Anatomical variations in the circle of Willis on magnetic resonance angiography in a south Trinidad population.

Objectives: This article seeks to determine the prevalence of a complete circle of Willis (CoW) and its common morphological variations in a south Trinidad population, while also investigating the influence of gender, age, and ethnicity on CoW morphology. Methods: A prospective, descriptive, cross-sectional study was done on the magnetic resonance images for consecutive patients who had a brain MRI/magnetic resonance angiography at a tertiary health institution in south Trinidad between October 2019 and September 2020. Patients with significant cerebrovascular disease and/or a history of prior neurosurgical intervention were excluded. Results: A complete CoW was seen in 24.3%, with more complete circles observed in younger participants (≤45 years) and Afro-Trinidadians. No gender predilection for a complete CoW was demonstrated. The most common variations in the anterior and posterior parts of the circle were a hypoplastic anterior communicating artery (8.6%, n = 13) and bilateral aplastic posterior communicating arteries (18.4%, n = 28), respectively. Conclusions: Significant variations exist in the CoW of a south Trinidad population with a frequency of complete in 24.3%, and more complete circles in younger patients and Afro-Trinidadians. Gender did not influence CoW morphology. Advances in knowledge: Structural abnormalities in the CoW may be linked to future incidence of cerebrovascular diseases and should therefore be communicated to the referring physician in the written radiology report. Knowledge of variant anatomy and its frequency for a particular populations is also required by neurosurgeons and neuro-interventional radiologists to help with preprocedural planning and to minimize complications.

Lumbar Spine Anatomy in Supine versus Weight- Bearing Magnetic Resonance Imaging: Detecting Significant Positional Changes and Testing Reliability of Quantification.

STUDY DESIGN: Testing between and within group differences and assessing reliability of measurements. PURPOSE: To study and compare lumbar spine morphology in supine and weight-bearing (WB) magnetic resonance imaging (MRI). OVERVIEW OF LITERATURE: Upright lumbar MRI may uncover anatomical changes that may escape detection when using conventional supine imaging. This study quantified anatomical dimensions of the lumbar spine in the supine and WB MRI, compared specific morphometric differences between them, and tested the intra-rater reliability of the measurements. Repeated measures analysis was used to compare within- and between-session measurements performed on the supine and WB images. Reliability and agreement were assessed by calculating intraclass correlation (ICC) coefficient. METHODS: Data from 12 adults without any history of back pain were used in this study. Sagittal T2-weighted images of the lumbar spine were acquired in the supine and WB positions twice (in two separate sessions scheduled within a week). Linear, angular dimensions, and cross-sectional areas (CSAs) were measured using proprietary software. Supine and WB data acquired from the two imaging sessions were tested for intra-rater reliability. Quantified data were normalized for each session to test the significance of differences. ICC was calculated to test the reliability of the measurements. RESULTS: Linear, angular, and CSA measurements demonstrated strong within-position (supine and WB) correlations (r -values, 0.75-0.97). Between-position (supine vs. WB) differences were significant for all measured dimensions (p<0.05). Between-session measurements demonstrated a strong correlation (r -values, 0.64-0.83). Calculated ICC showed strong agreement among the measurements. CONCLUSIONS: Anatomical dimensions of the lumbar spine may demonstrate consistent and significant differences between supine and WB MRI for specific structural parameters.

Choledocholithiasis in Pregnancy: A Case Report.

Cholelithiasis during pregnancy and the postpartum period has an incidence of 12%, with pregnancy being an important risk factor for gallstones. Patients with choledocholithiasis can experience complications, such as obstructive jaundice, cholangitis, and pancreatitis, which may be detrimental to both mother and fetus. A case of cholelithiasis in a second-trimester pregnancy was complicated by choledocholithiasis and obstructive jaundice. Ultrasonography (US), magnetic resonance cholangiopancreatography (MRCP), along with serial blood tests, confirmed the diagnosis. Treatment was safely achieved using endoscopic retrograde cholangiopancreatography (ERCP). In pregnancy, complicated cholelithiasis is investigated using blood tests, ultrasonography, and cholangiography. Evidence supports the use of intraoperative or endoscopic cholangiography for the management of such complicated gallstone disease in pregnancy.

Missed myocardial infarction in a vicenarian with malignant anomalous right coronary artery causing acute coronary syndrome: a case report.

BACKGROUND: Traditional coronary artery disease risk factors are well established and help risk stratify most patients presenting with chest pain syndromes. Young patients (under age 30 years) without other risk factors are thought to be at very low risk of coronary artery disease and acute coronary syndromes. CASE PRESENTATION: We highlight the case of a 27-year-old Afro-Caribbean male who presented to hospital with chest pain and was discharged from the emergency room because he was thought to be low risk for ischemic heart disease. Laboratory investigations subsequently confirmed acute coronary syndrome. He was found to have an anomalous right coronary artery with a malignant origin running between the aorta and pulmonary artery eventually requiring surgical correction. Anomalous origins of the coronary arteries are rare causes of acute coronary syndromes, chest pain, and sudden cardiac death. CONCLUSION: Our patient could have easily had an adverse outcome as his diagnosis was missed by the initial treating physician. It is important to consider anomalous coronary artery origin in the evaluation of young symptomatic patients who may be otherwise low risk and not have traditional risk factors for ischemic heart disease.

Partial Anomalous Pulmonary Venous Connection: A Great Imitator?

In isolated partial anomalous pulmonary venous connections (PAPVCs), an abnormal vein connects venous blood from the pulmonary circulation to the systemic circulation, resulting in an extracardiac shunt. A single aberrant pulmonary vein (PV) is usually hemodynamically insignificant, and affected patients are generally asymptomatic. We describe a young Caribbean-Black woman with an isolated, singular PAPVC from the left inferior PV to the left innominate (brachiocephalic) vein that was hemodynamically significant, obfuscated by recurrent pleural effusions from catamenial pleural endometriosis.

The Quandary of the Quadricuspid Aortic Valve-The "Unlucky" 4-Leaf Clover: Case Report and Brief Clinical Review.

The quadricuspid aortic valve is an exceedingly rare congenital valvular anomaly, characterized by a tetrad of leaflets that typically presents with aortic regurgitation. Almost one third of cases are associated with coexisting cardiac defects with one fifth warranting surgical intervention. In this article, we describe the first documented-in-Caribbean case and present a brief clinical review of its pathophysiology, diagnosis, and management.

A pictorial review of the less commonly encountered patterns of metastatic prostate carcinoma.

Usually late in the course of advanced prostate carcinoma, atypical nodal and distant metastases may be encountered. Accurate characterisation of disease spread and assessment of disease response have significant treatment and prognostic implications. Surveillance imaging, therefore, along with clinical and biochemical parameters, is a key factor in directing appropriate management. Atypical metastases may also require histological re-evaluation, as they may indicate differentiation into aggressive histologic subtypes, which can lead to management alteration. We present a pictorial review of the less common patterns of metastatic prostate carcinoma, to aid in timely recognition and diagnosis.

Imaging features of thalassaemia.

This article highlights the range of osseous findings that can be encountered as well as the imaging features of extramedullary haematopoiesis. As iron overload remains a major cause of morbidity and mortality in these disorders, we also discuss the MRI evaluation of hepatic and cardiac hemosiderosis, to aid in the optimization of iron chelation therapy. Future imaging use will be dictated by evolving clinical needs, such as in screening for emerging morbidities, including hepatic fibrosis and hepatocellular carcinoma.

Abdominal Imaging Findings in Neurocutaneous Syndromes: Looking Below the Diaphragm.

OBJECTIVE: Neurocutaneous syndromes are a heterogeneous group of multisystemic disorders. We review the multimodality imaging findings in the disorders with a propensity for intraabdominal disease. We highlight more recently recognized disease patterns and discuss imaging surveillance optimization. CONCLUSION: Knowledge of varied intraabdominal phenotypic expressions can increase diagnostic rates. Limitation of radiation dose must be considered in screening this tumor-prone population. Early detection of neoplastic findings is critical for morbidity and mortality reduction.

Multi-organ benign and malignant tumors: recognizing Cowden syndrome: a case report and review of the literature.

BACKGROUND: Cowden syndrome is an autosomal dominant disorder with a predisposition to multiple benign and malignant tumors. In our patient, in addition to breast and endometrial malignancies as well as facial trichilemmomas, she was noted to have multiple meningiomas, pancreatic lipomas and lung cysts. These latter lesions have been noted in previous Cowden syndrome case reports, but are not included in the diagnostic criteria at this time. To our knowledge, this is the first case of multiple meningiomas in this syndrome. Further studies are therefore warranted to assess the significance of these findings in Cowden syndrome. CASE PRESENTATION: A middle-aged Afro-Caribbean known endometrial carcinoma patient (post surgery and adjuvant radiotherapy), presented with a locally advanced breast carcinoma. She received neoadjuvant chemotherapy followed by a modified radical mastectomy and axillary lymph node clearance. Her past medical history included a sphenoid wing meningioma for which she received definitive external beam radiotherapy. She was also known to have a multinodular goiter, anal polyp and longstanding mucocutaneous lesions. Further workup revealed additional smaller meningiomas, a parotid arteriovenous malformation, a lung cyst and pancreatic lipomas. Overall, consortium criteria were met for the diagnosis of Cowden syndrome. Furthermore, genetic testing identified a pathogenic mutation in the PTEN gene. She will be closely followed with annual clinical examination, dermatologic assessment and screening colonoscopies. She will perform interval whole body contrast enhanced CT for continued surveillance for metastatic disease. CONCLUSION: Cowden syndrome is likely to be an under diagnosed condition, but critically important to identify due to its cancer predisposition. When encountering multi-organ tumors, diagnostic criteria for Cowden syndrome should be sought in order to increase the diagnostic rates. Cancer surveillance for carcinoma detection in the early and curative stages remains the most critical aspect of management.

Right sided spleen laying retro-duodenal: A case report and review of the literature.

INTRODUCTION: Unlike left sided accessory spleen that are seen in 10-30% of cases at autopsy, cases of right accessory spleens are extremely rare. This congenital body of healthy splenic tissue simulates tumors from neighboring organs and presents a challenge in formulating a differential diagnosis. PRESENTATION OF CASE: We present the case of a patient whose CT scan of the abdomen showed a large mass, 11×8cm, arising retro-duodenal and lying just anterior to the right kidney. To the best of our knowledge, this is the only case where the accessory spleen was found retro-duodenal, directly anterior to the kidney and completely separate from the supra-renal gland. The chief complaint of the patient was right upper quadrant pain, radiating to the back, and colicky in nature. The patient was diagnosed with duodenal gastro-intestinal stromal tumor and a retro-peritoneal sarcoma. The mass was removed via a Kocher's incision and immunohistological examination showed that it was a right sided accessory spleen. The patient's left sided spleen appeared normal. DISCUSSION: Efforts to distinguish an accessory spleen from a retroperitoneal tumor with available scans, percutaneous biopsy or biochemical tests are inconclusive. Differential diagnosis between a retroperitoneal tumor and an accessory spleen can only be made after surgical exploration. CONCLUSION: This case highlights the fact that surgeons should consider the possibility of an accessory spleen when making a differential diagnosis of retroperitoneal tumors.

Is same-day sonography of the gallbladder feasible after intravenous urography or contrast-enhanced computed tomography?

OBJECTIVE: To determine whether same-day sonographic evaluation of the gallbladder is possible after the use of oral or intravenous iodinated contrast agents during intravenous urography or computed tomography. METHODS: One hundred fifty-three patients involved in this prospective study received low-osmolar or conventional contrast material. Each preparation contained 300 mg/mL iodine. Sixty-six patients received contrast agents intravenously, and 87 received them orally. Gallbladder volume was estimated sonographically, and the precontrast volume was used to calculate the volume after contraction at 30-minute intervals up to 2 hours after contrast agent administration. RESULTS: Gallbladder volume returned to precontrast values at 2 hours irrespective of the type of contrast agent or route of administration. The mean volume after contraction at 0.5 hour was 71% after intravenous contrast agent administration and 76% after oral contrast agent administration. Both changes were statistically significantly different from precontrast values (P < .01, null hypothesis) and were unaffected by the osmolarity of the contrast agent. CONCLUSIONS: Gallbladder volume was restored to precontrast values 2 hours after contrast agent administration. Thus any strategy involving simultaneous same-day sonographic or computed tomographic assessment of the gallbladder after contrast agent administration can be confidently undertaken after this period. This finding may have cost-saving implications.

The role of labelled red blood cell scintigraphy in the detention of acute gastrointestinal bleeding

This paper describes the experience with 99m Technetium labelled red blood cell (99mTc RBC) scintigraphy in twenty-two patients presenting with acute gastrointestinal (GI) tract bleeding. Studies were postitive in thirteen cases - eight from the lower GI tract and five from the upper. The data from surgical intervention were available in ten cases. Scintigraphy cannot diagnose the cause of GI bleeding, as it is a nonspecific study. Its usefulness lies in its ability to accurately diagnose the bleeding site, as was shown in this study where there was good surgical correlation. The simplicity, reproducibility and reliability of the technique, particularly when bleeding rates are low and intermittent, make it, in our view, the first line of investigation in any patient with suspected bleeding from the colon or upper GI tract if endoscopic evaluation is not possible in the latter. Its current under-utilisation in the Caribbean may be a reflection of the lack of nuclear imaging facilities.(Au)

Reactivation of plasmodium malariae infection in a Trinidadian man after neurosurgery

Malaria often presents as an acute febrile illness with fever, headache, rigors, anemia, and splenomegaly. The only malaria parasite associated with cerebral complications, Plasmodium falciparum usually blocks cerebral capillaries because of its endothelial adhesiveness. Infections with P. marlariae can persist for decades and are associated with splenomegaly and the nephrotic syndrome but not with cerebral complications. We describe P. malariae infection that was reactivated after neurosurgery after decades of latency. Infections with P. malariae may be asymptomatic and can be reactivated decades after the initial infection. The epidemiologic significance of asymptomatic cases of P. malariae infection has been well documented during outbreaks in Trinidad and Tobago and Grenada. Most of the symptomatic cases were detected by microscopial analysis, whereas the asymptomatic cases were diagnosed with the use of immunofluorescence antibody assays. Subclinical infections in humans may serve as the source of the protozoa in mosquitoes. Consequently, it is recommended that a sensitive technique that is based on the polymerase chain reaction be used to screen persons for persistent malaria infections, especially those who live in regions where the disease was once common but has since been eradicated

Intrathoracic cystic hygroma in an infant with respiratory failure

A 6 month old infant presenting initially with clinical signs of bronchiolitis developed acute symptoms of large airway obstruction and respiratory failure despite treatment of bronchiolitis. Endotracheal intubation and oxygen therapy resulted in immediate and dramatic improvement of respiratory failure. Plain chest radiograph, computerized tomography and surgical biopsy with subsequent histological examination established that the respiratory failure was due to a mediastinal cystic hygroma.(AU)

Implications of abnormal myocardial perfusion and normal angiography in patints with associated risk factors for coronary disease

Comparison between coronary angiography (CA) and SPECT myocardial perfusion scintigraphy (MPS) using Tc-99m labeled compounds in 30 patients (23 males, 7 females) yielded a sensitivity of 97 percent and a specificity of 76 percent for lesion detectability (p<0.01) using CA as the reference standard. Angiographic analysis initially ascribed the scintigraphic defects in 8 patients (5 males, 3 females) as falsely positive. Eleven coronary artery territories were involved: eight within the LAD and three within the RCA. Patient symptomatology however, prompted angiographic review which revealed myocardial bridging of the LAD in one male patient and differential perfusion of the LAD in two male patients. A review of the patients' history revealed associated risk factors such as diabetes, hyperlipidaemia, hypertension and smoking. Based on these findings, critical re-evaluation of other pathophysiolocial abnormalities in the absence of vascular stenosis should thus be sought in patients with positives MPD and associated risk factors to avoid unsuspected patient morbidity (AU)

Coronary angiography and myocardial perfusion scintigraphy: a correlative analysis - abstract

The assessment of myocardial perfusion has for many years been performed with thallous chloride (T1-201). This imaging agent suffers, however, from a number of well-recognized limitations, which has prompted a global search for better radiopharmaceuticals. Within the last two years, Technetium labelled myocardial perfusion imaging agents, namely, Sestamibi (Du Pont Pharma) and Tetrofosmin (Amersham) became available, and prompted us to evaluate the efficacy with respect to coronary angiography (CA) recently introduced at our institution. The data for both imaging agents were analyzed in fifty consecutive patients (ages 30 to 70 years), referred over the past eighteen months for myocardial perfusion scintigraphy (MPS). Twenty-five patients had combined MPS and CA studies. Comparative analysis for individual coronary artery territories yielded a sensitivity of 97 percent, specificity of 80 percent and an overall accuracy of 80 percent for MPS. Angiographic review of initially ascribed false positive MPS in eight patients revealed pathophysiological abnormalities other than coronary artery stenosis which accounted for the observed perfusion deficits. These included differential blood flow in two patients and myocardial bridging in one. The remaining false positives were attributed to diaphragmatic or breast attenuation (AU)