A review of common anatomical variants of paranasal sinuses and nasal cavity and its frequency of occurrence as evidenced on multi-detector computed tomography

This study was carried out to know the frequency of occurrence of common anatomic variants in computed tomography of paranasal sinuses and nasal cavity. Non contrast Computed tomography (CT) of paranasal sinuses of 100 patients referred to Department Of Radiology, Saveetha Medical College were retrospectively studied. The Multi-detector computed tomography (MDCT) scans were evaluated for various anatomical variants of paranasal sinuses and nasal cavity. The frequency of occurrence was calculated in percentage.We found out that deviated nasal septum (DNS) was the most common variant in this study, seen in 86% of cases, followed by Agger nasi cells which was seen in 56% and the third most common was supra-orbital ethmoidal cells seen in 42% of the study population. All the cases included in the study, had minimum of one variant. Most of the study population showed multiple anatomical variations of paranasal sinus and nasal cavity. In conclusion, multidetector Computed tomography plays an important role is the assessment of various anatomical variants of the paranasal sinuses and nasal cavity. Pre-operative MDCT of Paranasal sinuses, gives the surgeons most if not all of the anatomical information they need to tailor surgeries. Considering the relatively high frequency of occurrence of these variants, it is essential for the radiologists to have a precise knowledge of imaging features of normal anatomy and anatomical variants of Paranasal sinuses.

Reliability in detection and differentiation between calcification and hemorrhage by 3 d GRE/ SWI technique compared to CT

This study was conducted to evaluate the sensitivity of Magnetic Resonance (MR) Susceptibility- Weighted Imaging (SWI) and also to compare the sensitivity of Magnetic Resonance (MR) susceptibility-Weighted Imaging (SWI) and Computed Tomography (CT), such that SWI can replace the use of CT as a standard protocol in the detection and differentiation between calcification and hemorrhage. A series of 70 patients included in this study with clinical suspicion or known history of intracranial hemorrhage/ calcifications for follow up, were scanned using both Philips Multiva 1.5T (MRI/SWI) and Philips Ingenuity 128 slice (CT). Results showed that SWI had 100% relative sensitivity, as it was able to detect both hemorrhage and calcifications in all the cases identified in CT. In addition, SWI detected hemorrhage in 2 additional cases that were nonspecific in CT. Furthermore, SWI detected signal from micro bleeds, which was missed on CT in three cases, and also detected calcification in two cases, which were not positively identified in CT. In conclusion, Susceptibility- Weighted Imaging (SWI) is highly sensitive for the detection and differentiation of hemorrhage and calcifications using Phase reconstructed images compared to conventional MRI methods and Computed Tomography