Incidental findings on brain magnetic resonance imaging (MRI) in adults: a review of imaging spectrum, clinical significance, and management.

Utilization of brain MRI has dramatically increased in recent decades due to rapid advancement in imaging technology and improving accessibility. As a result, radiologists increasingly encounter findings incidentally discovered on brain MRIs which are performed for unrelated indications. Some of these findings are clinically significant, necessitating further investigation or treatment and resulting in increased costs to healthcare systems as well as increased patient anxiety. Moreover, management of these incidental findings poses a significant challenge for referring physicians. Therefore, it is important for interpreting radiologists to know the prevalence, clinical consequences, and appropriate management of these findings. There is a wide spectrum of incidental findings on brain MRI such as asymptomatic brain infarct, age-related white matter changes, microhemorrhages, intracranial tumors, intracranial cystic lesions, and anatomic variants. This article provides a narrative review of important incidental findings encountered on brain MRI in adults with a focus on prevalence, clinical implications, and recommendations on management of these findings based on current available data.

Proatlas anomalies in craniofacial malformations: 5-year experience in King Chulalongkorn Memorial Hospital.

PURPOSE: To review the prevalences of proatlas anomalies in craniofacial malformations and evaluate the relation between craniofacial malformation and proalast anomalies. METHODS: The 221 patients with craniofacial malformation who underwent CT facial bone and 3D brain in King Chulalongkorn Memorial Hospital (KCMH). Then, the craniofacial malformed patients are classified into six groups composed of craniosynostosis, cephalocele, midface anomaly, facial and branchial arch syndrome, facial cleft face, and others. Reviewing image finding by the researcher and the radiologist advisor was done separately and gave the consensus in the case with disagreement. Qualitative analysis of the prevalence of proatlas anomalies was achieved. In addition, assessment of the relationship between craniofacial malformation and proatlas anomalies was conducted using Pearson's chi-square test to determine statistical significance. RESULT: The proatlas anomalies were presented in 26 patients of 221 craniofacial malformed patients. Details of frequentative proatlas anomalies consist of pre-basioccipital arch in eight patients, os odontoideum in five patients, bony mass along the margin of foramen magnum in three patients, atlas assimilation in two patients, hypertrophic occipital condyle in one patient, third occipital condyle in one patient, and mixed characteristic of proatlas anomalies in six patients. These results represented pre-basioccipital arch and os odontoideum as the two most common presentations among proatlas anomalies and also showed significant existence of proatlas diseases in craniofacial malformation (p value = 0.006). CONCLUSION: Our results emphasize the existence of proatlas anomalies which should be carefully looked for, particularly in craniofacial malformed patients due to significant statistical correlation.

WNT1-associated osteogenesis imperfecta with atrophic frontal lobes and arachnoid cysts.

A rare form of osteogenesis imperfecta (OI) caused by Wingless-type MMTV integration site family 1 (WNT1) mutations combines central nervous system (CNS) anomalies with the characteristic increased susceptibility to fractures. We report an additional case where arachnoid cysts extend the phenotype, and that also confirms the association of intellectual disabilities with asymmetric cerebellar hypoplasia here. Interestingly, if the cerebellum is normal in this disorder, intelligence is as well, analogous to an association with similar delays in a subset of patients with sporadic unilateral cerebellar hypoplasia. Those cases typically appear to represent vascular disruptions, and we suggest that most brain anomalies in WNT1-associated OI have vascular origins related to a role for WNT1 in CNS angiogenesis. This unusual combination of benign cerebellar findings with effects on higher functions in these two situations raises the possibility that WNT1 is involved in the pathogenesis of the associated sporadic cases as well. Finally, our patient reacted poorly to pamidronate, which appears ineffective with this form of OI, so that a lack of improvement is an indication for molecular testing that includes WNT1.

Arterial spin labeling in neuroimaging.

Arterial spin labeling (ASL) is a magnetic resonance imaging technique for measuring tissue perfusion using a freely diffusible intrinsic tracer. As compared with other perfusion techniques, ASL offers several advantages and is now available for routine clinical practice in many institutions. Its noninvasive nature and ability to quantitatively measure tissue perfusion make ASL ideal for research and clinical studies. Recent technical advances have increased its sensitivity and also extended its potential applications. This review focuses on some basic knowledge of ASL perfusion, emerging techniques and clinical applications in neuroimaging.

Multiple cranial nerve enhancement in mitochondrial neurogastrointestinal encephalomyopathy.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare disease that often presents with nonspecific white matter abnormalities on magnetic resonance imaging. Ptosis and ophthalmoparesis are a part of its clinical features. We report multiple cranial nerve contrast enhancement on magnetic resonance imaging in a patient with MNGIE and postulate that demyelination may be the responsible substrate for this previously unreported finding. This finding may also explain the cranial neuropathies that patients with MNGIE have.