scholarly journals The Role of Imaging in Radiation Therapy Planning: Past, Present, and Future

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Gisele C. Pereira ◽  
Melanie Traughber ◽  
Raymond F. Muzic

The use of ionizing radiation for cancer treatment has undergone extraordinary development during the past hundred years. The advancement of medical imaging has been critical in helping to achieve this change. The invention of computed tomography (CT) was pivotal in the development of treatment planning. Despite some disadvantages, CT remains the only three-dimensional imaging modality used for dose calculation. Newer image modalities, such as magnetic resonance (MR) imaging and positron emission tomography (PET), are also used secondarily in the treatment-planning process. MR, with its better tissue contrast and resolution than those of CT, improves tumor definition compared with CT planning alone. PET also provides metabolic information to supplement the CT and MR anatomical information. With emerging molecular imaging techniques, the ability to visualize and characterize tumors with regard to their metabolic profile, active pathways, and genetic markers, both across different tumors and within individual, heterogeneous tumors, will inform clinicians regarding the treatment options most likely to benefit a patient and to detect at the earliest time possible if and where a chosen therapy is working. In the post-human-genome era, multimodality scanners such as PET/CT and PET/MR will provide optimal tumor targeting information.

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2348
Author(s):  
Leon Riehakainen ◽  
Chiara Cavallini ◽  
Paolo Armanetti ◽  
Daniele Panetta ◽  
Davide Caramella ◽  
...  

Non-invasive longitudinal imaging of osseointegration of bone implants is essential to ensure a comprehensive, physical and biochemical understanding of the processes related to a successful implant integration and its long-term clinical outcome. This study critically reviews the present imaging techniques that may play a role to assess the initial stability, bone quality and quantity, associated tissue remodelling dependent on implanted material, implantation site (surrounding tissues and placement depth), and biomarkers that may be targeted. An updated list of biodegradable implant materials that have been reported in the literature, from metal, polymer and ceramic categories, is provided with reference to the use of specific imaging modalities (computed tomography, positron emission tomography, ultrasound, photoacoustic and magnetic resonance imaging) suitable for longitudinal and non-invasive imaging in humans. The advantages and disadvantages of the single imaging modality are discussed with a special focus on preclinical imaging for biodegradable implant research. Indeed, the investigation of a new implant commonly requires histological examination, which is invasive and does not allow longitudinal studies, thus requiring a large number of animals for preclinical testing. For this reason, an update of the multimodal and multi-parametric imaging capabilities will be here presented with a specific focus on modern biomaterial research.


Author(s):  
Rola Khamisy-Farah ◽  
Leonardo B. Furstenau ◽  
Jude Dzevela Kong ◽  
Jianhong Wu ◽  
Nicola Luigi Bragazzi

Tremendous scientific and technological achievements have been revolutionizing the current medical era, changing the way in which physicians practice their profession and deliver healthcare provisions. This is due to the convergence of various advancements related to digitalization and the use of information and communication technologies (ICTs)—ranging from the internet of things (IoT) and the internet of medical things (IoMT) to the fields of robotics, virtual and augmented reality, and massively parallel and cloud computing. Further progress has been made in the fields of addictive manufacturing and three-dimensional (3D) printing, sophisticated statistical tools such as big data visualization and analytics (BDVA) and artificial intelligence (AI), the use of mobile and smartphone applications (apps), remote monitoring and wearable sensors, and e-learning, among others. Within this new conceptual framework, big data represents a massive set of data characterized by different properties and features. These can be categorized both from a quantitative and qualitative standpoint, and include data generated from wet-lab and microarrays (molecular big data), databases and registries (clinical/computational big data), imaging techniques (such as radiomics, imaging big data) and web searches (the so-called infodemiology, digital big data). The present review aims to show how big and smart data can revolutionize gynecology by shedding light on female reproductive health, both in terms of physiology and pathophysiology. More specifically, they appear to have potential uses in the field of gynecology to increase its accuracy and precision, stratify patients, provide opportunities for personalized treatment options rather than delivering a package of “one-size-fits-it-all” healthcare management provisions, and enhance its effectiveness at each stage (health promotion, prevention, diagnosis, prognosis, and therapeutics).


Author(s):  
Kuofeng Hung ◽  
Andy Wai Kan Yeung ◽  
Ray Tanaka ◽  
Michael M. Bornstein

The increasing use of three-dimensional (3D) imaging techniques in dental medicine has boosted the development and use of artificial intelligence (AI) systems for various clinical problems. Cone beam computed tomography (CBCT) and intraoral/facial scans are potential sources of image data to develop 3D image-based AI systems for automated diagnosis, treatment planning, and prediction of treatment outcome. This review focuses on current developments and performance of AI for 3D imaging in dentomaxillofacial radiology (DMFR) as well as intraoral and facial scanning. In DMFR, machine learning-based algorithms proposed in the literature focus on three main applications, including automated diagnosis of dental and maxillofacial diseases, localization of anatomical landmarks for orthodontic and orthognathic treatment planning, and general improvement of image quality. Automatic recognition of teeth and diagnosis of facial deformations using AI systems based on intraoral and facial scanning will very likely be a field of increased interest in the future. The review is aimed at providing dental practitioners and interested colleagues in healthcare with a comprehensive understanding of the current trend of AI developments in the field of 3D imaging in dental medicine.


2011 ◽  
Vol 1 (4) ◽  
pp. 673-685 ◽  
Author(s):  
J. Alison Noble ◽  
Nassir Navab ◽  
H. Becher

The fields of medical image analysis and computer-aided interventions deal with reducing the large volume of digital images (X-ray, computed tomography, magnetic resonance imaging (MRI), positron emission tomography and ultrasound (US)) to more meaningful clinical information using software algorithms. US is a core imaging modality employed in these areas, both in its own right and used in conjunction with the other imaging modalities. It is receiving increased interest owing to the recent introduction of three-dimensional US, significant improvements in US image quality, and better understanding of how to design algorithms which exploit the unique strengths and properties of this real-time imaging modality. This article reviews the current state of art in US image analysis and its application in image-guided interventions. The article concludes by giving a perspective from clinical cardiology which is one of the most advanced areas of clinical application of US image analysis and describing some probable future trends in this important area of ultrasonic imaging research.


2016 ◽  
Vol 8 (3) ◽  
pp. 151-156
Author(s):  
Javier Elías Fernández

El foramen mentoniano accesorio es un orificio adicional al foramen mentoniano que se localiza en la cara anterolateral externa del cuerpo mandibular y que se conecta con el conducto dentario inferior.  Su ubicación es posteroinferior al foramen mentoniano.  De acuerdo a su clasificación también se lo conoce como foramen mental doble, foramen mental adicional, foramen mental múltiple, foramen mental accesorio o foramen mandibular bucal suplementario. Su frecuencia de aparición varía del 1% al 10 %, cuando son unilaterales y del 0,47% al 1,2% cuando son bilaterales.  El  foramen mentoniano accesorio es una rara variante anatómica de poca frecuencia pero de gran relevancia clínico-quirúrgica ya que está asociado a un paquete vasculonervioso por lo cual es necesario su diagnóstico radiográfico ya sea por métodos convencionales o por alta resolución para evitar posibles complicaciones en los diferentes procedimientos odontológicos. Se presenta un caso de foramen mentoniano accesorio de un paciente remitido al Servicio de Radiología de la Facultad de Odontología de la UNC. La tomografía computada constituye el estudio por imágenes de excelencia ante la presunción de un foramen accesorio ya que los diferentes cortes tomográficos y la reconstrucción 3D nos permiten localizarlo de manera precisa e inequívoca. Constituye generalmente un hallazgo radiográfico o se observa durante procedimientos quirúrgicos al quedar al descubierto por el desplazamiento de los tejidos blandos. Cuando se localiza antes de cualquier procedimiento odontológico se deben tomar todos los recaudos necesarios para evitar daño del paquete vasculonervioso y futuras complicaciones como hemorragias o parestesias, principalmente en prácticas como la colocación de implantes dentales o las apicectomías. Accessory mental foramen (AMF) is defined as any openings in addition to mental foramen, with connection to the mandibular canal in the anterolateral aspect of mandible. According to its classification, an AMF is known as double mental foramen, additional mental foramen, multiple mental foramen, supplementary mandibular buccal foramen. The accessory mental foramen is a radiological finding or is detected during surgical procedures. Its prevalence ranges from 1.4 to 10% when it is unilateral and ranges from 0,47% to 1,2% when it is bilateral. Accessory mental foramen is an important and rare anatomical variation associated with a neurovascular bundle. Its prevalence is low. The diagnosis by conventional radiological methods or three-dimensional radiographic imaging techniques is effective to avoid complications in dental procedures. An accessory mental foramen case of a male patient referred to the Department of Radiology at the National University of Córdoba School of Dentistry is reported. The computed tomography is the most accurate imaging modality for the identification of an accessory foramen through multiplanar reformatted images and three dimensional images. When the existence of AMF is identified before dental procedures, appropriate actions should be taken to avoid damages of the neurovascular bundle and eventual complications such as hemorrhage and paresthesia principally in procedures like dental implant insertion or periapical surgery.


2016 ◽  
Vol 796 ◽  
pp. 558-587 ◽  
Author(s):  
Ronny Pini ◽  
Nicholas T. Vandehey ◽  
Jennifer Druhan ◽  
James P. O’Neil ◽  
Sally M. Benson

We report results of an experimental investigation into the effects of small-scale (mm–cm) heterogeneities on solute spreading and mixing in a Berea sandstone core. Pulse-tracer tests have been carried out in the Péclet number regime $Pe=6{-}40$ and are supplemented by a unique combination of two imaging techniques. X-ray computed tomography (CT) is used to quantify subcore-scale heterogeneities in terms of permeability contrasts at a spatial resolution of approximately $10~\text{mm}^{3}$, while [11C] positron emission tomography (PET) is applied to image the spatial and temporal evolution of the full tracer plume non-invasively. To account for both advective spreading and local (Fickian) mixing as driving mechanisms for solute transport, a streamtube model is applied that is based on the one-dimensional advection–dispersion equation. We refer to our modelling approach as semideterministic, because the spatial arrangement of the streamtubes and the corresponding solute travel times are known from the measured rock’s permeability map, which required only small adjustments to match the measured tracer breakthrough curve. The model reproduces the three-dimensional PET measurements accurately by capturing the larger-scale tracer plume deformation as well as subcore-scale mixing, while confirming negligible transverse dispersion over the scale of the experiment. We suggest that the obtained longitudinal dispersivity ($0.10\pm 0.02$  cm) is rock rather than sample specific, because of the ability of the model to decouple subcore-scale permeability heterogeneity effects from those of local dispersion. As such, the approach presented here proves to be very valuable, if not necessary, in the context of reservoir core analyses, because rock samples can rarely be regarded as ‘uniformly heterogeneous’.


2021 ◽  
Vol 11 (3) ◽  
pp. 1028-1036
Author(s):  
Ziqiang Zhou

Ultrasound imaging technology can not only show neck tear the degree and extent of disease, to help make the correct diagnosis, can also be used to assess shoulder neck inflammation after surgery to repair a shoulder muscle neck tissue integrity and healing. Ultrasound imaging with high-resolution, real-time operation, low cost, etc. gradually become shoulder neck inflammatory disease preferred imaging modality. The sensitivity and specificity for three-dimensional ultrasound imaging of shoulder neck inflammation were 78% and 93% in this study. The full-thickness inflammation sensitivity and specificity were 50% and 95%. The sensitivity and specificity of inflammation were 57% and 87%, respectively. This study shows that the diagnostic accuracy of 3D ultrasound imaging in shoulder and neck inflammation and surrounding tissue lesions is close to that of MRI. Three-dimensional appearance of new technologies such as ultrasound imaging will further improve ultrasound imaging techniques in shoulder neck inflammation application in the diagnosis and treatment assessment.


2003 ◽  
Vol 98 (3) ◽  
pp. 536-543 ◽  
Author(s):  
Federico Colombo ◽  
Carlo Cavedon ◽  
Paolo Francescon ◽  
Leopoldo Casentini ◽  
Umberto Fornezza ◽  
...  

Object. Radiosurgical treatment of a cerebral arteriovenous malformation (AVM) requires the precise definition of the nidus of the lesion in stereotactic space. This cannot be accomplished using simple stereotactic angiography, but requires a combination of stereotactic biplanar angiographic images and stereotactic contrast-enhanced computerized tomography (CT) scans. In the present study the authors describe a method in which three-dimensional (3D) rotational angiography is integrated into stereotactic space to aid treatment planning for radiosurgery. Methods. Twenty patients harboring AVMs underwent treatment planning prior to linear accelerator radiosurgery. Planning involved the acquisition of two different data sets, one of which was obtained using the standard method (a combination of biplanar stereotactic angiography with stereotactic CT scanning), and the other, which was procured using a new technique (nonstereotactic 3D rotational angiography combined with stereotactic CT scanning by a procedure of image fusion). The treatment plan that was developed using the new method was compared with that developed using the standard one. For each patient the number of isocenters and the dimension of selected collimators were the same, based on the information supplied in both methods. Target coordinates were modified in only five cases and by a limited amount (mean 0.7 mm, range 0.3–1 mm). Conclusions. The new imaging modality offers an easier and more immediate interpretation of 3D data, while maintaining the same accuracy in target definition as that provided by the standard technique. Moreover, the new method has the advantage of using nonstereotactic 3D angiography, which can be performed at a different site and a different time with respect to the irradiation procedure.


2021 ◽  
pp. 20210388
Author(s):  
Makoto Hosono ◽  
Mamoru Takenaka ◽  
Hajime Monzen ◽  
Mikoto Tamura ◽  
Masatoshi Kudo ◽  
...  

Positron emission tomography (PET)/computed tomography (CT) is an essential imaging modality for the management of various diseases. Increasing numbers of PET/CT examinations are carried out across the world and deliver benefits to patients; however, there are concerns about the cumulative radiation doses from these examinations in patients. Compared to the radiation exposure delivered by CT, there have been few reports on the frequency of patients with a cumulative effective radiation dose of ≥100 mSv from repeated PET/CT examinations. The emerging dose tracking system facilitates surveys on patient cumulative doses by PET/CT because it can easily wrap up exposure doses of PET radiopharmaceuticals and CT. Regardless of the use of a dose tracking system, implementation of justification for PET/CT examinations and utilisation of dose reduction measures are key issues in coping with the cumulative dose in patients. Despite all the advantages of PET/MRI such as eliminating radiation exposure from CT and providing good tissue contrast in MRI, it is expensive and cannot be introduced at every facility; thus, it is still necessary to utilise PET/CT with radiation reduction measures in most clinical situations.


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