Acute and Chronic Kernicterus: MR Imaging Evolution of Globus Pallidus Signal Change during Childhood.

BACKGROUND AND PURPOSE: Despite its rarity in Western countries, kernicterus resulting from severe neonatal hyperbilirubinemia and its associated neurologic consequences still persists. Subtle MR imaging patterns may be overlooked, leading to diagnostic and prognostic uncertainties. The study systematically analyzes MR imaging pattern over time. MATERIALS AND METHODS: A retrospective MR imaging study was conducted in Departments of Pediatric Neurology at the University Children's Hospitals in Leipzig, Germany, or Tübingen, Germany, between 2012 and 2022 in patients who presented beyond the neonatal period suspected of having chronic kernicterus. RESULTS: Eight patients with a total of 15 MR images were identified. The clinical diagnosis of kernicterus was confirmed in all cases on the basis of typical MR imaging findings: Bilateral, diffuse hyperintensity of the globus pallidus was observed in the neonatal period on T1WI (1 MR imaging, at 2 weeks), in infancy on T2WI (4 MR images, at 9-26 months). In children 2 years of age and older, bilateral hyperintensity on T2WI was limited to the borders of the globus pallidus (8 MR images, at 20 months -13 years). Notably, 2 children exhibited normal initial MR imaging findings at 2 months of age. Hence, MR imaging depiction of kernicterus pathology evolves with time, first evident on T1WI, subsequently on T2WI, with a "blind window" during early infancy. The T2WI signal change initially involves the entire globus pallidus and later is limited to the borders. Kernicterus had not been diagnosed in any except 2 patients by previous investigators. CONCLUSIONS: All patients presented with a characteristic clinical history and signs and an evolving MR imaging pattern. Nonetheless, the diagnosis of kernicterus was frequently missed. Abnormalities on later MR images appear to be underrecognized.

Whole-body [18F]-FDG-PET/MRI for staging of pediatric non-Hodgkin lymphoma: first results from a single-center evaluation.

AIM: In 2015, the revised International Pediatric Non-Hodgkin Lymphoma Staging System was published. It mentions [18F]-FDG-PET/MRI as the latest method to perform whole-body imaging. However, supporting data are pending. Our aim was to investigate the performance of whole-body [18F]-FDG-PET/MRI in pediatric non-Hodgkin lymphoma patients by using a limited number of MRI sequences. MATERIALS AND METHODS: Ten pediatric patients with histologically proven non-Hodgkin lymphoma underwent whole-body [18F]-FDG-PET/MRI at staging. The retrospective analysis included three steps: First, [18F]-FDG-PET and MR scans were evaluated separately by a nuclear medicine physician and a pediatric radiologist. Nineteen nodal and two extranodal regions as well as six organs were checked for involvement. Second, discrepant findings were reviewed together in order to reach consensus. Third, [18F]-FDG-PET/MRI findings were correlated with the results of other clinical investigations. RESULTS: Of the 190 lymph node regions evaluated, four were rated controversial. Consensus was reached by considering metabolic, functional and morphologic information combined. Concordantly, [18F]-FDG-PET and MRI detected Waldeyer's ring involvement in two patients whose Waldeyer's ring was negative on clinical assessment. In four patients MRI showed pleural effusion. However, in only two of them an increased glucose metabolism as a reliable sign of pleural involvement was detectable. In six patients [18F]-FDG-PET and MRI detected skeletal lesions although bone marrow biopsy was positive in only one of them. CONCLUSION: Despite the small number of cases evaluated, whole-body [18F]-FDG-PET turned out to be a valuable tool for staging of pediatric non-Hodgkin lymphoma.

[Differential diagnosis of cystic abdominal masses in children]. / Differenzialdiagnosen zystischer abdominaler Raumforderungen im Kindesalter.

BACKGROUND: Cystic abdominal masses are a common main or incidental finding in daily radiological practice; however, differentiation is not always trivial. OBJECTIVES: In children, cystic abdominal masses represent a special feature compared to adults, since the spectrum of congenital lesions must be taken into consideration. The article gives a structured overview of the most common entities. MATERIALS AND METHODS: The standard methods in abdominal imaging in pediatric radiology are ultrasound and MRI. Based on a literature review, the most important differential diagnoses with their characteristics in ultrasound and MRI were compiled. RESULTS AND DISCUSSION: With anatomical classification, presence or absence of solid components as well as the contrast agent behavior in the MRI, the cystic masses can be well differentiated and classified into three groups: congenital and acquired cysts as well as neoplasms.

[Accident or maltreatment? Radiographic X­ray patterns in non­accidental trauma : The concept of sentinel injuries]. / Unfall oder Misshandlung? Radiologische Befunde beim nichtakzidentiellen Trauma : Das Konzept der "sentinel injuries".

The focus of this review article is on child abuse and the radiographic pattern of X­ray findings. The radiologist should be able to recognize typical injuries resulting from child abuse. In some cases the findings are highly specific for abuse and these include metaphyseal corner fractures of the long bones in children aged up to 24 months. In other cases the fractures are not specific but highly indicative of child abuse: rib fractures, for example can be associated with child abuse in more than 50 % of the cases; however, maltreatment is difficult to diagnose without taking the entire pattern of skeletal findings into consideration so that a radiological screening of the entire skeleton is often necessary. The concept of sentinel injuries might be helpful for deciding in which cases a complete skeletal screening should be performed. In the age group up to 24 months old a complete skeletal status (with some exceptions) is recommended if one of the three sentinel injuries of rib fractures, intracranial bleeding and abdominal trauma is present.

Striated Nephrogram as an Incidental Finding in MRI Examination of Children.

PURPOSE: A highly striated contrast pattern of the kidneys occasionally appears in abdominal MRI examinations of children following the administration of gadolinium. As this phenomenon is well known but has not yet been explicitly described in literature, we investigated how frequently and in which clinical context this occurred. MATERIAL AND METHODS: 855 abdominal MRI examinations with contrast media of 362 children between 2006 and 2014 were analysed retrospectively. RESULTS: A striated renal parenchyma was found in a total of nine children and eleven examinations (1.3 % of examinations) and did only occur at a field strength of 3 Tesla. Of these children, seven had previously had tumors and chemotherapy. In two children there was no evidence of a previously serious condition with medications or a kidney disease. All of them had a normal renal function. CONCLUSION: A noticeably striated nephrogram in the later phase of an MRI examination following administration of gadolinium may appear as an incidental finding in examinations at 3 Tesla without pathological relevance. KEY POINTS: • striated nephrograms may appear at a field strength of 3 Tesla. • incidental finding without pathological relevance.

Significance of MR angiography in the diagnosis of aberrant renal arteries as the cause of ureteropelvic junction obstruction in children.

PURPOSE: To determine the importance of MRI with contrast-enhanced MRA for the detection or exclusion of aberrant or obstructing renal arteries in ureteropelvic junction obstruction in children. MATERIALS AND METHODS: Key word-based search in RIS database (ureteropelvic junction obstruction/ MRI) and retrospective comparison of arterial findings from preoperative contrast -enhanced MRA and intra-operative inspection. From 2007 to 2013, 19 children with ureteropelvic junction obstruction underwent contrast-enhanced MRA. Based on the results of the MRI scan and MAG3 scintigraphy, the children were referred to surgery (Anderson-Hynes-pyeloplasty). RESULTS: An aberrant renal artery was diagnosed with MRI in 14 of 19 children, and intra-operative inspection confirmed 13 of those 14. In the remaining 5 children, no aberrant vessel could be observed in MRI and this was confirmed intra-operatively in 3 of the 5 cases, while in the remaining 2, an aberrant vessel was found. Of the 14 children with aberrant vessels, 12 underwent surgery due to assumed ureteral obstruction, which was confirmed by surgery in 11 cases. In one case, an aberrant artery was found intra-operatively, but obstruction could not be confirmed. In one of the 14 children, the vessel was found in MRI, but its obstructing character was negated via MRA, which was confirmed intra-operatively. In the diagnosis of aberrant and obstructing renal arteries, contrast-enhanced MRA presents 85% sensitivity and 80% specificity, with a positive predictive value of 0.8. CONCLUSION: MRI with contrast-enhanced MRA is suitable to detect aberrant and obstructing renal arteries. An obstructive effect of the aberrant vessel is to be assumed if the vessel has a close relationship to the ureteropelvic junction and if it is linearly stretched. KEY POINTS: • MRI with contrast-enhanced MRA is a sure method for the detection of aberrant renal arteries in children with ureteropelvic junction obstruction. • The obstructive effect of the aberrant vessel can be derived from the close proximity of the vessel to the ureteropelvic junction and from the streched course of the vessel.

[Propranolol therapy for periocular and orbital infantile haemangiomas]. / Propranolol-Therapie bei infantilen Hämangiomen im Lid- und Orbitabereich.

In spite of the self-limiting natural course of infantile haemangiomas of the eyelids and orbit, the effects of amblyopia, compression of the optic nerve, and impairment of the aesthetic appearance may develop. Since the serendipitous discovery of the effects of propranolol, a non-selective beta-blocker, on infantile haemangioma in 2008, it has largely replaced the former standard treatments with corticosteroids, laser or surgical procedures. This review discusses the pathogenesis, classification, indication for treatment, and treatment options for infantile haemangiomas. In addition, the results of patients with infantile haemangiomas of the eyelids and orbit treated with systemic propranolol are shown. With additional confirmation of data, including a positive effect-risk-analysis, propranolol will potentially replace high-dose corticosteroids and surgery in the treatment of infantile haemangiomas in the eyelids and orbit. Further clinical studies are necessary to optimise the dosage, treatment period, and application modalities (oral or topical). In the future, propranolol accompanied with paediatric-cardiological monitoring should emerge as the first-line therapy for problematic infantile haemangiomas.

Performance of an automatic dose control system for CT: patient studies.

PURPOSE: To study the effect of an automatic dose control (ADC) system with adequate noise characteristic on the individual perception of image noise and diagnostic acceptance compared to objectively measured image noise and the dose reductions achieved in a representative group of patients. MATERIALS AND METHODS: In a retrospective study two matched cohorts of 20 patients each were identified: a manual cohort with exposure settings according to body size (small - regular - large) and an ADC cohort with exposure settings calculated by the ADC system (DoseRight 2.0™, Philips Healthcare). For each patient, 12 images from 6 defined anatomic levels from contrast-enhanced scans of chest and abdomen/pelvis were analyzed by 4 independent readers concerning image noise and diagnostic acceptance on a five-point Likert scale and evaluated for objectively measured image noise. Radiation exposure was calculated from recorded exposure data. RESULTS: Use of the ADC system reduced the average effective dose for patients by 36 % in chest scans (3.2 vs. 4.9 mSv) and by 17 % in abdomen/pelvis scans (7.6 vs. 8.3 mSv). Average objective noise was slightly lower in the manual cohort (11.1 vs. 12.8 HU), correlating with a slightly better rating in subjective noise score (4.4 vs. 4.2). However, diagnostic acceptance was rated almost equal in both cohorts with excellent image quality (4.6 vs. 4.5). CONCLUSION: Use of an ADC system with adequate noise characteristic leads to significant reductions in radiation exposure for patients while maintaining excellent image quality.

Evaluating childhood obesity: magnetic resonance-based quantification of abdominal adipose tissue and liver fat in children.

PURPOSE: The purpose of this study is to establish and validate a magnetic resonance (MR)-based fat quantification package that provides an accurate assessment of abdominal adipose tissue and liver fat in children. MATERIALS AND METHODS: Ex vivo trials with a torso model and water-oil mixtures are conducted. Abdominal adipose tissue (AAT) is covered by magnetic resonance imaging (MRI) using a fat-selective sequence and is analyzed by a plug-in based on the open source software ImageJ. Liver fat (LF) is measured with localized 1H Magnetic Resonance Spectroscopy (1H MRS) and the jMRUI (java-based Magnetic Resonance User Interface) software package. Evaluation of the clinical methodology involved a study of 10 children in this feasibility study (mean age and body mass index: 13.3 yr; 33.3 kg/m²). To evaluate the method's validity, reference measurements were performed. RESULTS: Ex vivo trials with the torso model showed that adipose tissue was measured appropriately with a systematic underestimation by 9.3 ± 0.2 % (0.32 ± 0.064 kg). Coefficients of variation for both intra- and inter-observer measurements ranged between 0 - 2.7 % and repeated analyses showed significant equivalent results (p < 0.01). The lipid content obtained by 1H MRS ex vivo revealed significant equivalence with the predefined fat content in water-oil mixtures (p < 0.01). In vivo, the homemade plug-in significantly overestimated the AAT, with the visceral adipose tissue being most affected (+ 15.7 ± 8.4 %). CONCLUSION: Although an overestimation of the AAT by the presented plug-in should be taken into consideration, this children-friendly package enables the quantification of both LF and AAT within 30 min on a freeware-based platform.

[Developmental malformations of the cerebral cortex]. / Heterotopie, Polymikrogyrie, Lissenzephalie und Co - Malformationen der kortikalen Hirnentwicklung.

Migration disorders (MD) are increasingly recognized as an important cause of epilepsy and developmental delay. Up to 25 % of children with refractory epilepsy have a cortical malformation. MD encompass a wide spectrum with underlying genetic etiologies and clinical manifestations. Research regarding the delineation of the genetic and molecular basis of these disorders has provided greater insight into the pathogenesis of not only the malformation but also the process involved in normal cortical development. Diagnosis of MD is important since patients who fail three antiepileptic medications are less likely to have their seizures controlled with additional trials of medications and therefore epilepsy surgery should be considered. Recent improvements in neuroimaging have resulted in a significant increase in the recognition of MD. Findings can be subdivided in disorders due to abnormal neurogenesis, neuronal migration, neuronal migration arrest and neuronal organization resulting in different malformations like microcephaly, lissencephaly, schizencephaly and heterotopia. The examination protocol should include T 1-w and T 2-w sequences in adequate slice orientation. T 1-w turbo-inversion recovery sequences (TIR) can be helpful to diagnose heterotopia. Contrast agent is needed only to exclude other differential diagnoses.

Whole-body MRI for primary evaluation of malignant disease in children.

OBJECTIVE: The aim of this study was to compare diagnostic accuracy of whole-body (WB) MRI to a combined reference standard of conventional cross-sectional imaging methods and FDG-PET in the detection of malignant disease spread in children. MATERIALS AND METHODS: 24 children (age between 5 and 18 years) with malignant diseases (mainly Hodgkin's lymphoma and different types of sarcoma) initially examined with conventional cross-sectional imaging methods (ultrasound, computed tomography, or magnetic resonance imaging) were examined prospectively with whole-body MRI (1.5T) and FDG-PET. Studies were read by two nuclear medicine physicians (FDG-PET) and two radiologists (WB-MRI) independently in a blinded manner and each study type was evaluated in consensus. The reference standard was defined as pathological lesions detected in the same location both in FDG-PET and another conventional cross-sectional imaging method. RESULTS: Overall 190 lesions were detected by WB-MRI and 155 lesion were found by FDG-PET. 106 lesions fulfilled the criteria of the reference standard (42 osseous and 64 extraosseous lesions) from which 102 were detected by WB-MRI (sensitivity of 96%). All bone lesions were detected and extra-skeletal lesions were identified with a sensitivity of 93.8%. Overall 88 lesions detected by WB-MRI were not part of the reference standard from which 33 were lesions of the peripheral skeleton not imaged by conventional cross-sectional imaging studies. 4 lesions of the reference standard were not identified by WB-MRI which were all lymph nodes. CONCLUSION: WB-MRI is a radiation free imaging technique with high sensitivity for the detection of malignant disease spread in particular beneficial for children. In patients with suspected bone lesions it should be considered for initial disease evaluation prior to specific and regional imaging methods to reduce the overall number of imaging examinations and radiation exposure.

[Assessment of clinical image quality in feline chest radiography with a needle-image plate (NIP) storage phosphor system--an approach to the evaluation of image quality in neonatal radiography]. / Untersuchungen zur Qualität von Thoraxaufnahmen bei Katzen mit einem auf einer Nadelstruktur basierenden Speicherfoliensystem - Modelluntersuchungen zur Bewertung der Bildqualität bei Neugeborenen.

PURPOSE: Is the image quality of thoracic radiographs of cats obtained with a needle-based storage phosphor (NIP) system superior to conventional (PIP) storage phosphor radiography? Is it possible to decrease the mAs by 50 % with the NIP system without significant loss of information? MATERIALS AND METHODS: From each of the 20 animals, three lateral radiographs were acquired. The assessment of the exposure level was based on the generated lgM-values. Images were acquired 1. with the NIP system and exposure settings equivalent to an lgM of 1.9, 2. with the PIP system and identical settings, and 3. with the NIP system and 50 % of the mAs. Six blinded readers used a 5-step scale to assess the reproducibility of five anatomical structures and image noise sensation. Data were analysed using Visual Grading Characteristics Analysis (VGC). RESULTS: While applying identical exposure values the NIP system for all features revealed superior ratings to those of the PIP system (AUC (VGC) values ranged from 0.81 for "cardiac silhouette" to 0.92 for "trachea"). Even when reducing mAs by 50 % in the NIP images all features were rated better compared with the PIP images and original settings (AUC (VGC) values ranged from 0.60 for "cardiac silhouette" to 0.74 for "trachea" and "caudal thoracic field"). CONCLUSION: The NIP system demonstrates clearly better image quality compared to the reference PIP system. A dose reduction of 50 % seems to be possible without relevant detraction from image quality. The results obtained in the animal model are valid for simulating conditions in neonatal radiological practise.

Acute portal vein thrombosis after splenic embolization and splenectomy for autoimmune pancytopenia.

Postsplenectomy portal vein thrombosis for hematological diseases is uncommon in the pediatric population. The case summarized is, to our knowledge, the first manifestation of portal vein thrombosis in a child after preoperative splenic artery embolization and subsequent splenectomy for severe hypersplenism. We suggest that early routine diagnosis by Doppler ultrasonography and subcutaneous low molecular weight heparin therapy are useful steps for a successful outcome.

Endoluminal stent-graft placement for acute rupture of the descending thoracic aorta.

AIMS: To investigate the results of endovascular stent-graft placement for the treatment of acute perforating lesions of the descending thoracic aorta. METHODS AND RESULTS: A total of 31 consecutive patients underwent interventional treatment for perforating lesions of the descending aorta. In 21 cases (group A), the aortic perforation was due to rupture of a descending thoracic aneurysm or dissection, whereas 10 patients (group B) were treated for traumatic transection of the descending aorta. A total of 42 endoprostheses were implanted. The implantation procedure was successful in all cases without peri-interventional complications. In one case, implantation of a second endoprosthesis became necessary due to type I endoleak. Overall, the 30-day mortality was 9.7%. As all three deaths occurred in group A, the mortality rate in this group was 14.3% versus 0% in group B. Similarly, postinterventional complications were more prevalent, with 28.6% in group A (renal failure n = 4; stroke n = 2) versus 10.0% in group B (renal failure n = 1). No paraplegia and no further deaths or ruptures occurred during follow-up (mean 17 months). CONCLUSION: Interventional stent-graft placement is an effective treatment option for the emergency repair of descending aortic perforations.

[Percutaneous revascularization of long-standing chronic occlusion of the superficial femoral artery. A pilot study]. / Perkutane Revaskularisation langstreckiger chronischer Verschlüsse der Arteria femoralis superficialis. Eine Pilotstudie.

BACKGROUND AND OBJECTIVE: The treatment of long chronic occlusion of peripheral arteries remains unsatisfactory. In particular occlusions of the superficial femoral artery (SFA) are not considered suitable for percutaneous interventions. It was the aim of our study to evaluate this technique, the initial technical success and the follow-up patency rates after percutaneous revascularization of long chronic occlusion of the the SFA. PATIENTS AND METHODS: 58 consecutive patients (mean age 64.8 +/- 9.7/40-80 years, 40 men/69.0%) were included. Of these patients 15 had bilateral SFA-occlusions and 14 showed additional disease in the popliteal artery. The mean occlusion length was 21.9 +/- 14.8 cm. At baseline absolute treadmill walking distance was 125 +/- 61 m. in all cases a balloon angioplasty was performed, additional excimer laser in 80.8% and stenting in 50.9%. RESULTS: A primary technical success was achieved in 89.0%. According to the American Heart Association guidelines a markedly clinical improvement was shown: +3 in 16.2%, +2 in 74.4%, +1 in 9.3% of the patients. The 12-months cumulative primary patency rate was 43.6%, primary assisted patency and secondary patency rate was 85.5% and 69.1% respectively. CONCLUSION: Long chronic occlusion can be successfully treated by percutaneous techniques. To maintain a high patency rate frequent clinical follow-up is mandatory.