Efficacy of High Frequency Ultrasound in Localization and Characterization of Orbital Lesions.
BACKGROUND
The complicated anatomy of orbit and the wide spectrum of pathological conditions present a formidable challenge for early diagnosis, which is critical for management. Ultrasonography provides a detailed cross sectional anatomy of the entire globe with excellent topographic visualization and real time display of the moving organ.


OBJECTIVE
To evaluate the efficacy of high frequency Ultrasound in localization of orbital diseases and to characterize various orbital pathologies sonologically.


METHODS
Hundred eyes of 85 patients were examined with ultrasound using linear high frequency probe (5 to 17 MHz) of PHILPS IU22 ultrasound system. Sonological diagnosis was made based on location, acoustic characteristics, kinetic properties and Doppler flow dynamics. Final diagnosis was made based on clinical & laboratory findings/higher cross-sectional imaging/surgery & histopathology (as applicable). Diagnostic accuracy of ultrasonography was evaluated and compared with final diagnosis.


RESULTS
The distinction between ocular and extraocular pathologies was made in 100% of cases. The overall sensitivity, specificity, NPV and accuracy of ultrasonography were 94.2%, 98.8%, 92.2% & 94.9% respectively for diagnosis of ocular pathologies and 94.2%, 99.2%, 95.9% & 95.2% respectively for extra ocular pathologies.


CONCLUSIONS
Ultrasonography is a readily available, simple, cost effective, non ionizing and non invasive modality with overall high diagnostic accuracy in localising and characterising orbital pathologies. It has higher spatial and temporal resolution compared to CT/MRI. However, CT/MRI may be indicated in certain cases for the evaluation of calcifications, bony involvement, extension to adjacent structures and intracranial extension.
Assistant Professor, Department of Radiodiagnosis, P K Das Institute of Medical Sciences , Palakkad, Kerala, India .
Rashmi M
RM
Nagaraju
Professor, Department of Radiodiagnosis, Siddhartha Medical College , Tumkur, Karnataka, India .
G
G
Gurushankar
Senior Resident, Department of Radiodiagnosis, P K Das Institute of Medical Sciences , Palakkad, Kerala, India .
Bhimarao
Consultant, Brindavan Hospital , Mysore, Karnataka, India .
Bindushree
B
Kadakola
CT; Colour doppler; MRI