SPECT/CT Imaging Agent Solves The Problem Of Difficult To Diagnose Cases Of Infectious Endocarditis

When combined with standard diagnostic tests, functional imaging procedures have been shown to reduce the rate of misdiagnosed cases of infectious endocarditis. According to new research published in the August issue of The Journal of Nuclear Medicine, single photon emission computed tomography (SPECT)/computed tomography (CT) with 99mTc-hexamethylpropleneamine oxime-labeled white blood cells (99mTc-HMPAO-WBC) can improve the diagnosis of infectious endocarditis in hard-to-diagnose cases.
Infectious endocarditis is an infection of the lining of the heart chambers and heart valves that is caused by bacteria, fungi or other infectious substances. It affects 2-4 people per 100,000 each year, with 25-50 percent of the cases occurring in patients older than 60 years. Mortality from infectious endocarditis remains high when this condition is undiagnosed and, therefore, not adequately treated.
The diagnosis of infectious endocarditis is becoming progressively more challenging in the past years because of a variety of factors: the indiscriminate use of antimicrobial agents in some clinical settings, the increased number of individuals with predisposing or underlying conditions (i.e., frail and elderly, immune-suppressed persons), and the increasing number of interventional cardiovascular procedures and placement of valve prostheses, intravascular devices and cardiac devices.
“SPECT/CT with 99mT-HMPAO-WBC is a nuclear medicine technique currently used for the management of patients with infection; its application in infectious endocarditis has been restricted to few reports,” said Paola A. Erba, MD, lead author of the study. “With this work we aimed to open new perspective for the application of this technique.”
Researchers conducted 99mTc-HMPAO-WBC SPECT/CT scans on 131 consecutive patients with suspected infectious endocarditis. Patients with permanent cardiac devices were excluded from the research as the devices might have introduced the infection. Results from the scans were compared to diagnostic tests for standard infectious endocarditis – transthoracic or transesophageal echocardiography, blood cultures and the modified Duke Endocarditis Service criteria, which are recommended for classification.
Of the 131 patients, 97 were found to have uptake indicating infection.The 99mTc-HMPAO-WBC SPECT/CT scan was true-positive in 46 of 51 patients and false negative in 5 of 51 cases (90 percent sensitivity, 94 percent negative predictive value and 100 percent specificity and positive predictor value). In addition, septic embolism was detected in 41 percent of the patients.
“When the results of the 99mTc-HMPAO-WBC SPECT/CT scan were associated with either positive echocardiography or a positive blood culture, no cases of infectious endocarditis went undiagnosed,” noted Erba. “This demonstrates the added value that 99mTc-HMPAO-WBC SPECT/CT scans can provide to assist physicians in their diagnosis and treatment decisions. Cardiologists and infectivologists dealing with infectious endocarditis should consider using 99mT-HMPAO-WBC when they are facing difficult situation.”
Related Posts

Tuberclosis(TB) being the infectious disease is communicated almost exclusively by coughed aerosols carrying pathogens of Mycobacterium tuberclosis (Mtb). As reported by World Health Organization (WHO) it causes disease in 9.6 millions people each year and ranks with human immunodeficiency virus (HIV) as a leading cause of disease. A well timed diagnosis and appropriate treatment can […]
Read More »
A researcher at Moffitt Cancer Center and his international team of colleagues have reported study results on a novel multireceptor-targeted somatostatin analogue called pasireotide (SOM230) manufactured by Novartis Pharma AG. The Phase II, open-label, multicenter study in patients with advanced neuroendocrine tumors (NET) whose symptoms were no longer responsive to octreotide LAR therapy found that […]
Read More »
In a large epidemiologic study, researchers at UCLA’s Jonsson Cancer Center found that the children of U.S.-born Latina women are at higher risk of having retinoblastoma, a malignant tumor of the retina which typically occurs in children under six. The study, which focused on babies born in California, also found that offspring of older fathers […]
Read More »
Since June 2012, it is official: The World Health Organisation (WHO) has classified diesel soot as a lung carcinogen. Artur Braun, a physicist at Empa and an X-ray spectroscopy expert, has made crucial contributions to analyzing the structure and composition of soot particles. Soot particles are dangerous – there is nothing new in this knowledge. […]
Read More »
A new clinical trial published in the August edition of Clinical Cancer Research has revealed that cancer patients who drink one glass of grapefruit juice per day achieve the same benefits from an anti-cancer drug as they would get from more than three times as much of the drug by itself. It could also help […]
Read More »
On 14 February 2012, the German Institute for Quality and Efficiency in Health Care (IQWiG) published the results of a literature search for evidence-based clinical practice guidelines on the treatment of people with heart failure. The aim of the report is to identify those recommendations from current guidelines of high methodological quality that may be […]
Read More »
When combined with standard diagnostic tests, functional imaging procedures have been shown to reduce the rate of misdiagnosed cases of infectious endocarditis. According to new research published in the August issue of The Journal of Nuclear Medicine, single photon emission computed tomography (SPECT)/computed tomography (CT) with 99mTc-hexamethylpropleneamine oxime-labeled white blood cells (99mTc-HMPAO-WBC) can improve the […]
Read More »
For years, scientists have been looking for a good source of heart cells that can be used to study cardiac function in the lab, or perhaps even to replace diseased or damaged tissue in heart disease patients. To do this, many are looking to stem cells. Researchers at Sanford-Burnham Medical Research Institute (Sanford-Burnham), the Human […]
Read More »
A new genetic analysis focusing on Jews from North Africa has provided an overall genetic map of the Jewish Diasporas. The findings support the historical record of Middle Eastern Jews settling in North Africa during Classical Antiquity, proselytizing and marrying local populations, and, in the process, forming distinct populations that stayed largely intact for more […]
Read More »
University of Minnesota School of Public Health researchers have found that medical group practices can reduce costs for patients with diabetes by investing in improved quality of care. In the study, which appears in the August issue of Health Affairs, University of Minnesota researchers analyzed 234 medical group practices providing care for more than 133,000 […]
Read More »