Pannee Visrutaratna

IAEA Survey of Pediatric CT Practice in 40 Countries in Asia, Europe, Latin America, and Africa. Part 1 : Frequency and Appropriateness

OBJECTIVE The purpose of this study was to assess the frequency of pediatric CT in 40 less-resourced countries and to determine the level of appropriateness in CT use. MATERIALS AND METHODS Data on the increase in the number of CT examinations during 2007 and 2009 and appropriate use of CT examinations were collected, using standard forms, from 146 CT facilities at 126 hospitals. RESULTS The lowest frequency of pediatric CT examinations in 2009 was in European facilities (4.3%), and frequencies in Asia (12.2%) and Africa (7.8%) were twice as high. Head CT is the most common CT examination in children, amounting to nearly 75% of all pediatric CT examinations. Although regulations in many countries assign radiologists with the main responsibility of deciding whether a radiologic examination should be performed, in fact, radiologists alone were responsible for only 6.3% of situations. Written referral guidelines for imaging were not available in almost one half of the CT facilities. Appropriateness criteria for CT examinations in children did not always follow guidelines set by agencies, in particular, for patients with accidental head trauma, infants with congenital torticollis, children with possible ventriculoperitoneal shunt malfunction, and young children (< 5 years old) with acute sinusitis. In about one third of situations, nonavailability of previous images and records on previously received patient doses have the potential to lead to unnecessary examinations and radiation doses. CONCLUSION With increasing use of CT in children and a lack of use of appropriateness criteria, there is a strong need to implement guidelines to avoid unnecessary radiation doses to children.

Survey of pediatric MDCT radiation dose from university hospitals in Thailand: a preliminary for national dose survey

Background Increasing pediatric CT usage worldwide needs the optimization of CT protocol examination. Although there are previous published dose reference level (DRL) values, the local DRLs should be established to guide for clinical practice and monitor the CT radiation. Purpose To determine the multidetector CT (MDCT) radiation dose in children in three university hospitals in Thailand in four age groups using the CT dose index (CTDI) and dose length product (DLP). Material and Methods A retrospective review of CT dosimetry in pediatric patients (<15 years of age) who had undergone head, chest, and abdominal MDCT in three major university hospitals in Thailand was performed. Volume CTDI (CTDIvol) and DLP were recorded, categorized into four age groups: <1 year, 1–< 5 years, 5–<10 years, and 10–<15 years in each scanner. Range, mean, and third quartile values were compared with the national reference dose levels for CT in pediatric patients from the UK and Switzerland according to International Commission on Radiological Protection (ICRP) recommendation. Results Per age group, the third quartile values for brain, chest, and abdominal CTs were, respectively, in terms of CTDIvol: 25, 30, 40, and 45 mGy; 4.5, 5.7, 10, and 15.6 mGy; 8.5, 9, 14, and 17 mGy; and in terms of DLP: 400, 570, 610, and 800 mGy cm; 80, 140, 305, and 470 mGy cm; and 190, 275, 560,765 mGy cm. Conclusion This preliminary national dose survey for pediatric CT in Thailand found that the majority of CTDIvol and DLP values in brain, chest, and abdominal CTs were still below the diagnostic reference levels (DRLs) from the UK and Switzerland regarding to ICRP recommendation.

A study to establish international diagnostic reference levels for paediatric computed tomography

The article reports results from the largest international dose survey in paediatric computed tomography (CT) in 32 countries and proposes international diagnostic reference levels (DRLs) in terms of computed tomography dose index (CTDI vol) and dose length product (DLP). It also assesses whether mean or median values of individual facilities should be used. A total of 6115 individual patient data were recorded among four age groups: <1 y, >1-5 y, >5-10 y and >10-15 y. CTDIw, CTDI vol and DLP from the CT console were recorded in dedicated forms together with patient data and technical parameters. Statistical analysis was performed, and international DRLs were established at rounded 75th percentile values of distribution of median values from all CT facilities. The study presents evidence in favour of using median rather than mean of patient dose indices as the representative of typical local dose in a facility, and for establishing DRLs as third quartile of median values. International DRLs were established for paediatric CT examinations for routine head, chest and abdomen in the four age groups. DRLs for CTDI vol are similar to the reference values from other published reports, with some differences for chest and abdomen CT. Higher variations were observed between DLP values, based on a survey of whole multi-phase exams. It may be noted that other studies in literature were based on single phase only. DRLs reported in this article can be used in countries without sufficient medical physics support to identify non-optimised practice. Recommendations to improve the accuracy and importance of future surveys are provided.

Brain Imaging and Neurodevelopment in HIV-uninfected Thai Children Born to HIV-infected Mothers.

Background: Perinatal use of combination antiretroviral therapy dramatically reduces vertical (mother-to-child) transmission of HIV but has led to a growing population of children with perinatal HIV-exposure but uninfected (HEU). HIV can cause neurological injury among children born with infection, but the neuroanatomical and developmental effects in HEU children are poorly understood. Methods: We used structural magnetic resonance imaging with diffusion tensor imaging to compare brain anatomy between 30 HEU and 33 age-matched HIV-unexposed and uninfected (HUU) children from Thailand. Maps of brain volume and microstructural anatomy were compared across groups; associations were tested between neuroimaging measures and concurrent neuropsychological test performance. Results: Mean (standard deviation) age of children was 10.3 (2.8) years, and 58% were male. All were enrolled in school and lived with family members. Intelligence quotient (IQ) did not differ between groups. Caretaker education levels did not differ, but income was higher for HUU (P < 0.001). We did not detect group differences in brain volume or diffusion tensor imaging metrics, after controlling for sociodemographic factors. The mean (95% confidence interval) fractional anisotropy in the corpus callosum was 0.375 (0.368–0.381) in HEU compared with 0.370 (0.364–0.375) in HUU. Higher fractional anisotropy and lower mean diffusivity were each associated with higher IQ scores in analyses with both groups combined. Conclusions: No differences in neuroanatomical or brain integrity measures were detectable in HEU children compared with age-matched and sex-matched controls (HUU children). Expected associations between brain integrity measures and IQ scores were identified suggesting sufficient power to detect subtle associations that were present.

Angiostrongylus cantonensis infection mimicking a spinal cord tumor

Angiostrongylus cantonensis is the most common cause of eosinophilic meningitis and meningoencephalitis. Almost all cases are self‐limiting and are diagnosed by cerebrospinal fluid eosinophilia and enzyme‐linked immunosorbent assay; pathology reports are restricted to postmortem samples from lethal cases. We report on what we believe is the first case of A. cantonensis infection diagnosed by biopsy in a living patient. The spinal cord was biopsied because of the unusual clinical presentation of a myelopathy without meningeal symptoms, together with a mass lesion that was clinically and radiologically diagnosed as a spinal cord tumor.

Cryptophthalmos, dental and oral abnormalities, and brachymesophalangy of second toes : New syndrome or Fraser syndrome?

We report on an 8-year-old Thai girl with bilateral complete cryptophthalmos, facial asymmetry, delayed bone age, brachymesophalangy and medial deviation of the second toes, and dental anomalies. The dental anomalies consist of delayed dental development, congenital absence of the second premolars, microdontia of the deciduous molars. A fibrous band of the buccal mucosa was found. Dental anomalies are rare among patients with Fraser syndrome. They have not been reported in either isolated or other syndromic cryptophthalmos. The oral manifestations and brachymesophalangy of the second toes found in our patient may represent newly recognized findings associated with cryptophthalmos or they may represent a newly recognized syndrome.

Pulmonary hypertension in non-transfusion-dependent thalassemia: Correlation with clinical parameters, liver iron concentration, and non-transferrin-bound iron

Abstract Background Pulmonary hypertension is a major cardiac complication in non-transfusion-dependent thalassemia (NTDT). Several clinical and laboratory parameters, including iron overload, have been shown to have a positive correlation with the incidence of pulmonary hypertension. Non-transferrin-bound iron (NTBI) is a form of free-plasma iron that is a good indicator of iron overload. Objectives The aim of this study was to determine the prevalence of pulmonary hypertension in patients with NTDT and to investigate its correlation with the clinical parameters, liver iron concentration (LIC) and NTBI. Methods Patients with NTDT were evaluated using echocardiography, and magnetic resonance imaging for cardiac T2* and LIC. Pulmonary hypertension was defined as peak tricuspid regurgitation velocity ≥2.9 m/s measured using trans-thoracic echocardiography. Clinical parameters and the status of iron overload as determined by LIC, serum ferritin, and NTBI level were evaluated for their association with pulmonary hypertension. Results Of 76 NTDT patients, mean age 23.7 ± 8.5 years, seven patients (9.2%) had pulmonary hypertension. Previous splenectomy (71.4 vs. 24.6%, P-value 0.019), higher cumulative red blood cell (RBC) transfusions (received ≥10 RBC transfusions 85.7 vs. 33.3%, P-value 0.011), higher nucleated RBCs (353 ± 287 vs. 63 ± 160/100 white blood cells, P-value <0.001), and a high NTBI level (5.7 ± 3.0 vs. 3.3 ± 2.8 µmol/l, P-value 0.034) were associated with pulmonary hypertension. There was no significant correlation between LIC or serum ferritin and pulmonary hypertension. Conclusion Pulmonary hypertension in NTDT is common, and is associated with splenectomy and its related factors. NTBI level shows a significant correlation with pulmonary hypertension.

Pediatric renovascular hypertension in Thailand: CT angiographic findings

BackgroundRenovascular disease is an uncommon but important cause of hypertension in children. When unrecognized and untreated, renovascular hypertension in children can have serious complications.ObjectiveTo review the causes of renovascular hypertension and computed tomography angiographic (CTA) findings in children and adolescents.Materials and methodsTwenty-eight CTAs from January 2004 to March 2008 of 23 children and adolescents with hypertension were reviewed for the causes and CTA findings.ResultsNine of the 23 children (39%) had abnormal renal arteries with or without abnormal abdominal aortas. Four of these children had Takayasu arteritis, one had moyamoya disease, and one had median arcuate ligament syndrome. One with chronic pyelonephritis had severe stenosis of the proximal right renal artery. The other two children had renal artery stenosis with a nonspecific cause. One child with a normal abdominal aorta and renal arteries had a right suprarenal mass. On pathological examination a ganglioneuroma was found.ConclusionCTA can help in diagnosis of renovascular hypertension in children and adolescents. Although CTA is not a screening modality, it is appropriate in some situations.

Clinical prediction rules for failed nonoperative reduction of intussusception

Purpose The nonoperative reduction of intussusception in children can be performed safely if there are no contraindications. Many risk factors associated with failed reduction were defined. The aim of this study was to develop a scoring system for predicting the failure of nonoperative reduction using various determinants. Patients and methods The data were collected from Chiang Mai University Hospital and Siriraj Hospital from January 2006 to December 2012. Inclusion criteria consisted of patients with intussusception aged 0–15 years with no contraindications for nonoperative reduction. The clinical prediction rules were developed using significant risk factors from the multivariable analysis. Results A total of 170 patients with intussusception were included in the study. In the final analysis model, 154 patients were used for identifying the significant risk factors of failure of reduction. Ten factors clustering by the age of 3 years were identified and used for developing the clinical prediction rules, and the factors were as follows: body weight <12 kg (relative risk [RR] =1.48, P=0.004), duration of symptoms >48 hours (RR =1.26, P<0.001), vomiting (RR =1.63, P<0.001), rectal bleeding (RR =1.50, P<0.001), abdominal distension (RR =1.60, P=0.003), temperature >37.8°C (RR =1.51, P<0.001), palpable mass (RR =1.26, P<0.001), location of mass (left over right side RR =1.48, P<0.001), ultrasound showed poor prognostic signs (RR =1.35, P<0.001), and the method of reduction (hydrostatic over pneumatic, RR =1.34, P=0.023). Prediction scores ranged from 0 to 16. A high-risk group (scores 12–16) predicted a greater chance of reduction failure (likelihood ratio of positive [LR+] =18.22, P<0.001). A low-risk group (score 0–11) predicted a lower chance of reduction failure (LR+ =0.79, P<0.001). The performance of the scoring model was 80.68% (area under the receiver operating characteristic curve). Conclusion This scoring guideline was used to predict the results of nonoperative reduction and forecast the prognosis of the failed reduction. The usefulness of these prediction scores is for informing the parents before the reduction. This scoring system can be used as a guide to promote the possible referral of the cases to tertiary centers with facilities for nonoperative reduction if possible.

Mediastinal pancreatic pseudocyst in chronic pancreatitis

A 14-year-old girl with chronic pancreatitis presented with palpitations, dysphagia, and pain in the subxyphoid region radiating to her back for 3 months. A contrast-enhanced CT showed a large cystic mass in the mediastinum compressing the heart and esophagus (Fig. 1, arrow). It arose from the pancreas, extending into the mediastinum through the esophageal hiatus (Fig. 2). Note pancreatic calcifications (Fig. 2, arrow). Pancreatic pseudocysts are complications of acute or chronic pancreatitis; they can extend well beyond the