Ignasi Barber

Side Effects of Oncologic Therapies in the Pediatric Central Nervous System: Update on Neuroimaging Findings

The need for early, accurate diagnosis of central nervous system (CNS) complications occurring during and after pediatric cancer treatment is growing because of the improvement in overall survival rates related to innovative and aggressive oncologic therapies. An elevated degree of suspicion is needed to recognize the radiologic features of these CNS complications. Radiologists need familiarity with the early and late side effects of cancer therapy in the pediatric CNS (eg, toxic effects, infection, endocrine or sensory dysfunction, neuropsychologic impairment, second malignancies), in order to accelerate the imaging diagnosis and minimize as much as possible the associated morbidity. Acquisition of knowledge about these complications will enable the development of more appropriate therapeutic trials and more effective patient surveillance and will lead to an improved quality of life by decreasing the long-term sequelae in survivors.

EFFECT OF ADMINISTRATION OF PLATELET-RICH PLASMA IN EARLY PHASES OF DISTRACTION OSTEOGENESIS: AN EXPERIMENTAL STUDY IN AN OVINE FEMUR MODEL

BACKGROUND It has been suggested that platelet-rich plasma (PRP) might enhance bone formation. The aim of this study was to quantify the effect of PRP administered in the early phases of distraction osteogenesis in an ovine femur model. METHODS Twenty sheep aged 4 months underwent osteotomy of the femoral diaphysis followed by distraction osteogenesis. The sheep were divided into two groups of 10. One group received three injections of PRP on days 0, 10, and 20 of the procedure (PRP group) and the other received no additional treatment (control group). The results were evaluated by computed tomography (CT) and histology on completion of distraction osteogenesis (day 40). CT evaluation included measurement of the callus and bone density. Femur size was also measured proximally and distally. Histological evaluation was used to quantify osteoblasts, osteoclasts, vascular lumens, and trabecular maturity by zones and to calculate trabecular bone, fibrous tissue, and cartilage ratios. RESULTS Radiological and histological evaluation of the regenerate bone showed no significant differences between the PRP group and the control group for any of the variables analysed. The only significant difference detected was a wider femur (increased diaphyseal thickness) at the proximal and distal levels in the PRP group. CONCLUSION We found no radiological or histological evidence that the administration of PRP in the early phases of distraction osteogenesis enhances bone formation.

Fetoscopic release of umbilical cord amniotic band in a human fetus

Umbilical cord amniotic bands occur in approximately 10% of cases of amniotic band syndrome and are a well‐known cause of fetal death. An unexpected amniotic band encircling the umbilical cord was diagnosed during a fetoscopic procedure to release a leg constriction. Both bands were released fetoscopically using a YAG laser. We report the first case of an amniotic band involving the umbilical cord diagnosed and released prenatally. Copyright

Fetoscopic release of extremity amniotic bands with risk of amputation.

With the advent of less-invasive fetal surgery techniques, nonlethal disorders are considered amenable to intrauterine treatment. Extremity amniotic band syndrome fulfils the criteria of intrauterine disorders conformable with fetal treatment: capability of prenatal diagnosis and severity. We report 2 cases of extremity amniotic bands with risk of limb amputation released fetoscopically with YAG laser.

Thoracic Findings of Systemic Diseases at High-Resolution CT in Children

Pulmonary involvement in systemic diseases is common, but the radiographic appearance of early-stage pulmonary changes is often subtle. Computed tomography (CT) has higher sensitivity and specificity than radiography, and high-resolution CT is the method of choice for accurate assessment of diffuse parenchymal lung disease. Even with reductions in the peak voltage and tube charge to minimize the exposure of pediatric patients to radiation, CT performed with a meticulous acquisition technique can provide detailed information. In some cases, high-resolution CT may depict clinically silent lung lesions. The information provided by CT is invaluable for planning therapy in pediatric patients with pulmonary involvement in connective tissue disease (eg, juvenile rheumatoid arthritis, dermatomyositis, systemic sclerosis, systemic lupus erythematosus, or mixed connective tissue disease), vasculitis, a primary or acquired immune deficiency disorder, immotile cilia syndrome, cystic fibrosis, or Langerhans cell histiocytosis.

Imaging of skeletal injuries associated with abusive head trauma

Skeletal injuries are commonly encountered in infants and young children with abusive head trauma. Although certain patterns of intracranial injury suggest abuse, none are diagnostic. Therefore demonstration of associated unsuspected skeletal injuries has important implications, particularly when highly specific fractures are present. Skull fractures are commonly associated with intracranial injury, but no fracture pattern is indicative of physical abuse. Other skeletal injuries including classic metaphyseal lesions and rib, spine and scapular fractures are strong predictors of abusive head trauma in infants with intracranial injury. It is mandatory to perform rigorous skeletal surveys in infants and young children with clinical and neuroimaging findings concerning for abusive head trauma.

Pathology of the thoracic wall: congenital and acquired.

This review aims to cover the main congenital and acquired lesions that arise in the thoracic wall of infants and children. Imaging often plays an essential role in the evaluation of symptomatic and asymptomatic thoracic wall abnormalities. The use of appropriate imaging modalities for each condition will be addressed, as well as the range of benign and malignant conditions that can occur.

Accuracy of whole-body MRI in the assessment of splenic involvement in lymphoma

Background Accurate evaluation of the spleen is an important component of staging lymphoma, because this may have prognostic and therapeutic implications. Purpose To determine the diagnostic value of whole-body magnetic resonance imaging (MRI), including diffusion-weighted imaging (whole-body MRI-DWI) in the detection of splenic involvement in lymphoma. Material and Methods This IRB approved, prospective multicenter study included a total of 107 patients with newly diagnosed, histologically proven lymphoma who underwent 1.5 T whole-body MRI-DWI and FDG-PET/CT. Whole-body MRI-DWI and FDG-PET/CT were independently evaluated by a radiologist and a nuclear medicine physician, in a blinded manner. Splenic involvement at MRI was defined as splenic index > 725 cm3 or discrete nodules. At FDG-PET/CT splenic involvement was defined as splenic uptake greater than liver uptake or hypodense nodules at contrast-enhanced CT. FDG-PET/CT augmented with follow-up imaging after treatment was used as reference standard. Results Splenic involvement was detected with FDG-PET/CT in 21 patients, all demonstrating response to treatment. The sensitivity, specificity, positive predictive value, and negative predictive value of whole-body MRI-DWI for the detection of splenic involvement were 85.7 %, 96.5 %, 85.7%, and 96.5%, respectively. Three out of six discrepancies were related to suboptimal criterion of splenic size used with whole-body MRI-DWI versus the size-independent FDG uptake. Conclusion Whole-body MRI-DWI is reasonably accurate in the detection of splenic lymphomatous involvement.

Rib and vertebral bone fibrous dysplasia in a child with tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder characterized by benign hamartomas in multiple organ systems, primarily the skin, brain, heart, kidneys, lungs, and eyes. The skeletal system is commonly affected in patients with TSC, but these bone lesions are generally asymptomatic and have not been well characterized. We present clinically significant bone growth in two ribs and vertebrae in an 8‐year‐old male patient with TSC and discuss the effects of mammalian target of rapamycin (mTOR) inhibitors as a possible treatment for these osseous abnormalities. This report suggests that skeletal lesions may hold more clinical significance than previously assumed and that further research should be directed toward understanding bone involvement in TSC.

Muscular and glenohumeral changes in the shoulder after brachial plexus birth palsy: an MRI study in a rat model

Background Shoulder abnormalities are the major cause of morbidity in upper brachial plexus birth palsy (BPBP). We developed a rat model of upper trunk BPBP and compared our findings to previously reported animal models and to clinical findings in humans. Methods Forty-three 5-day-old newborn rats underwent selective upper trunk neurectomy of the right brachial plexus and were studied 3 to 20 weeks after surgery. The passive shoulder external rotation was measured and the shoulder joint was assessed bilaterally by a 7.2T MRI bilaterally. Results We found a marked decrease in passive shoulder external rotation, associated with a severe subscapularis muscle atrophy and contracture. None however developed the typical pattern of glenohumeral dysplasia. Conclusions In contradiction with previous reports, our study shows that the rat model is not adequate for preclinical studies of shoulder dysplasia. However, it might serve as a useful model for studies analyzing shoulder contracture occurring after upper BPBP.