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Transcranial ultrasound has been described as a tool to identify intracranial pathology, however, it is seldom used in the adult patient population due to poor imaging windows and rapid availability of more advanced imaging such as CT and MRI. We report a unique population in which transcranial ultrasound may be beneficial: those with a history of hemicraniectomy. We present a case of a 65-year-old male with a history of hemicraniectomy who suffered head trauma after a fall from his wheelchair. An initial non-contrast head CT scan identified an intracranial hemorrhage. Point-of-care bedside transcranial ultrasound was able to identify the progression of intracranial hemorrhage, which was confirmed by interval head CT. This prompted repeat CT imaging followed by neurosurgical intervention with the placement of an external ventricular drain in the right lateral ventricle. While ultrasound is unlikely to replace the need for more advanced imaging in these patients, point-of-care transcranial ultrasound may be a useful tool that can be employed rapidly at the bedside for interval screening in patients with hemicraniectomy and concern for new or worsening intracranial hemorrhage. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40477-021-00588-6.

In recent decades, diagnostic imaging became an important generator of large increases in medical spending. Inappropriate head CT referrals also increase population irradiation and unnecessarily burden and frighten patients. To validate previously proposed clinical criteria for referral to head imaging (age > 55 years, focal neurological deficit, changed mental state, nausea or vomiting, coagulation disorder, cancer) in a setting of emergency neurological service. We retrospectively analyzed electronic records of 500 consecutive referrals to neurological emergency and 500 referrals to emergency head imaging. In patients with several referrals, only results of the first evaluation were further analyzed. We calculated relations between clinical predictors, referrals, and findings of head imaging. Of 486 first referrals of consecutive patients, 216 (44%) were referred to the emergency, and 100 (21%) to non-emergency head imaging. Remaining 170 (35%) were not referred to head imaging. Clinical predictors of pathologic head imaging fulfilled 77%, 41%, and 43% of patients, respectively. Pathologic head imaging had 153 of 490 (31%) referred patients. Referral criteria fulfilled 146 (sensitivity 95%) of them. Intracranial pathology was found in 7 of 125 patients not fulfilling referral criteria (negative predictive value 94%): 3 reported transient neurological symptoms, 2 sudden headache, and 2 headache with nausea and vomiting. We confirmed utility of previously proposed clinical criteria for referral to head CT in emergency neurological setting. In addition, we found transient neurological symptoms, sudden severe headache, and headache with nausea or vomiting as additional independent indications for emergency head imaging.

Intracranial vessel wall MRI (IVWM) is a new diagnostic imaging approach with the goal of evaluating intracranial vascular pathology by directly visualizing arterial vessel wall abnormalities with MR sequences, preferably at 3 Tesla field strength, that suppress blood and have excellent spatial resolution. The differentiation of intracranial vascular pathology has historically relied on luminal imaging techniques that depict the alteration of flow created by atherosclerotic stenosis or vasospasm. With IVWM, it is possible to identify distinct radiologic findings of the pathology within the intracranial vessel wall itself, ranging from arterial dissection to vasculitis. Futhermore, IVWM imaging characteristics, such as post-contrast enhancement, can elucidate the temporal relationship between imaging findings and clinical pathology; and may predict future behavior of unruptured aneurysms or atherosclerotic plaques. We present a review of the basic IVWM imaging techniques and the relevant published literature on IVWM, with a focus on evidence-based diagnostic indications for IVWM and discussion of the strengths and weaknesses of each indication. Finally, we discuss how IVWM can be used to differentiate between intracranial pathology and future directions for IVWM research.

The purpose of this pictorial essay is to review the benefits of spiral head computed tomography (CT) with routine multiplanar reformations in the evaluation of acute intracranial pathology. This technique is particularly useful in trauma patients for detection of skull base or calvarial fractures, thin tentorial subdural hematomas, or for more specific characterization of intracranial hemorrhage. The benefits of multiplanar reformations have been described for a variety of other diagnoses in the chest, abdomen, extremities, and spine, and their routine use continues to grow with the widespread availability of multi-slice CT scanners. In this article, we describe spiral head CT technique with multiplanar reformations as an alternative to the routinely used sequential technique. Subtle findings and lesions aligned predominantly in the axial plane can often be visualized to better advantage with multiplanar reformations. We also address technical factors for optimizing spiral technique.

Most existing image-based approaches neglect the difference in radiological symmetry between the human brain and head. Thus, it is important to analyze and quantify the spatial relationship between the brain symmetry plane (BSP) and the head symmetry plane (HSP) on radiological images. The HSP and BSP were calculated through maximizing local symmetry within the head or cerebrum followed by outlier removal. The HSPs and BSPs for 145 diversified MRI datasets (80 normal, 23 pathological, and 42 synthesized) were extracted and compared. The average angular and distance deviations between the HSP and BSP were 0.49° and 1.65 mm, respectively. These deviations are dependent upon ethnicity and gender, being: (1) (0.56°, 1.85 mm) and (0.42°, 0.91 mm) for Caucasians and Asians, respectively; and (2) (0.33°, 1.17 mm) and (0.51°, 1.58 mm) for males and females, respectively. The HSP is generally different from the BSP on MR images. Statistically, they can be used interchangeably if accuracy of (0.49°, 1.65 mm) is acceptable. The BSP is preferred for a high accuracy Talairach transformation and localization of the anterior and posterior commissures. Either BSP or HSP can be used for medium accuracy Talairach transform. The HSP is preferred for detecting intracranial pathology.

MRI imaging has significantly improved the detection of brain lesions over the past few decades. It has high sensitivity to intracranial pathology but confident preoperative tissue diagnosis is relatively unusual. MR spectroscopy provides in-vivo biochemical information and has been used to improve the low specificity of tumour diagnosis. During the last decade there have been a number of reports making the case that proton spectroscopy can distinguish different grades of glial tumours and in some situations provide information on histological type. We report four children who presented with neurological symptoms and focal masses on MRI. MRS in each of them gave results consistent with textbook descriptions of malignancy, but in all four cases the abnormalities were subsequently shown to be due to demyelination. We reiterate that spectroscopic appearances are nonspecific and spectroscopic data should be evaluated in the light of concurrent imaging features and the clinical presentation.

We studied clinical predictors of cranial computed tomography (CT) abnormalities in patients with acute or acutely worsened headache. Data were collected from chart review of 333 consecutive patients presenting to an emergency department and who were clinically selected for cranial CT. Patients with a positive neurologic examination were at 10.7 times greater risk for a positive CT than the rest of the sample (p

We report a 4 year old girl with ring enhancing lesions in brain CT, initially diagnosed as neurocysticercosis but did not respond to cysticidal therapy. A Magnetic resonance spectropscopy (MRS) revealed lipid peaks suggestive of tuberculoma which was successfully treated with antituberculosis therapy. This report highlights the role of MRS in the diagnosis of ring enhancing lesios.

The aim of this study was to characterize intracranial tumors based on MR measurements of regional cerebral blood volume. In 8 patients without intracranial pathology and 42 patients with intracranial tumors a T2*-weighted image series was acquired during bolus injection of gadolinium-DTPA, and regional cerebral blood volume maps were calculated. The regional cerebral blood volume index (rCBVi) of vital tumor was expressed in percent of the value measured in contralateral gray matter. In extra-axial tumors (meningiomas) rCBVi was higher (124 ± 110%), and in low-grade intra axial tumors rCBVi was lower (79 ± 65%), than in contralateral cortex. In malignant intra-axial tumors the distribution of rCBV was heterogenous: high in vital tumor (glioblastomas: rCBVi = 165 ± 85%; metastases: rCBVi = 106 ± 79%), but low in necrosis (rCBVi = 33% of contralateral white matter) and edema (rCBVi = 53% of contralateral white matter). rCBVi was highest in arteriovenous malformations (1053 ± 584% of contralateral gray matter). We conclude that the regional cerebral blood volume distribution is useful to characterize intracranial tumors, although the large biological variability of individual tumor entities indicates limitations.

Mechanical ventilation with PEEP is the cornerstone of treatment of patients with ALI and ARDS, but it is not free of adverse effects. This study aims to examine the effect of varying levels of PEEP on the intraocular pressure in critically ill patients with intracranial pathology.

The results obtained in 179 encephalographies using the i.v. urea technique of Ruggiero and Pacifico are reported. A solution of 30% urea in 5% glucose was used in 49 cases; in the remaining 130 cases 40% urea in 10% mannitol was employed. The administration rate was 60 drops per min and the total amount of urea injected never exceeded 40 g. A definitive radiological diagnosis was made in all cases. 103 received further verification, either at operation or at necroscopy. The technique proved to be more useful in: a) single than multiple, b) supratentorial than infratentorial, c) extracerebral than intracerebral, d) lateralized than midline, expanding lesions. Urea does not modify the encephalographic picture of non-neoplastic intracranial pathology.

Real time (RT) ultrasonic sector scanning of the head was performed through the anterior fontanelle in 130 neonates for the following indications: birth weight

The marked narrowing of the head which develops in many preterm infants often causes concern to their parents, who may worry that the unusual shape will persist or that it may be associated with intracranial pathology and developmental delay. The biparietal (BP) and anteroposterior (AP) diameters were measured weekly in 203 preterm infants during their stay in NICU, and at regular intervals up to three years of age. The AP/BP ratio was calculated (Baum J D and Searls D, Dev Med and Child Neurol. 1971 13: 576-581). This ratio rose from a mean of 1.36 in the first week to a mean of 1.48 at six weeks and fell to a mean of 1.42 by 13 weeks. Less mature babies and those with lower birth weights showed more flattening but this was not statistically significant. The presence of intracranial pathology detected by ultrasound did not affect head shape. 11% of babies showed marked early flattening (AP/BP ratio 1.55). These were compared with the rest of the group. At three years there was no significant difference in AP/BP ratio or in Griffiths Development Quotient. We conclude that by the age of 3 years the babies showing very marked early head flattening did not differ from the rest of the cohort in the areas examined. (NICU = Neonatal Intensive Care Unit)