MDCT of acute thrombotic and nonthrombotic pulmonary emboli

Nontrombotic Pulmonary Embolism: Different Etiology, Same Significant Consequences

Nontrombotic pulmonary embolism represents the embolization of different types of materials (cells, organisms, gas, foreign material) into pulmonary circulation. The disease is uncommon, and clinical presentation together with laboratory findings are nonspecific. Its pathology is usually misdiagnosed based on imaging findings as pulmonary thromboembolism, but the correct diagnosis is essential because different therapeutic approaches are required. In this context, knowledge of the risk factors associated with nontrombotic pulmonary embolism and specific clinical symptoms is fundamental. Our objective was to discuss the specific features of the most common etiologies of nontrombotic pulmonary embolism, gas, fat, amniotic fluid, sepsis and tumors, to provide assistance for a rapid and correct diagnosis. Because the most common etiologies are iatrogenic, knowledge of the risk factors could be an important tool for prevention or rapid treatment if the disease develops during different procedures. The diagnosis of nontrombotic pulmonary embolisms represent a laborious challenge, and endeavors should be made to prevent development and increase awareness of this disease.

[Nonthrombotic pulmonary embolisms]

The term nonthrombotic pulmonary embolism (NTPE) is defined as embolization of pulmonary arteries caused by foreign bodies (e. g. detached catheter fragments), biological substances (e. g. septic thrombus) or exogenous substances (e. g. gas). The frequency of NTPE is underestimated. Symptoms can cover the spectrum from undetectable to sudden death. In addition to mechanical obstruction of the pulmonary arteries, some NTPEs trigger an inflammatory cascade that causes deterioration of vascular, pulmonary and cardiac function. Radiological imaging in combination with the medical history of patients is sufficient to identify most NTPEs with certainty. The aim of this article is to make readers aware of the symptoms, frequency, relevance, classification, pathophysiology, laboratory findings and radiological findings of the most frequent forms of NTPE. The spectrum of forms presented here includes pulmonary embolisms due to foreign bodies (intravascular, intracorporeal and extracorporeal), amniotic fluid, endogenous tissue, fat, tumors, septic thrombi, hydatids, cement, metallic mercury, gas, silicone and particles.

Massive Pulmonary Calculi Embolism: A Novel Complication of Pneumatic Lithotripsy: A Case Report

Pneumatic lithotripsy is a minimally invasive technique mainly for the treatment of urinary staghorn stones. Previous literatures have reported some therapeutic complications during or after this procedure, but calculi embolism has not been mentioned before.We report here a fatal case of calculi-induced pulmonary embolism in an adult woman who underwent pneumatic lithotripsy. An autopsy did not reveal any evidence of pulmonary embolism. However, light microscopy revealed noticeable presence of calculi in pulmonary arterioles and capillaries, as evidenced by environmental scanning electron microscope and energy dispersive X-ray analysis. The primary determinants of calculi embolism include intrarenal pressure, and volume and viscosity of the calculi fragments formation. Vascular intravasation of smashed calculi might increase pulmonary vascular resistance and hypoxemia and decrease cardiac output.This case report intends to provide information for clinicians to consider the probability of intraoperative calculi embolism during lithotripsies when patients develop typical symptoms of acute pulmonary embolism.

Imaging acute complications in cancer patients: what should be evaluated in the emergency setting?

Increased incidence world-wide of cancer and increased survival has also resulted in physicians seeing more complications in patients with cancer. In many cases, complications are the first manifestations of the disease. They may be insidious and develop over a period of months, or acute and manifest within minutes to days. Imaging examinations play an essential role in evaluating cancer and its complications. Plain radiography and ultrasonography (US) are generally performed initially in an urgent situation due to their wide availability, low cost, and minimal or no radiation exposure. However, depending on a patient's symptoms, evaluation with cross-sectional imaging methods such as computed tomography (CT) and magnetic resonance imaging (MRI) is often necessary. In this review article, we discuss some of the most important acute noninfectious oncological complications for which imaging methods play an essential role in diagnosis.

A pilot study of computed tomography-detected asymptomatic pulmonary filling defects after hip and knee arthroplasties

We asked what the incidence of asymptomatic filling defects is on routine multidetector computed tomography (MDCT) in primary hip (total hip arthroplasty [THA]) and knee arthroplasties (TKA) patients. We prospectively performed MDCT scans on the first postoperative day for THA (n = 21)/TKA (n = 27). Patients underwent routine postoperative care, and data were collected for symptoms such as tachycardia or shortness of breath. More patients undergoing TKA had positive computed tomography scans than those undergoing THA: 11 (41%) vs 1 (5%), respectively. All patients diagnosed with a filling defect were discharged from the hospital without treatment of symptomatic pulmonary embolism. Our study demonstrates a high rate of abnormal MDCT early after lower extremity arthroplasty, the clinical importance of which may be benign.

Chemical pneumonitis after intravenous injection of isoparaffin: Characteristic clinico-radiologic findings

A 23-year-old man presented with chest pain after intravenous (IV) injection of isoparaffin (C12-C13, 99%). This report describes the chest computed tomography (CT) pattern of chemical pneumonitis after IV isoparaffin injection. When injected IV, hydrocarbon can cause chemical pneumonitis, mimicking pulmonary infarction on chest CT. The CT pattern is attributable to diffusion of hydrocarbons through systemic veins into small pulmonary arteries and capillary beds, causing extensive local reactions and chemical pneumonitis or pleuritis.