3D CT PNS

3D CT PNS Overview

Introduction 

3D computed tomography (CT) of the paranasal sinuses (PNS) is a unique computed radiological technique capable of producing three-dimensional images of the sinus cavities. It plays a major role in the diagnosis of sinusitis as well as in the assessment of sinus anatomy prior to surgical intervention, alongside the detection of neoplasms or other abnormal constitutional disorders. 

What is a 3D CT PNS? 

In a 3D CT PNS scan, X-ray radiography is utilized to capture several axial images of the sinuses, which are then processed into a three-dimensional contour. It gives a complete view of the cavernous sinuses, including the layered accumulations of mucus, and the bone encasing them.

Parameters Considered

• Patency of the sinus cavities. 
• Mucosal thickness. 
• Air-fluid levels or opacification. 
• Obstruction of the osteomata complex. 
• Erosions or deforming bone. 
• Deviated nasal septum or concha bullosa. 

Reasons for the Test

• Assess chronic sinusitis and facial pain syndrome. 
• Surgical planning, for example, FESS. 
• Find possible anatomical causes for obstructive rhinitis. 
• Identify infections, cysts, or neoplasms. 

When and Who Needs a 3D CT PNS? 

Indications: 

• Ongoing or recurrent sinusitis. 
• Treatment-resistant facial pain or pressure. 
• Nasal blockage or congestion. 
• Assessment of tumours or other anomalies in the sinuses. 
• Planning of surgical procedures involving the sinuses and/or the nose. 

Patient Demographics: 

• Adults and children with chronic sinus symptoms. 
• Patients who are candidates for ENT surgery. 
• Patients with a history of trauma to the nose. 
• Patients who may have tumours or polyps of the sinuses. 

Benefits of Taking the Test

• Provides high quality images of the sinuses. 
• Obtained through a quick, painless scan. 
• Useful in precise surgical procedure planning. 
• Identifies variants and pathological conditions with great accuracy. 

Conditions Diagnosed

• Acute or chronic sinusitis. 
• Sinus polyps or malignancies. 
• Mycotic infections of the sinuses. 
• Facial bone fracture(s). 
• Congenital sinus deformities. 

Preparation

• Relaxed, metal-free attire. 
• No food or drink restrictions for non-contrast scans. 
• Must report face-related recent surgeries or implants. 

Pre-requisites 

• ENT or GP referral. 
• Check kidney function if a contrast medium is needed. 

Best Time to Take the Scan 

• While symptoms linger and remain constant. 
• Prior to moving forward with the surgical intervention. 

Eligibility 

• Most patients are safe. 
• Pregnant women and children require careful consideration. 

Procedure 

• Patient reclines on CT table in a supine position. 
• Head is aligned to the scan and held securely. 
• Scan lasts for 5 to 10 minutes. 
• 3D images are reconstructed digitally for review, and contrast is only injected if explicitly requested. 
• Hold still throughout the entirety of the scan. 
• Inform the radiology staff of any pre-existing implants, allergies, or required implants. 

Caution 

• Avoid body movement throughout the scan 
• Inform radiology staff regarding any allergies or implants