Pediatric Radiology

Vitamin A toxicity in the infant, which now occurs rarely from dietary overdosage, was recognized in the 1940s as painful periostitis with rare progression to premature closure of the lower limb epiphyses. Decades later, most cases of vitamin A-induced premature epiphyseal closure (physeal obliteration) occur in pediatric dermatologic patients given vitamin A analogues. This phenomenon resembles a strange disease discovered in more recent years in calves with closed epiphyses of the hind limbs, known as hyena disease. This was a mystery until proved to be caused by vitamin A toxicity from enriched grain that causes the calves to have short hind limbs that resemble those of a hyena and gait disturbance. This historical review links the human and veterinary literature in terms of vitamin A-induced epiphyseal closure using a case report format of a 16-month-old human infant with closed knee epiphyses and gait disturbance that is reminiscent of hyena disease seen in calves.

Background. Cat-scratch disease (CSD) is considered to be an emerging disease worldwide and is caused by Bartonella henselae, a gram-negative bacterium introduced by a scratch or bite of a cat. The most common clinical manifestation is regional lymphadenopathy, but clinical recognition may be difficult, as atypical manifestations may occur. The diagnosis is confirmed with serologic testing and histology is rarely needed. This paper is based on our experience with the use of ultrasonography in the diagnosis of CSD.¶Objective. The aim of this study was to describe the sonographic and color Doppler appearances of regional lymphadenopathy in CSD, as this has not widely reported in the literature. ¶Materials and methods. Forty-seven patients (average 9.4 years) were included who all had serologically and/or histologically proven CSD and had been studied using US early in the clinical course. All had a positive history of exposure to cats and exhibited regional lymphadenopathy.¶Results. US showed large hypoechoic adenopathy with some transmission enhancement and high vascularization on color-flow Doppler imaging. In 30 patients, abdominal US was also performed and splenic and/or hepatic granulomata were found in 10.¶Conclusions. In our experience, sonography and especially color-Doppler and power-Doppler sonography was helpful in the diagnosis of CSD. We believe it should be used in the initial study of children with regional lymphadenopathy, and serologic testing should be performed when CSD is suspected.

Hepatic involvement is frequent in patients with cystic fibrosis (CF), with focal biliary cirrhosis being the pathognomonic hepatic manifestation. In around one-quarter of CF patients, it results in CF-associated liver disease (CFLD). This occurs as a relatively early complication with the majority of patients presenting in childhood or their early teens. However, a normal US does not preclude significant liver fibrosis and liver biopsy is an invasive procedure that is hampered by potential sampling errors. Transient elastography (TE) (Fibroscan) is a non-invasive, user-friendly and quick technique that provides an objective and reproducible measure of liver stiffness. This is accomplished with a device using an US probe mounted in the axis of a vibrator. Vibrations are transmitted by the transducer, inducing an electronic shear wave that propagates through the underlying tissue. We aimed to prospectively compare TE and transabdominal US scanning in children and adults attending a CF clinic. A total of 134 consecutive patients with documented CF were prospectively studied. In each case, transient elastography measurement was performed immediately after the routine annual US evaluation of the liver. Sonographic appearance of the liver was classified from 1 to 5. Ten validated TE measurements were performed in each patient with the result expressed in kilopascals (kPa). The median value was considered representative of the elastic modulus of the liver. Measurements were performed in 59 CF adults, 75 CF children and 31 control children. There was no relationship between age and liver stiffness in either the control group or CF patients. Elasticity values of controls, CF pancreatic sufficient (PS) patients and pancreatic insufficient (PI) CF patients with a US score <3 were comparable and significantly lower than in CF patients with a US score ≥ 3 (all PI) (P < 0.002). Median elasticity in CF patients was significantly higher in males (4.7 kPa) than in females (3.9 kPa) (P = 0.0013). Considering the limitations of US and the low risk-benefit rate of liver biopsy in most CF patients, this preliminary study suggests that TE is an attractive non-invasive way to assess and follow-up liver disease in these patients.

Children with cat-scratch disease (CSD) commonly present with fever and tender lymphadenopathy. The disease is mild and manifestations of infection resolve spontaneously within several weeks. However, some children with CSD have unusual features that present diagnostic challenges. Children with atypical CSD may present with prolonged fever, hepatosplenic disease or ocular disease. We performed an MRI on a child who presented with persistent back pain. The MRI demonstrated a paravertebral mass with intraspinous extension and the collapse of T7 vertebral body. A biopsy was reported to show a small round blue cell tumor. An evaluation for malignancy was negative, but Bartonella henselae DNA was detected by polymerase chain reaction on the biopsy specimen. We present this case because it is a rare but important radiological presentation of CSD.

Abstract Background. Acute pyelonephritis is distinguished from renal scarring using repeat cortical scintigraphy. The defects of acute pyelonephritis resolve, while those of scars persist. Objective. To determine the duration of reversible cortical defects following acute pyelonephritis and the time interval required to differentiate infection from scars. Materials and methods. An observational prospective study of 193 children (386 kidneys) aged less than 5 years following their first proven urinary tract infection (UTI). Renal cortical scintigraphic defects were detected in 112 (29%) kidneys within 15 days of diagnosis. Of these, 95 underwent repeat renal cortical scans 2 years after the UTI, including 50 with additional scans performed within 2–6 months of infection. Results. Of the 50 kidneys undergoing a second renal cortical scan within 2–6 months of the first UTI, 22 (44%) had persistent defects. A third scan was performed on 17 (77%) kidneys after 2 years, by which time defects had resolved in another 8 (47%) kidneys. The predictive value of defects detected within 2–6 months of UTI representing scars is 53% (95% CI 28, 77). Overall, nine (18%) kidneys with initial renal cortical abnormalities had permanent defects. In the 45 kidneys undergoing a second cortical scan more than 6 months after the UTI, 11 (24%) had persistent defects. None of the 95 kidneys undergoing serial scans developed new or larger defects. Conclusions. Renal scars may not be reliably diagnosed by cortical scintigraphy performed within 6 months of UTI because the inflammatory lesions may not have fully resolved.

This radiographically documented case of synchronous ileoileocolic intussusception and sigmoid volvulus is without apparent precedence. Etiological factors relevent to each of these conditions are discussed. Reasons for possible underdiagnosis of sigmoid volvulus and simultaneous lesions are included.