A mini review on neurofibromatosis type 1 from the radiological point of view

Abstract

Neurofibromatosis type one (NF1) belongs to the most frequent rare diseases, requiring various methods of diagnostic imaging at different stages of diagnostics and follow-up. Magnetic resonance imaging (MRI) is a method of choice in diagnostics of brain: unidentified neurofibromatosis objects, optic pathway gliomas and other tumours which can spontaneously regress. NF1 patients suffer from vascular abnormalities with a predominance of aortic, renal, mesenteric, and carotid-vertebral stenoses or aneurysms. These are evaluated by ultrasound, computed tomography- or MRI-angiography and by digital subtraction angiography. In our material we described twofold higher occurrence of arterial variants in brain in NF1 than in the control group. Characteristic skeletal changes include tibial pseudarthrosis, scoliosis, sphenoid wing dysplasia, rib penciling, and gracile bones, usually diagnosed with plain radiographs. Outside CNS we deal with neurofibromas and plexiform neurofibromas in any location in the body. Their malignant transformation leads to development of malignant peripheral nerve sheath tumour, or malignant triton tumour. Rhabdomyosarcoma, juvenile myelomonocytic leukemia and phaeochromocytoma are also encountered in NF1 patients with increased frequency. Regular imaging follow-up studies should not be routinely performed in NF1 patients. MRI is recommended for follow-up of clinically suspected tumours, single whole-body MR is recommended at transition to adulthood. Positron emission tomography/computed tomography is useful for the detection of malignant transformation of tumours in NF1 patients.