Brain topography on adult ultrasound images: Techniques, interpretation, and image library

Abstract

Background and Purpose Many studies have explored the possibility of using cranial ultrasound for discerning intracranial pathologies like tumors, hemorrhagic stroke, or subdural hemorrhage in clinical scenarios where computer tomography may not be accessible or feasible. The visualization of intracranial anatomy on B‐mode ultrasound is challenging due to the presence of the skull that limits insonation to a few segments on the temporal bone that are thin enough to allow transcranial transmission of sound. Several artifacts are produced by hyperechoic signals inherent in brain and skull anatomy when images are created using temporal windows. Methods While the literature has investigated the accuracy of diagnosis of intracranial pathology with ultrasound, we lack a reference source for images acquired on cranial topography on B‐mode ultrasound to illustrate the appearance of normal and abnormal structures of the brain and skull. Two investigators underwent hands‐on training in Cranial point‐of‐care ultrasound (c‐POCUS) and acquired multiple images from each patient to obtain the most in‐depth images of brain to investigate all visible anatomical structures and pathology within 24 hours of any CT/MRI imaging done. Results Most reproducible structures visible on c‐POCUS included bony parts and parenchymal structures. Transcranial and abdominal presets were equivalent in elucidating anatomical structures. Brain pathology like parenchymal hemorrhage, cerebral edema, and hydrocephalus were also visualized. Conclusions We present an illustrated anatomical atlas of cranial ultrasound B‐mode images acquired in various pathologies in a critical care environment and compare our findings with published literature by performing a scoping review of literature on the subject.

Transcranial ultrasonography to detect intracranial pathology: A systematic review and meta‐analysis

“…Multiple other structures in the cranium create the image of two parallel hyperechoic lines characteristically used to identify the ventricles, resulting in a lack of reliable identification of the third and lateral ventricles on B‐mode imaging 4,22,26,30,65 . Many investigations have already discounted the diagnostic ability of ultrasound to accurately detect cerebral ischemia, which is what we also found in our work 4,9,22,26,44 . We also excluded parenchymal assessment for diagnosis of cerebral edema using TCU, due to significant heterogeneity in its sonographic appearance, based on our own experience and a few published studies 4,22,26,37,39 .…”

“…4,22,26,30,65 Many investigations have already discounted the diagnostic ability of ultrasound to accurately detect cerebral ischemia, which is what we also found in our work. 4,9,22,26,44 We also excluded parenchymal assessment for diagnosis of cerebral edema using TCU, due to significant heterogeneity in its sonographic appearance, based on our own experience and a few published studies. 4,22,26,37,39 We only found case reports for epidural hematoma that did not meet the study eligibility criteria.…”

“…[3][4][5][6][7] Studies have explored B-mode TCU in patients with an intact skull for the detection of intracranial hemorrhage (ICH), subdural hemorrhage (SDH), cerebral edema using midline shift, and hydrocephalus assessed by measuring the size of the third ventricle. 1,8,9 Rapid availability of round-the-clock computed tomography, the need for provider presence to perform B-mode TCU by the bedside, and a lack of standardized resources for learning cranial anatomy and pathology have not allowed more widespread use of this modality. With technological advances in ultrasound devices, the availability of portable machines, and the increasing complexity of patients being managed with advanced hemodynamic support in austere and critical care environments, ultrasound offers an attractive diagnostic modality for the evaluation of intracranial pathology where routine neuroimaging may not be accessible.…”

“…In adults with intact skulls, B‐mode TCU utilizes the temporal bone, which allows insonation of the brain in 80% of patients with thin temporal bones 3–7 . Studies have explored B‐mode TCU in patients with an intact skull for the detection of intracranial hemorrhage (ICH), subdural hemorrhage (SDH), cerebral edema using midline shift, and hydrocephalus assessed by measuring the size of the third ventricle 1,8,9 . Rapid availability of round‐the‐clock computed tomography, the need for provider presence to perform B‐mode TCU by the bedside, and a lack of standardized resources for learning cranial anatomy and pathology have not allowed more widespread use of this modality.…”