Neha Kwatra

Pediatric whole-body MRI: A review of current imaging techniques and clinical applications.

There are many congenital, neoplastic, inflammatory, and infectious processes in the pediatric patient for which whole‐body imaging may be of benefit diagnostically and prognostically. With recent improvements in magnetic resonance imaging (MRI) hardware and software and resultant dramatically reduced scan times, imaging of the whole body with MRI has become a much more practicable technique in children. Whole‐body MRI can provide a high level of soft tissue and skeletal detail while avoiding the exposure to ionizing radiation inherent to computed tomography and nuclear medicine imaging techniques. This article reviews the more common current whole‐body MRI techniques in children and the primary pathologies for which this imaging modality may be most useful to the radiologists and referring clinicians. J. MAGN. RESON. IMAGING 2016;44:783–793.

White matter integrity on fractional anisotropy maps in encephalopathic neonates post hypothermia therapy with normal-appearing MR imaging

BackgroundNeonatal encephalopathy (NE) is a clinically defined neurological syndrome commonly caused by ischemia.ObjectiveWe investigated white matter integrity in children with NE using diffusion tensor imaging (DTI) and examined the hypothesis that white matter insults not visible on conventional MRI may have abnormal fractional anisotropy (FA) on DTI.Materials and methodsDTI was performed on 36 term encephalopathic neonates who had hypothermia therapy. Of these, 12 neonates had normal conventional MRI findings (NNE) and 24 neonates had abnormal MRI findings (ANE). Twelve term-equivalent premature neonates with normal clinical neuroimaging and neurological function served as the control group.ResultsWe found significant reductions in measured FA in white matter in the ANE neonates compared to the control group. There were, however, no significant differences in measured FA in white matter between the NNE and the control group.ConclusionWe did not find white matter changes detectable by DTI in encephalopathic neonates post hypothermia with normal conventional MRI findings. Further studies would be required to determine whether this unexpected finding is a direct result of neuroprotective effects of hypothermia, or more sophisticated measures of FA are required to detect subtle white matter injury.

Scintigraphic features of duplex kidneys on DMSA renal cortical scans

The spectrum of manifestations of duplex kidneys on 99mTc-dimercaptosuccinic acid (DMSA) renal cortical scans and correlating findings on other imaging modalities are presented. Relevant embryology of the duplex systems and technical aspects of DMSA scintigraphy are reviewed.

Imaging in laparoscopic cholecystectomy—What a radiologist needs to know

Laparoscopic cholecystectomy is the gold standard treatment option for cholelithiasis. In order to properly assess for the complications related to the procedure, an understanding of the normal biliary anatomy, its variants and the normal postoperative imaging is essential. Radiologist must be aware of benefits and limitations of multiple imaging modalities in characterizing the complications of this procedure as each of these modalities have a critical role in evaluating a symptomatic post-cholecystectomy patient. The purpose of this article is describe the multi-modality imaging of normal biliary anatomy and its variants, as well as to illustrate the imaging features of biliary, vascular, cystic duct, infectious as well as miscellaneous complications of laparoscopic cholecystectomy. We focus on the information that the radiologist needs to know about the radiographic manifestations of potential complications of this procedure.

Operational and Dosimetric Aspects of Pediatric PET/CT

No consistent guidelines exist for the acquisition of a CT scan as part of pediatric PET/CT. Given that children may be more vulnerable to the effects of ionizing radiation, it is necessary to develop methods that provide diagnostic-quality imaging when needed, in the shortest time and with the lowest patient radiation exposure. This article describes the basics of CT dosimetry and PET/CT acquisition in children. We describe the variability in pediatric PET/CT techniques, based on a survey of 19 PET/CT pediatric institutions in North America. The results of the survey demonstrated that, although most institutions used automatic tube current modulation, there remained a large variation of practice, on the order of a factor of 2–3, across sites, pointing to the need for guidelines. We introduce the approach developed at our institution for using a multiseries PET/CT acquisition technique that combines diagnostic-quality CT in the essential portion of the field of view and a low-dose technique to image the remainder of the body. This approach leads to a reduction in radiation dose to the patient while combining the PET and the diagnostic CT into a single acquisition. The standardization of pediatric PET/CT provides an opportunity for a reduction in the radiation dose to these patients while maintaining an appropriate level of diagnostic image quality.

How we read pediatric PET/CT: indications and strategies for image acquisition, interpretation and reporting

PET/CT plays an important role in the diagnosis, staging and management of many pediatric malignancies. The techniques for performing PET/CT examinations in children have evolved, with increasing attention focused on reducing patient exposure to ionizing radiation dose whenever possible and minimizing scan duration and sedation times, with a goal toward optimizing the overall patient experience.This review outlines our approach to performing PET/CT, including a discussion of the indications for a PET/CT exam, approaches for optimizing the exam protocol, and a review of different approaches for acquiring the CT portion of the PET/CT exam. Strategies for PACS integration, image display, interpretation and reporting are also provided.Most practices will develop a strategy for performing PET/CT that best meets their respective needs. The purpose of this article is to provide a comprehensive overview for radiologists who are new to pediatric PET/CT, and also to provide experienced PET/CT practitioners with an update on state-of-the art CT techniques that we have incorporated into our protocols and that have enabled us to make considerable improvements to our PET/CT practice.

Two-phase whole-body skeletal scintigraphy in children—revisiting the usefulness of the early blood pool phase

The usefulness of whole-body blood pool imaging as part of Tc-99m methylene diphosphonate (MDP) skeletal scintigraphy in detection of marrow infiltrative processes and unexpected soft-tissue and visceral abnormalities is demonstrated via illustrative case examples. Technical aspects of this simple and fast scanning technique are also highlighted.

The duplicated collecting system of the urinary tract: embryology, imaging appearances and clinical considerations

Duplication anomalies of the urinary collecting system are common and can be discovered and characterized with multiple imaging modalities. The embryology, imaging manifestations and clinical ramifications of duplicated ureters and renal collecting systems vary from a normal anatomical variant to urological pathology and are discussed and illustrated in this review.

Can Coronary Artery Involvement in Kawasaki Disease be Predicted

Background: Coronary artery involvement is seen in approximately 15–20% of children with Kawasaki disease. There is conflicting literature regarding the clinical and laboratory findings associated with coronary artery involvement. In this retrospective study, we attempt identification of predictive factors for coronary artery involvement at our institute and review the existing literature. Methods and results: A review of 203 patients (65% males) with Kawasaki disease was performed, of whom 33 (16.3%) had coronary artery involvement. High erythrocyte sedimentation rate, high platelet count, low hematocrit, low albumin levels, and refractory Kawasaki disease showed significant association with coronary artery involvement. High erythrocyte sedimentation rate and refractory Kawasaki disease were found to be independent predictors of coronary artery involvement. Review of literature suggested a wide range of coronary involvement (<5% to >60%), and highly conflicting clinical and laboratory associations. Conclusion: It remains difficult to accurately determine risk of coronary artery involvement, although some laboratory markers may provide information that is helpful for parental counseling and clinical follow up. Future identification of novel biomarkers and host predispositions may further our understanding of coronary artery risks and help personalize therapy for Kawasaki disease.

QT dispersion in familial dysautonomia: study by Nussinovitch et al.

We read with great interest the study by Nussinovitch et al. [1] on 13 subjects with Familial Dysautonomia. The values of all lead QT interval dispersion (QTd) obtained in their study are surprising. They reported a mean QTd of 92.88 ms in the control group. This number is much higher than previously reported values for healthy individuals. In a review of 51 studies by Malik et al. [2] (a total of 8,455 healthy control subjects of various ages, including healthy children), the mean QT dispersion values ranged from 11 to 71 ms. The weighted mean was 33.4 ± 20.3 ms and the median was 37 ms. The suggested upper normal limit of QT dispersion in normal in healthy subjects is 65 ms. In the same study, the highest mean QTd was reported in patients with long QT syndrome but even in these subjects the mean was 83.2 ms (Fig. 1). We are unsure of the reason for these differences but the technique of measurement and computer algorithms used may, at least in part, explain the numbers.