Feasibility and Safety of Contrast-Enhanced Ultrasound of the Neonatal Brain: A Prospective Study Using MRI as the Reference Standard.

BACKGROUND. MRI is the reference standard for neonatal brain imaging, but it is expensive, time-consuming, potentially limited by availability and accessibility, and contraindicated in some patients. Transfontanelle neonatal head ultrasound is an excellent alternative but may be less sensitive and specific than MRI. Contrast-enhanced ultrasound (CEUS) has the potential to improve the capabilities of ultrasound. OBJECTIVE. The purpose of this study is to prospectively evaluate the feasibility, safety, and diagnostic performance of transfontanelle neonatal brain CEUS, with MRI used as the reference standard. METHODS. Neonates in the institutional neonatal ICU who were undergoing MRI as part of their clinical care were prospectively recruited to undergo portable brain ultrasound and CEUS for research purposes. Brain ultrasound and CEUS were performed portably without moving the patient from the isolette or crib in the neonatal ICU. Adverse events were recorded. Two radiologists independently evaluated ultrasound and CEUS images for abnormalities and then reached consensus regarding discrepancies. A separate radiologist reviewed MRI examinations. Sensitivity, specificity, and interreader agreement were evaluated, with MRI used as the reference. Qualitative post hoc image review was performed. RESULTS. Twenty-six neonates (nine boys and 17 girls; mean [± SD] age, 15.2 ± 14.0 days) were included. No significant alteration in patient vital signs or adverse reaction to the ultrasound contrast agent (UCA) occurred. The mean duration of the examination was significantly shorter for combined ultrasound and CEUS than for MRI (21.1 ± 4.7 vs 74.2 ± 34.8 minutes; p < .001). Interrater agreement for any abnormality was almost perfect for both ultrasound and CEUS (κ = 0.92 and 0.85, respectively). Sensitivity for any abnormality was 86.7% for ultrasound and 93.3% for CEUS; specificity was 100.0% for both. CEUS had sensitivity of 87.5% for acute or subacute ischemia and 100.0% for chronic ischemia; its specificity was 100.0% for acute or subacute ischemia and chronic ischemia. For both ultrasound and CEUS, sensitivity for subdural and intraparenchymal hemorrhage was poor (22.2-50.0%). On CEUS but not on MRI, post hoc review showed a case of postischemic hyperperfusion, which was confirmed by subsequently performed contrast-enhanced CT. CONCLUSION. The use of portable brain CEUS in neonates is feasible, safe, and more rapid than MRI. CLINICAL IMPACT. The potential diagnostic utility of brain neonatal CEUS relative to conventional ultrasound, particularly for ischemia, warrants further investigation.

Systemic and Nodular Hyperinflammation in a Patient with Refractory Familial Hemophagocytic Lymphohistiocytosis 2.

Familial hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome resulting from defective cytotoxicity. A previously healthy 3-month-old female presented with fever, irritability, abdominal distention, and tachypnea. She ultimately met all eight HLH-2004 diagnostic criteria, accompanied by elevated CXCL9. Initial empiric anti-inflammatory treatment included anakinra and IVIg, which stabilized ferritin and cytopenias. She had molecular and genetic confirmation of perforin deficiency and was started on dexamethasone and etoposide per HLH-94. She clinically improved, though CXCL9 and sIL-2Ra remained elevated. She was readmitted at week 8 for relapsed HLH without clear trigger and HLH-94 induction therapy was reinitiated. Her systemic HLH symptoms failed to respond and she soon developed symptomatic CNS HLH. She was incidentally found to have multifocal lung and kidney nodules, which were sterile and consisted largely of histiocytes and activated, oligoclonal CD8 T cells. The patient had a laboratory response to salvage therapy with alemtuzumab and emapalumab, but progressive neurologic decline led to withdrawal of care. This report highlights HLH foci manifest as pulmonary/renal nodules, demonstrates the utility of monitoring an array of HLH biomarkers, and suggests possible benefit of earlier salvage therapy.

Constipation on abdominal radiograph as potential risk factor for recurrent urinary tract infection development.

BACKGROUND: To compare clinical history and measurements of fecal load on abdominal radiography (AR) in the prediction of urinary tract infection (UTI) recurrence in children. METHODS: We combined data from two multicenter longitudinal studies in which children less than 6 years of age with a first or second UTI were followed for recurrence of UTI. Two radiologists reviewed the scout abdominal radiographs of initial voiding cystourethrograms obtained at enrollment from children at two participating sites and measured stool visible in various parts of the colon. We examined how well clinical variables (e.g., voiding and bowel history, use of laxatives at enrollment) and measurements of fecal load predicted recurrence of UTI within 12 months of enrollment. RESULTS: One hundred and ninety-two children were included. On univariate analyses, age, vesicoureteral reflux (VUR), cecal diameter, rectal diameter, and total stool length on AR were associated with recurrence of UTI. After controlling for age, the odds of recurrent UTI in children with VUR at baseline was 3.85 (95% CI: 1.62, 9.14) higher than in children without VUR. Recurrent UTI was 2.57 (95% CI: 1.01, 6.55) times more likely in children with cecal diameter > 3.10 cm than children with lower cecal diameters; time to first recurrent UTI was shorter in children with elevated cecal diameters (p = 0.0023). CONCLUSIONS: Cecal diameter on abdominal radiographs predicts UTI recurrence in children with a previous UTI. However, its accuracy is suboptimal to serve as a screening test. Accordingly, its routine use for this indication is not supported. If cecal diameter on an AR ordered for another indication is > 3.10 cm, then management of constipation could be considered.

Mapping hepatic blood oxygenation by quantitative BOLD (qBOLD) MRI.

PURPOSE: Abnormalities in hepatic oxygen delivery and oxygen consumption may serve as a significant indicator of hepatic cellular dysfunction and may predict treatment response. However, conventional and oxygen-enhanced hepatic BOLD MRI can only provide semiquantitative assessment of hepatic oxygenation. METHODS: A hepatic quantitative BOLD (qBOLD) model was proposed for noninvasive mapping of hepatic venous blood oxygen saturation (Yv ) and deoxygenated blood volume (DBV) in human subjects. The validity and the estimation bias of the proposed model were evaluated by Monte Carlo simulations. Eight healthy subjects were scanned after written consent with institutional review board approval. RESULTS: Monte Carlo simulations demonstrated that the proposed single-compartment hepatic qBOLD model leads to significant deviation of the predicted T2* decay profile from the simulated signal due to high hepatic blood volume fraction. Small relative estimation bias for hepatic Yv and significant overestimation for hepatic DBV were observed, which can be corrected by applying the calibration curves established from simulations. After correction, the mean hepatic Yv in human subjects was 56.8 ± 6.8%, and the mean hepatic DBV was 0.190 ± 0.035, consistent with measurements from other invasive approaches. Except in regions with significant vascular contamination, the maps for hepatic Yv and DBV were relatively homogenous. CONCLUSIONS: With estimation bias correction, the hepatic qBOLD approach enables noninvasive mapping of hepatic blood volume and oxygenation in human subjects. The established protocol may be used to quantitatively assess hepatic tissue hypoxia in multiple liver diseases.

White Matter Injuries in Mild Traumatic Brain Injury and Posttraumatic Migraines: Diffusion Entropy Analysis.

Purpose To determine the performance of Shannon entropy (SE) as a diagnostic tool in patients with mild traumatic brain injury (mTBI) with posttraumatic migraines (PTMs) and those without PTMs on the basis of analysis of fractional anisotropy (FA) maps. Materials and Methods The institutional review board approved this retrospective study, with waiver of informed consent. FA maps were obtained and neurocognitive testing was performed in 74 patients with mTBI (57 with PTM, 17 without PTM). FA maps were obtained in 22 healthy control subjects and in 20 control patients with migraine headaches. Mean FA and SE were extracted from total brain FA histograms and were compared between patients with mTBI and control subjects and between patients with and those without PTM. Mean FA and SE were correlated with clinical variables and were used to determine the areas under the receiver operating characteristic curve (AUCs) and likelihood ratios for mTBI and development of PTM. Results Patients with mTBI had significantly lower SE (P < .001) and trended toward lower mean FA (P = .07) compared with control subjects. SE inversely correlated with time to recovery (TTR) (r = -0.272, P = .02). Patients with mTBI with PTM had significantly lower SE (P < .001) but not mean FA (P = .15) than did other patients with mTBI. SE provided better discrimination between patients with mTBI and control subjects than mean FA (AUC = 0.92; P = .01), as well as better discrimination between patients with mTBI with PTM and those without PTM (AUC = 0.85; P < .001). SE of less than 0.751 resulted in a 16.1 increased likelihood of having experienced mTBI and a 3.2 increased likelihood of developing PTM. Conclusion SE more accurately reveals mTBI than mean FA, more accurately reveals those patients with mTBI who develop PTM, and inversely correlates with TTR. (©) RSNA, 2016.

Effects of body mass index, mesenteric and abdominal subcutaneous adipose tissue on the spinopelvic parameters.

PURPOSE: The purpose of this study was to investigate the effects of body mass index (BMI), thickness of the abdominal subcutaneous adipose tissue (ASAT), thickness of the mesenteric adipose tissue (MAT), weight and height on spinopelvic parameters. METHODS: A total of 400 patients presented to the radiology department for whole abdominal computed tomography were included in the study. Patients' weight and height were measured to calculate BMI. Thickness of ASAT and MAT, lumbosacral angle (LSA), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI) were measured from the images obtained. We analyzed the effects of BMI, ASAT, and MAT on spinopelvic parameters. In addition, patients included in the study were screened for isthmic spondylolisthesis and transitional vertebrae. Statistical analysis was carried out using SPSS 15.0 package software. p < 0.05 Values were considered statistically significant. RESULTS: BMI and thickness of ASAT and MAT increased with aging both in male and female individuals. There was a positive correlation between PI and weight, thickness of ASAT and thickness of MAT, while a negative correlation was found between PI and height (p < 0.01). SS angle was positively correlated with weight (p < 0.01). A weak positive correlation was found between PT angle and thickness of MAT and height (p < 0.05). The rate of transitional vertebrae and isthmic spondylolisthesis was 2 and 4.6%, consecutively. PI and SS values were significantly higher in the subjects having spondylolisthesis than normal population (p < 0.01). CONCLUSION: It should be kept in mind that obesity might increase the risk for development of spondylolisthesis by causing increase in PI angle.

Evaluation of White Matter Injury Patterns Underlying Neuropsychiatric Symptoms after Mild Traumatic Brain Injury.

PURPOSE: To determine if a central axonal injury underlies neuropsychiatric symptoms after mild traumatic brain injury (mTBI) by using tract-based spatial statistics analysis of diffusion-tensor images. MATERIALS AND METHODS: The institutional review board approved this study, with waiver of informed consent. Diffusion-tensor imaging and serial neurocognitive testing with the Immediate Post-Concussion Assessment and Cognitive Testing evaluation were performed in 45 patients with mTBI (38 with irritability, 32 with depression, and 18 with anxiety). Control subjects consisted of 29 patients with mTBI without neuropsychiatric symptoms. Fractional anisotropy and diffusivity maps were analyzed by using tract-based spatial statistics with a multivariate general linear model. Diffusion-tensor imaging findings were correlated with symptom severity, neurocognitive test scores, and time to recovery with the Pearson correlation coefficient. RESULTS: Compared with control subjects, patients with mTBI and depression had decreased fractional anisotropy in the superior longitudinal fasciculus (P = .006), white matter around the nucleus accumbens (P = .03), and anterior limb of the internal capsule (P = .02). Patients with anxiety had diminished fractional anisotropy in the vermis (P = .04). No regions of significantly decreased fractional anisotropy were seen in patients with irritability relative to control subjects. Injury in the region of the nucleus accumbens inversely correlated with recovery time in patients with depression (r = -0.480, P = .005). CONCLUSION: Unique white matter injury patterns were seen for two major posttraumatic neuropsychiatric symptoms. Injury to the cerebellar vermis in patients with mTBI and anxiety may indicate underlying dysfunction in primitive fear conditioning circuits in the cerebellum. Involvement of the nucleus accumbens in depression after mTBI may suggest an underlying dysfunctional reward circuit that affects the prognosis in these patients.

Fully automated segmentation of cartilage from the MR images of knee using a multi-atlas and local structural analysis method.

PURPOSE: To develop a fully automated method to segment cartilage from the magnetic resonance (MR) images of knee and to evaluate the performance of the method on a public, open dataset. METHODS: The segmentation scheme consisted of three procedures: multiple-atlas building, applying a locally weighted vote (LWV), and region adjustment. In the atlas building procedure, all training cases were registered to a target image by a nonrigid registration scheme and the best matched atlases selected. A LWV algorithm was applied to merge the information from these atlases and generate the initial segmentation result. Subsequently, for the region adjustment procedure, the statistical information of bone, cartilage, and surrounding regions was computed from the initial segmentation result. The statistical information directed the automated determination of the seed points inside and outside bone regions for the graph-cut based method. Finally, the region adjustment was conducted by the revision of outliers and the inclusion of abnormal bone regions. RESULTS: A total of 150 knee MR images from a public, open dataset (available atwww.ski10.org) were used for the development and evaluation of this approach. The 150 cases were divided into the training set (100 cases) and the test set (50 cases). The cartilages were segmented successfully in all test cases in an average of 40 min computation time. The average dice similarity coefficient was 71.7%±8.0% for femoral and 72.4%±6.9% for tibial cartilage. CONCLUSIONS: The authors have developed a fully automated segmentation program for knee cartilage from MR images. The performance of the program based on 50 test cases was highly promising.

Estimation of single-kidney glomerular filtration rate without exogenous contrast agent.

PURPOSE: Measurement of single-kidney filtration fraction and glomerular filtration rate (GFR) without exogenous contrast is clinically important to assess renal function and pathophysiology, especially for patients with comprised renal function. The objective of this study is to develop a novel MR-based tool for noninvasive quantification of renal function using conventional MR arterial spin labeling water as endogenous tracer. THEORY AND METHODS: The regional differentiation of the arterial spin labeling water between the glomerular capsular space and the renal parenchyma was characterized and measured according to their MR relaxation properties (T1ρ or T2 ), and applied to the estimation of filtration fraction and single-kidney GFR. The proposed approach was tested to quantify GFR in healthy volunteers at baseline and after a protein-loading challenge. RESULTS: Biexponential decay of the cortical arterial spin labeling water MR signal was observed. The major component decays the same as parenchyma water; the minor component decays much slower as expected from glomerular ultra-filtrates. The mean single-kidney GFR was estimated to be 49 ± 9 mL/min at baseline and increased by 28% after a protein-loading challenge. CONCLUSION: We developed an arterial spin labeling-based MR imaging method that allows us to estimate renal filtration fraction and singe-kidney GFR without use of exogenous contrast.

Hepatic steatosis in diabetic patients does not predict adverse liver-related or cardiovascular outcomes.

BACKGROUND & AIMS: Steatosis is a defining feature of nonalcoholic fatty liver disease (NAFLD). However, evidence that severity of steatosis can predict adverse outcomes in NAFLD or nonalcoholic steatohepatitis (NASH) is lacking. The aim of this study was to determine whether steatosis assessed by computed tomography (CT) imaging predicts adverse outcomes in diabetic patients at risk for NAFLD/NASH. METHODS: We studied deaths, liver-related and cardiovascular adverse outcomes in a 5-year retrospective observational cohort of 2343 type 2 diabetic patients in a large care network who had noncontrast CT imaging for clinical indications. We measured steatosis by subtraction of spleen from liver attenuation, a method that showed low sensitivity (0.417) and high specificity (0.882) compared with histopathological scoring. We evaluated outcomes prediction using multivariate Cox proportional hazards modelling of steatosis both as a categorical (≥ 30%) and continuous variable. RESULTS: Steatosis ≥ 30% was present in 233 (9.9%) of the cohort at baseline. Over 5 years, there were 372 total deaths, 18 liver-related and 99 cardiovascular deaths, 48 liver transplants, 51 occurrences of hepatic encephalopathy, 41 hepatocellular carcinomas, 653 myocardial infarctions, 66 strokes, 180 occurrences of angina, 735 occurrences of arrhythmia and 772 occurrences of congestive heart failure. Steatosis had no predictive value for any adverse outcome. Patients with steatosis averaged 8 years younger than those without it. Age had a strong covariate influence on occurrence of total deaths, cardiovascular deaths, myocardial infarctions, arrhythmias and congestive heart failure. CONCLUSION: Although steatosis on imaging is often the abnormality that triggers diagnosis and assessment of NAFLD/NASH, it lacks predictive value for adverse clinical outcomes.

The rate of resolution of clot burden measured by pulmonary CT angiography in patients with acute pulmonary embolism.

OBJECTIVE: The purpose of this article is to quantitatively assess the rate of resolution of clot burden detected on pulmonary CT angiography (CTA) in patients with acute pulmonary embolism (PE). MATERIALS AND METHODS: We evaluated 111 consecutive patients (55 men and 56 women) in a retrospective cohort who were diagnosed with PE by pulmonary CTA and had at least one follow-up pulmonary CTA within 1 year. Two radiologists in consensus measured the volume of each clot using a semiautomated quantification program. Semiquantitative measures of clot burden were also computed. The resolution rates of the total clot volume, as well as clot volumes of the central (main and lobar) and peripheral vessels (segmental and subsegmental), were analyzed. RESULTS: The mean (± SD) clot volume per study was 3403.3 ± 6505.6 mm(3) at baseline and 531.6 ± 2383.5 mm(3) at the follow-up pulmonary CTA. Overall, 85 patients (77% ) showed complete resolution at the follow-up pulmonary CTA. Complete resolution was seen in 17 of 30 patients (56.7%) at a follow-up interval of 1-14 days, in 24 of 31 patients (77.4%) at 29-90 days, and in 32 of 34 patients (94.1%) after 90 days. The total clot volume measurements summed for all patients decreased by 78% (central clot, 69.4%; peripheral clot, 86.0%) at 14 days, by 96.6% (central clot, 93.4%; peripheral clot, 100%) at 90 days, and by 97.7% (central clot, 95.9%; peripheral clot, 100%) after 90 days. CONCLUSION: Clot burden resolved completely in 77% of patients during the follow-up period. Our analysis showed that clots resolved faster in the peripheral arteries than in the central pulmonary arteries.

Application of first-pass contrast bolus tracking sequence for the assessment of morphology and flow dynamics in cardiac MRI.

PURPOSE: There are two well-known indications for first-pass perfusion in the literature. First is the evaluation of myocardial ischemia, and the other is the evaluation of tumor vascularity. Our aim was to assess the value of a first-pass contrast bolus tracking sequence (FPCBTS) for cases unrelated to these pathologies. MATERIALS AND METHODS: A total of 35 patients (age range, 1 day to 66 years; mean age, 10.4±19.2 years; median age, 4.5 months) with suspected congenital (n=31) and acquired (n=4) heart and great vessel disease were included in the study. All the patients underwent cardiac magnetic resonance imaging (MRI) and FPCBTS, and 20 patients underwent contrast enhanced magnetic resonance angiography (CE-MRA). We used cardiac MRI and CEMRA for anatomic evaluation and FPCBTS for dynamic flow evaluation. RESULTS: Truncus arteriosus, double outlet right ventricle, tetralogy of Fallot, corrected transposition of great arteries, atrial and ventricular septal defect, aortic rupture, cardiac hydatid cyst, tricuspid atresia, anomalous pulmonary venous return, and interrupted aorta were detected using the technique described here. Septal defects in six patients and atrial aneurysm in two patients were excluded. The shunt gap and flow direction of the septal defects, a ruptured wall in a dissected aorta, a hydatid cyst, and the atrial relationship in two cases with paracardiac masses were diagnosed easily using this dynamic evaluation technique. CONCLUSION: FPCBTS can be performed in addition to cardiac MRI and CEMRA to reveal flow dynamics and morphology.

Congenitally corrected transposition of great arteries with severe rhythm disturbances.

Within recent years, much scientific attention has been devoted to adults with congenital heart disease (CHD) and probable complications. Congenitally corrected transposition of the great arteries (CCTGA) is a rare, complex form of congenital heart defects. CCTGA is characterized by atrioventricular (AV) and ventriculoarterial (VA) discordance and, hence, by a physiologically normal direction of blood flow. The development of complete AV block and global ventricular dysfunction has been identified as the cause of cardiac death. Although the development of arrhythmias represents a major cause of morbidity and mortality in patients with CHD, the account of all implantations of pacemakers and implantable cardioverter defibrillators (ICD) is less than one percent. This paper presents a case of CCTGA with severe rhythm disorders, discusses probable treatment options, and offers indications of ICD implantation in patients with CHD.

The morphometric analysis of the V2 and V3 segments of the vertebral artery: normal values on MDCT.

A potential hazard in midline posterior fossa craniectomy may be the injury of vertebral artery. That's why vertebral artery evaluation prior to surgery may prevent dangerous complications. Advancements in multidetector computed tomography (MDCT) have provided detailed demonstration of the vertebral artery at the craniocervical junction and its relationships with atlas and axis. We aimed to define the normal anatomic relationship of the V2 and V3 part of the vertebral artery on MDCT. In total, 33 patients underwent MDCT angiography scan with suspected cranial aneurysm. V2 and V3 segments of vertebral artery were evaluated. Eight measurements (B, C, D, E, G, H, X, and Y line) were taken from MDCT images. For B and C, a line initially passing through the body of axis and spinous process and determining the midline was formed. Then, the vertical distance of vertebral artery from the level of transverse foramen of axis and loop to this midline was measured. For D and G, the vertical distance of vertebral artery to the midline from the upper and lower margin levels of transverse foramen of atlas was measured after a line establishing the midline passing through the anterior and posterior tubercles of atlas was drawn first. For E, transverse diameter of vertebral artery was measured at the loop level of V2 segment. For H, the vertical distance at the point where vertebral artery entered dura in the line passing from the midline of foramen magnum at anterior-posterior plane was measured. For X and Y, two different points of horizontal part of the vertebral artery were determined. One of these two points was the lateral one which was the origin of the horizontal part in the transverse foramen, the other was the intersection point on atlas. Average distances for both sides from transverse foramen of the axis, the loop of axoatlantal part and the lower border of the atlas of the vertebral artery to the midline were 20.97 mm on the right, 22.29 mm on the left; 27.19 mm on the right, 28.34 mm on the left; and 25.75 mm on the right and 27.21 mm on the left, respectively. Average distances for both sides from the upper border of the atlas, and at its penetration through dura were 27.40 mm on the right, 28.94 mm on the left; and 10.90 mm on the right and 10.93 mm on the left, respectively. Distances between spinous process and intersection of vertebral artery with horizontal part were 35.79 mm on the right and 36.63 mm on the left laterally, and 22.27 mm on the right and 22.62 mm on the left medially. MDCT angiography is a powerful test to demonstrate the vasculature of the head and neck. Bony structures and adjacent vessel morphology can be evaluated by this technique. The evaluation of craniocervical region prior to surgery with MDCT may be helpful to avoid intraoperative vascular injuries.