Use of CEUS for Imaging Evaluation of Pediatric Peritonsillar Abscess

PURPOSE

Peritonsillar abscess can be diagnosed by B-mode ultrasound and cross-sectional imaging. The latter (with MRI being the modality of first choice in children) is associated with higher effort and risk for pediatric patients due to the administration of X-rays and/or the need of sedation. The purpose of this study is to evaluate whether the introduction of CEUS into the diagnostic algorithm for suspected pediatric peritonsillar abscess is suitable and advantageous.

MATERIALS AND METHODS

Single-institution retrospective review of data of pediatric patients who were presented to the department of pediatric radiology for sonographic evaluation under the suspicion of peritonsillar abscess. Diagnostic performance of CEUS was evaluated by using surgical exploration or clinical follow-up as the reference standard.

RESULTS

284 children included in the study underwent B-mode ultrasound. Mean age of all patients was 6,23 years. Peritonsillar abscess was the diagnosis in 42 patients. Diagnosis of peritonsillar abscess was made by B-mode ultrasound alone in 13 of 42 patients (31 %). In 17 of 42 patients (40 %), diagnosis was made by a combination of B-mode ultrasound and CEUS. Sensitivity rose from 37 % to 86 % in cases where B-mode ultrasound remained unclear and CEUS was used.

CONCLUSION

Contrast-enhanced ultrasound (CEUS) is suitable and efficient for the diagnosis of peritonsillar abscess in pediatric patients. It increases the sensitivity for the diagnosis of peritonsillar abscess and thereby reduces the need of additional cross-sectional imaging for the pediatric patients.

Comprehensive neurological evaluation of a cohort of patients with neurofibromatosis type 1 from a single institution

Neurofibromatosis type 1 (NF1) is a phenotypically heterogenous multisystem cancer predisposition syndrome manifesting in childhood and adolescents. Central nervous system (CNS) manifestations include structural, neurodevelopmental, and neoplastic disease. We aimed to (1) characterize the spectrum of CNS manifestations of NF1 in a paediatric population, (2) explore radiological features in the CNS by image analyses, and (3) correlate genotype with phenotypic expression for those with a genetic diagnosis. We performed a database search in the hospital information system covering the period between January 2017 and December 2020. We evaluated the phenotype by retrospective chart review and imaging analysis. 59 patients were diagnosed with NF1 [median age 10.6 years (range, 1.1-22.6); 31 female] at last follow-up, pathogenic NF1 variants were identified in 26/29. 49/59 patients presented with neurological manifestations including 28 with structural and neurodevelopmental findings, 16 with neurodevelopmental, and 5 with structural findings only. Focal areas of signal intensity (FASI) were identified in 29/39, cerebrovascular anomalies in 4/39. Neurodevelopmental delay was reported in 27/59 patients, learning difficulties in 19/59. Optic pathway gliomas (OPG) were diagnosed in 18/59 patients, 13/59 had low-grade gliomas outside the visual pathways. 12 patients received chemotherapy. Beside the established NF1 microdeletion, neither genotype nor FASI were associated with the neurological phenotype. NF1 was associated with a spectrum of CNS manifestations in at least 83.0% of patients. Regular neuropsychological assessment complementing frequent clinical and ophthalmologic testing for OPG is necessary in the care of each child with NF1.

MR Imaging and Clinical Characteristics of Diffuse Glioneuronal Tumor with Oligodendroglioma-like Features and Nuclear Clusters

BACKGROUND AND PURPOSE

Diffuse glioneuronal tumor with oligodendroglioma-like features and nuclear clusters (DGONC) is a new, molecularly defined glioneuronal CNS tumor type. The objective of the present study was to describe MR imaging and clinical characteristics of patients with DGONC.

MATERIALS AND METHODS

Preoperative MR images of 9 patients with DGONC (median age at diagnosis, 9.9 years; range, 4.2-21.8 years) were reviewed.

RESULTS

All tumors were located superficially in the frontal/temporal lobes and sharply delineated, displaying little mass effect. Near the circle of Willis, the tumors encompassed the arteries. All except one demonstrated characteristics of low-to-intermediate aggressiveness with high-to-intermediate T2WI and ADC signals and bone remodeling. Most tumors (n = 7) showed a homogeneous ground-glass aspect on T2-weighted and FLAIR images. On the basis of the original histopathologic diagnosis, 6 patients received postsurgical chemo-/radiotherapy, 2 were irradiated after surgery, and 1 patient underwent tumor resection only. At a median follow-up of 61 months (range, 10-154 months), 6 patients were alive in a first complete remission and 2 with stable disease 10 and 21 months after diagnosis. The only patient with progressive disease was lost to follow-up. Five-year overall and event-free survival was 100% and 86±13%, respectively.

CONCLUSIONS

This case series presents radiomorphologic characteristics highly predictive of DGONC that contrast with the typical aspects of the original histopathologic diagnoses. This presentation underlines the definition of DGONC as a separate entity, from a clinical perspective. Complete resection may be favorable for long-term disease control in patients with DGONC. The efficacy of nonsurgical treatment modalities should be evaluated in larger series.

Endocavitary Contrast-Enhanced Ultrasound

BACKGROUND

 Ultrasound is one of the most important imaging methods in the daily routine. Contrast-enhanced ultrasound (CEUS) has put ultrasound on equal footing with computed tomography and magnetic resonance imaging in many areas. Although ultrasound contrast agents are commonly administered intravenously, endocavitary application as performed in the case of iodine-containing contrast agents is also possible.

METHOD

 Based on the current literature, this overview provides information regarding possible endocavitary applications of ultrasound contrast agents as they are used and could be used in the daily routine in radiology. Examples are provided to illustrate the advantages and disadvantages of clinical use.

RESULTS AND CONCLUSION

 Endocavitary CEUS broadens the spectrum of possible ultrasound applications and can be safely used for patient diagnosis and treatment. The method can be safely used for diagnosis and patient management, particularly in patients in whom examinations including exposure to radiation with iodine-containing contrast agents may be contraindicated and who have limited mobility due to disease severity.

KEY POINTS

  · Endocavitary CEUS is a safe method that can be readily learned by those with prior ultrasound training. Radiologists benefit from their existing knowledge of contrast-enhanced imaging.. · With ultrasound contrast agents, endocavitary examinations comparable to CT and fluoroscopy can be performed without having to take radiation exposure, preexisting conditions, and patient mobility into consideration.. · In principle, endocavitary CEUS can access every body cavity (physiological and pathological) and body orifice with any access device.. · The method is mainly used for interventions including puncture and drainage. The diluted ultrasound contrast agent can be continuously visualized in the access device and in the target region, including distribution within the target region, with high spatial and temporal resolution. Voiding urosonography and visualization of the salivary duct system should also be mentioned in the radiological context.. · Poor B-mode imaging conditions typically also mean poor CEUS conditions. Imaging methods that can reliably evaluate low-lying structures and structures with overlying air, particularly in obese patients, without artifacts and can provide a good overview have a clear advantage here..

CITATION FORMAT

· Vollert K, Clevert DA, Kleffel T. Endocavitary Contrast-Enhanced Ultrasound. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1826-0325.

Heterozygous NOTCH1 variants cause CNS immune activation and microangiopathy

NOTCH1 belongs to the NOTCH family of proteins that regulate cell fate and inflammatory responses. Somatic and germline NOTCH1 variants have been implicated in cancer, Adams-Oliver syndrome and cardiovascular defects. We describe seven unrelated patients grouped by the presence of leukoencephalopathy with calcifications and heterozygous de novo gain-of-function variants in NOTCH1. Immunologic profiling showed upregulated CSF IP-10, a cytokine secreted downstream of NOTCH1 signaling. Autopsy revealed extensive leukoencephalopathy and microangiopathy with vascular calcifications. This evidence implicates that heterozygous gain-of-function variants in NOTCH1 lead to a chronic CNS inflammatory response resulting in a calcifying microangiopathy with leukoencephalopathy. This article is protected by copyright. All rights reserved.

NFB-03. Neurological manifestations in children and adolescents with Neurofibromatosis type 1 - Implications for management and surveillance

INTRODUCTION: We aimed to (1) characterize the spectrum of clinical phenotypes of NF1 in a random pediatric population, (2) correlate genotype with phenotypic expression for those with a genetic diagnosis, and (3) explore radiological features of NF1 in the central nervous system (CNS) by radiomics analyses to predict clinical course. METHODS: We performed a database search in the hospital information system of the University Children′s Hospital between January 2017 and December 2020 for patients with NF1 and evaluated the clinical phenotype by retrospective chart review. RESULTS: 75 children/adolescents were identified with suspicion/clinical diagnosis of NF1 (median age 10.0 years (range, 1.1-22.6); 35 female), confirmatory revised “diagnostic criteria” were met in 57 patients at the last follow-up. Per number of documented items, major signs were detected as 73/75 café-au-lait macules, 31/63 freckling, 38/71 neurofibromas (thereof 21 plexiform neurofibromas), 18/43 optic pathway glioma, 5/66 Lisch nodules, and two patients with sphenoid dysplasia. Genetic analysis (31/75) identified pathogenic NF1 variants in 27 patients. In 20/66 cases a parent met diagnostic criteria. Cognitive symptoms included developmental delay (28/68), learning deficits (12/48), attention-deficit hyperactivity disorder (3/53), and behavior anomalies (7/63). Classical unidentified bright objects were seen in 29/43, other intracranial tumors in 7/43, and cerebrovascular abnormalities in 5/43. Analysis of imaging features of the CNS in these patients will involve lesion segmentation and radiomics features. Symptomatic/progressive low-grade glioma necessitated neurosurgical resection (4/25) and/or chemotherapy (12/25). In 10/25 neuropsychological functions were assessed by the German neuropsychological basic diagnostic instrument. Until June 30th, 2021, one patient died of progressive plexiform neurofibroma.

CONCLUSIONS: A wide range of neurological manifestations, including neuropsychological deficits, should raise the suspicion of NF1 in an unselected pediatric population. We expect imaging features of the CNS to better predict the clinical course and enhance decision-making.

Imaging pediatric gastrointestinal stromal tumor (GIST)

BACKGROUND

Gastrointestinal stromal tumors (GIST) are extremely rare in children. Imaging plays a key role in staging and monitoring therapy (surgical and with tyrosine kinase inhibitors). The vast majority of articles addressing imaging of GIST base on adults and are based on CT. The subtype "pediatric GIST" - if at all - is only mentioned in a dependent clause. Although the imaging features in children and adults are similar, histology, clinical course and thus imaging approach are different.

METHODS

A PubMed search using the search terms "Gastrointestinal stromal tumor, GIST, WT GIST, children, pediatric, carney's triad, imaging, staging, follow-up, MRI, CEUS, ultrasonography, Positron emission tomography" was conducted. Studies that reported on laparoscopy, endoscopy and surgical techniques only were excluded.

RESULTS

Based on our selective literature review, we present alternative radiological imaging strategies using MRI, contrast enhanced ultrasound (CEUS) and PET-CT to stage and follow-up pediatric GIST patients. As pediatric GIST often is a chronic disease, minimizing exposure to ionizing radiation is mandatory.

CONCLUSION

MRI, contrast enhanced ultrasound and PET-CT instead of CT are the imaging modalities to evaluate pediatric GIST.

TYPE OF STUDY

Systematic review LEVEL OF EVIDENCE: III.

[True thymic hyperplasia : Differential diagnosis of thymic mass lesions in neonates and children]

Reactive and neoplastic thymic pathologies are the main considerations in the case of masses in the anterior and middle part of the mediastinum, while neurogenic tumors are predominant in the posterior mediastinum (which are not dealt with here). In neonates and infants, the commonest pathologies in the anterior mediastinum comprise germ cell tumors (mainly teratomas), congenital thymic cysts and true thymic hyperplasia (TTH). In toddlers, teratomas, yolk sac tumors and cysts predominate. In children over 5 years of age, lymphomas are the commonest mass lesions whereas thymomas and thymic carcinomas are rare. In addition, inflammation-linked hyperplasia in myasthenia gravis and rebound thymic hyperplasia after chemotherapy must be considered. Although rare at all ages, sarcomas must be considered in the differential diagnosis from birth onwards and throughout adolescence. Based on the report of a rare case of recurrent TTH, the differential diagnosis of this benign but potentially life-threatening condition is discussed.

Invasive aspergillosis osteomyelitis in children--a case report and review of the literature

Immunocompromised patients are at high risk of secondary infection associated with high morbidity. In children these complications include fungal osteomyelitis due to continuous infiltration or hematogenous spread. The case of a 4-year-old boy is presented who developed lumbalgia and thigh pain during ongoing chemotherapy for acute lymphatic leukemia. MRI revealed infarct-like lesions in the femur and L5 vertebra, which were biopsied. The histologic diagnosis was consistent with angioinvasive aspergillosis. A multifocal osseous presentation has rarely been described in children and an overview of the literature is presented. Invasive aspergillosis is a rare complication to be considered in children with MRI-detected bony lesions of infarct-like appearance.

Percutaneous treatment of a ruptured superior mesenteric artery aneurysm in a child

Splanchnic artery aneurysms are very rare in children. We report a 10-year-old girl with a large atraumatic ruptured superior mesenteric artery aneurysm that was considered inoperable. She was ultimately treated with two percutaneous US-guided thrombin injections, which led to complete occlusion of the aneurysm. The aetiology of the aneurysm remained unclear, but a family history was suggestive of a congenital connective tissue disease such as Ehlers-Danlos syndrome subtype IV.

Die Behandlung iatrogener femoraler Pseudoaneurysmen durch Thrombininjektion - Ergebnisse bei 54 Patienten

PURPOSE

To evaluate ultrasound-guided percutaneous thrombin injection to treat iatrogenic femoral pseudoaneurysms following catheter interventions.

MATERIALS AND METHODS

In a period of 2 years and 11 months, 55 iatrogenic femoral pseudoaneurysms were treated in 54 patients (male : female = 29 : 25) by percutaneous thrombin injection under continuous color Doppler control. Mean maximum diameter of the perfused lumen was 2.5 cm (SD +/- 1 cm). The injected thrombin doses varied between 10 and 2,000 U (median 200 U).

RESULTS

Following thrombin injection, the pseudoaneurysm occlusion rate was 100 % (n = 55/55). Complete and persistent occlusion was achieved in 54 of 55 (98 %) pseudoaneurysms. A repeated procedure was necessary in 6 pseudoaneurysms. In one case (2 %), discrete signs of reperfusion were observed after primary occlusion within 24 hours of the initial procedure (lumen diameter 3 x 5 mm), followed by spontaneous thrombosis without further treatment. No complications, in particular no clinically manifest thromboembolic events, were observed.

CONCLUSION

Ultrasound-guided percutaneous thrombin injection is an effective and safe method for the treatment of iatrogenic post catheterization femoral pseudoaneurysms.

Power Doppler sonography with and without echo-enhancing contrast agent and contrast-enhanced MRI for the evaluation of rheumatoid arthritis of the shoulder joint: differentiation between synovitis and joint effusion

OBJECTIVE

To evaluate patients with clinically active rheumatoid arthritis (RA) of the shoulder for joint effusion and synovitis using conventional sonography, power Doppler (PD) sonography with and without echo-enhancing contrast agent, and contrast-enhanced MRI.

DESIGN AND PATIENTS

Twenty-four patients (mean age 64 years) with known RA had one symptomatic shoulder evaluated by conventional gray-scale sonography and PD sonography before and after intravenous administration of the echo-enhancing contrast agent Levovist (300 mg/ml, 2.5 g). The degree and extent of the altered echo pattern in the subacromial bursa, axillary recess and glenohumeral joint seen by conventional gray-scale sonography and the intensity of vascular signals of PD sonography were compared with the findings of MRI obtained with T2-weighted turbo spin-echo sequences and contrast-enhanced T1-weighted fat-saturated spin-echo sequences. MRI was evaluated by two readers in consensus without knowledge of the sonographic findings.

RESULTS

MRI, which was used as the reference examination, detected joint effusion in 71% (17/24) and synovitis in 92% (22/24) of the patients. Conventional sonography revealed an abnormal articular echo pattern in 96% (23/24) of the patients, especially in the axillary recess and subacromial bursa, but failed to attribute the altered echo pattern to either fluid or specific synovitis. PD sonography allowed a specific diagnosis of synovitis in 33% (8 patients), which increased to 50% (12 patients) after administration of an echo-enhancing contrast agent. In 42% (10/24) of the patients, the findings of synovitis demonstrated by MRI corresponded to an altered echo pattern by conventional sonography, but vascular signals were absent by PD sonography with or without echo-enhancing contrast agent.

CONCLUSIONS

Using MRI as the "gold standard," PD sonography with and without echo-enhancing contrast agent cannot reliably identify synovitis or distinguish synovial inflammation from effusion in the shoulder joint.

Ultrasonography of acute musculoskeletal disease

With technical improvements (higher frequency and extended field-of-view sonography) the ability of ultrasound to detect pathology in the musculoskeletal system has been greatly increased. As in MRI, and unlike conventional radiography, soft tissue lesions in muscles, tendons and occasionally in joints can be shown directly. An advantage is real-time imaging of joints during stress. A disadvantage is limited demonstration of internal structures within joints. This paper provides an overview of various pathologies with emphasis on acute disorders.