Stroke atlas: a 3D interactive tool correlating cerebrovascular pathology with underlying neuroanatomy and resulting neurological deficits.

Understanding stroke-related pathology with underlying neuroanatomy and resulting neurological deficits is critical in education and clinical practice. Moreover, communicating a stroke situation to a patient/family is difficult because of complicated neuroanatomy and pathology. For this purpose, we created a stroke atlas. The atlas correlates localized cerebrovascular pathology with both the resulting disorder and surrounding neuroanatomy. It also provides 3D display both of labeled pathology and freely composed neuroanatomy. Disorders are described in terms of resulting signs, symptoms and syndromes, and they have been compiled for ischemic stroke, hemorrhagic stroke, and cerebral aneurysms. Neuroanatomy, subdivided into 2,000 components including 1,300 vessels, contains cerebrum, cerebellum, brainstem, spinal cord, white matter, deep grey nuclei, arteries, veins, dural sinuses, cranial nerves and tracts. A computer application was developed comprising: 1) anatomy browser with the normal brain atlas (created earlier); 2) simulator of infarcts/hematomas/aneurysms/stenoses; 3) tools to label pathology; 4) cerebrovascular pathology database with lesions and disorders, and resulting signs, symptoms and/or syndromes. The pathology database is populated with 70 lesions compiled from textbooks. The initial view of each pathological site is preset in terms of lesion location, size, surrounding surface and sectional neuroanatomy, and lesion and neuroanatomy labeling. The atlas is useful for medical students, residents, nurses, general practitioners, and stroke clinicians, neuroradiologists and neurologists. It may serve as an aid in patient-doctor communication helping a stroke clinician explain the situation to a patient/family. It also enables a layman to become familiarized with normal brain anatomy and understand what happens in stroke.

Bridging neuroanatomy, neuroradiology and neurology: three-dimensional interactive atlas of neurological disorders.

Understanding brain pathology along with the underlying neuroanatomy and the resulting neurological deficits is of vital importance in medical education and clinical practice. To facilitate and expedite this understanding, we created a three-dimensional (3D) interactive atlas of neurological disorders providing the correspondence between a brain lesion and the resulting disorder(s). The atlas contains a 3D highly parcellated atlas of normal neuroanatomy along with a brain pathology database. Normal neuroanatomy is divided into about 2,300 components, including the cerebrum, cerebellum, brainstem, spinal cord, arteries, veins, dural sinuses, tracts, cranial nerves (CN), white matter, deep gray nuclei, ventricles, visual system, muscles, glands and cervical vertebrae (C1-C5). The brain pathology database contains 144 focal and distributed synthesized lesions (70 vascular, 36 CN-related, and 38 regional anatomy-related), each lesion labeled with the resulting disorder and associated signs, symptoms, and/or syndromes compiled from materials reported in the literature. The initial view of each lesion was preset in terms of its location and size, surrounding surface and sectional (magnetic resonance) neuroanatomy, and labeling of lesion and neuroanatomy. In addition, a glossary of neurological disorders was compiled and for each disorder materials from textbooks were included to provide neurological description. This atlas of neurological disorders is potentially useful to a wide variety of users ranging from medical students, residents and nurses to general practitioners, neuroanatomists, neuroradiologists and neurologists, as it contains both normal (surface and sectional) brain anatomy and pathology correlated with neurological disorders presented in a visual and interactive way.

Three-dimensional interactive atlas of cranial nerve-related disorders.

Anatomical knowledge of the cranial nerves (CN) is fundamental in education, research and clinical practice. Moreover, understanding CN-related pathology with underlying neuroanatomy and the resulting neurological deficits is of vital importance. To facilitate CN knowledge anatomy and pathology understanding, we created an atlas of CN-related disorders, which is a three-dimensional (3D) interactive tool correlating CN pathology with the underlying surface and sectional neuroanatomy as well as the resulting neurological deficits. A computer platform was developed with: 1) anatomy browser along with the normal brain atlas (built earlier); 2) simulator of CN lesions; 3) tools to label CN-related pathology; and 4) CN pathology database with lesions and disorders, and the resulting signs, symptoms and/or syndromes. The normal neuroanatomy comprises about 2,300 3D components subdivided into modules. Cranial nerves contain more than 600 components: all 12 pairs of cranial nerves (CN I - CN XII) and the brainstem CN nuclei. The CN pathology database was populated with 36 lesions compiled from clinical textbooks. The initial view of each disorder was preset in terms of lesion location and size, surrounding surface and sectional neuroanatomy, and disorder and neuroanatomy labeling. Moreover, path selection from a CN nucleus to a targeted organ further enhances pathology-anatomy relationships. This atlas of CN-related disorders is potentially useful to a wide variety of users ranging from medical students and residents to general practitioners, neuroradiologists and neurologists, as it contains both normal brain anatomy and CN-related pathology correlated with neurological disorders presented in a visual and interactive way.

The human brain in 1700 pieces: design and development of a three-dimensional, interactive and reference atlas.

As the human brain is the most complex living organ, constructing its detailed model with exploration capabilities in a form of an atlas is a challenge. Our overall goal is to construct an advanced, detailed, parcellated, labeled, accurate, interactive, three-dimensional (3D), and scalable whole human brain atlas of structure, vasculature, tracts and systems. The objectives of this work are three-fold; to present: (1) method of atlas design and development including design principles, accuracy requirements, atlas content, architecture, functionality, user interface, and customized tools; (2) creation of an atlas of structure and systems including its modeling method and validation; and (3) integration of this atlas with the cerebrovasculature and tracts created earlier. The atlas is created from multiple in vivo 3/7 T scans. Its design based on "pyramidal principle" enables scalability while preserving design principles and exploits interaction paradigm "from blocks to brain". The atlas contains (1) navigator with modules for system/object/object state management, interaction, user interfacing, and rendering; and (2) brain model with cerebrum, cerebellum, brainstem, spinal cord, white matter, deep structures, systems, ventricles, arteries, veins, sinuses, and tracts. The brain model is parcellated, labeled, consistent, realistic, of high resolution, polygonal/volumetric, dissectible, extendable, and deformable. It has over 1700 3D components. The atlas has sub-voxel accuracy of 0.1mm and the smallest vessels of 80 µm. Brain exploration includes dynamic scene composition, manipulation-independent 3D labeling, interaction combined with animation, meta-labeling, and quantification. This atlas is useful in education, research, and clinical applications. It can potentially be foundation for a multi-level molecular-cellular-anatomical-physiological-behavioral platform.

Three-dimensional reference and stereotactic atlas of human cerebrovasculature from 7Tesla.

Although there exist some reference and stereotactic anatomical human brain atlases, there is no equivalent cerebrovascular atlas. A 3D reference atlas of the human cerebrovasculature that is interactive, stereotactic, very detailed, completely parcellated, fully labeled, extendable, dissectible, deformable, and user friendly, is needed in education, training, research, and clinical applications. We constructed a sophisticated and very detailed cerebrovascular atlas with 1325 vascular segments, the smallest of 80 µm in diameter. The atlas was created from multiple 3 and 7T scans by employing tools and methods developed in our lab. In contrast to a sort of "sampled" vascular geometry cited in the literature, we provide information about the "continuous" geometry of the vascular model measurable in 3D at every location and along any vascular segment for both hemispheres. This cerebrovascular atlas was validated taking into account domain knowledge from various fields including angiography, neurosurgery, neuroradiology, (clinical) neuroanatomy, and terminology. Validation was considered as a confirmation of the created vascular model to a typical (conventional) cerebrovascular system with nearly average dimensions. It was done in terms of vessel subdivision, origin, course, surrounding anatomy, patterns, length, diameter, and branches. This validation demonstrates that the constructed cerebrovascular model generally represents a normal, typical cerebrovasculature with its dimensions close to average. This 7T atlas along with the vascular model is a rich source of knowledge about the human cerebrovasculature. The atlas is applicable in education, research, and clinical applications; it has already been applied in deep brain stimulation.

Validation of [13C]urea breath test for Helicobacter pylori using a simple gas chromatograph-mass selective detector.

OBJECTIVE: Isotope ratio mass spectrometry (IRMS) is the accepted method for accurately measuring the 13CO2:12CO2 ratio in the non-invasive and non-radioactive [13C]urea breath test (13C-UBT) for Helicobactor pylori. The IRMS instrument, an expensive and highly specialized analyser, is rarely available. The objective of this project was to modify and validate the use of a simple bench-top gas chromatograph-mass selective detector (GC-MSD) for 13C-UBT. METHODS: Breath samples from 71 patients were taken at baseline and 30 min after ingestion of 100 mg [13C]urea. The breath samples were analysed using GC-MSD in the selected ion monitoring mode. The reference 13CO2:12CO2 ratio was from NBS19 obtained from the US National Institute of Standards and Technology. 13CO2:12CO2 ratios of the breath samples were determined. Excess delta per thousand (per mil, delta/thousand) of the 30 min sample over the baseline (deltadelta/thousand) of > or = 6deltadelta/thousand was considered H. pylori positive. Results from 13C-UBT and histology determined blind to each other were compared. RESULTS: The coefficient of variation of the reference 13CO2:12CO2 ratio was 0.06%. Using histology as the 'gold standard', the sensitivity (97.9%) and specificity (95.8%) of the GC-MSD 13C-UBT were comparable to those of other methods of H. pylori diagnosis. CONCLUSION: A gas chromatograph coupled to a mass selective detector that is available in many analytical and biomedical laboratories can be used for the 13C-UBT. This method will increase the availability and reduce the cost of this non-invasive, non-radioactive diagnostic test.

Pharmacokinetics of propofol infusion in Asian patients undergoing coronary artery bypass grafting.

The pharmacokinetics of propofol was studied in 11 Asian patients with fentanyl-isoflurane anaesthesia during cardiopulmonary bypass (CPB) and undergoing elective coronary artery bypass grafting (CABG). Instead of the usual increments of morphine and a benzodiazepine, propofol (4 mg/kg/h) was initiated at the start of CPB and ceased at CPB separation. Whole blood propofol concentrations were determined during and postinfusion using high-performance liquid chromatography with fluorescence detection. Data from four patients seemed to fit a two-compartment model, whereas those from seven patients were significantly (F test, p < 0.05) better fitted to a three-compartment model. The pharmacokinetic parameters were as follows: The mean (SD) of the initial distribution phase t1/2 pi, intermediate distribution phase t1/2 alpha, and elimination phase t1/2 beta were 2.22 (1.04) min, 42.9 (16.4) min, and 370 (138) min, respectively. The mean clearance of 1.31 (0.50) L/min was lower than those reported from other studies, whereas the mean blood concentration of 2.2 (1.0) mg/L at the 1-h infusion period was higher. The mean calculated apparent Css was 3.9 (1.5) mg/L. The low clearance is likely to be due to hemodynamic changes during CPB and CABG, thereby affecting drug distribution and blood flow to the liver.