Congenital mediastinal cysts are uncommon benign lesions generally caused by an abnormal embryological development of the foregut or coelomic cavity. They are expansive lesions, frequently asymptomatic that may manifest as a result from compression of adjacent structures. Bronchogenic, pericardial, enteric, thymic, esophageal duplication cysts and lymphangiomas are the main entities in this group of lesions. Congenital mediastinal cysts morphology is typical and imaging methods allow a correct diagnosis in a great number of cases. Surgical treatment is indicated only in cases of symptomatic lesions, considering that these lesions present no potential for malignant degeneration. The present study was aimed at commenting and illustrating the most relevant imaging findings of these lesions based on a retrospective review of ten cases collected in the records of the involved institutions.

Keywords: Congenital mediastinal cysts, Cystic neoplasms, Cysts

Sacroiliitis is a non-infectious inflammatory process involving the sacroiliac joint, and is a diagnostic criterion for seronegative spondyloarthropathies. Imaging methods are of great value for confirming the diagnosis of this condition. The present study is a review of cases included in didactic files and in the literature to illustrate the anatomy, techniques, and main imaging findings in x-ray, computed tomography and magnetic resonance imaging for determining the diagnosis of sacroiliitis, also approaching main differential diagnoses.

Keywords: Sacroiliitis, Spondyloarthropathy, X-ray, Computed tomography, Magnetic resonance imaging

Acute appendicitis is the most important cause of abdominal pain requiring surgical intervention in the Western world. The early diagnosis of this disease is of paramount relevance for minimizing its morbidity. Imaging methods have represented a huge progress in the diagnosis of this entity, which used to be based essentially on clinical history, physical examination and laboratory tests results, considering that 20% to 33% of patients present with atypical symptoms. Diagnostic difficulty is higher in children, the elderly, and women in childbearing age. The main imaging methods for evaluation of acute appendicitis are ultrasound and computed tomography. The present study is aimed at describing the disease physiopathology, commenting main computed tomography technical aspects, demonstrating and illustrating tomographic findings, and describing main differential diagnoses.

Keywords: Acute appendicitis, Vermiform appendix, Computed tomography

Leukokoria is an abnormal pupillary reflex most commonly seen in children that usually results from an intra-ocular abnormality. The evaluation of a child with leukokoria should be performed particularly to rule out a retinoblastoma (the cause of leukokoria in half of the cases). The authors present the main clinical and imaging features for the diagnosis of the most common causes of leukokoria.

Keywords: Eye, Leukokoria, Childhood, Ultrasonography, Computed tomography, Magnetic resonance imaging

Callosal dysgenesis is a malformation of the corpus callosum with origins in the embryogenesis of the telencephalon. We reviewed the computed tomography and magnetic resonance imaging findings of 11 patients with callosal dysgenesis and one patient with normal corpus callosum associated with a lipoma. The patients were divided into three distinct groups: total agenesis (three patients), partial agenesis (six patients) and hypoplasia (two patients). Associated abnormalities were observed in nine patients, including Chiari II malformation (one patient), schizencephaly (one patient), interhemispheric cyst (two patients), Dandy-Walker cyst (one patient), nodular heterotopy (one patient) and lipoma of the corpus callosum (four patients). This paper presents a review that may contribute to the diagnosis of these disorders.

Keywords: Dysgenesis of the corpus callosum, Brain malformation, Developmental anomalies, Lipoma of the corpus callosum