Evaluation of variations of optic nerve course in relation to posterior paranasal sinuses in MDCT in a tertiary care center of Nepal: a retrospective cross-section study.

Background: The proximity of optic nerves to the posterior paranasal sinuses (PNS) is a critical consideration in preventing optic nerve injuries during functional endoscopic sinus surgery. Methods: A retrospective cross-sectional study was conducted on 367 patients aged 13 years and above. Four radiologists, each with 2-6 years of experience, evaluated computed tomography scans of the PNS and the head of these patients. The optic nerves were classified into four types based on DeLano's classification, and their respective prevalence rates were determined. Additionally, the prevalence of optic nerve dehiscence and pneumatization of the anterior clinoid process was assessed. Results: A total of 734 optic nerves were evaluated and categorized into four groups as per DeLano's classification. The most common type was classified as type 1 optic nerve, representing 65.4% of all optic nerves. Types 2, 3, and 4 optic nerves accounted for 16.9, 8.6, and 9.1%, respectively. The prevalence rates of type 1, type 2, type 3, and type 4 optic nerves were 76.6, 24.5, 12.3, and 14.4%, respectively. Optic nerve dehiscence was observed in 14.3% of cases, with a prevalence of 21.2% in the study. Type 3 optic nerves were most commonly associated with dehiscence, with 49.2% of them showing dehiscence in their course through the ethmoid or sphenoid sinus. The prevalence of pneumatization of the anterior clinoid process in the study population was 28.3%, with type 3 optic nerves being the most frequently associated. Conclusion: An understanding of the relationship between optic nerves and posterior PNS, as well as awareness of optic nerve dehiscence, is essential in preventing injuries during sinus surgeries. Type 1 optic nerve predominates among Nepalese patients visiting our hospital.

Delayed presentation of congenital sigmoid colon stenosis: a rare entity.

Congenital sigmoid colon stenosis is a rare entity that can mimic Hirschsprung disease. Presentation of congenital colon stenosis is usually within first few weeks of life. Our case presented with features of distal bowel obstruction at 2 years of age with the history of chronic constipation and progressive abdominal distention from first week of life and bilious vomiting for the last 1 week. Clinical diagnosis of Hirschsprung disease was made. Contrast enhanced CT abdomen showed bowel obstruction with transition point at the level of proximal sigmoid colon. There was a short segment stenosis at the level of proximal sigmoid colon. Contrast enema showed stenosis at proximal sigmoid colon. The bowel distal to stenosis was normal in calibre. Similar findings were seen during surgery. Mesocolon was present in stenosed segment of the bowel. The resected stenotic segment showed adequate ganglion cells in histopathology.

Von Hippel Lindau Disease with central nervous system and multiple visceral manifestations: A case report.

Von Hippel-Lindau (VHL) disease is an autosomal-dominant syndrome caused by mutations in the VHL gene, located on the short arm of chromosome 3. Patients with VHL are likely to manifest with a spectrum of multiple benign and malignant tumors involving various organ systems. We present a case of a 28-year-old female without a remarkable family history who presented with complaints of hematuria and abdominal discomfort. Initial laboratory investigations confirmed hematuria. Subsequent abdominal computed tomography scan revealed heterogeneous enhancing solid mass in bilateral kidneys, avidly enhancing mass in the right adrenal gland, bilateral simple renal cortical cysts, and a pancreatic cyst. With a provisional diagnosis of VHL disease, an MRI of the brain and spine was performed, which showed the presence of a cerebellar hemangioblastoma. Her catecholamine and vanillylmandelic acid levels were in the normal range not in line with pheochromocytoma. The patient then underwent bilateral partial renal nephrectomy and right adrenalectomy. Histopathologic examination reported clear renal cell carcinoma and pheochromocytoma of the right adrenal gland mass. Molecular genetic testing confirmed the presence of VHL disease.

Pituitary stalk interruption syndrome: A case report.

Pituitary stalk interruption syndrome (PSIS) is a rare congenital abnormality. It comprises the triad of thin or interrupted pituitary stalk, aplasia or hypoplasia of anterior pituitary gland, and absent or ectopic posterior pituitary gland. The patient usually presents with a spectrum of symptoms predominantly secondary to anterior pituitary hormonal deficiency. The etiology of this syndrome is not well-established but the genetic cause is considered to be the most common etiology. Early diagnosis is crucial in preventing and reducing morbidity. The prognosis is good if the condition is diagnosed early and the hormonal therapy is started promptly. The diagnosis of PSIS is primarily based on magnetic resonance imaging (MRI) findings.

Computed Tomography Chest Findings in COVID-19 Patients.

BACKGROUND: COVID-19 which has caused significant morbidity and mortality around the world has been declared by the World Health Organization to be a global health emergency. Our objective was to find out the lung parenchymal patterns commonly evident in high resolution Computed Tomography in patients with COVID-19 pneumonia. METHODS: A retrospective cross-sectional study was conducted at a tertiary multi-specialty hospital in Kathmandu, Nepal. With ethical clearance from the institutional review board, a total of 235 patients with positive reverse transcriptase polymerase chain reaction for COVID-19 and having respiratory symptoms were included in the study. High Resolution Computed Tomography images of chest were retrieved from picture archiving and communication systems retrospectively and studied for the findings commonly attributed to COVID-19 pneumonia. The data was then analyzed using Stata version 14 (Stata Corp, College Station, TX, USA). Descriptive statistics were presented as mean and median while chi-square test was used to assess the association between socio-demographic characteristics and CT severity indices. RESULTS: Out of 235 patients, 174 (74.0%) were males and 61(26%) were females with a mean age of 54.8±14.5 years. The most commonly encountered pattern of pulmonary changes was bilateral involvement in 222 (94.5%) patients followed by ground-glass opacities in 218 (92.8%) patients and peripheral predominance of ground-glass opacities in 211 (89.8%) patients. CONCLUSIONS: Chest Computed Tomography abnormalities are common in COVID-19 positive patients with respiratory symptoms. These findings can guide in the assessment of the severity of the disease as well as patient management.

Multiparametric MRI Evaluation of Complex Ovarian Masses.

OBJECTIVE: To assess the role of diffusion-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging in the categorization of complex ovarian masses into benign and malignant. MATERIALS AND METHODS: This prospective study was done on 33 complex ovarian masses. T1 and T2-weighted sequences, diffusion-weighted imaging, apparent diffusion coefficient, and dynamic contrast-enhanced magnetic resonance imaging were performed on 1.5 T MRI. Time-intensity curves, tissue signal intensity on unenhanced T1 images (SI0), maximum absolute contrast enhancement (SImax), time to reach SImax (Tmax), maximum relative SI (SIrel = [SImax - SI0]/SI0 ×100), maximum Slope (Slopemax = SIrel/Tmax ×100), and wash in rate (WIR = [SImax - SI0]/Tmax) were calculated. Histopathological diagnosis was taken as gold standard. RESULTS: A total of 20/33 masses were benign, 2/33 were borderline tumors, and 11/33 were malignant. Diffusion restriction was seen in all malignant masses and 13/20 benign masses. The mean apparent diffusion coefficient values showed a significant difference between malignant and benign, with 81.8% sensitivity and 63.6% specificity. Type III curve showed 100% specificity for malignant lesions. Tmax and Slopemax were useful in differentiating benign and malignant masses; with Tmax cut-off at 73.5 seconds having a high specificity (81.8%) and Slopemax cut-off at 0.83%/s having high sensitivity (91%) and negative predictive value (94.4%). CONCLUSION: Multiparametric MRI confers high diagnostic accuracy in stratifying complex ovarian masses.

Mechanical Thrombectomy for Basilar Artery Occlusion Stroke: A Case Report.

Posterior circulation strokes are potentially devastating events that carry a significant risk of morbidity and mortality. Acute basilar artery occlusion stroke is a rare posterior circulation stroke that needs emergent management. We report the case of a 67-year-old woman who developed an acute basilar artery occlusion. We achieved complete recanalization of the occluded basilar artery and its branches with endovascular mechanical thrombectomy. It is possible to achieve excellent results with mechanical thrombectomy in acute basilar artery occlusion if timely diagnosis and reperfusion can be done. We are not aware of any previous publication from Nepal describing this technique in acute basilar artery occlusion.

The First Successful Endovascular Management of Posterior Fossa Arteriovenous Malformations in Nepal: Case Series.

Posterior fossa arteriovenous malformations represent 7-15% of all intracranial AVMs. They carry a higher risk of rupture than supratentorial AVMs and are associated with considerable rates of morbidity and mortality. Available treatment options include conservative management, microsurgical resection, radiosurgery, endovascular embolization, or combinations of these modalities. Recent advances in endovascular techniques have revolutionized their management with better clinical outcomes. We illustrate two cases of posterior fossa AVMs treated by endovascular techniques with good clinical outcomes. The first patient also had associated flow-related aneurysms. One of these aneurysms had already ruptured, so it was coiled first followed by AVM nidus embolization using the same microcatheter. The second patient had a diffuse type of posterior fossa AVM for which staged-embolization was planned and the first-stage partial embolization was successfully performed.