Background: Computed Tomography (CT) guided Fine Needle Aspiration Cytology (FNAC) is an established, safe, reliable and accurate procedure for cytological diagnosis of any intra-thoracic lesion which is deep seated and inaccessible by Ultrasonography (USG). Aims & Objectives: To study the sensitivity, specificity and diagnostic accuracy of CT guided FNAC and to correlate its diagnosis with histopathology (HP) in intrathoracic lesions. Materials & Methods: CT guided Fine Needle Aspirations (FNA) were performed in 63 patients with various intra-thoracic lesions during May 2009 to December 2011. Their cytological diagnosis was compared to HP diagnosis. True and false (positive and negative) data was analyzed to measure sensitivity, specificity and diagnostic accuracy of CT guided FNAC. Results: Out of 63 cases, adequate material was aspirated in 59 cases (Sample adequacy 93.7 %.) so remaining 4 cases were excluded from study. Maximum cases were from Lung (39) followed by Mediastinum (9), Pleura (6) and Vertebral & Para-spinal region (5). FNAC was diagnostic in all 59 cases which had adequate material. Among which, 40 (67.8 %) cases were malignant and 19 (32.2%) were benign. HP correlation was available in 37 (62.7%) cases. HP diagnosis was different from FNAC diagnosis in only 3 (8.1%) cases. Diagnostic accuracy of CT guided FNAC was 91.8% with 90.3% sensitivity and 100% specificity. Conclusion: Having high sensitivity, specificity and diagnostic accuracy, CT guided FNAC is an OPD based safe, reliable and accurate diagnostic procedure for various intrathoracic lesions which are inaccessible by USG. It helps the clinician to select the treatment modality avoiding costly surgical biopsies and unnecessary thoracotomy for diagnostic purposes.

Keywords: CT Guided; FNAC; Intra-Thoracic; Sensitivity; Specificity; Accuracy