Role of Multidetector Computed Tomography in Differentiation of Benign and Malignant Cavitary Lung Lesions With a Histopathological Correlation: A Retrospective Cross-Sectional Study.

Introduction Cavitary lung disease has a wide range of differential diagnoses, which include both benign and malignant lesions. Imaging differentiation of benign from malignant cavitary lesions has always been a challenge due to overlapping imaging findings. The present study describes the most accurate multidetector computed tomography (MDCT) findings that could help in differentiating benign from malignant conditions in correlation with the histopathological reports. Methods This retrospective study was carried out on diagnosed cases of cavitary lung lesions on MDCT from January 2022 to February 2023. We evaluated the number of cavitary lung lesions, their location with respect to lung segment/lobe, the maximum diameter of the largest lesion, the maximum wall thickness of the largest cavity, and additional findings associated with these lesions. Measurements of the maximum wall thickness were plotted on a graph. Statistical analysis was done, and a receiver operating characteristic curve (ROC) was calculated to find the accurate cut-off wall thickness for malignant and non-malignant lesions. These findings were then correlated with the histopathological report. Results A review of the MDCT scans of 47 patients was done; 30 (63.8%) of those were male with a mean age of 47.93±14.68 (SD) years while 17 (36.2%) were female with a mean age of 52.53 ±18.38 (SD) years. Out of 47 patients, 27 (57.4%) had benign lesions and 20 (42.5%) had malignant lesions. Significant differences (p<0.05) were found between benign and malignant lesions while comparing the averages of maximum wall thickness (8.1 mm and 14.5 mm, respectively) and the irregular inner margin of the largest cavitary lesions. The presence of consolidation and centrilobular nodules correlated significantly (p<0.05) with the benign nature of cavitary lung lesions. The maximum cut-off wall thickness was <6 mm and >17 mm for the differentiation of benign from malignant lung lesions, respectively. Conclusions The maximum wall thickness and irregular inner margin of cavitary lung lesions was a good indicator for the differentiation of benign and malignant etiologies on MDCT while consolidation and centrilobular nodules favoured the benign etiology more.

Primary pancreatic lymphoma-diagnosed on computed tomography: A rare case report.

Primary pancreatic lymphoma is a rare disease. It comprises less than 0.5 % of pancreatic neoplasm and 0.1% of malignant lymphoma. It should be differentiated from pancreatic adenocarcinoma because management differs. At computed tomography, 2 types of morphology of primary pancreatic lymphoma have been described- a localized well-circumscribed tumoral form and another diffuse enlargement infiltrating or replacing most of the pancreatic gland. Here, we are presenting computed tomography (CT) imaging features of a case of primary pancreatic lymphoma in a 27 year old female who presented with a complaint of abdominal pain radiating to the back for 3 months and yellowish discoloration of sclera and skin for the last 15 days. In contrast-enhanced computed tomography an exophytic homogenously hypoenhancing mass arising from head and neck region of pancreas was seen. Involvement of common bile duct (CBD) and duodenum was there. The main pancreatic duct was not dilated. Common hepatic artery was encased by mass without arterial luminal narrowing or distortion. Diagnosis of primary pancreatic lymphoma was suggested on basis of imaging findings and further confirmed with fine-needle aspiration cytology.

Quantitative Extra Long PCR to Detect DNA Lesions in Patients Exposed to Low Doses of Diagnostic Radiation

Background: Radiation causes oxidative lesions and strand breaks in DNA of exposed cells. Extended length PCR is a reliable method for assessing DNA damage. Longer DNA strands with DNA damage are difficult to amplify compared to smaller DNA strands by PCR. The present study was aimed to evaluate DNA damage caused by ionising radiation exposure in therapeutic and diagnostic medicine. Materials and Methods: The study group comprised 50 cases with low dose single exposure (LDS), low dose multiple exposure (LDM) and low dose angiography (LDA) which were compared with 25 high dose controls (HDC) and 25 controls with no exposure (NEC). Blood samples were collected within 1 hour of radiation exposure. DNA was isolated using a kit based protocol, 50 ng aliquots of DNA were used to amplify a long 13kbp DNA fragment of the ß-actin gene by conventional PCR and band intensity was then quantified. Relative amplification was calculated and damage was expressed in terms of lesions per kilobase (kbp) by assuming a Poisson distribution. Result: Relative amplification was found to be 1.0, 0.87, 0.86, 0.72 and 0.69 with NEC, LDS, LDM, LDA and HDC groups, respectively. Cases undergoing angiography as well as high dose controls had high values, compared to NEC. The lesions/kbp calculated for LDS was 0.13, for LDM 0.15, for LDA 0.32 and for HDC 0.37 suggesting a linear increase in quantity with increasing radiation dose. Conclusion: DNA damage, even at low doses of radiation can be assessed by quantitative extra long PCR.

Flow cytometric detection of gamma-H2AX to evaluate DNA damage by low dose diagnostic irradiation.

INTRODUCTION: γH2AX assay has been used for DNA damage assessment at higher doses of radiation exposure. Its expression has not been studied in cases with diagnostic low dose radiation exposure. Concerns have been raised about the after-effects of radiation in diagnostic procedures like Computed Tomography (CT) scan, Angiography etc especially when such scans are repeated within short span of time. The purpose of the present study was to assess immediate DNA damage after exposure to low level of ionizing radiation by the flow cytometric method of gamma-H2AX. MATERIAL AND METHODS: Study sample includes total 60, cases and controls with two groups Group I-Normal controls (n = 15); Group II-Low dose, further divided in three groups: Group IIA-single CT scan (n = 15); Group IIB-Multiple CT scans (n = 15); and Group IIC-angiography single exposure (n = 15). For Low dose group blood was collected within 1 h after exposure in EDTA vaccutainers and immediately kept on ice. Lymphocytes were isolated and were fixed in 80% chilled ethanol and stored at -20 °C till further analysis. The H2AX assay was done and 10,000 cells were analysed for gamma H2AX positivity in flowcytometer. RESULTS: Significant gamma-H2AX positivity was found in cases versus control, the most significant DNA damage amongst cases was observed in cases with multiple CT scans. CONCLUSION: The exposure to multiple CT scans causes more double strand breaks as compared to single scan. DNA damage can be studied by flow cytometric analysis of gamma-H2AX in human peripheral lymphocytes.

Proton NMR metabolic profiling of CSF reveals distinct differentiation of meningitis from negative controls.

BACKGROUND: Cerebrospinal fluid (CSF) is an essential bio-fluid of the central nervous system (CNS), playing a vital role in the protection of CNS and performing neuronal function regulation. The chemical composition of CSF varies during onset of meningitis, neurodegenerative disorders (positive controls) and in traumatic cases (negative controls). METHODS: The study design was broadly categorized into meningitis cases, negative controls and positive controls. Further differentiation among the three groups was carried out using Principal Component Analysis (PCA) followed by supervised Partial Least Square Discriminant Analysis (PLS-DA). RESULTS: The statistical analysis of meningitis vs. negative controls using PLS-DA model resulted in R2 of 0.97 and Q2 of 0.85. There was elevation in the levels of ketone bodies, total free amino acids, glutamine, creatine, citrate and choline containing compounds (choline and GPC) in meningitis cases. Similarly, meningitis vs. positive controls resulted in R2 of 0.80 and Q2 of 0.60 and showed elevation in the levels of total free amino acids, glutamine, creatine/creatinine and citrate in the meningitis group. Four cases of HIV were identified by PLS-DA model as well as by clinical investigations. CONCLUSION: On the basis of metabolic profile it was found that negative control CSF samples are more appropriate for differentiation of meningitis than positive control CSF samples.