Magnetic resonance imaging of diabetic foot complications

This pictorial review aims to illustrate the various manifestations of the diabetic foot on magnetic resonance (MR) imaging. The utility of MR imaging and its imaging features in the diagnosis of pedal osteomyelitis are illustrated. There is often difficulty encountered in distinguishing osteomyelitis from neuroarthropathy, both clinically and on imaging. By providing an accurate diagnosis based on imaging, the radiologist plays a significant role in the management of patients with complications of diabetic foot.     

Clinics in diagnostic imaging (159). Jejunal intussusception due to Peutz-Jeghers syndrome.

A 21-year-old woman presented with acute onset of upper abdominal pain. A diagnosis of Peutz-Jeghers syndrome (PJS) was made based on the clinical picture of perioral pigmentation with imaging findings of transient jejunojejunal intussusceptions and small bowel polyps, and confirmed by characteristic histopathological appearances of Peutz-Jeghers polyps. PJS is a rare hereditary condition characterised by unique hamartomatous polyps, perioral mucocutaneous pigmentations, and increased susceptibility to gastrointestinal and extraintestinal neoplasms. Patients usually present with recurrent abdominal pain due to intussusception caused by polyps. Other modes of presentations include rectal bleeding and melaena. We describe the imaging findings of PJS and provide a brief review of bowel polyposis syndromes. The latter are relatively rare disorders characterised by multiple polyps in the large or small intestine, with associated risk of malignancies and other extraintestinal manifestations. Awareness of the manifestations and early diagnosis of these syndromes is crucial to prevent further complications.     

Imaging features of an intraosseous arteriovenous malformation in the tibia

Primary intraosseous arteriovenous malformations (AVMs) are rare and have only been occasionally reported. We herein report a histologically proven case of primary intraosseous AVM in the tibia, which mimicked a fibrous tumour on radiography. This presentation carries a risk of triggering acute large haemorrhage through unnecessary biopsy. In intraosseous AVM, the magnetic resonance (MR) imaging features typical of a soft tissue AVM are absent, making diagnosis difficult. In this report, peculiar MR features in the presence of a connecting vessel between the normal deep venous system of the lower extremity and the tumour provide a clue for the early diagnosis of primary intraosseous AVM.     

Delayed presentation of port-site metastasis from an unknown gastrointestinal malignancy following laparoscopic cholecystectomy

Port-site metastasis (PSM) is often encountered during laparoscopic surgery in patients with malignancy. We report a 45-year-old woman who presented with a single PSM from papillary adenocarcinoma after undergoing laparoscopic cholecystectomy for calculus cholecystitis. Post cholecystectomy, a diagnosis of chronic cholecystitis was confirmed on histopathology. The patient presented with a mass at the site of epigastric port 28 months after surgery. PSM was suspected on clinical examination, which was supported by findings on computed tomography and further confirmed by fine-needle aspiration cytology of the lump. The patient underwent surgical clearance of the mass, and histopathological examination proved the lesion to be papillary adenocarcinoma. The site of the primary tumour was not detected even after thorough examination. Based on the histopathology report following local surgical clearance, the patient was started on chemotherapy. This case is unusualbecause of the long delay prior to the presentation of PSM and the unknown primary malignancy.     

Hepatic tuberculosis: a rare cause of fluorodeoxyglucose hepatic superscan with background suppression on positron emission tomography

Fluorodeoxyglucose (FDG) hepatic superscan refers to the diffuse intense uptake of 18F-FDG in the liver on positron emission tomography (PET), with reduced physiological activity in the brain and heart. The common causes include lymphoma and metastasis. In this case report, we describe the imaging features of tuberculosis as a rare cause of FDG hepatic superscan. PET imaging may be the only clue to a diagnosis of hepatic tuberculosis, as other imaging modalities may demonstrate only nonspecific hepatomegaly. It is important to consider this entity in the differential diagnosis of patients presenting with FDG hepatic superscan and proceed with liver biopsy for a definitive diagnosis.     

Clinics in diagnostic imaging (162). Meckel’s diverticulum

A 28-year-old Chinese man presented with acute bleeding per rectum. Computed tomography showed a posterior outpouching arising from the distal ileum. The outpouching had hyperaemic walls, but no active contrast extravasation was detected. Technetium-99m pertechnetate scintigraphy showed focal areas of abnormal uptake in the right side of the pelvis, superior and posterior to the urinary bladder. These areas of uptake appeared simultaneously with the gastric uptake and demonstrated gradual increase in intensity on subsequent images. The diagnosis of Meckel’s diverticulum was confirmed on surgery and the lesion was resected. The clinical and imaging features of Meckel’s diverticulum are discussed.     

Imaging in noncardiovascular thoracic emergencies: a pictorial review

Cardiovascular and noncardiovascular conditions are commonly encountered in the emergency department. While the majority of patients have underlying cardiovascular aetiologies, such as acute myocardial infarction, congestive heart failure, aortic dissection and pulmonary embolism, a small subset of patients have underlying noncardiovascular conditions, although they present with similar symptoms of chest pain, dyspnoea, cough, haemoptysis and haematemesis. This article aims to describe the imaging findings in common noncardiovascular conditions of the chest that are frequently encountered in the emergency department, with a review of the existing literature.     

Electrocardiographic findings in pulmonary embolism

Pulmonary embolism (PE) poses a challenge to physicians, as it can be difficult to diagnose but results in significant mortality and morbidity in patients. Diagnosing PE requires an integrated approach using clinical findings, electrocardiography (ECG), blood investigations and imaging modalities. Abnormalities in ECG are common among patients with massive acute PE and can serve as a prognostic indicator. In this article, we describe the ECG presentations of two patients diagnosed with PE, and review the literature on the various types of ECG presentations and their role in predicting the prognosis of PE.     

Clinics in diagnostic imaging (158). Duodenal ectopic pancreas

A 46-year-old man presented with right loin tenderness following a road traffic accident. Computed tomography and magnetic resonance imaging showed a well-defined, smooth, enhancing oval lesion in the wall of the first part of the duodenum. The lesion was seen separately from the normal pancreas. It showed attenuation, intensity and enhancement similar to that of normal pancreas. Based on the imaging appearance, a diagnosis of ectopic pancreas was made. The patient underwent oesophagogastroduodenoscopy, endoscopic ultrasonography and fine-needle aspiration cytology of the lesion, which confirmed ectopic pancreatic tissue. Since the patient was asymptomatic, surgical resection was deferred. The embryologic origin, various locations, imaging appearance and clinical significance of ectopic pancreas are discussed.     

Clinics in diagnostic imaging (166)

A 68-year-old woman with poorly controlled diabetes mellitus presented to the emergency department with choreoathetoid movements affecting the upper and lower left limbs. Computed tomography of the brain did not show any intracranial abnormalities. However, subsequent magnetic resonance (MR) imaging of the brain revealed an increased T1 signal in the right basal ganglia, raising the suspicion of nonketotic hyperglycaemic chorea-hemiballismus. Management consisted of adjusting her insulin dose to achieve good glycaemic control. The patient subsequently recovered and was discharged after eight days. There are many causes of basal ganglia T1 hyperintensity, including hyperglycaemia in patients with poorly controlled diabetes mellitus. This case emphasises the importance of MR imaging in the early diagnosis of hyperglycaemia as a cause of chorea-hemiballismus, to enable early treatment and a better clinical outcome.     

Gastric variceal bleeding precipitated by a mycotic splenic arteriovenous fistula in a cirrhotic patient: radiological diagnosis and endovascular treatment

Splenic arteriovenous fistula (SAVF) is an unusual cause of portal hypertension, and is rarely associated with an infective aetiology. It is often difficult to identify SAVF clinically, and thus, radiological modalities are invariably required for diagnosis and treatment. We herein describe a case of SAVF occurring in a patient with compensated cirrhosis as a sequel to salmonella gastroenteritis, and presenting with acute gastric variceal bleeding. Selective transcatheter embolisation of the splenic artery was effective in controlling bleeding.     

Dural metastasis of nasopharyngeal carcinoma: rare,but worth considering

Metastasis of nasopharyngeal carcinoma (NPC) to the dura, an extremely rare condition, can be symptomatically silent and mistaken for a benign entity radiographically. Missed diagnosis can lead to serious consequences or prove immediately fatal. We report a woman with dural metastasis of NPC that mimicked a meningioma on radiography. Craniectomy with tumour resection was performed due to rapid progression from the onset of symptoms to disability. The patient was still alive two years after surgery. This case emphasises the need to keep in mind the possibility of dural metastasis of NPC in patients with abnormal imaging features. This would not only avoid wrong and optimistic diagnosis, but also allow for appropriate treatment in a timely manner. To our knowledge, this is the first report of metastasis of NPC to the dura. We provide detailed information on the neoplastic lesion, which masqueraded as a benign entity and caused potentially fatal consequences.     

Clinics in diagnostic imaging (165)

Oesophageal rupture is a life-threatening complication of balloon tamponade for bleeding oesophageal varices. We herein describe the clinical course and imaging findings in a 33-year-old Indian man who had a Sengstaken-Blakemore (SB) tube inserted for uncontrolled haematemesis, which was unfortunately complicated by malposition of the gastric balloon with resultant oesophageal rupture. The inflated SB tube gastric balloon was visualised within the right hemithorax on chest radiography after the SB tube insertion. Further evaluation of the thorax on computed tomography confirmed the diagnosis of oesophageal rupture associated with right-sided haemopneumothorax. It is crucial for both the referring clinician and reporting radiologist to recognise early the imaging features of an incorrectly positioned SB tube gastric balloon, so as to ensure prompt intervention and a reduction in patient morbidity and mortality.     

Electrocardiographic changes in acute perimyocarditis

Pericarditis and myocarditis are characterised by electrocardiographic changes and elevated cardiac enzymes, respectively, and patients with perimyocarditis often complain of chest discomfort. These findings are nonspecific and often lead to diagnostic difficulties, as ST-elevation myocardial infarction commonly presents in a similar fashion. Clinical differentiation between perimyocarditis and myocardial infarction are especially important because adverse side effects can occur if reperfusion therapy is administered for a patient with acute pericarditis or if a diagnosis of acute myocardial infarction is missed. We herein describe a case of perimyocarditis with ST elevation and raised cardiac markers, which led to two emergency coronary angiographies that were subsequently found to be normal. We include the three serial electrocardiographies (ECGs) performed to show the characteristic features of perimyocarditis and further discuss the importance of identifying typical and atypical ECG features of pericarditis.     

Coronary artery bypass grafting in a patient with pituitary adenoma: can alertness prevent tragedy?

Pituitary apoplexy is a rare, life-threatening complication that may occur after coronary artery bypass graft surgery for patients with pituitary adenomas. The dynamics of cardiopulmonary bypass may contribute to a sudden expansion of silent pituitary adenomas and result in the compression of surrounding structures. A range of clinical features have been described, and the condition requires prompt diagnosis and treatment to prevent further complications. Herein, we present an uncomplicated case highlighting the importance of diagnosing pituitary apoplexy, ensuring high alertness to the condition, so as to prevent life-threatening tragedy due to missed diagnosis.     

Not all unexplained hypoxia is pulmonary embolism

Acute myocardial infarction is one of the conditions frequently managed in the emergency department. There are many complications associated with right ventricular infarction, and the incidence of right ventricular infarction associated with inferior myocardial infarction is as high as 51% based on electrocardiographic findings. We herein report the case of a 45-year-old Chinese man with inferior myocardial infarction complicated by right ventricular failure. He had hypoxaemia refractory to supplemental oxygen due to an acute right-to-left shunting through a patent foramen ovale (PFO). He underwent coronary angioplasty and closure of the PFO. It is crucial for the attending physician to consider the presence of a right-to-left shunt when there is persistent uncorrectable hypoxaemia despite maximal oxygen supplementation in the setting of right ventricular infarction, as there are clinical implications and certain clinical managing principles that should be applied.     

Tension pneumocephalus

Tension pneumocephalus is a rare but treatable neurosurgical emergency. Prompt and accurate diagnosis of tension pneumocephalus requires a high index of clinical suspicion corroborated by imaging. Herein, we describe a case of extensive tension pneumocephalus in a patient who had undergone transsphenoidal surgery and repair of the sellar floor, with subsequent successful decompression. This case report discusses the pertinent imaging features of tension pneumocephalus and its management.     

Normalisation of urinary biomarkers to creatinine for clinical practice and research – when and why

Acute kidney injury (AKI) and chronic kidney disease (CKD) are major health problems. Urinary biomarkers have both diagnostic and prognostic utility in AKI and CKD. However, how biomarker excretion rates should be reported, especially whether they should be normalised to urinary creatinine concentration (uCr), is controversial. Some studies suggest that normalisation to uCr may be inappropriate at times, as urinary creatinine excretion rate may vary greatly, depending on the situation. Notably, recent studies suggest that while normalisation of values to UCr may be valid for the evaluation of CKD and prediction of AKI sequelae and occurrences, it could be inappropriate for the diagnosis of AKI, or in the presence of certain acute kidney disease states.     

Clinics in diagnostic imaging (160). Levocardia with abdominal situs inversus

Levocardia (left-sided cardiac apex) with abdominal situs inversus is extremely rare. This is also known as isolated levocardia and is almost always associated with severe forms of congenital heart defects with poor prognosis. We report isolated levocardia in a 13-year-old symptomatic male patient. The purpose of this paper is to outline the imaging features of isolated levocardia and to highlight the role of cardiovascular magnetic resonance imaging (CMR) in the diagnosis and management of such cases. Other forms of cardiac malposition, including dextrocardia, mesocardia and criss-cross heart, with chest radiograph and CMR correlation, are also discussed.     

Anaesthetic management of acute airway obstruction

The acutely obstructed airway is a medical emergency that can potentially result in serious morbidity and mortality. Apart from the latest advancements in anaesthetic techniques, equipment and drugs, publications relevant to our topic, including the United Kingdom’s 4th National Audit Project on major airway complications in 2011 and the updated American Society of Anesthesiologists’ difficult airway algorithm of 2013, have recently been published. The former contained many reports of adverse events associated with the management of acute airway obstruction. By analysing the data and concepts from these two publications, this review article provides an update on management techniques for the acutely obstructed airway. We discuss the principles and factors relevant to the decision-making process in formulating a logical management plan.