Development and Validation of a Pediatric MRI-Based Perianal Crohn Disease (PEMPAC) Index-A Report from the ImageKids Study

BACKGROUND

As part of the prospective multicenter ImageKids study, we aimed to develop and validate the pediatric MRI-based perianal Crohn disease (PEMPAC) index.

METHODS

Children with Crohn disease with any clinical perianal findings underwent pelvic magnetic resonance imaging at 21 sites globally. The site radiologist and 2 central radiologists provided a radiologist global assessment (RGA) on a 100 mm visual analog scale and scored the items selected by a Delphi group of 35 international radiologists and a review of the literature. Two weighted multivariable statistical models were constructed against the RGA.

RESULTS

Eighty children underwent 95 pelvic magnetic resonance imaging scans; 64 were used for derivation and 31 for validation. The following items were included: fistula number, location, length and T2 hyperintensity; abscesses; rectal wall involvement; and fistula branching. The last 2 items had negative beta scores and thus were excluded in a contending basic model. In the validation cohort, the full and the basic models had the same strong correlation with the RGA (r = 0.75; P < 0.01) and with the adult Van Assche index (VAI; r = 0.93 and 0.92; P < 0.001). The correlation of the VAI with the RGA was similar (r = 0.77; P < 0.01). The 2 models and the VAI had a similar ability to differentiate remission from active disease (area under the receiver operating characteristic curve, 0.91-0.94). The PEMPAC index had good responsiveness to change (area under the receiver operating characteristic curve, 0.89; 95% confidence interval, 0.69-1.00).

CONCLUSIONS

Using a blended judgmental and mathematical approach, we developed and validated an index for quantifying the severity of perianal disease in children with CD. The adult VAI may also be used with confidence in children.

A Distinct Metabolite Profile Correlates with Neurodegenerative Conditions and the Severity of Congenital Hydrocephalus

In congenital hydrocephalus, cerebrospinal fluid accumulation is associated with increased intracranial pressure (ICP), ischemia/hypoxia, metabolic impairment, neuronal damage, and astrocytic reaction. The aim of this study was to identify whether a metabolite profile revealing tissue responses according to the severity of hydrocephalus can be detected. The hyh mutant mouse used for this study exhibits 2 different forms of hydrocephalus, severe and moderate. In a comprehensive investigation into the 2 progressions of hydrocephalus, mice with severe hydrocephalus were found to have higher ICP and astrocytic reaction. Several metabolites from the mouse brain cortex were analyzed with 1H high-resolution magic angle spinning nuclear magnetic resonance (1H HR-MAS NMR) spectroscopy. A differential profile for metabolites including glutamate and glutamine was found to correlate with the severity of hydrocephalus and can be explained due to differential astrocytic reactions, neurodegenerative conditions, and the presence of ischemia. The glutamate transporter EAAT2 and the metabolite taurine were found to be key histopathological markers of affected parenchymata. In conclusion, a differential metabolite profile can be detected according to the severity of hydrocephalus and associated ICP and therefore can be used to monitor the efficacy of experimental therapies.

[Infantile myofibromatosis. Study of a case using whole body ultrasound and MRI]

Infantile myofibromatosis, despite being considered a rare condition, is the most common fibrous tumour in infancy. It is characterised by the presence of benign fibroblastic-myofibroblastic lesions. It usually occurs in children under two years-old, but it can appear at any age. The solitary form (myofibromas) may affect the skin, subcutaneous cellular tissue, muscle or bone. In the multi-centred form (myofibromatosis), there may also be visceral lesions. The lesions usually regress spontaneously in one or two years, with the prognosis being excellent in these cases. However, when there is visceral involvement, the prognosis is poor and treatment with chemotherapy is indicated. Lung involvement is more associated with a poor prognosis. Although the definitive diagnosis is by histopathology, diagnostic imaging tests are essential for characterising the lesions, establishing the extent of the disease, assessing visceral involvement, and following up the progression of the lesions.

Papiloma y carcinoma de plexos coroideos en la edad pediátrica

Papillomas of the choroid plexus are rare tumors of neuroectodermal origin; they represent less than 5% of all central nervous system (CNS) tumors in pediatric patients. Choroid plexus carcinomas are even rarer. We reviewed the incidence of these neoplasms at our reference hospital and found six tumors of the choroid plexus (five papillomas and one carcinoma) in five patients. Patient age ranged from prenatal to 25 months. All five patients underwent computed tomography (CT) examination. Four perinatal patients underwent ultrasound examination, four magnetic resonance imaging (MRI), and one (years ago) angiography. All patients had tumors located in the lateral ventricles, and one patient had a second tumor located in the third ventricle. These tumors are predominantly solid, intraventricular, with well-defined polylobulated margins. They show intense vascularization on Doppler studies and marked contrast enhancement on CT and MRI studies. Hydrocephalus was present in three cases. All patients underwent surgery; total resection was achieved in the five papillomas, whereas the carcinoma was partially resected and the patient is currently undergoing chemotherapy. The three patients with a single papilloma are disease free at follow-up (range 7 months to 11 years). The patient with two papillomas shows good recovery at follow-up, whereas the patient with carcinoma of the choroid plexus has a poor prognosis.

[Intrathoracic lipoblastoma with costal involvement]

We report the case of a two-year-old girl with a lipoblastoma arising from the chest wall with intrathoracic extension and costal involvement. The diagnosis was confirmed histologically after surgery. Plain-film chest x-rays showed an extrapleural mass; computed tomography (CT) and magnetic resonance imaging (MRI) suggested fatty contents. The differential diagnosis is mainly versus liposarcoma, which is extremely rare in children.

[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.

Nephrogenic rests, nephroblastomatosis, and associated lesions of the kidney

The fetal kidney is formed by the development of nephrons from fetal metanephric blastema surrounding the ureteric bud. The fetal renal tissue matures into normal renal parenchyma during gestation, but, occasionally, fetal tissue persists into infancy as microscopic foci called nephrogenic rests. Nephrogenic rests are found in approximately 1% of infant kidneys at autopsy. Nephrogenic rests are associated with an increased risk of Wilms tumor, and it is theorized that nephrogenic rests undergo neoplastic change into Wilms tumor. Fortunately, this transformation occurs in less than 1% of young children with nephrogenic rests. Nephrogenic rests are associated with many syndromes, including Beckwith-Wiedemann syndrome, hemihypertrophy, and sporadic aniridia. Children with identifiable syndromes, once diagnosed, should be screened for the development of Wilms tumor. Nephrogenic rests are associated with other lesions such as multilocular cystic nephroma and multicystic dysplasia, usually without malignant complications.