Role of Combined CT Pulmonary Angiography and Indirect CT Venography in Diagnosing Venous Thromboembolism in COVID-19 Patients - Experience From an Indian Quaternary Centre.

OBJECTIVES: To study the role of combined CTPA and indirect CT venogram to diagnose venous thromboembolism (VTE) in patients with COVID-19 pneumonia and to compare the clinical characteristics, laboratory parameters, CT findings and clinical outcomes between the VTE positive and negative groups. METHODS: In this retrospective study, 131 patients with COVID-19 pneumonia who underwent CTPA and venogram between August 2020 and January 2021 were included. Relevant demographical, clinical and laboratory data and CT images were collected. Two thoracic radiologists independently reviewed the CTPA and venogram images. RESULTS: VTE was identified in 29 patients (22% of the study population). CT venogram identified DVT in 9 patients. No statistical difference was observed between the two groups with respect to age, gender, BMI and presence of comorbidities. There was a significant difference in the hospital stay duration, which is increased in the VTE positive group. The number of patients who were dependent on oxygen and mortality were also high in the positive group. There was statistically significant difference in the mean D-dimer value and the mean Neutrophil/lymphocyte ratio, which were higher in the VTE positive group. CONCLUSION: Combined CTPA and venogram can be used as a one-stop investigation for diagnosing PE and DVT of lower limbs in patients with COVID-19 pneumonia. CTPA with venogram should be performed in patients with D-dimer value in the range of 1000 - 1200 µg/L and above to rule out VTE as the hospital stay duration and final outcomes vary between the positive and negative groups.

Newly proposed classification of celiac artery variations based on embryology and correlation with computed tomography angiography.

Purpose: We studied the prevalence of celiac trunk and its anatomical variations on diagnostic computed tomography angiography (CTA) studies and have proposed a new classification to define the celiac artery (CA) variations based on embryology. Material and methods: We retrospectively assessed the celiac trunk variations in 1113 patients who came to our department for diagnostic CTA for liver and renal donor workup. The patient data were acquired from the Picture Archiving and Communication System of our institutions. We analysed the celiac trunk's origin and branching pattern, including the superior mesenteric artery (SMA) and inferior phrenic artery (IPA). Results: We evaluated the CTA studies of 1050 patients. A normal trifurcation pattern, the most common type, was observed in 39% of cases. Variation with CA + left IPA was the most common subtype. Other variations noted in the study and their incidences are listed in the table below. We attempted to propose a new classification based on embryo-logy, which comprises 6 main types and their subtypes. We also analysed previous studies from the literature, including cadaveric, post-mortem, CTA, and digital subtraction angiography studies and compared them with the present study. Conclusions: Because variations of CA classifications reported to date do not encompass all CA branching pattern variants, we have proposed a new classification that incorporates most of the variants. We reiterate the clinical importance of anatomical variants of CA, IPA, and SMA in surgical and interventional radiology procedures.

Salmonella Bacteremia Causing Mycotic Pseudoaneurysm of Right Common Iliac Artery Complicated by Septic Caval Thrombosis.

Mycotic pseudoaneurysm (MPA) is a blind, saccular outpouching of the arterial lumen of infective origin. MPA is a rare life-threatening condition and if not treated early, has a 67% mortality rate due to sepsis and hemorrhage. Major predisposing factors are diabetes mellitus, chronic renal failure, malignancy, steroids, and intravenous drug use. Imaging modalities include Doppler ultrasound, contrast-enhanced computed tomography, and digital subtraction angiography. We report a unique case of Salmonella bacteremia-related MPA of the right common iliac artery complicated by septic inferior vena cava (IVC) thrombosis in a patient with uncontrolled diabetes. Such transcompartmental involvement of IVC has hitherto not been described in the literature and hence makes for interesting documentation. This case ponders upon the aggressiveness of the invasive nontyphoidal Salmonella infection pathogen and the need for early imaging of suspicious patients to reduce morbidity and mortality.

COVID-19 Associated Acute Necrotizing Pancreatitis with Normal Serum Amylase and Lipase Levels: Report of an Unusual Finding.

Coronaviruses are a large family of single-stranded RNA viruses infecting humans and animals, causing a multitude of symptoms. COVID-19 is not only known to affect the respiratory system, but shows unusual gastrointestinal complications. Pancreatitis can be caused by biliary stones, alcohol abuse, viruses, drug intake, metabolic syndromes, or trauma. Diagnosis of acute pancreatitis requires any two of the three criteria: acute onset of severe upper abdominal pain, consistent with pancreatitis; elevation of serum amylase or lipase, three times the upper limit of normal; and/or characteristic imaging findings. COVID-19 associated pancreatitis is thought to be mediated by the angiotensin-converting enzyme-2 receptor on the host cells, which are highly expressed in the pancreatic cells. Here, we report a unique case of acute necrotizing pancreatitis caused by COVID-19 with hyperglycemia and normal amylase and lipase levels.

Xanthogranulomatous pyelonephritis with calculus migration into the psoas abscess: an unusual complication.

Xanthogranulomatous pyelonephritis (XGP) is a rare variant of chronic pyelonephritis. It is characterized by progressive parenchymal destruction caused by chronic renal obstruction due to calculus, stricture, or rarely tumor, resulting in kidney function loss. Herein, we describe the case of a 36-year-old female who presented with left loin pain, left lower limb pain, and dysuria. On contrast-enhanced computed tomography (CECT), multiple abscesses and an obstructive staghorn calculus were depicted in the left kidney with the classical appearance of "Bear Paw Sign." An abscess with calculi was also present within the left psoas muscle. Though psoas muscle abscess in association with XGP was described, a ureteric fistula and calculi within the psoas muscle have not yet been reported in the literature. Left nephrostomy was performed, which came out to be positive for E. coli on culture. The patient underwent left nephrectomy, and the histopathological report of the surgical specimen confirmed XGP.

Systemic arterio-venous thrombosis in COVID-19: A pictorial review.

Coronavirus disease 2019 (COVID-19) is caused by the novel coronavirus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Systemic complications include cardiovascular, neurological, hepatic, renal and altered coagulation. Derangements in haemostasis with SARS-CoV-2 infection have been termed COVID-19 associated coagulopathy (CAC). CAC is postulated to be one of the significant causes for sudden deaths in this pandemic, with infection of endothelial cells and subsequent endotheliitis through angiotensin-converting enzyme-2 receptors playing a key role in the pathogenesis. In this pictorial review, we describe the imaging findings in a multitude of extrapulmonary arterial (aorta, cerebral, mesenteric, renal and peripheral arterial system) and venous thrombotic phenomena detected on contrast-enhanced computed tomography and magnetic resonance imaging of COVID-19 patients which could not be attributed to any other causes. Knowledge of incidence of these complications, lowering the threshold for diagnostic imaging in symptomatic patients and timely radiological detection can play a vital role in subsequent management of these critically ill patients.

Xanthogranulomatous pyelonephritis with calculus migration into the psoas abscess: an unusual complication

Xanthogranulomatous pyelonephritis (XGP) is a rare variant of chronic pyelonephritis. It is characterized by progressive parenchymal destruction caused by chronic renal obstruction due to calculus, stricture, or rarely tumor, resulting in kidney function loss. Herein, we describe the case of a 36-year-old female who presented with left loin pain, left lower limb pain, and dysuria. On contrast-enhanced computed tomography (CECT), multiple abscesses and an obstructive staghorn calculus were depicted in the left kidney with the classical appearance of "Bear Paw Sign." An abscess with calculi was also present within the left psoas muscle. Though psoas muscle abscess in association with XGP was described, a ureteric fistula and calculi within the psoas muscle have not yet been reported in the literature. Left nephrostomy was performed, which came out to be positive for E. coli on culture. The patient underwent left nephrectomy, and the histopathological report of the surgical specimen confirmed XGP.

Imaging of Pharyngocele: An Occupational Overuse Syndrome.

Pharyngocele is a rare pathology of the pharynx caused by the laxity of the thyrohyoid membrane. Only about 60 true lateral pharyngocele cases have been reported in the literature over the last 133 years. Laryngocele is a close differential, and the two are difficult to tell apart. Though they have been described well in the literature, they are often misdiagnosed or interchangeably diagnosed. The acquired type of pharyngocele is due to prolonged increased intrapharyngeal pressure and pharyngeal wall weakness, and it is more common than congenital pharyngoceles. Close differential diagnoses include Zenker's diverticulum, laryngocele, and jugular venous phlebectasia. Acquired lateral pharyngoceles are seen in wind instrument musicians and glassblowers. Hence, these diverticula are described as 'overuse syndrome'. We present a case of bilateral neck swelling, which occurred doing the Valsalva maneuver with imaging studies.

Primary Hyperoxaluria-Imaging of Renal Oxalosis.

Primary Hyperoxaluria is a rare autosomal recessive hereditary disorder due to deficient alanine-glyoxylate aminotransferase enzyme with defective glyoxylate metabolism leading to excessive oxalate production and deposition into the tissues (oxalosis). Deposition of excessive calcium oxalates in nephrons leads to crystallization (nephrocalcinosis) which increases risk for end-stage renal disease. We are presenting a case of primary hyperoxaluria type I confirmed with genetic studies.

Alkaptonuria-an atypical case: multi-modality imaging review.

Alkaptonuria is a rare inborn metabolic disorder due to a mutation in the homogentisic acid oxidase enzyme (HGO) gene on chromosome 3q. As HGO is deficient in alkaptonuria patients, there is an accumulation of homogentisic acid in the blood and urine. Homogentisic acid gets deposited in the soft tissues, tendons, cartilages, large joints and intervertebral discs. Ochronosis usually affects the dorsolumbar spine and typically spares the cervical spine and sacroiliac joints. However, in this case of isolated ochronosis, we report co-existent extensive cervical spine degenerative changes and cervical vertebral fusion, which has not been described in the literature so far.