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The History of Nuclear Medicine
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
One radiopharmaceutical that accelerated the acceptance and development of PET was 18F-FDG (2-uorodeoxy-D-glucose), which, similar to many other radiopharmaceuticals, had been already developed at the Brookhaven National Laboratory in 1978. However, it became as important as 99Tcm in nuclear imaging only after several decades. Two successful radiopharmaceuticals for SPECT brain imaging that were introduced were 99Tcm-HMPAO (Ceretec®, Amersham) and 99Tcm-ECD (Neurolite). These complexes cross the intact blood brain barrier and are trapped within the brain parenchyma. In 1985, Peter Ell and colleagues published the world’s first cerebral blood flow image using 99Tcm-HMPAO. Because both are liposoluble, they became an alternative to 111In-oxine for labelling of leukocytes for imaging of unknown inflammations, as shown by Peters and colleagues (1988) [39].
Neurology
Published in Faye Hill, Sash Noor, Neel Sharma, Tiago Villanueva, Medical and Surgical Emergencies for Students and Junior Doctors, 2021
Faye Hill, Sash Noor, Neel Sharma
Blood investigations can help to determine cause such as evidence of polycythaemia, thrombocytosis, thrombocytopenia or deranged coagulation. Brain imaging in the form of a CT scan or an MRI should be performed in the following cases: indications for thrombolysis or early anticoagulation treatmenton anticoagulant treatmenta known bleeding tendencya depressed level of consciousness (Glasgow Coma Scale score <13)unexplained progressive or fluctuating symptomspapilloedema, neck stiffness or feversevere headache at onset of stroke symptoms. Additional imaging modalities include transcranial Doppler ultrasound, and an echocardiogram to exclude cardiogenic embolism should be instigated.
Current in vivo Models for Brain Disorders
Published in Carla Vitorino, Andreia Jorge, Alberto Pais, Nanoparticles for Brain Drug Delivery, 2021
Marta Guerra-Rebollo, Cristina Garrido
What is more important, brain imaging using CT and MRI could be applied to assess patients for brain diseases. The principal treatment for patients with acute stroke is the tissue plasminogen activator (tPA), but this treatment could induce haemorrhage. Studies using CT angiography show that the haemorrhage transformation was correlated with an increase of the BBB permeability so CT could be used to evaluate the risk of haemorrhage before tPA treatment [67]. Another example is the use of Gd-micelles, which were elaborate as an MRI contrast agent for tumour imaging [68] and they could also be used to examine BBB permeability. MRI images with Gd-micelles show a significant contrast area in the ischaemic hemisphere, indicating BBB permeability for macromolecules.
Current perspectives on the clinical management of cryptogenic stroke
Published in Expert Review of Neurotherapeutics, 2023
Dixon Yang, Mitchell S. V. Elkind
Cryptogenic stroke is a diagnosis of exclusion and, therefore, should only be diagnosed after ruling out major causative mechanisms. The American Heart Association (AHA) considers ischemic stroke to be cryptogenic after a minimum standard stroke evaluation, which involves basic laboratory tests, brain imaging, neurovascular imaging, and cardiac evaluation (Table 2) [19]. Routine laboratory tests will screen for myocardial ischemia, hematologic disorders, and traditional vascular risk factors (hyperlipidemia and diabetes mellitus). Structural brain imaging may be acquired by computed tomography (CT) or magnetic resonance imaging (MRI). While CT is more readily available, brain MRI has added sensitivity for detecting acute infarction, especially small or brainstem infarcts, and may provide helpful information on infarct topography [20]. For instance, acute infarct in multiple vascular territories may suggest a proximal embolic source, while multiple infarcts in the same vascular territory may point toward a culprit large artery lesion (Figure 2). Though small subcortical infarcts on neuroimaging with a corresponding lacunar stroke syndrome are generally considered to be etiologically small vessel disease, small deep infarcts may be cryptogenic in some patients; as a rule of thumb, small deep infarcts may be considered cryptogenic in patients aged <50 years without any traditional vascular risk factors and no neuroimaging features of small vessel disease [1].
Current understanding of the etiology of cyclic vomiting syndrome and therapeutic strategies in its management
Published in Expert Review of Clinical Pharmacology, 2022
Rosita Frazier, Thangam Venkatesan
Testing for CVS should generally be limited to upper endoscopy and abdominal imaging to rule out organic pathology such as gastric volvulus or intermittent small bowel obstruction. Biochemical testing including CBC, basic chemistry panel, amylase, lipase, and liver tests may be performed. Gastric emptying can be normal, delayed, and often rapid in CVS and is not recommended. Extensive testing should be avoided and only pursued in the appropriate clinical setting [56,57]. For example, brain imaging might be considered in patients with localized neurological symptoms. In the appropriate setting, other conditions such as acute hepatic porphyria which can have a similar clinical presentation might be considered. In this scenario, testing with a spot urine porphobilinogen and aminolevulinic acid should be done. If hypoglycemia or hyponatremia is noted, testing for adrenal insufficiency is recommended. In children, investigations to rule out urea cycle defects are recommended when episodes are triggered by fasting, intercurrent illness, or high protein meals.
Intracranial effect of osimertinib in relapsed EGFR-mutated T790M-positive and -negative non-small cell lung cancer patients: results from a phase II study
Published in Acta Oncologica, 2021
Inger Johanne Zwicky Eide, Harald Grut, Åslaug Helland, Simon Ekman, Jens Benn Sørensen, Karin Holmskov Hansen, Bjørn Henning Grønberg, Saulius Cicenas, Jussi Pekka Koivunen, Anders Mellemgaard, Odd Terje Brustugun
We also found that the risk of progression in the brain was only 6% at 12 months for the T790M-positive patients in the full study cohort. Taking into account that similar to the AURA3-study [19], brain imaging was not mandated for patients without known brain lesions at baseline and hence small asymptomatic new CNS-lesions might not be discovered in all patients, this analysis could be under-estimating the true risk. On the other hand, the majority of these patients were far down the trajectory of their disease, and as the incidence of brain metastases increases during the course of EGFR-mutated disease [4], they had a high risk of developing symptomatic as well as asymptomatic brain metastases. Thus, the low risk of progressive brain disease probably reflects a protective effect of osimertinib and is of clinical value for the individual patients.