Diagnostic Ultrasound for Acute Appendicitis: The Gold Standard.

BACKGROUND: Acute appendicitis may present a diagnostic dilemma. The aim of this study was to review the accuracy of ultrasound in the diagnosis of paediatric acute appendicitis. METHOD: Ultrasound studies performed for investigation of appendicitis during 2015-2021 were retrieved from a tertiary paediatric hospital database and reviewed. Medical records were reviewed to determine operative intervention, further imaging, and final diagnosis. Diagnostic accuracy was assessed by sensitivity, specificity, predictivity, and overall accuracy. All appendicectomy specimens underwent histopathological confirmation. This study was approved by the local Human Research Ethics Committee. RESULTS: A total of 8555 consecutive ultrasound examinations were performed during the study period. Mean patient age was 10.8 years ( ± 3.7). Overall diagnostic accuracy was 96.1% (8221/8555) with a visualisation rate of 91.0%. Sensitivity and specificity were 96.2% (CI 95.3-97.0%) and 96.1% (CI 95.6-96.5%), respectively. When limited to positive/negative scans, sensitivity was 99.6% (CI 99.2-99.8%) and specificity 99.0% (CI 98.7-99.3%). Positive and negative predictive values were 96.9% and 99.9%, respectively. Repeat ultrasound following a non-diagnostic scan led to a definitive diagnosis in 76.1%. Negative appendicectomy rate was 5.5% overall in children who had undergone pre-operative ultrasound (107/1938), and 4.4% when other surgical pathologies were excluded. CONCLUSION: Ultrasound examination provides gold-standard accuracy in the diagnosis of paediatric appendicitis and reduces rates of negative appendicectomy. Given the disadvantages of computed tomography and magnetic resonance imaging, ultrasound should be considered the first-line investigation of choice in the diagnosis of acute appendicitis in children. LEVEL OF EVIDENCE: III.

Ultrasound guided hydrostatic enema reduction of ileocolic intussusception: a safe and effective technique.

BACKGROUND: Currently, the primary management of ileocolic intussusception in children is usually by non-operative image-guided enema reduction. In most centres around the world especially in Australasia the predominant technique is the pneumatic reduction under fluoroscopic guidance. At our institution, we have been performing ultrasound-guided hydrostatic reduction since 2012.This is an audit to determine the efficacy and safety of ultrasound-guided hydrostatic reduction for intussusception. METHODS: Following ethics approval, a retrospective review of all patients presenting to our institution with intussusception and subsequently undergoing hydrostatic reduction over a period of 9 years (2012 to-2020) was performed. The parameters studied included (i) successful reduction, (ii) recurrence, (iii) need for surgery and (iv) lead point at surgery. RESULTS: The mean age at presentation was 12 months. One hundred and eight children were diagnosed to have ileocolic intussusception. One hundred and six underwent ultrasound-guided hydrostatic reduction with successful reduction in 96 (90.5%) patients. Reduction was unsuccessful in 10 patients (9.5%). Of these eight were noted to have a pathological lead point (four-Meckel's diverticulum and four-Lymphoma) at the time of the surgery. The intussusception recurred in six patients (6.25%) within 24 h. No reduction related perforation occurred during the study period. CONCLUSION: Ultrasound-guided hydrostatic reduction is a safe and effective technique for managing intussusception as it allows continuous monitoring of the reduction of the intussusception without exposing the children to ionizing radiation.

Ultrasound diagnosis of hypertrophic pyloric stenosis - Time to change the criteria.

Introduction: Ultrasound is the examination of choice for the diagnosis of hypertrophic pyloric stenosis (HPS). A correct diagnosis is dependent on the technique and measurement accuracy. However, in the world literature there is a wide range of values suggested for the diagnosis of this condition. The current minimum measurements used to diagnose HPS seem excessively large, and therefore, we set out to redefine these values. Methods: A retrospective study was performed on 607 patients (615 scans) being investigated for HPS. The length and transverse diameter of the pyloric canal, and thickness of the pyloric muscle were measured. All results were correlated with clinical and surgical findings. Results: In this study, the muscle thickness in the normal group was <2.0 mm than in HPS infants having a muscle thickness of 2.0-5.0 mm. All the pyloric canal lengths in the normal group were <5.0 mm than in those with HPS having a length of 10.0-24.0 mm. The transverse diameters ranged from 6.0 to 11.0 mm in the normal group compared with those with HPS having a diameter between 8.0 and 16.0 mm. Conclusions: The current criteria for sonographic diagnosis of HPS should be redefined. The canal length is the single most important discriminator, with a clear separation between normal and abnormal. The commonly used 16.0-mm measurement is too long and should be reduced to 10.0 mm (without the risk of false positives). In many cases, the muscle thickness in those with HPS is as low as 2.0 mm, considerably less than the 3.0 mm that is currently used. The transverse diameter is not a useful discriminator for HPS. The use of current values will delay the diagnosis and timely treatment of this condition.

Fibrodysplasia ossificans progressiva: Diagnosis with ultrasound.

Fibrodysplasia ossificans progressiva (FOP) is an extremely rare connective tissue disease, diagnosed by genetic testing. This is the first report in English literature wherein an ultrasound examination suggested this specific diagnosis. In this case, a two month old girl presented with bi-parieto-occipital swellings that were being managed as subgaleal haematoma. The parents were anxious that there was no resolution of the swellings. The suspicion of FOP was raised during the ultrasound examination where a review of the images prompted a questioning of the parents about other lesions in the body. Ultrasound examination of a lump in the thigh revealed calcifications in the vastus lateralis muscle. The appearances on the ultrasound combined with the presence of hallucis valgi suggested a diagnosis of FOP. The diagnosis was subsequently confirmed by genetic studies. This case highlights the need for good communication between the physician, patient and the imaging department.

Ultrasound imaging as the first line of investigation to diagnose intestinal malrotation in children: Safety and efficacy.

BACKGROUND: Upper gastrointestinal contrast study is considered the gold standard investigation to diagnose intestinal malrotation and midgut volvulus which is potentially devastating condition. Ultrasound imaging is an alternative but has been considered unreliable due to significant false negative results. At our institution we have been using ultrasound imaging as the first line investigation to diagnose malrotation since 2008 with a preliminary study of 139 patients published in 2014. This is an ongoing audit of a further much larger cohort of patients to determine the efficacy and safety of ultrasound imaging in the diagnosis of intestinal malrotation. MATERIALS AND METHODS: Following ethics approval, a retrospective analysis of a prospectively collected patient database undergoing ultrasound scans to exclude malrotation at our centre was performed from 2012 to 2019. RESULTS: 539 patients underwent ultrasound to assess for malrotation. The mean age of presentation was 365 days (median 30 days, mode 1 day). Malrotation was diagnosed in 17 with 5 having volvulus, with findings confirmed at surgery. 12 had equivocal findings and subsequent contrast studies ruled out malrotation. The remaining 510 patients with no evidence of malrotation were managed conservatively. CONCLUSION: We have shown ultrasound to be a safe and effective tool to assess intestinal malrotation without exposure to ionizing radiation. LEVEL OF EVIDENCE: Level IV.

Background ionising radiation: a pictorial perspective.

Ionising radiation from natural sources, known as background radiation, has existed on earth since the earth's formation. The exposure of humans and other living creatures to this radiation is a feature of the earth's environment which is continuing and inescapable. The word "radiation" brings fear to many people: a fear of the unknown, as human's senses cannot detect the presence of ionising radiation. In this study, a catalogue of images of the distribution of radioactivity in every day objects and foods has been produced using an imaging plate from a computed radiography cassette. The aim of the study is that by visually demonstrating that every day objects and foods are radioactive would alleviate the fear of "radiation" by becoming aware that we live in a radioactive environment and even our body is radioactive.

Randomized trial using ultrasound to assess intramuscular vaccination at a 60° or 90° needle angle.

OBJECTIVE: Globally, recommendations differ on the ideal angle of needle insertion to ensure vaccinate deposition in muscle for optimal safety and immunogenicity. This study aimed to compare the level of vaccinate deposition during vaccination, using two different needle angles (60° and 90°), in young children, adolescents and adults. METHODS: In this randomized cross-over study, two doses of a licensed hepatitis vaccine, were administered to study participants, at a 60° or 90° angle using a fixed template. Ultrasonography was performed with a Philips iu22 ultrasound system. Real time clips and hard copies of images were recorded showing the injection and level of deposition of the vaccinate. Reactogenicity at the site of administration was assessed by participants/parents. RESULTS: Nineteen participants were enrolled including children, adolescents and adults. Of the total 38 injections performed, 29 (76%) were confirmed by ultrasound as intramuscular (IM), 3 (8%) as not IM, and 6 (16%) unknown. For vaccinations visualised and administered at 60°, 87% (13/15) were intramuscular vs 94.1% (16/17) for those administered at 90°. A body mass index (BMI)≤25 was associated with a higher likelihood of IM injection compared to BMI>25 (p=0.038). There were no differences in reactogenicity for either 60° or 90° angle of administration. CONCLUSION: For the majority of vaccinees, a 60-90° angle of vaccine administration is appropriate for IM deposition of vaccinate. The likelihood of intramuscular deposition is reduced for individuals with a BMI>25. The increasing rates of obesity globally highlight the importance of tailoring vaccination procedures accordingly.

Preoperative use of ultrasonography to localize an ingested foreign body.

We report a 9-year-old boy who had swallowed a small dressmaker's pin during an art & craft class. Confirmation of ingestion of the pin and its passage through the gut was achieved with abdominal radiography. When the pin had not passed after 8 days, and with increasing concern about the likelihood of perforation, US was used to locate its exact position to allow surgical removal. This case report illustrates the unique use of US to reveal the intraappendiceal location of an ingested foreign body, facilitating its surgical removal.

Hs-CRP is associated with weight, BMI, and female sex but not with endothelial function in children with type 1 diabetes.

BACKGROUND: Atherosclerosis is an inflammatory process, and high-sensitivity C-reactive protein (Hs-CRP), a marker of inflammation, predicts cardiovascular events in adults. Vascular endothelial and smooth muscle dysfunction, measurable precursors of atherosclerosis, begin in childhood. Therefore, we sought to determine if Hs-CRP is associated with vascular endothelial and smooth muscle dysfunction in children with type 1 diabetes mellitus (T1DM) and healthy control subjects. METHODS: Hs-CRP and endothelial function assessed by flow-mediated dilatation (FMD) and smooth muscle function assessed by glyceryl-trinitrate (GTN)-induced dilatation were measured in 121 subjects with T1DM aged 14.1 (2.9) yr, of whom 31 were also studied at 4 and 8 wk, and in 33 healthy controls aged 14.2 (3.6) yr. RESULTS: Hs-CRP did not differ between subjects with T1DM and healthy, age-matched controls. In both controls and subjects with T1DM, Hs-CRP did not relate to FMD or GTN at baseline or at intervals over 8 wk in T1DM. Hs-CRP did not change over time. In T1DM, but not healthy controls, Hs-CRP related to body mass index (BMI) z-score (r = 0.47, p < 0.001), weight z-score (r = 0.41, p < 0.001), and female sex (p = 0.008). CONCLUSIONS: Hs-CRP is not associated with early vascular dysfunction in children with T1DM. However, in children and adolescents with T1DM, Hs-CRP was associated with female sex and children with higher BMI, suggesting that these groups may be at greater cardiovascular risk. Maintenance of a healthy BMI may be important in the prevention of vascular disease of T1DM.

Folic acid does not improve endothelial function in obese children and adolescents.

OBJECTIVE: Obese children have severe endothelial dysfunction as measured by flow-mediated dilation (FMD). We have shown that folic acid normalizes endothelial function in children with type 1 diabetes who have a similar degree of endothelial dysfunction but lower total plasma homocyst(e)ine (tHcy) and higher folate status. Our aim was to evaluate, for the first time, the effect of folate supplementation on endothelial dysfunction in obese children. RESEARCH DESIGN AND METHODS: A total of 53 obese subjects (26 male, mean +/- SD age 13.3 +/- 2.2 years, and BMI Z score 2.29 +/- 0.25) participated in a randomized, double-blind, placebo-controlled, parallel trial of oral folic acid (5 mg/day) or placebo for 8 weeks. Before and after the intervention, we assessed endothelial function (FMD), smooth muscle function (glyceryl trinitrate-induced dilatation [GTN]), high-sensitivity C-reactive protein (hsCRP), tHcy, serum folate, red cell folate (RCF), and lipids. RESULTS: There were no group differences at baseline. FMD did not change with the intervention (folic acid group pre- and postintervention: 6.42 +/- 5.03 and 6.56 +/- 4.79%, respectively, vs. placebo group: 5.17 +/- 3.54 and 5.79 +/- 4.26%, respectively; P = 0.6). Folate supplementation increased serum folate and RCF by 18.4 nmol/l (P < 0.001) and 240.1 nmol/l (P < 0.001), respectively, and decreased tHcy by 0.95 microl (P = 0.008). The intervention did not change GTN, hsCRP, or lipids. CONCLUSIONS: Folic acid supplementation does not improve endothelial function in obese children without diabetes despite increasing folate status and reducing tHcy. This is in contrast to the response to folate in children with type 1 diabetes.

Ultrasound examination of extensive limb swelling reactions after diphtheria-tetanus-acellular pertussis or reduced-antigen content diphtheria-tetanus-acellular pertussis immunization in preschool-aged children.

OBJECTIVE: The aim of this study was to determine the site, extent, and resolution of tissue involvement when extensive limb swelling occurred in the injected limb for children who received diphtheria-tetanus-acellular pertussis or reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine at 4 to 6 years of age. METHODS: Children who had experienced an injection site reaction at 18 months of age were assigned randomly to receive an intramuscular injection of either reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine or diphtheria-tetanus-acellular pertussis vaccine between 4 and 6 years of age. Children who developed extensive limb swelling were recruited for assessment by clinical examination; ultrasound studies of the affected and opposite (control) arms were performed 24 to 48 hours after immunization and 48 to 96 hours later. RESULTS: Twelve children with extensive limb swelling were enrolled in the study. Ultrasound examinations demonstrated swelling of both the subcutaneous and muscle layers of the vaccinated arm. Ultrasound assessment showed that the swelling exceeded the clinical measurements of skin redness and swelling. Subcutaneous and muscle tissues expanded to 281% and 111% of the tissue thicknesses of the control arm, respectively. Repeat ultrasound examinations after 48 to 96 hours showed considerable resolution of muscle swelling, compared with subcutaneous tissue swelling. There was no significant difference in the extent of swelling detected between children who received diphtheria-tetanus-acellular pertussis vaccine and those who received reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine. CONCLUSION: Extensive limb swelling reactions after diphtheria-tetanus-acellular pertussis or reduced-antigen content booster immunizations involved swelling of subcutaneous and muscle tissues with swelling and duration more marked in subcutaneous tissue.

Vascular endothelial and smooth muscle function relates to body mass index and glucose in obese and nonobese children.

CONTEXT: Endothelial and smooth muscle dysfunction are critical precursors of atherosclerosis. These can be detected in children at risk of cardiovascular disease. OBJECTIVE: The objective of this study is to evaluate endothelial and smooth muscle function and their determinants using flow-mediated dilatation (FMD) and glyceryl trinitrate-mediated dilatation (GTN) in obese, nonobese, and type 1 diabetes mellitus (T1DM) children. DESIGN: This is a cross-sectional study. SUBJECTS: The study subjects were 270 children [140 males, mean age 13.7 (2.8) yr] including 58 obese, 53 nonobese, and 159 T1DM children. MEASUREMENTS: Vascular function (FMD and GTN), body mass index (BMI) z-score, blood pressure, glucose, glycosylated hemoglobin, lipids, folate, homocysteine, and high sensitive C-reactive protein were measured. RESULTS: FMD and GTN were significantly lower in obese and T1DM compared with nonobese subjects (P < 0.001, P < 0.001). FMD and GTN were similarly reduced in obese and T1DM subjects (P = 0.22, P = 0.28). In all nondiabetic subjects (n = 111), both FMD and GTN were significantly and independently related to BMI z-score (r = -0.28, P = 0.003, beta = -0.36, P < 0.001) and weight z-score (beta = -0.31, P = 0.002; r = -0.52, P < 0.001). FMD related independently to total cholesterol (beta = -0.22, P = 0.02). GTN related independently to vessel diameter (beta = -0.49, P < 0.001). GTN related to glucose within the normal range (r = -0.34, P = 0.001). CONCLUSIONS: Children with obesity and T1DM have a similar degree of vascular dysfunction. BMI and weight adjusted for age and sex relate to endothelial and smooth muscle function in nonobese and obese children. Glucose relates to smooth muscle function in nonobese nondiabetic children. This suggests a continuum effect of BMI and glucose within the normal range on vascular function in childhood.

Folate and vitamin B6 rapidly normalize endothelial dysfunction in children with type 1 diabetes mellitus.

BACKGROUND: Endothelial dysfunction, a precursor of vascular disease, begins early in type 1 diabetes mellitus and is associated with folate status. METHODS: A randomized, double-blind, placebo-controlled study of folate (5 mg daily) and vitamin B6 (100 mg daily) in 124 children with type 1 diabetes determined the immediate and 8-week effects of these vitamins, alone and in combination, on endothelial function. Endothelial function, assessed as flow-mediated dilation and glyceryltrinitrate-induced dilation with high-resolution ultrasound of the brachial artery, was measured at baseline, at 2 and 4 hours after the first dose (n = 35), and at 4 and 8 weeks of treatment (n = 122). RESULTS: Flow-mediated dilation normalized in all treatment groups. From baseline to 8 weeks, flow-mediated dilation improved with folate from 2.6% +/- 4.3% (mean +/- SD) to 9.7% +/- 6.0%, with vitamin B6 from 3.5% +/- 4.0% to 8.3% +/- 4.2%, and with folate/vitamin B6 from 2.8% +/- 3.5% to 10.5% +/- 4.4%. This improvement in flow-mediated dilation occurred within 2 hours and was maintained at 8 weeks for each treatment. Flow-mediated dilation in the placebo group, and glyceryltrinitrate-induced dilation in all groups, did not change. Increases in serum folate, red cell folate, and serum vitamin B6 levels related to increases in flow-mediated dilation. Improvement in flow-mediated dilation was independent of changes in total plasma homocyst(e)ine, glucose, hemoglobin A1c, and high-sensitivity C-reactive protein levels. Baseline red cell folate levels and baseline diastolic blood pressure were related inversely to improvement in flow-mediated dilation. Serum triglyceride and low-density lipoprotein cholesterol inversely related to baseline flow-mediated dilation. CONCLUSIONS: High-dose folate and vitamin B6 normalized endothelial dysfunction in children with type 1 diabetes. This effect was maintained over 8 weeks, with no additional benefit from combination treatment.

Dried apricots: an unusual cause of bowel obstruction.

We report an unusual cause of intestinal obstruction in a 16-month-old boy who presented with abdominal pain of 6 h duration. The patient was thought to have an intussusception, with plain radiographic evidence of a small-bowel obstruction (SBO). A subsequent US examination showed no evidence of intussusception but resulted in a diagnosis of SBO caused by the ingestion of whole dried apricots. The apricots had been eaten several hours earlier and had swelled in the intestinal lumen. The US imaging findings and experimental correlation are presented.

Longitudinal study of normal hip development by ultrasound.

In the management of a newborn's hips, ultrasonography has proven to be useful. The progression of measurements at different ages in normal hips has not been thoroughly investigated. The purpose of this prospective study was to assess the longitudinal development of clinically stable hips. Forty newborns (80 hips) were assessed by ultrasonography at birth and at 6 and 12 weeks of age. Femoral head coverage (FHC), alpha angles, and beta angles were measured. The results showed a significant change in values between the three points in time for all measurements (P < 0.001). The mean FHC progressed from 58.4% to 65.6% to 69.3%, the mean alpha angle from 70.2 degrees to 76.8 degrees to 80.3 degrees , and the mean beta angle from 52.1 degrees to 45.7 degrees to 42.9 degrees . In clinically stable hips, the FHC and alpha and beta angles change significantly over time; therefore, it is important to consider the child's age when interpreting ultrasound images.

Benefits of sonographic-guided hydrostatic reduction opposed to air reduction in a case of intussusception due to lymphoma.

A case of intussusception due to a pathological lead point in a child is presented. Such cases are uncommon in the paediatric age-group. The pathological lead point was missed at air enema reduction but it was clearly defined on sonographic-guided hydrostatic reduction. The advantages and disadvantages of these reduction methods are discussed.