Kearns-Sayre syndrome: pediatric neuroradiologic findings in computed tomography and magnetic resonance imaging

Clinical presentation of mitochondrial disorders is heterogeneous because the affected organs are those depending on a high rate of aerobic metabolism. They can appear at any age and evolution is progressive. Signs that guide diagnostic suspicion, especially in the pediatric age group, are heterogeneous clinical presentation and multisystem involvement. Within the spectrum of diseases caused by mitochondrial myopathy, there are clearly defined syndromes such as Kearns-Sayre syndrome. Muscle biopsy shows ragged red fibers and approximately 80 % of patients present sporadic deletions in mitochondrial DNA. Imaging studies reveal areas of hypointensity in basal ganglia and midbrain that are not visible after administration of contrast enhancement in computed tomography, and symmetric T2 hyperintensity lesions in these areas in magnetic resonance imaging. We present a patient with Kearns-Sayre syndrome, in whom radiological alterations were helpful in reaching the diagnosis.     

Cranial computed tomography in pediatric migraine

Two children with migraine showed low-density areas with an irregular enhancement pattern on CT scans of the head after contrast infusion. Angiography was normal in both patients. These abnormalities probably were due to transient blood-brain barrier damage. This knowledge is important when excluding other disorders like vascular malformations.     

Use of computed tomography in pediatric oncology

Computed tomography (CT) has dramatically changed the imaging of pediatric oncologic disease. CT precisely displays and characterizes cross-sectional anatomic pathology. This provides important information for diagnosing and staging tumors in infants and children. The principles, techniques, and indications for computed tomography in the evaluation of pediatric extracranial tumors are reviewed in this article. Selected applications of computed tomography for pediatric tumors of the mediastinum, chest wall, lung parenchyma, abdomen, pelvis, and extremities are discussed and illustrated.     

MDCT angiography of pediatric vascular diseases of the abdomen, pelvis, and extremities

Multi-detector-row computed tomography (MDCT) enables rapid, noninvasive, high-resolution, and three-dimensional imaging of pediatric vascular diseases. In this paper, we explore the adaptation of the MDCT angiographic principles to pediatric patients for vascular diseases of the abdomen, pelvis, and extremities. Special emphasis is placed on the practical aspects of how to perform these studies. Optimizations of scan parameters, contrast medium usage, radiation dose, and three-dimensional image processing are discussed in detail. We provide practical guidance on how to choose between MR angiography and CT angiography. Finally, we review important pediatric vascular diseases, categorized into traumatic injuries, inherited vascular diseases, congenital vascular diseases, vasculitides, and surgical planning and assessment. In each category, we discuss how CT angiography can be tailored to maximize its clinical benefits.     

Radiation doses from small-bowel follow-through and abdomen/pelvis MDCT in pediatric Crohn disease

Background The onset of Crohn disease (CD) can occur in childhood. Imaging, which often involves radiation, is frequent in CD both for disease diagnosis and follow-up. However, information regarding radiation dose for contemporary CT and fluoroscopy is not available for determining the cost/benefit ratio for imaging strategies. Objective To compare effective dose (ED) for small-bowel follow-through (SBFT) and abdomen/pelvis MDCT in pediatric CD. Materials and methods Average fluoroscopic time and number of radiographs were obtained for 30 consecutive pediatric SBFTs. The numbers of SBFTs and CT scans performed per child among children with CD (1990–2005) were determined. The ED was determined (ICRP 60, 10-year-old phantom, MOSFET) for a 5-min fluoroscopy examination of the central abdomen and right lower quadrant (110 kVp, 0.3 mA) and pelvis (110 kVp, 0.35 mA). The ED for a 16-slice abdomen/pelvis MDCT scan was determined using the 10-year-old protocol: 16×1.25 mm, pitch 1.375, 27.5 mm/rotation, 0.5 s, 140 kVp, 85 mA. Results A total of 176 children with CD underwent imaging, averaging 1.2 SBFTs and 1.1 CT scans. On average SBFT took 5.1 min with 3.3 abdominal radiographs. The EDs (mSv) for a 5-min fluoroscopy were 0.15 for the central abdomen, 0.35 for the right lower quadrant, and 0.56 for the pelvis, yielding an average ED for SBFT (5-min fluoroscopy, 3.3 abdominal radiographs) of 1.8–2.2 mSv. The ED for MDCT was 3.48 mSv. Conclusion Although the ED for MDCT might be up to twice that for SBFT, excessive fluoroscopy time and number of abdominal radiographs can result in actual EDs that are equivalent. Attention must be paid to SBFT technique to minimize radiation dose and to the indication to determine the appropriate examination.     

Utilization of computed tomography imaging in the pediatric emergency department

Background

In recent years, there has been a movement toward more judicious use of computed tomography (CT) imaging in an attempt to limit exposure of pediatric patients to ionizing radiation. The Image Gently Alliance and like-minded movements began advocating for safe and high-quality pediatric imaging worldwide in the late 2000s.

Objective

In the context of these efforts, we evaluate CT utilization rates in the pediatric emergency department at a major academic medical center.

Materials and methods

We tracked utilization in several categories of CT, magnetic resonance imaging (MRI) and ultrasonography (US) between July 2008 and June 2017 and compared them with utilization rates from 2000 to 2006.

Results

A total of 4,955 pediatric patients underwent a total of 5,973 CT scans, 2,775 US studies and 293 MRI scans while in the pediatric emergency department during the 2008–2017 study period. We observed decreases in CT scans across all categories, ranging from a 19% decrease in abdominal CT to a 66% decrease in chest CT. Relatively greater decreases in CT scans were observed in patients younger than 3 years of age as compared to older children and adolescents. Abdominal and pelvic US increased. Brain MRI also increased over the final two years of the study.

Conclusion

CT utilization decreased throughout the 2008–2017 study period.

     

Comparison of ultrasound versus computed tomography for the detection of kidney stones in the pediatric population: a clinical effectiveness study

Background

The incidence of pediatric nephrolithiasis in the United States is increasing. There is a paucity of literature comparing the diagnostic performance of computed ultrasound (US) to tomography (CT) in the pediatric population.

Objective

To determine the diagnostic performance of renal US for nephrolithiasis in children using a clinical effectiveness approach.

Materials and methods

Institutional review board approval with a waiver of informed consent was obtained for this retrospective, HIPAA-complaint investigation. Billing records and imaging reports were used to identify children (≤18 years old) evaluated for nephrolithiasis by both US and unenhanced CT within 24 h between March 2012 and March 2017. Imaging reports were reviewed for presence, number, size and location of kidney stones. Diagnostic performance of US (reference standard=CT) was calculated per renal unit (left/right kidney) and per renal sector (four sectors per kidney). For sector analysis, US was considered truly positive if a stone was identified at CT in the same or an adjacent sector.

Results

There were 68 renal stones identified by CT in 30/69 patients (43%). Mean patient age was 14.7±3.6 years, and 35 were boys. For detecting nephrolithiasis in any kidney, US was 66.7% (48.8–80.8%) sensitive and 97.4% (86.8–99.9%) specific (positive predictive value=95.2% [77.3–99.8%], negative predictive value=79.2% [65.7–88.3%], positive likelihood ratio=26.0). Per renal sector, US was 59.7% (46.7–71.4%) sensitive and 97.4% (95.5–98.5%) specific (positive predictive value=72.3% [58.2–83.1%], negative predictive value=95.4% [93.2–96.9%], positive likelihood ratio=22.5). Of the 30 stones not detected by US, only 3 were >3 mm at CT.

Conclusion

In clinical practice, US has high specificity for detecting nephrolithiasis in children but only moderate sensitivity and false negatives are common.

     

Osteopetrosis: Brain ultrasound and computed tomography findings

A case of osteopetrosis presenting with rare features of dysmorphism with proptosis due to hypoplasia of the orbits and the temporal bone is described. The case also had calcifications in the periventricular regions, the falx cerebri and the corpora colliculi. These features and sonographic findings of osteopetrosis have not been reported previously. The sensitivity and specificity of imaging modalities in the diagnosis of intracranial calcifications is discussed.     

Computed tomography of the abdomen and pelvis: documentation of tumor response and progression in disseminated prostate cancer

Computed tomography of the abdomen and pelvis has been used to stage early prostatic cancer. We investigated its value in monitoring tumor response in more advanced disease. Serial computed tomography of the abdomen and pelvis was obtained along with multiple other staging tests prior to treatment and at 3- to 4-month intervals thereafter in 32 patients with stage D2 tumor treated initially with combination chemotherapy and with hormones at progression. Pretreatment lymphography with follow-up abdominal films was also performed. Initial computed tomography of the abdomen and pelvis showed evidence of node metastases in 35% of patients while lymphography was positive in 54%. Among 19 patients with tumor response and 25 with progression, the results of treatment were objectively documented by improvement or worsening, respectively, in a mean of 5.1 and 5.0 other staging tests, exclusive of computed tomography. Computed tomography of the abdomen and pelvis improved in 85% of responding patients examined. Progression was confirmed by worsening of computed tomography in 32%. Although lymphography was often abnormal prior to treatment, in our hands it was not useful in serial monitoring of tumor status. We conclude that serial computed tomography of the abdomen and pelvis, when initially positive, is a useful test to document objectively tumor response and progression in disseminated prostatic cancer.     

仿真CT肠镜与大肠镜在小儿外科的应用

目的 对仿真CT肠镜与大肠镜在小儿外科的应用进行比较。方法 对33例患儿采用日本Olympus PCF20大肠镜及美国GE公司Hispead型螺旋CT仿真大肠镜进行检查。大肠镜检查使用Endoview软件记录内镜图像，完毕后再进行CT检查，使用Insight软件进行CT三维图像重建，利用Modify Endoscopy程序显示肠腔内的形态结构。结果 本组33例患儿，仿真CT肠镜（CTVE）检出肠重复畸形2例，肠旋转不良3例，结肠冗长症5例，大肠息肉10例（漏诊5例），溃疡性结肠炎、大肠血管畸形未能检出；大肠镜检出肠放置不良2例（漏诊1例），结肠冗长症5例，大肠息肉15例，溃疡性结肠炎6例，大肠血管畸形2例，肠重复畸形未能检出。仿真CT肠镜对诊断肠道畸形具有较高的准确性，但对于直径小于0.5cm的大肠息肉、肠血管畸形检出率低，易漏诊；对小儿溃疡性结肠炎的粘膜显示不理想。大肠镜则对于诊断大肠息肉、溃疡性结肠炎、大肠血管畸形有较高的准确性。结论 仿真CT肠镜是诊断肠道畸形的一种有效途径，但是对肠道粘膜的病变的显示不理想；是大肠镜检的一种重要补充手段。     

The utilization of pediatric computed tomography in a large Israeli Health Maintenance Organization

Background Concern has been raised about the potential risks related to radiation exposure from CT scans, particularly among children. However, to date, there are few data available describing the magnitude of pediatric CT utilization.Objective The aim of the study was to explore patterns of CT use in pediatric patients, with respect to time, use of multiple scans, body regions imaged, and medical diagnoses.Materials and methods Records of 22,223 scans performed on 18,075 people aged ≤18 years over the period 1999–2003, including diagnoses recorded within 21 days after the examination, were obtained from a large Israeli Health Maintenance Organization (1,600,000 members).Results The highest annual CT examination rate (per 1,000) was recorded in 2001 (10.1) compared to 7.0 and 6.3 in 1999 and 2003, respectively. The lowest rate (three scans per 1,000) was found for 3-year-old children, with increasing rates with age. The head was the most frequently scanned region, both in young children (78%) and adolescents (39%). Symptoms of ill-defined conditions and injuries were documented in 22% and 10% of all scans, respectively.Conclusions Although the results suggest that children comprise only 3% of all patients undergoing CT, this important modality must be carefully used because of their increased radiosensitivity, higher effective radiation doses, and longer life expectancy.     

Temporal bone computed tomography findings in bilateral sensorineural hearing loss

AIM—To examine the yield of computed tomography (CT) of the temporal bones when investigating sensorineural hearing loss (SNHL) and to identify factors associated with CT findings.
METHODS—Retrospective analysis of 116 consecutively investigated children with bilateral SNHL at the audiology department of Great Ormond Street Hospital, London. Main outcome measures were CT results, hearing loss parameters, history, and clinical examination.
RESULTS—A total of 33 (28.4%) CT scans were identified as abnormal. Children with profound and/or progressive hearing loss and/or craniofacial abnormalities were more likely to have an abnormal CT scan and together accounted for 25 abnormal CT scans. Sex, consanguineous parents, or family history of SNHL were not associated with CT findings. Dilated vestibular aqueduct was significantly correlated with the presence of progressive SNHL.
CONCLUSIONS—All children with SNHL should undergo radiological investigation of the petrous bones/inner ear; abnormalities are more likely to be found in cases with craniofacial abnormalities, or profound or progressive hearing loss. The decision whether to perform a CT or magnetic resonance imaging will depend on scanner availability, expertise, and management considerations, but cochlear implant candidates will require both.

     

Characterisation of computed tomography angiography findings in paediatric patients with heterotaxy

Pediatric Radiology - Heterotaxy refers to the abnormal arrangement of organs across the left–right axis and is typically associated with complex cardiovascular malformations. To characterise...