POCUS in diagnosis of pediatric transient synovitis

By Amerigo Allegretto, AuntMinnie.com staff writer

July 13, 2021 -- Point-of-care-ultrasound (POCUS) in combination with a decision-support checklist can help accurately diagnose transient synovitis in pediatric patients, according to research published July 13 in JAMA Network Open.

A group led by Marah Zoabi, a research assistant from the Technion-Israel Institute of Technology in Haifa, found that a POCUS decision-support algorithm can help provide more efficient diagnosis of transient synovitis and avoid unnecessary blood tests.

"To our knowledge, this study is the first to suggest a rule-in diagnostic tool for transient synovitis, instead of one of exclusion," Zoabi and colleagues wrote. "The traditional approach advocates the use of laboratory tests to differentiate between transient synovitis and other serious diseases."

Transient synovitis causes acute hip pain and is confirmed by excluding other severe diseases, such as septic arthritis, osteomyelitis, and Legg-Calvé-Perthes disease. Hip effusion, meanwhile, is typically found using ultrasonography.

The team's POCUS decision-support algorithm is used regularly to identify transient synovitis in pediatric patients. It includes a set of five clinical criteria that must be met, followed by bedside ultrasonography of the hip joint. The criteria include the following:

• Age 3-10 years
• Fever less than 38° C
• Pain with weight-bearing movement
• Concerns started seven days ago or earlier
• Absence of paleness, splenomegaly, and generalized lymphadenopathy

The researchers wanted to test the accuracy of the algorithm in diagnosing the disease. To do so, they looked at data gathered from 1,461 children with nontraumatic hip tenderness between October and November 2020.

The POCUS algorithm was applied to 621 patients (429 boys, 192 girls) with an average age of 5.5 years. Out of these patients, 539 were correctly diagnosed as having transient synovitis. Meanwhile, 22 patients were correctly diagnosed as not having synovitis and 54 were misdiagnosed as not having synovitis, but they were correctly diagnosed at follow-up visits.

Six emergency department patients were misdiagnosed as having synovitis, but they were found to have another condition at follow-up visits.

The algorithm showed high sensitivity at 90.9% and high positive predictive value at 98.9%. Specificity, meanwhile, was 78.6% and negative predictive value was 28.9%.

The algorithm's positive likelihood ratio of 4.25 suggests it can be helpful in ruling in the diagnosis of transient synovitis, the authors concluded.

Hip effusion may not always be present when patients present with transient synovitis. This is reflected by the limited specificity and low negative predictive value, suggesting the algorithm cannot reliably rule out synovitis, they added.

Potential limitations of the study included its retrospective nature, the operator-dependent nature of the ultrasonography exam, the absence of an objective reference standard, and the lack of external validation of the algorithm, according to Zoabi and colleagues.

However, "these data provide evidence for the safety of the POCUS decision-support algorithm," they wrote.

US finds brain differences in infants exposed to Zika virus

By Amerigo Allegretto, AuntMinnie.com staff writer

July 6, 2021 -- Cranial ultrasound found lenticulostriate vasculopathy to be more common in infants exposed to the mosquito-borne Zika virus, according to research from Brazil published June 29 in Radiology.

A team of researchers led by Sara Reis Teixeira, PhD, from the University of São Paulo found that lenticulostriate vasculopathy, a cranial ultrasound finding related to pre- or perinatal brain injury, was 9 times more frequent in infants exposed to the Zika virus infants compared with otherwise healthy infants.

"Our results demonstrate a spectrum of neuroimaging findings in a large cohort of infants born to infected pregnant women and support recent guidelines in recommending postnatal cranial ultrasound for all infants with possible congenital Zika virus infection, regardless of the presence of microcephaly," the study authors said.

Zika virus infection during pregnancy may lead to a wide range of central nervous system changes, the researchers said. While most previous studies have assessed patients who are severely affected, such as having microcephaly, there is little information on abnormalities in infants with normal head size.

The investigators wanted to find out the prevalence of cranial ultrasound findings in a large group of infants born to women with Zika virus infection with infants born to mothers not infected. They also wanted to study signs of prenatal Zika virus exposure on cranial ultrasound scans, looking at infants from the 2015-2016 Zika virus outbreak in southeast Brazil.

"Neuroimaging is a fundamental component of the diagnostic evaluation of infants at risk for congenital Zika virus syndrome," the study authors wrote. "Information regarding the spectrum of brain findings in a large cohort of infants born to infected women is still scarce."

The study included 220 infants exposed to the Zika virus, with an average age of 53.3 days. Of these, 113 were boys and 107 were girls. Meanwhile, 170 infants with an average age of 45.6 days (102 boys, 68 girls) who were not exposed to the virus were in a control group.

Cranial ultrasound found a Zika virus-like pattern in 11 of the 220 virus-exposed infants, but not in the control group infants.

Calcifications and subcortical calcifications were found only in Zika-exposed infants. Other intracranial calcifications, such as those in the basal ganglia, periventricular area, and scattered in the brain, were also associated with virus exposure. However, the frequency of most mild cranial ultrasound findings was not significantly different between both groups.

However, the finding of lenticulostriate vasculopathy was found in 12 of the virus-exposed infants, while being found in only one infant in the control group (p = 0.01).

The team said that further studies are needed to evaluate the potential clinical significance of lenticulostriate vasculopathy and other mild cranial ultrasound findings in infants exposed to Zika virus.

An accompanying editorial written by Dr. Carol Benson from Harvard Medical School said that long-term neurodevelopmental outcomes in infants exposed to the virus in utero are also needed to determine how best to counsel patients exposed while pregnant, as well as to understand the clinical significance of mild sonographic abnormalities in infants.