RESUMEN
Purpose: The aim of the study was to compare the image noise, radiation dose, and image quality of ultra-low-dose computed tomography (CT) and standard CT in the imaging of pulmonary pathologies. Material and methods: This observational study was performed between July 2020 and August 2021. All enrolled patients underwent both ultra-low-dose and standard CTs. The image noise, image quality for normal pulmonary structures, presence or absence of various pulmonary lesions, and radiation dose were recorded for each of the scans. The findings of standard-dose CT were regarded as the gold standard and compared with that of ultra-low-dose CT. Results: A total of 124 patients were included in the study. The image noise was higher in the ultra-low-dose CT compared to standard-dose CT. The overall image quality was determined to be diagnostic in 100% of standard CT images and in 96.77% of ultra-low-dose CT images with proportional worsening of the image quality as the body mass index (BMI) range was increased. Ultra-low-dose CT offered higher (> 90%) sensitivity for lesions like consolidation (97%), pleural effusion (95%), fibrosis (92%), and solid pulmonary nodules (91%). The effective radiation dose (mSv) was many times lower in ultra-low-dose CT when compared to standard-dose CT (mean ± SD: 0.50 ± 0.005 vs. 3.99 ± 1.57). Conclusions: The radiation dose of ultra-low-dose chest CT was almost equal to that of a chest X-ray. It could be used for the screening and/or follow-up of patients with solid pulmonary nodules (> 3 mm) and consolidation.
RESUMEN
Purpose: The aim of our study was to prospectively evaluate the role of third-generation, dual-source, dual-energy computed tomography (DECT) in the characterization of renal calculi, with ex vivo renal stone evaluation using Fourier transform infrared spectroscopy (IS) as the reference standard. Material and methods: In our study 50 patients with history suggestive of renal calculi were subjected to DECT using 100 kVp and Sn150 kVp. With DECT, renal stone attenuation at low and high kVp was attained, and the attenuation ratios were measured. The result of DECT was compared with IS to identify the chemical composition of the extracted renal stones. IBM SPSS version 22 was used for statistical analysis. Results: In our study, the mean attenuation ratio of the renal stone was 1.57 ± 0.25. Out of 50 patients, the stones of 39 patients were predicted as calcium-containing stones, in 4 patients as cystine stones, and in 7 as uric acid stones on DECT. In IS analysis, 43 patients had calcium-containing stones, and 7 patients had uric acid stones. The accuracy rate of DECT for detecting calcium and uric acid stones in our study were 90% and 100%, respectively. The positive predictive value for the DECT to assess the chemical composition of renal calculi was found to be 92%. Conclusions: Third-generation DECT scan had 100% accuracy in differentiating uric acid stones from non-uric acid stones in our study. Because the treatment is different for different chemical compositions of stones, identification of specific chemical components is very important, and it can be accurately done by DECT.
RESUMEN
PURPOSE: Our study aimed to compare the sensitivity of T2 relaxometry and positron emission tomography - computed tomography (PET/CT) in patients with a history suggestive of mesial temporal lobe epilepsy using video electroencephalography (EEG) as the reference standard. MATERIAL AND METHODS: In our study, 35 patients with a history suggestive of mesial temporal lobe epilepsy were subjected to conventional magnetic resonance imaging (MRI), T2 relaxometry, and PET/CT. The results of each of the studies were compared with video EEG findings. Analyses were performed by using statistical software (SPSS version 20.0 for windows), and the sensitivity of conventional MRI, T2 relaxometry, and PET/CT were calculated. RESULTS: The sensitivity of qualitative MRI (atrophy and T2 hyperintensity), quantitative MRI (T2 relaxometry), and PET/CT in lateralizing the seizure focus were 68.6% (n = 24), 85.7% (n = 30), and 88.6% (n = 31), respectively. CONCLUSIONS: The sensitivity of MRI in lateralization and localization of seizure focus in temporal lobe epilepsy can be increased by adding the quantitative parameter (T2 relaxometry) with the conventional sequences. T2 Relaxometry is comparable to PET/CT for localization and lateralization of seizure focus and is a useful tool in the workup of TLE patients.
RESUMEN
PURPOSE: To prospectively estimate the reliability of B-mode ultrasonography and sonoelastography in differentiating benign and malignant cervical lymph nodes with cytological findings as to the reference standard. MATERIALS AND METHODS: A total of 50 patients referred for sonography for enlarged cervical lymph nodes were included in the study. They were subjected initially to B-mode ultrasonography and sonoelastography and later underwent fine-needle aspiration cytology (FNAC) in the same sitting. Sensitivity, specificity, and accuracy were compared. RESULTS: Out of 50 cases, 33 were males, and 17 were females. On B-mode ultrasonography, 15 enlarged cervical lymph nodes were benign-looking and 35 were malignant-looking. When studied on elastography, 12 were benign-looking and 38 showed features of malignancy. However, when studied histopathologically, 18 were benign and 32 were malignant. The sensitivity, specificity, and diagnostic accuracy were compared, and the results were better in sonoelastography than B-mode ultrasonography. When both B-mode and sonoelastography were combined, an increase in the sensitivity for differentiation was achieved. However, a decrease in specificity was noted when both modalities were combined in our study, probably due to a significant number of patients with tuberculous cervical lymphadenopathy. CONCLUSION: In countries like India, where granulomatous infection like tuberculosis is prevalent, the combination of sonoelastography with B-mode ultrasonography has decreased specificity in the differentiation of benign and malignant cervical lymph nodes, and histopathology is always needed for the final confirmation of diagnosis. The decreased specificity on elastography is attributed to simultaneous coexisting inflammation and fibrosis in chronic granulomatous lymphadenopathy.