NASA Image Processing Technology Applied to Medicine: Ten Unsolved Problems in Medical Imaging

The solutions to current diagnostic imaging problems will be found, at least in part, in digital image processing technology developed by NASA. The adaptation of appropriate technology that can be applied clinically to improve the care of patients is a major concern of radiologists. We have considered ten problems with clinical significance in diagnostic medical imaging, and discuss the impact of NASA image processing technology presently and predict future developments in this area

Perceptual asymmetry in the subjective duration of ramped and damped sounds

International audienceTime-varying-level sounds that increase or decrease in level are well established to induce auditory perceptual asymmetries, for loudness and subjective duration. Several studies revealed ramped sounds to be perceived louder than equivalent damped sounds using durations from few milliseconds to few seconds. In addition, other studies revealed ramped sounds to be perceived longer than damped sounds for durations from 10 ms to 500 ms. As a consequence, it could be hypothesized that the perceived duration asymmetry may be responsible for the loudness asymmetry. Thus, the aim of the present study was to extend the results about asymmetries in subjective duration for tones above 500 ms, in order to test the plausibility of the hypothesis under these conditions. Using a 2I-2AFC adaptive method, ramped and damped tones were matched in duration to the point of subjective equality. At equal subjective duration, short-damped sounds (< 0.5 s) were matched longer than short-ramped sounds, confirming previous results, whereas long-damped sounds (0.5 to 2 s) were matched to the same duration as long-ramped sounds, which question the hypothesis for durations above 500 ms

Protocolo vascular por meio da 3D-TC utilizando a computação gráfica para avaliação de lesões maxilo-faciais

In this paper we present the aspect of a mandibular giant cell granuloma in spiral computed tomography-based three-dimensional (3D-CT) reconstructed images using computer graphics, and demonstrate the importance of the vascular protocol in permitting better diagnosis, visualization and determination of the dimensions of the lesion. We analyzed 21 patients with maxillofacial lesions of neoplastic and proliferative origins. Two oral and maxillofacial radiologists analyzed the images. The usefulness of interactive 3D images reconstructed by means of computer graphics, especially using a vascular setting protocol for qualitative and quantitative analyses for the diagnosis, determination of the extent of lesions, treatment planning and follow-up, was demonstrated. The technique is an important adjunct to the evaluation of lesions in relation to axial CT slices and 3D-CT bone images.Neste trabalho, demonstramos os aspectos de um granuloma central de células gigantes por meio da tomografia computadorizada (TC) em espiral baseada na reconstrução de imagem em três dimensões (3D), utilizando a computação gráfica, e a importância do protocolo vascular permitindo um melhor diagnóstico, visualização e obtendo dimensões da lesão. Foram analisados 21 pacientes com lesões maxilo-faciais de origens neoplásicas e proliferativas. Dois radiologistas analisaram as imagens. A utilidade da interação da reconstrução da imagem por meio da computação gráfica, especialmente utilizando o protocolo vascular para análises qualitativas e quantitativas para o diagnóstico, planejamento de tratamento e evolução, assim como para a localização da extensão da lesão foi demonstrada. Isto é um importante adjunto para a evolução destas lesões em relação a cortes axiais em TC e para imagens por meio de 3D-TC para estruturas ósseas

Computed tomography imaging strategies and perspectives in orbital fractures

OBJECTIVE: The objective of this study was to demonstrate the sensitivity and specificity of multislice computed tomography (CT) for diagnosis of orbital fractures following different protocols, using an independent workstation. MATERIALS AND METHODS: CT images of 36 patients with maxillofacial fractures (symptomatic to orbit region) who were submitted to multislice CT scanning were analyzed, retrospectively. The images were interpreted based on 5 protocols, using an independent workstation: 1) axial (original images); 2) multiplanar reconstruction (MPR); 3) 3D images; 4) association of axial/MPR/3D images and 5) coronal images. The evaluated anatomical sites were divided according to the orbital walls: lateral (with or without zygomatic frontal process fracture); medial; superior (roof) and inferior (anterior, medial). The collected data were analyzed statistically using a validity test (Youden's J index;

Aerosolized In Vivo 3D Localization of Nose-to-Brain Nanocarrier Delivery Using Multimodality Neuroimaging in a Rat Model—Protocol Development

The fate of intranasal aerosolized radiolabeled polymeric micellar nanoparticles (LPNPs) was tracked with positron emission tomography/computer tomography (PET/CT) imaging in a rat model to measure nose-to-brain delivery. A quantitative temporal and spatial testing protocol for new radio-nanotheranostic agents was sought in vivo. LPNPs labeled with a zirconium 89 (89Zr) PET tracer were administered via intranasal or intravenous delivery, followed by serial PET/CT imaging. After 2 h of continuous imaging, the animals were sacrificed, and the brain substructures (olfactory bulb, forebrain, and brainstem) were isolated. The activity in each brain region was measured for comparison with the corresponding PET/CT region of interest via activity measurements. Serial imaging of the LPNPs (100 nm PLA–PEG–DSPE+89Zr) delivered intranasally via nasal tubing demonstrated increased activity in the brain after 1 and 2 h following intranasal drug delivery (INDD) compared to intravenous administration, which correlated with ex vivo gamma counting and autoradiography. Although assessment of delivery from nose to brain is a promising approach, the technology has several limitations that require further development. An experimental protocol for aerosolized intranasal delivery is presented herein, which may provide a platform for better targeting the olfactory epithelium

Imaging of intranasal drug delivery to the brain

Intranasal (IN) delivery is a rapidly developing area for therapies with great potential for the treatment of central nervous system (CNS) diseases. Moreover, in vivo imaging is becoming an important part of therapy assessment, both clinically in humans and translationally in animals. IN drug delivery is an alternative to systemic administration that uses the direct anatomic pathway between the olfactory/trigeminal neuroepithelium of the nasal mucosa and the brain. Several drugs have already been approved for IN application, while others are undergoing development and testing. To better understand which imaging modalities are being used to assess IN delivery of therapeutics, we performed a literature search with the key words “Intranasal delivery” and “Imaging” and summarized these findings in the current review. While this review does not attempt to be fully comprehensive, we intend for the examples provided to allow a well-rounded picture of the imaging tools available to assess IN delivery, with an emphasis on the nose-to-brain delivery route. Examples of in vivo imaging, for both humans and animals, include magnetic resonance imaging (MRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT), gamma scintigraphy and computed tomography (CT). Additionally, some in vivo optical imaging modalities, including bioluminescence and fluorescence, have been used more in experimental testing in animals. In this review, we introduce each imaging modality, how it is being utilized and outline its strengths and weaknesses, specifically in the context of IN delivery of therapeutics to the brain