Impact of fixed dental prosthesis on neuroimaging: assessment of artefacts.

Objectives: To determine the frequency and extent of artefacts in magnetic resonance imaging and/or computed tomography scans of head caused by fixed dental prosthesis. METHODS: The retrospective study was conducted at Aga Khan University Hospital from July to December 2021, and comprised magnetic resonance imaging and/or computed tomography scans from January 2015 to December 2020 of the head of individuals with existing fixed dental prosthetic work at the time of exposure. They were analysed for the presence of artefacts. The association between artefacts and the presence of fixed dental prosthesis was explored. Data was analysed using SPSS 23. RESULTS: Of the 297 images evaluated, 173 (58%) were magnetic resonance imaging scans, and 124(42%) were computed tomography scans. The most common artefacts was grade I 148(49.8%), followed by grade II 140(47.1%) and grade III 9(3%). There was no significant association between fixed dental prosthesis and the artefacts (p>0.05). Conclusion: There should be no reservations in placing fixed metal prosthesis in individuals on account of future brain scans.

Frequency of cd44 expression in diagnosed cases of oral Epithelial dysplasia and squamous cell carcinoma.

Background: Oral cavity cancer is one of the most widespread head and neck cancers in the world. 90 percent of oral cavity cancers are squamous cell carcinoma (SCC). Oral Potentially Malignant Disorder (OPMD), are well known to develop into squamous cell carcinoma. CD44 is a glycoprotein present on the cell surface and plays a vital role in cancer cell invasion, migration, metastasis of cancers and prognosis. The present study aims to detect the frequency of CD44 immunomarker expression in epithelial dysplasia and squamous cell carcinoma samples and correlates the expression with histologic grades of this lesion. Methods: Cross sectional study at the Department of Pathology, BMSI, JPMC, Karachi between 01-01-2018 to 31-12-2021. 95 patients diagnosed on morphological characterization of the lesion as squamous cell carcinoma/dysplasia were selected by using non-probability purposive sampling technique, among them 41 were diagnosed as epithelial dysplasia and 54 as SCC and were subjected to immunohistochemistry. Results: A total of 95 cases were selected. The mean age was 49.32 years. The majority of cases were seen in 4th and 5th decades. 69 (72.6%) were males and 26 (27.4%) were females with male to female ratio 2.65:1. The closest site was buccal mucosa 75(78.9%). Among 41 cases of dysplasia, 36 showed membranous positivity for CD44 (87.8%), and 45 showed positive membranous CD44 immunoreactivity (83.3%) among 54 cases of squamous cell carcinoma. Conclusion: Increased frequency of CD44 expression was found with increasing grades of dysplasia and squamous cell carcinoma, which may be a possible indicator of malignant transformation and can serve as a prognostic biomarker for oral SCC.

Paediatric posterior reversible encephalopathy syndrome: is there an association of blood pressure with imaging severity and atypical magnetic resonance characteristics?

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is relatively uncommon in paediatric patients; however, its pathophysiology remains obscure. OBJECTIVE: The aims of this study were to find an association or correlation between (1) blood pressures and (2) imaging severity and the presence of atypical imaging features in children with PRES. MATERIALS AND METHODS: We performed a retrospective cross-sectional evaluation in children diagnosed with PRES. We reviewed radiologic findings along with each patient's clinical profile and outcome. We categorised imaging severity into mild, moderate and severe, and assessed the MR imaging pattern, enhancement and diffusion restriction for each child. We assessed both associations and correlations between variables using the chi-square test, Cramer V and Kendall tau b. RESULTS: A total of 63 children met the inclusion criteria (31 boys; mean age 9.7 years). A total of 42 children (67%) had an elevated blood pressure. Imaging showed parieto-occipital lobe involvement pattern in 24 (38%) children, frontal lobe pattern in 25 (40%) and cerebellar involvement in 12 (19%). Three (5%) had haemorrhage, 15 (24%) had contrast enhancement and 19 (30%) had positive diffusion restriction (cytotoxic oedema). We found no statistically significant association between imaging severity and blood pressures (P=0.11), nor any association between blood pressure and atypical imaging findings such as diffusion restriction (P=0.1), enhancement (P=0.11) or haemorrhage (P=0.33). CONCLUSION: According to our results, there is no statistically significant association or correlation between blood pressure and either imaging severity or atypical imaging features in children with PRES. Further prospective studies are warranted.

Bilateral Cerebral Hemorrhagic Infarctions: An Early Presentation of Carbon Monoxide Poisoning.

Carbon monoxide (CO) poisoning is one of the most common causes of morbidity secondary to accidental or intentional exposure. It is a potentially life-threatening disease. We present the case of a 23-year-old male patient who slept with a gas generator the whole night in a closed room. The next morning the patient presented to emergency with altered mentation. His Glasgow Coma Scale score was 8/15 on arrival. The patient had cerebral hemorrhages on presentation with diffuse cerebral hypoxic injury and bilateral globus pallidus signals. Hemorrhagic infarction in the brain is a rare presentation of CO poisoning and even rarer as an early manifestation of this disease. We present a case of bilateral posterior cerebral hemorrhagic infarctions with a diffuse hypoxic insult as an early presentation of CO poisoning in a young male, which to our knowledge has rarely been reported. Early imaging and prompt medical attention can be life-saving.

The association of chest radiographic findings and severity scoring with clinical outcomes in patients with COVID-19 presenting to the emergency department of a tertiary care hospital in Pakistan.

INTRODUCTION: While chest x-rays (CXRs) represent a cost-effective imaging modality for developing countries like Pakistan, their utility for the prognostication of COVID-19 has been minimally explored. Thus, we describe the frequency and distribution of CXR findings, and their association with clinical outcomes of patients with COVID-19. METHODS: All adult (≥ 18 years) patients presenting between 28th February-31st May to the emergency department of a tertiary care hospital in Pakistan, who were COVID-19 positive on RT-PCR with CXR done on presentation, were included. A CXR Severity Score (CXR-SS) of 0-8 was used to quantify the extent of pulmonary infection on CXR, with a score of 0 being negative and 1-8 being positive. The patients' initial CXR-SS and their highest CXR-SS over the hospital course were used for analysis, with cut-offs of 0-4 and 5-8 being used to assess association with clinical outcomes. RESULTS: A total of 150 patients, with 76.7% males and mean age 56.1 years, were included in this study. Initial CXR was positive in 80% of patients, and 30.7% of patients had an initial CXR-SS between 5-8. The mortality rate was 16.7% and 30.6% patients underwent ICU admission with intubation (ICU-Int). On multivariable analysis, initial CXR-SS (1.355 [1.136-1.616]) and highest CXR-SS (1.390 [1.143-1.690]) were predictors of ICU-Int, and ICU-Int was independently associated with both initial CXR-SS 5-8 (2.532 [1.109-5.782]) and highest CXR-SS 5-8 (3.386 [1.405-8.159]). Lastly, age (1.060 [1.009-1.113]), initial CXR-SS (1.278 [1.010-1.617]) and ICU-Int (5.047 [1.731-14.710]), were found to be independent predictors of mortality in our patients. CONCLUSION: In a resource-constrained country like Pakistan, CXRs may have valuable prognostic utility in predicting ICU admission and mortality. Additional research with larger patient samples is needed to further explore the association of CXR findings with clinical outcomes.