Computed tomography characteristics of equine paranasal sinus cysts

Abstract

Background Computed tomography (CT) is commonly used to investigate equine paranasal sinus disease, however, only limited information is available in the literature about the detailed CT appearance of equine paranasal sinus cysts. Objectives To investigate if paranasal sinus cysts have specific characteristics in CT images that allow differentiation from other sinus diseases. Study design Retrospective observational study. Methods Evaluation and comparison of CT studies of eight horses with surgically and/or histopathologically confirmed paranasal sinus cysts and 10 horses with other confirmed paranasal sinus diseases. Results A discrete hyperattenuating wall‐like structure was detected in the periphery of the sinus lesion in precontrast acquisition in 7/8 horses with paranasal sinus cysts. A similar wall‐like structure was detected in 3/10 horses with other sinus diseases, however, in contrast to horses with paranasal sinus cysts, two of these also had hyperattenuating regions within the contents of the sinus lesion. Bone destruction and formation affecting cancellous and cortical bone and dental disease were frequent in horses with paranasal sinus cysts. No significant difference in attenuation values was found when the fluid/soft tissue attenuation contents of lesions in horses with paranasal sinus cysts (mean 28.9 ± SD 9.2 HU) were compared with other sinus diseases when ethmoid haematomas were excluded (30.4 ± 12.9 HU, P = .8). Main limitations Low number of cases. Conclusions Detection of a hyperattenuating cystic wall is a helpful feature for identifying paranasal sinus cysts in CT images of horses. In contrast, measurement of attenuation values of the soft tissue/fluid contents of the sinus lesions was not helpful in identifying paranasal sinus cysts.

Diagnosis and Surgical Treatment of Idiopathic Primary Sino-Nasal Obstruction in Miniature Horse Breeds: Long-Term Follow-Up of Seven Cases

“…Paranasal sinus cysts are commonly unilateral; bilateral disease is only rarely reported. In a recent study (19) investigating CT characteristics of paranasal sinus cysts, seven of eight cysts demonstrated a soft tissue to mineral attenuating wall; this finding was not detected in this case series of sino-nasal obstruction. Paranasal sinus cysts are typically expansile lesions; therefore, bone distortion is a common finding.…”

“…In the patient with secondary infection following trephination, the recorded values did not differ from those measured in sinus compartments filled with clear fluid. A recent study demonstrated that HU measurements are not reliable to differentiate between cyst fluid and sinus mucus or exudate ( 19 ). Recorded HU were in the same range as those measured in the present study excluding HU as a means of differentiating between primary sinusitis and the idiopathic pathology in this case series.…”

Outcomes following single, caudally based bilateral versus unilateral frontonasal sinusotomy for treatment of equine paranasal sinus disease

“…Multiplanar diagnostic imaging (CT, magnetic resonance imaging) provides detailed information in assessing sinus disease in horses for a more accurate preoperative diagnosis to guide surgical planning (Easley & Freeman, 2013;Ostrowska et al, 2019;Textor et al, 2012).…”

“…Multiplanar diagnostic imaging (CT, magnetic resonance imaging) provides detailed information in assessing sinus disease in horses for a more accurate preoperative diagnosis to guide surgical planning (Easley & Freeman, 2013 ; Ostrowska et al., 2019 ; Textor et al., 2012 ). Patients that experience recurrence or lack of resolution of clinical signs following sinusotomy are good candidates for CT examination if the cause of recurrence is not apparent (Barakzai & Dixon, 2014 ).…”

Advances in the Diagnosis of Equine Respiratory Diseases: A Review of Novel Imaging and Functional Techniques

“…Henninger et al provided detailed CT descriptions regarding the most common features of sinusitis and alveolitis [32]. Diagnosis and surgical treatment of sinonasal cysts have been described [33][34][35]. Solano et al depicted CT images of empyema, even though endoscopy is the preferred method for the diagnosis process of guttural pouches [24].…”