Scurvy is a rare disease in developed nations. In the field of pediatrics, it primarily is seen in children with developmental and behavioral issues, malabsorptive processes, or diseases involving ...dysphagia. We present the case of an otherwise developmentally appropriate 4-year-old boy who developed scurvy after gradual self-restriction of his diet. He initially presented with a limp and a rash and was subsequently found to have anemia and hematuria. A serum vitamin C level was undetectable, and after review of the MRI of his lower extremities, the clinical findings supported a diagnosis of scurvy. Although scurvy is rare in developed nations, this diagnosis should be considered in a patient with the clinical constellation of lower-extremity pain or arthralgias, a nonblanching rash, easy bleeding or bruising, fatigue, and anemia. This case highlights the importance of carefully assessing a child's dietary and developmental status at well-child visits, which can help avoid a more invasive workup.
A palpable finding along the chest wall is a frequent indication for pediatric US. Accurate identification of benign lesions can reassure families and appropriately triage children who need ...follow-up, cross-sectional imaging, or biopsy. In this pictorial essay, we review chest wall anatomy, illustrate US techniques and discuss key US imaging features of common benign lesions and normal variants.
The purposes of this study were to visualize the human median nerve on diffusion tensor imaging and to determine the normal fractional anisotropy (FA) value and apparent diffusion coefficient (ADC) ...of the normal median nerve.
The wrists of 20 healthy volunteers and of two patients with carpel tunnel syndrome were examined with a 3-T MRI system with a standard eight-channel sensitivity-encoding head coil. Diffusion tensor imaging was performed with a spin-echo echo-planar sequence. A T1-weighted sequence was performed for anatomic reference. After tractography, the FA value and ADC of the whole nerve were calculated automatically. Manual focal measurements also were obtained at the levels of the flexor retinaculum, wrist, and forearm.
We visualized the median nerve with MR diffusion tensor tractography and followed the nerve for approximately 77.5 mm. We found the normative diffusion values of the median nerve were an FA of 0.709 +/- 0.046 (SD) and an ADC of 1.016 +/- 0.129 x 10(-3) mm2/s. There was a statistically significant difference between the FA values obtained at the level of the flexor retinaculum and the values obtained from the other parts of the median nerve (p < 0.0001). We found a decrease in FA value (p < 0.01) and an increase in ADC (p < 0.05) with advancing age.
The normative diffusion values of the human median nerve can be used as a reference in evaluation, diagnosis, and follow-up of entrapment, trauma, and regeneration of the median nerve.
Objective To evaluate the accuracy of renal and bladder ultrasonography (RBU) in predicting vesicoureteral reflux (VUR) in infants and children. Materials and Methods A total of 134 children who had ...VUR demonstrated on voiding cystourethrography (VCU) and also had RBU within 1 month of the VCU were included in the study, which took place between January 2005 and December 2012. VUR and hydronephrosis were graded with standard methods on VCU and RBU, respectively. Using VCU findings of reflux as the gold standard, diagnostic accuracy measures were performed for hydronephrosis and ureteral visualization on RBU, including sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. Results Reflux grade was significantly associated with the degree of hydronephrosis ( P = .0032). The sensitivity, negative predictive value, and accuracy of ultrasonography in predicting reflux was significantly higher for grade IV+ or grade V reflux compared with lower reflux grades. Also, the specificity of ultrasonography in predicting reflux was constant and at high level across all reflux grades, suggesting that ultrasonography is a good diagnostic screening tool. Conclusion Normal RBU is rare with grade IV-V reflux, and moderate to severe hydronephrosis is rare with reflux grades <IV. RBU is a valid screening test for the selection of patients with a first urinary tract infection who should undergo VCU. Diagnosis of grade IV and V reflux will be delayed in very few cases, using a definition of abnormal RBU to include all degrees of hydronephrosis (Society for Fetal Urology classification).
To compare gradient-echo (GRE) phase magnetic resonance (MR) imaging and quantitative susceptibility mapping (QSM) in the detection of intracranial calcifications and hemorrhages.
This retrospective ...study was approved by the institutional review board. Thirty-eight patients (24 male, 14 female; mean age, 33 years ± 16 standard deviation) with intracranial calcifications and/or hemorrhages diagnosed on the basis of computed tomography (CT), MR imaging (interval between examinations, 1.78 days ± 1.31), and clinical information were selected. GRE and QSM images were reconstructed from the same GRE data. Two experienced neuroradiologists independently identified the calcifications and hemorrhages on the QSM and GRE phase images in two randomized sessions. Sensitivity, specificity, and interobserver agreement were computed and compared with the McNemar test and k coefficients. Calcification loads and volumes were measured to gauge intermodality correlations with CT.
A total of 156 lesions were detected: 62 hemorrhages, 89 calcifications, and five mixed lesions containing both hemorrhage and calcification. Most of these lesions (146 of 151 lesions, 96.7%) had a dominant sign on QSM images suggestive of a specific diagnosis of hemorrhage or calcium, whereas half of these lesions (76 of 151, 50.3%) were heterogeneous on GRE phase images and thus were difficult to characterize. Averaged over the two independent observers for detecting hemorrhages, QSM achieved a sensitivity of 89.5% and a specificity of 94.5%, which were significantly higher than those at GRE phase imaging (71% and 80%, respectively; P < .05 for both readers). In the identification of calcifications, QSM achieved a sensitivity of 80.5%, which was marginally higher than that with GRE phase imaging (71%; P = .08 and .10 for the two readers), and a specificity of 93.5%, which was significantly higher than that with GRE phase imaging (76.5%; P < .05 for both readers). QSM achieved significantly better interobserver agreements than GRE phase imaging in the differentiation of hemorrhage from calcification (κ: 0.91 vs 0.55, respectively; P < .05).
QSM is superior to GRE phase imaging in the differentiation of intracranial calcifications from hemorrhages and with regard to the sensitivity and specificity of detecting hemorrhages and the specificity of detecting calcifications.
It has been suggested that increased hepatic and intramuscular fat is associated with insulin resistance, and that increased pancreatic fat is related to impaired insulin secretion.
We postulated ...that in obese nondiabetic teenagers insulin levels would be directly related to increases in intramuscular and hepatic fat and inversely related to increases in pancreatic fat.
MRI was used to assess the percentage of fat in the liver, muscle and pancreas in 15 healthy Mexican-American girls, 14-17 years old, with body mass indexes (BMIs) ranging from 17.7 kg/m(2) to 46 kg/m(2).
Strong correlations were observed between BMI and fat content in the liver, muscle, and pancreas (r(2)s between 0.50 and 0.89; P<0.003). Serum insulin levels were closely associated with fat measures in the muscle and liver (r(2s)=0.63 and 0.29, and P=0.001 and P=0.023, respectively). In contrast to our hypothesis, fat content in the pancreas was also directly related to insulin secretion (r(2)=0.74; P=0.001).
We conclude that in nondiabetic teenagers, obesity is associated with an increased accumulation of fat in the pancreas without impairment of insulin secretion.
Purpose
To achieve high‐resolution fetal brain anatomical imaging without introducing image artifacts by reducing the FOV, and to demonstrate improved image quality compared to conventional full‐FOV ...fetal brain imaging.
Methods
Reduced FOV was achieved by applying outer volume suppression (OVS) pulses immediately prior to standard single‐shot fast spin echo (SSFSE) imaging. In the OVS preparation, a saturation RF pulse followed by a gradient spoiler was repeated three times with optimized flip‐angle weightings and a variable spoiler scheme to enhance signal suppression. Simulations and phantom and in‐vivo experiments were performed to evaluate OVS performance. In‐vivo high‐resolution SSFSE images acquired using the proposed approach were compared with conventional and high‐resolution SSFSE images with a full FOV, using image quality scores assessed by neuroradiologists and calculated image metrics.
Results
Excellent signal suppression in the saturation bands was confirmed in phantom and in‐vivo experiments. High‐resolution SSFSE images with a reduced FOV acquired using OVS demonstrated the improved depiction of brain structures without significant motion and blurring artifacts. The proposed method showed the highest image quality scores in the criteria of sharpness, contrast, and artifact and was selected as the best method based on overall image quality. The calculated image sharpness and tissue contrast ratio were also the highest with the proposed method.
Conclusion
High‐resolution fetal brain anatomical images acquired using a reduced FOV with OVS demonstrated improved image quality both qualitatively and quantitatively, suggesting the potential for enhanced diagnostic accuracy in detecting fetal brain abnormalities in utero.
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