Algorithm-based approach to focal liver lesions in contrast-enhanced ultrasound.

Focal liver lesions are commonly encountered. Grey-scale and Doppler sonographic characteristics of focal liver lesions are often non-specific and insufficient to conclusively characterise lesions as benign or malignant. Contrast-enhanced ultrasound is useful for the characterisation of FLLs in patients who are unable to undergo contrast-enhanced computed tomography or magnetic resonance imaging. It is also easily available and relatively cheap. However, interpretation of contrast-enhanced ultrasound can be challenging without a systematic approach. In this pictorial essay, we highlight an algorithm-based approach to FLLs and discuss the characteristic contrast-enhanced ultrasound features of commonly encountered and clinically significant focal liver lesions.

Role of Intercostal Artery Embolization in Management of Traumatic Hemothorax.

Intercostal artery bleeding from trauma can result in potentially fatal massive hemothorax. Traumatic hemothorax has traditionally been treated with tube thoracostomy, video-assisted thoracoscopic surgery, or thoracotomy. Transcatheter arterial embolization (TAE), a well-established treatment option for a variety of acute hemorrhage is not widely practiced for the management of traumatic hemothorax. We present 2 cases of delayed massive hemothorax following chest trauma which were successfully managed by transarterial embolization of intercostal arteries. The published studies are reviewed and a systematic approach to the selection of patients for TAE versus emergency thoracotomy is proposed.

Primary extraskeletal osteosarcoma of small bowel mesentery presenting with acute bowel obstruction.

Extraskeletal osteosarcoma of the small bowel mesentery is an exceedingly rare condition. It is an aggressive malignant neoplasm of mesenchymal origin characterized by osteoid formation. Final diagnosis is often made by histopathological analysis. However, we believe that prospective radiological diagnosis may be possible through careful analysis of densities (ossification) within the mesenteric mass. To the best of our knowledge, there is no current literature describing the radiological approach to making a prospective diagnosis of this condition. We present the 12th case of extraskeletal osteosarcoma worldwide and describe a radiological approach that is potentially useful in making a prospective diagnosis.

Clinics in diagnostic imaging (203). Focal infarction of the falciform ligament fatty appendage.

A 56-year-old man presented to the emergency department with acute upper abdominal pain and mild leucocytosis. The pain was not relieved by intravenous analgesia. Computed tomography of the abdomen and pelvis demonstrated a focal area of fat stranding with a thin peripheral rim of high attenuation and a punctate central hyperdense dot in the vicinity of the falciform ligament. The diagnosis of focal infarction of the falciform ligament fatty appendage was made based on the imaging findings. The patient responded well to conservative management and was discharged for outpatient follow-up. Focal infarction of the falciform ligament fatty appendage is extremely rare and can mimic various causes of acute abdomen that require emergency surgery. Hence, correct radiological diagnosis is essential to avoid unnecessary surgical intervention. We herein discuss the similarities and differences with other common companion cases such as epiploic appendagitis and omental infarction.

Clinics in diagnostic imaging (196). Complete PCL tear.

A 21-year-old man presented with left knee pain and instability that persisted three months after a road traffic accident. Physical examination revealed a positive posterior drawer test. Anterior drawer and pivot tests were negative. Magnetic resonance imaging of the knee demonstrated a complete tear of the posterior cruciate ligament (PCL). Recognition of the normal and injured appearances of the PCL is useful to aid the reader in the detection and characterisation of PCL injuries. Isolated acute PCL tears are usually managed conservatively. However, an active search for associated injuries is essential, as their presence may upstage the patients for surgical management.

Sonographic assessment of musculoskeletal causes of calf pain and swelling.

Calf pain or swelling is a common presentation to the emergency department. The differential diagnoses are wide. Deep vein thrombosis (DVT) is often the first diagnosis to be excluded given its potentially fatal complications. Musculoskeletal causes of calf pain or swelling such as Baker's cyst, muscle or tendon tear, soft tissue infection, and inflammation are not uncommon and can often be confidently diagnosed with ultrasonography (US). Familiarity with these conditions and the sonographic findings would be useful in making timely and correct diagnosis.

Prevention and Management of Adverse Reactions Induced by Iodinated Contrast Media.

Iodinated radiocontrast media (IRCM) is widely used in current clinical practice. Although IRCM is generally safe, serious adverse drug reactions (ADRs) may still occur. IRCM-induced ADRs may be subdivided into chemotoxic and hypersensitivity reactions. Several factors have been shown to be associated with an increased risk of ADRs, including previous contrast media reactions, history of asthma and allergic disease, etc. Contrast media with lower osmolality is generally recommended for at-risk patients to prevent ADRs. Current premedication prophylaxis in at-risk patients may reduce the risk of ADRs. However, there is still a lack of consensus on the prophylactic role of premedication. Contrast-induced nephropathy (CIN) is another component of IRCM-related ADRs. Hydration remains the mainstay of CIN prophylaxis in at-risk patients. Despite several preventive measures, ADRs may still occur. Treatment strategies for potential contrast reactions are also summarised in this article. This article summarises the pathophysiology, epidemiology and risk factors of ADRs with emphasis on prevention and treatment strategies. This will allow readers to understand the rationale behind appropriate patient preparation for diagnostic imaging involving IRCM.

Renal-related adverse effects of intravenous contrast media in computed tomography.

Renal-related adverse effects of intravascular contrast media (CM) include contrast-induced nephropathy in computed tomography and angiography. While large retrospective studies have been published, the exact pathogenesis of this condition is still unknown. We review the main international guidelines, including the American College of Radiology white paper and the guidelines of European Society of Urogenital Radiology, Royal College of Radiologists and Canadian Association of Radiologists, as well as their references, regarding this subject. We present a simplified, concise approach to renal-related adverse effects of CM, taking into consideration the basis for each recommendation in these published guidelines. This will allow the reader to better understand the rationale behind appropriate patient preparation for cross-sectional imaging.