some regrowth of the tumour in the maxillary sinus, however, twenty-two months following surgery the mare did not show clinical signs of upper airway disease.     

Radiotherapy of a recurrent ossifying fibroma in the paranasal sinuses of a horse

A 7-year-old female Thoroughbred was admitted with a history of labored breathing, stridor, and exercise intolerance. Examination revealed a mass in the left paranasal sinuses that was determined to be an ossifying fibroma. Initial treatment consisted of surgical removal of the mass alone; however, the mass recurred 9 months after surgery. The mass was again removed, and adjunctive radiotherapy consisting of 3,000 cGy of cobalt radiation was administered. This time, the tumor did not recur for > 6 years. A third surgery was performed to remove the mass, and adjunctive radiotherapy consisting of 4,000 cGy of photon beam radiation from a linear accelerator was administered. The mass did not recur during the subsequent 3 years. Ossifying fibromas are uncommon tumors that frequently recur if incompletely excised. Results in this horse suggest that adjunctive radiotherapy may delay or prevent tumor recurrence in affected horses.     

Pseudallescheria boydii infection of the nasal cavity of a horse

An 18-year-old 454-kg (1,000-lb) American Quarter Horse gelding was evaluated because of chronic intermittent malodorous right-sided nasal discharge. Endoscopy revealed a mycotic plaque in the nasal cavity adjacent to the nasomaxillary opening of the right caudal maxillary sinus. The nasomaxillary opening appeared to be larger than normal. Fungal culture of specimens of the mycotic plaque yielded Pseudallescheria boydii. The horse was treated with 2% miconazole intranasally, sodium iodide i.v., and potassium iodide p.o. Thirty and 60 days after treatment was initiated, the nasal cavity was found to be free of infection.     

Malignant lymphoma in nasal cavity and paranasal sinuses of a dog

A case of a canine large cell type T-cell lymphoma, with features of high-grade malignancy is described. The tumour was found confined in the nasal cavity and the paranasal sinuses of a crossbred German Shepherd dog. Histological examination revealed the features of a highly malignant large cell lymphoma. Ultrastructurally, the lymphoid tumour cells bore cytoplasmic protrusions that interdigitated tightly. From a panel of tumour markers used, the neoplastic cells were stained only for vimentin. Immunophenotyping of the tumour cells by means of CD3, CD79, kappa-light chains and lambda-light chains detection was undertaken. The tumour stained only for CD3 and was classified as T-cell lymphoma.     

Orthovoltage radiation of normal canine nasal passages: assessment of depth dose

Frozen heads of 9 clinically normal dogs were irradiated with orthovoltage x-rays. Surface doses and nasal cavity depth doses were measured, and the percentage of surface dose (depth dose) was calculated at random depths from the dorsal cutaneous surface in transverse planes through the medial and lateral canthi. Depth dose of 2 orthovoltage x-ray beams having half-value layers of 1.5 mm of Cu (96 keV) and 2.6 mm of Cu (134 keV) were compared with and found to resemble that reported in depth dose tables based on soft tissue equivalent material. Any differences (identified graphically) in depth dose, compared with that described using a uniform (soft tissue equivalent) phantom, were explained by the variations in tissue composition and the presence of air within the normal nasal and paranasal cavities.     

Light and scanning electron microscopic studies of the nasal turbinates of the horse

The nasal turbinates of 5 young horses were studied by light and scanning electron-microscopy. Stratified cuboidal epithelium lined the rostral part of the dorsal and ventral nasal turbinates of the vestibular region. The polyangular microvillus cells of this region were separated by linear depressions. The mid and caudal parts of the dorsal and ventral nasal turbinates and the rostral part of the ethmoturbinates were lined by pseudostratified columnar ciliated respiratory epithelium. Numerous cilia with dilated blebs on the ciliated cells concealed adjacent non-ciliated supporting cells and goblet cells. The olfactory zone consisting of the olfactory vesicle and a dense network of olfactory cilia localized to the caudal part of the ethmoturbinates. The three regions were delineated from each other by transitional zones.