Paranasal Computed Tomography Research Articles

Modification of the maxillary bone in adults with nasal polyposis: a CT morphometric study

Nasal polyposis (NP) in adult population is a common problem in otorhinolaryngology outpatient practice. Computed tomography (CT) is the ideal imaging method to investigate paranasal sinus diseases. There is yet no study in the literature measuring the morphometry of maxillary bone in NP. The objectives of this study are to correlate the airway variables obtained by CT findings of both chronic nasal airway obstruction and control group in an adult population, and to investigate whether the bony structure of the airway is affected or not. Forty NP cases that were followed up for 1-5 years by an otorhinolaryngologist were included in this retrospective study. Forty subjects who had normal findings reported on paranasal CT scans were randomly selected from our CT database as the control group. Maxillary and palatine bones (PB) were evaluated: the plane angle between the maxillary alveolar processes (MAP) and PB, and depth of the maxillary arch of both groups were compared. The mean angle between MAP and PB plane was wider in the NP group (right 128.1 +/- 8.5 degrees and left 126.2 +/- 8.5 degrees ) than control group (right 106.6 +/- 8.1 degrees and left 105.5 +/- 7.3 degrees). The mean depth of maxillary arch was significantly smaller in the NP group (1.2 +/- 0.2 cm) than in the control group (1.4 +/- 0.2 cm). There could be a relationship between nasal polyposis in adults and maxillary shape. The flattening and shallowing of the maxillary arch detected in patients with NP may indicate that the bony structural changes continue in adulthood.

Ethmomaxillary sinus

Ethmomaxillary sinus is a variation of the posterior ethmoid cells. It is formed by the extension of the posterior ethmoid cells into the maxillary sinus and drains into superior nasal meatus. It is incidentally seen on paranasal sinus computerized tomography (CT) scans. Its prevalence has been reported as 0.7 and 2% in two studies. In this study, paranasal CT scans of 466 patients were investigated for the presence of ethmomaxillary sinus. The patients had paranasal CT with the preliminary diagnoses of septal deviation, chronic inflammatory paranasal sinus disease and nasal turbinate disorders. The ethmomaxillary sinus was present in nine of those patients (1.93%). It was septated in one of them. The CTs were further investigated for other anatomical variations and co-existent mucosal disease of the paranasal sinuses.

Identification of the anterior ethmoid arteries on thin-section axial images and coronal reformatted orbit images by means of multidetector row CT

The aim of this study was to identify anterior ethmoid arteries on thin-section axial images and coronal reformatted images of the orbits using multidetector row computed tomography (CT). One hundred and thirty-two patients underwent paranasal CT using a 16-row detector CT (n=59) or a 6-row detector CT machine (n=73) at 1 or 1.25 mm section width, respectively. Coronal images were reformatted at section widths of 3 and 1 mm. The anterior ethmoid arteries were identified for each patient. Differences were assessed using the chi-square test. All CT images were of approximately average diagnostic quality. Anterior ethmoid arteries were identified in 97.5 and 96.6% at section thicknesses of 1 and 1.25 mm on the axial images, respectively. There was no statistically significant difference in the detection rate (p=0.89). On the coronal images, anterior ethmoid arteries were presented tangentially in 75.4 and 90.2% at section widths of 3 and 1 mm, respectively. The visibility of the anterior ethmoid arteries was rated significantly better on coronal images at a section width of 1 mm than on those at section widths of 3 mm (p<0.001). Thin-section axial images and coronal reformatted images using multi-detector row CT mostly depict anterior ethmoid arteries, and are useful to identify anterior ethmoid arteries for preoperative evaluation of paranasal sinuses.

The role of Accompanying Sinonasal Abnormalities in the Outcome of Endonasal Dacryocystorhinostomy

Acquired nasolacrimal duct obstruction may occur simultaneously and possibly as a consequence of sinonasal disease, because the nasolacrimal system is anatomically related to important nasal and sinus structures. Thirty-seven patients with nasolacrimal canal obstruction (42 eyes) were evaluated with paranasal sinus computerized tomography (CT) to determine the presence of sinonasal abnormalities if any. All of the patients underwent endoscopic dacryocystorhinostomy (end-DCR) and accompanying sinonasal pathology was treated also in the same session. Paranasal sinus CT examinations revealed one or more sinonasal abnormalities in 26 (73.3%) patients. The postoperative success rate of end-DCR procedure in patients with sinonasal abnormalities was 82.8%, whereas this figure increased to 92.3% in patients without additional sinonasal disease. However, additional rhinological surgery did not affect the success rate of end-DCR procedure significantly (p = 0.640). These data establish a positive correlation between sinonasal abnormalities and the presence of nasolacrimal outflow obstruction, but the additional rhinological surgery does not significantly affect the results of the end-DCR procedure.

Hyperaeration of the frontal sinus

The nasal cavity and paranasal sinuses constitute an anatomical and functional unit. Paranasal sinuses communicate with the nasal cavities, which are covered by the same mucosa, via small openings and narrow ducts that allow both aeration and sinus drainage. Anatomical variations of the paranasal sinuses and nasal cavity are important in sinus diseases. Computerized tomography (CT) plays a critical role in evaluation of the patients with paranasal sinus pathology and variations. A 38-year-old man admitted to our clinic with headache and postnasal dripping for 1 year. His paranasal CT scanning revealed that there is hyperaeration of the frontal sinus which is in continuity with the sphenoid sinus. Hyperaeration of the sinuses may be kept in mind in a patient complaining of headache.

Three-slice computerized tomography for the diagnosis and follow-up of rhinosinusitis

Plain sinus radiography is the imaging technique most frequently used to investigate suspected rhinosinusitis, but it has low diagnostic sensitivity. Contiguous paranasal computerized tomography (CT) gives detailed information about the pathology, anatomy and anatomical variations of the paranasal sinuses, but this method also has limitations. The cost of using this technique for all cases of suspected rhinosinusitis is prohibitive, and complete CT scans involve considerable radiation exposure. The aim of this study was to devise a CT protocol for diagnosing and following rhinosinusitis that is more economical and involves much less radiation exposure than contiguous CT. In this retrospective study, three physicians independently reviewed the contiguous coronal paranasal CT studies of 136 patients. The study population comprised the adult patients who were investigated for suspected chronic rhinosinusitis. All scans had been obtained at the second visit, after the patient had completed a 3-week course of medical treatment. For each case, the same three slices were selected to form the "three-slice CT" exam, and the same physicians independently evaluated this set. Using the results from the contiguous set as the gold standard, we calculated the sensitivity and specificity of three-slice CT for identifying rhinosinusitis. The sensitivity and specificity of three-slice CT for identifying inflammatory sinus disease were 95.1 and 92.6%, respectively. Three-slice CT is a valuable method for diagnosing and following rhinosinusitis cases, and would be cheaper and involve less radiation exposure than contiguous coronal CT. However, despite the high cost and greater radiation exposure, contiguous CT remains the gold standard for evaluating detailed sinus anatomy and disease progression.

The unilateral opaque maxillary sinus on computed tomography

Computed tomography (CT) is the imaging method of choice for conditions that affect the paranasal sinuses. We reviewed all paranasal CT scans in the ear nose and throat (ENT) and maxillofacial surgery departments in 1 year. Of these 372 scans, unilateral opacity of the maxillary sinus was seen in 20 cases. Neoplastic disease was diagnosed in six of these, four of which were malignant. We describe the cases of neoplastic disease, particularly features of the history, examination, and scans that should alert the clinician to the possibility of sinister pathology. We emphasise the importance of nasendoscopic examination in the accurate assessment of sinonasal disease.