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Purpose: To estimate occurrence rate of high cumulative radiation exposure from paediatric computed tomography (CT), and to determine influential factors on high-dose inclination. Material and methods: Patients below 18 years old receiving at least 50 mSv of a cumulative dose during a 5-year period in a tertiary care centre were retrospectively enrolled. Individual patient characteristics, diagnoses, frequency of examinations, scanner sites, designated scans, and effective doses were recorded. Collective doses were compared among groups of the diagnoses and scanner sites, and regression analyses were applied. Results: Of 2771 patients, 3.2% received individual cumulative doses between 50 and 303 mSv (median, 74 mSv). Frequency of examinations ranged from 1 to 13 times (median, 4 times) per patient. About 70% of the patients had oncological illness. Radiation was predominantly high in a CT simulator that could contribute the percentage of collective dose to twice that of examinations owing to higher scanning parts and CT dose index. Some scanner sites used higher acquisition phases. Regression analysis showed that the number of scanning parts and phases significantly influenced the cumulative dose inclination (p < 0.05) while frequent examinations did not. Conclusions: There was a low occurrence of paediatrics with high dose accumulation. Significant factors affecting potentially high exposure were customized CT protocols in the specific scanners.

The authors report imaging findings of spontaneous thymic hemorrhage, which is a rare entity in infancy, in a 4-month-old boy with congenital factor VII deficiency presented with acute respiratory distress and anemia. Widening of superior mediastinum and left pleural effusion were detected on the chest radiograph. Ultrasound and computed tomography of the chest revealed diffusely enlarged thymus with heterogeneous parenchyma from poorly-defined areas of altered echogenicity or attenuation. Vascular flow was depicted within the abnormal thymus in color-mode sonography. The spontaneous involution of thymic abnormality seen on serial ultrasonography confirmed the diagnosis of thymic hemorrhage, resulting in avoidance of further unnecessary imaging or invasive procedure.

Chulalongkorn Medical Journal, 66, 4, 493-497

Background: Justification of imaging investigations is important, particularly in pediatrics underwent investigation using a relatively higher radiation such as CT, due to the higher radiation sensitivity of children. Objective: To assess the difference of viewpoints between pediatric physicians and pediatric radiologists on the appropriateness of pediatric CT utilization in a tertiary-care university hospital with limited MR capacity. Methods: Pediatric medical records of head CT, chest CT, and abdominal CT were retrospectively reviewed in consecutive date of the examination until having 100 head CTs and 100 body CTs with complete clinical and imaging information. The physicians and the radiologists were asked to suggest the imaging modality of choice for each patient according to the given data, regardless of the hospital’s limitation. If the suggested modality of choice was not CT, the CT request would be considered as “inappropriate”. They additionally scored the CT appropriateness, firstly using individual judgement, and secondly using the ACR Appropriateness Criteria. Both scoring methods used the same rating scale from 1 to 9; score 1-3 was considered “inappropriate”. Results: From the viewpoint of the physicians and radiologists, the number of inappropriate CT request was 20% and 54% according to “the modality of choice”, 2.5% and 17% according to “individual judgement”, 12% and 22% according to the “ACR Appropriateness Criteria”. The main difference was not from no indication for imaging but from the selected modality of imaging. The radiologists suggested 52% of head CTs and 64% of abdominal CTs could have been replaced by MRI if available. Conclusion: There are ten-percent disagreement on appropriateness of pediatric CT request between physicians and the radiologists when using the same guidelines and considering the hospital limitation.

There are many errors and pitfalls that are commonly encountered during ultrasound examinations. In normal ultrasound, pitfalls may arise from anatomic or physiologic variants of pediatric anatomy, settings, artifacts, patient conditions, operator misunderstanding, or inexperienced performance. In limited field and point-of-care ultrasound, common errors are usually due to limited access, misdiagnosis as a result of wrong timing, unsuitable patient conditions, limited transducer options, satisfaction of search, and unfamiliarity with pediatric sonography. Knowledge of these pitfalls helps improve a physician's performance and diagnosis.

Background: The criterion standard gonadotropin-releasing hormone (GnRH) stimulation tests to diagnose central precocious puberty (CPP) are time-consuming, inconvenient, and expensive. Objective: To determine predictive cut-off values codetermined by ultrasonographic parameters and basal gonadotropin levels in girls with premature sexual development and compare them results of criterion standard tests in a study of diagnostic accuracy. Methods: Retrospective review of hormonal investigations and ultrasonographic uterine and ovarian parameters in a consecutive sample of girls at a single center, tertiary care hospital in Bangkok, Thailand. Results: We separated data from 68 girls (age range 2–12 years) into 2 groups based on their response to a GnRH analogue agonist stimulation test. A “prepubertal response” group included girls with premature thelarche and thelarche variants (n = 18, 6.37 ± 1.77 years) and a “pubertal response” group, including girls with CPP (n = 50, 8.46 ± 1.46 years); excluding patients with pathological causes (n = 0). The basal level of luteinizing hormone (LH) had the largest area under receiver operating characteristic curves (AUC) of 0.84; 95% confidence interval [CI] 0.74–0.93) compared with basal levels of follicle stimulating hormone (AUC 0.77; 95% CI 0.64–0.90) or estradiol (0.70; 95% CI 0.56–0.85). An optimal cut-off of 0.25 IU/L LH was related to a pubertal response to GnRH analogue agonist stimulation tests with 75.0% sensitivity, 88.9% specificity, 94.7% positive predictive value (PPV), and 57.1% negative predictive value. Uterine and ovarian cut-off volumes of 3.5 cm3 and 1.5 cm3 were related to a pubertal response with 88.6% and 76.2% PPV, respectively. A uterine width cut-off of 1.7 cm combined with a basal LH cut-off of 0.25 IU/L increased specificity and PPV to 100%. Conclusion: Combining uterine and ovarian ultrasonographic parameters with basal gonadotropin levels, especially uterine width and basal LH level, appears useful for diagnosis of CPP.Figure 2. Receiver operating characteristic curves for various ultrasonographic and hormonal parameters. A. Basal luteinizing hormone. B. Basal follicle stimulating hormone. C. Basal estradiol. D. Uterine volume. E. Uterine width. F. Uterine length. G. Uterine thickness. H. Bilateral ovarian volume. Solid lines indicate the variable parameter and dashed lines indicate a reference line. Diagonal segments are produced by ties.Table 3. Sensitivity, specificity, PPV, and NPV when combining uterine ultrasonographic and basal hormonal parametersSPSS dataset (*.sav) to support Figure 2 provided. SPSS Output files (*.spv) to support Figure 2 and Table 3 provided.

Mesenchymal hamartoma of the chest wall is a rare tumor-like lesion of infancy and childhood. The few available descriptions of the findings on fine needle aspiration list spindle-shaped cells and cartilage or chondromyxoid material as essential features for this diagnosis. An aggressive appearance on imaging studies and a lack of familiarity with this lesion, can lead the pathologist to misdiagnose the cytologic findings as malignancy. We reported a 5-month-old male presenting with a mass of the right chest wall progressively for 2 months. Radiologic studies showed a mixed solid and cystic mass originating from the third, fourth and fifth ribs, and a diagnosis of malignancy was favored. Fine needle aspiration recovered only spindle-shaped cells and a few multinucleated giant cells of osteoclast type. After a review of the imaging, a diagnosis of mesenchymal hamartoma of the chest wall was raised. This diagnosis was confirmed by pathologic examination of the subsequently resected mass. This is the sixth report of a mesenchymal hamartoma of the chest wall diagnosed by fine needle aspiration. This case illustrates that this diagnosis can be suspected in the absence of cartilage or chondromyxoid material, given appropriate clinical and radiologic findings. Diagn. Cytopathol. 2014;42:890–894. © 2014 Wiley Periodicals, Inc.

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 (vol) and DLP were recorded, categorized into four age groups: 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.

CT has been used to save many patients’ lives and the demand for CT is still increasing. At the same time, there has been increasing concern of the probability of cancer induction by CT radiation. It is necessary for everyone involved in CT scanning, particularly physicians who have to communicate with patients when planning a CT scan, to have a basic knowledge of the CT radiation dose and its potential adverse effects. We have undertaken a systematic review of the literatures to document the radiation dose from CT, the lifetime cancer risk from CT exposure, CT dose parameters, the internationnal CT diagnostic reference levels, and the use and limitation of the CT effective dose. In addition, we conducted a brief survey of the use of CT scan in some university hospitals in Thailand and estimated current CT doses at these hospitals. Our review and survey suggests that CT scanning provides a great benefit in medicine but it also becomes the major source of X-ray exposure. Radiation doses from a CT scan are much higher than most conventional radiographic procedures. This raises concerns about the carcinogenic potentials. We encourage every CT unit to adhere to the International Guidelines of CT dose parameter references. Our preliminary survey from some university hospitals in Thailand revealed that CT radiation doses are within acceptable standard ranges. However, the justification for utilization of CT scans should also be required and monitored. The importance of adequate communication between attending physician and consulting radiologist is stressed.

Background: The undescended testis represents a common condition affecting male infants with significant clinical implications such as infertility and testicular malignancy. There is controversy as to the diagnosis when a clinical examination fails to identify a testis. Objective: Investigate the value of ultrasound in the diagnosis of undescended testis, and evaluate the correlation between the preoperative ultrasonographic data and operative findings. Material and method: Thirty-nine boys (age: 3months -12 years) with undescended testes were examined between January 2003 and December 2007. All the boys had undergone a sonogram performed for localizing the undescended testes. Only 20 boys were sent for inguinal exploration, or other surgical procedures for localizing the undescended testes. We calculated specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV), and the accuracy of ultrasonographic diagnosis in boys with undescended testes. Results: Twenty-nine undescended testes were included in this study. Ultrasonography had a sensitivity of 82%, a specificity of 0%, PPV of 96%, NPV of 0%, and accuracy of 79% in the diagnosis of the undescended testis. Conclusions: The sensitivity and specificity including NPV of uetrasound had the unsatisfactory outcomes. Keywords: Accuracy, pediatric, testis, ultrasound, undescended

Background: Early diagnosis of asplenia syndrome is important because prophylactic antibiotic and proper vaccination will prevent serious infection. Most children with asplenia syndrome present with symptoms of congenital heart disease. Chest X-ray is usually the first line imaging modality. Objective: Define useful findings in chest radiograph that could suggest the diagnosis of asplenia syndrome. Methods: Chest radiographs of pediatric patients who had asplenia syndrome diagnosed between January 1, 2002 and June 30, 2008 in a single institute were retrospectively reviewed for the positions of the visceral organs in the chest and abdomen. Results: Three hundred seventy one chest radiographs of 30 patients were reviewed. The mean age at diagnosis was 3 years old. Asplenia was diagnosed by ultrasound in 27 patients, by CT scan in two patients, and by damaged red blood cell scintigraphy in one patient. Six important findings detected from chest radiographs were, 1) bilateral minor fissures, 16 cases (53%), 2) bilateral eparterial bronchi, 16 cases (53%), 3) ipsilateral side of stomach and liver, 12 cases (40%), 4) ipsilateral side of minor fissure or eparterial bronchus and stomach, 10 cases(33%), 5) symmetrical transverse lie of the liver, nine cases (30%), and 6) contralateral side of minor fissure or eparterial bronchus and the liver in seven cases (23%). All except two patients (93%) had at least one of the above findings. All patients had congenital heart diseases. Most of the heart diseases were pulmonary atresia or pulmonary stenosis (88%) and single ventricle (85%). Conclusion: Chest radiographs have high sensitivity in suggesting the diagnosis of asplenia syndrome, when detecting one or more of the above findings, particular in patients with congenital heart disease and decreased pulmonary vasculature. Keywords: Asplenia, chest X-ray, children, congenital heart disease, heterotaxia, minor fissure, situs ambiguous

Ultrasound (US) of chest, even with inherent limitations of the US beam and air, has been useful in many pediatric chest conditions. It has extended its role and is now widely used by many subspecialists in medicine. This review article will cover techniques, indications, and applications of chest US in neonates, infants and children, including also different common as well as some rare and modern aspects and applications, such as pleural effusion, pneumothorax, pulmonary lesions, mediastinum, diaphragm, and chest wall. Other related imaging modalities are also briefly discussed.

Diagnosis of appendico-vesical fistula (AVF) is challenging because clinical symptoms are frequently nonspecific. Radiologists have to detect subtle abnormalities from frontline imaging modalities, such as plain abdominal radiograph or ultrasound (US); those may indicate more specific diagnostic modalities to demonstrate the fistula. Early recognition of indirect sign is meaningful, because delayed diagnosis may result in significant sequalae, for example, failure to thrive and anemia, which are particularly important in children. We report a boy with an AVF who presented with intractable recurrent urinary tract infection and – on basic imaging – had abnormally shaped urinary calculi on plain radiograph and an abnormal direction of ureteric bladder inflow jet on US. These findings led to further investigation with voiding cystourethrography and cystoscopy, from which the diagnosis was established, and eventually surgery confirmed the diagnosis.

Mesenchymal hamartoma of the chest wall is a rare tumor-like lesion of infancy and childhood. The few available descriptions of the findings on fine needle aspiration list spindle-shaped cells and cartilage or chondromyxoid material as essential features for this diagnosis. An aggressive appearance on imaging studies and a lack of familiarity with this lesion, can lead the pathologist to misdiagnose the cytologic findings as malignancy. We reported a 5-month-old male presenting with a mass of the right chest wall progressively for 2 months. Radiologic studies showed a mixed solid and cystic mass originating from the third, fourth and fifth ribs, and a diagnosis of malignancy was favored. Fine needle aspiration recovered only spindle-shaped cells and a few multinucleated giant cells of osteoclast type. After a review of the imaging, a diagnosis of mesenchymal hamartoma of the chest wall was raised. This diagnosis was confirmed by pathologic examination of the subsequently resected mass. This is the sixth report of a mesenchymal hamartoma of the chest wall diagnosed by fine needle aspiration. This case illustrates that this diagnosis can be suspected in the absence of cartilage or chondromyxoid material, given appropriate clinical and radiologic findings.

CTA plays an important role in evaluation of the major thoracic vessels in children. The purpose of this review is to describe the application of CTA in evaluation of the thoracic aorta, the pulmonary arteries and veins, and potential aortic-pulmonary collaterals. Indications, consideration, technical details of how to perform these investigations in children, restrictions and representative illustration are presented and discussed.

We report a 46-day-old female infant with xanthogranulomatous adrenalitis. Ultrasonography showed a complex, solid-cystic right suprarenal mass with poorly defined margins. Colour flow Doppler revealed the solid portion of the mass to be vascular. CT demonstrated a heterogeneous cystic and solid mass with some contrast enhancement in the inferior part of the lesion. There was compression of the adjacent upper pole of the right kidney and the lateral aspect of the inferior vena cava. The mass was completely removed; histological examination revealed xanthogranulomatous adrenalitis. At the time of this report she remained well 3 years following surgery.

This report documents a case of infiltrating cervical spinal mass, most likely a spinal tumor, in a girl with HIV infection that regressed following HAART and without treatment of the tumor or any anti-infectives.

To describe radiographic findings in physically abused children.The physically abused children diagnosed in King Chulalongkorn Memorial Hospital from 1998 to 2002 were retrospectively reviewed of medical records and radiographic imaging.Eighteen of 30 physically abused children had positive radiographic findings and 15 of 18 were related to head injury. Subdural hematomas and skull fractures were the two most common findings found in 11 cases and 9 cases respectively. Seven of 11 cases of head injury had retinal hemorrhage. Fractures other than the skull were detected in 6 patients, located at the long bones, ribs and spines. The abused children with positive radiographic findings were more commonly found in younger infants and mucocutaneous lesions might be absent.Inflicted head injury was the most common radiographic findings in the present series. Shaking-impact mechanism was likely to play a significant role in this group of patients.