Use Of Non-ionizing Radiation Research Articles

Nanoparticle-Mediated Hyperthermia and Cytotoxicity Mechanisms in Cancer.

Hyperthermia has the potential to damage cancerous tissue by increasing the body temperature. However, targeting cancer cells whilst protecting the surrounding tissues is often challenging, especially when implemented in clinical practice. In this direction, there are data showing that the combination of nanotechnology and hyperthermia offers more successful penetration of nanoparticles in the tumor environment, thus allowing targeted hyperthermia in the region of interest. At the same time, unlike radiotherapy, the use of non-ionizing radiation makes hyperthermia an attractive therapeutic option. This review summarizes the existing literature regarding the use of hyperthermia and nanoparticles in cancer, with a focus on nanoparticle-induced cytotoxicity mechanisms.

Novel Biophotonic Techniques for Phototherapy Enhancement: Cerenkov Radiation as a Bridge between Ionizing and Non-Ionizing Radiation Treatment

In oncology, tremendous research has been conducted on the use of alternative minimally invasive techniques for cancer treatment and diagnosis. The use of biophotonic techniques as a standalone treatment or together with conventional imaging techniques has gained interest among researchers in recent years, while biophotonic therapies such as photothermal and photodynamic therapies tend to bring the use of non-ionizing radiation in therapy back into the spotlight due to the progressive development of optical instrumentation, enhancement agents, molecular probes, light sources and nanocarriers. Thus, the coupling of non-ionizing with ionizing radiation (IR) and the combination of nanomedicine with nuclear medicine procedures are considered to be revolutionary strategies to optimize the therapeutic efficacy of biophotonic modalities and to develop theranostic applications for the better diagnosis and treatment of cancer. Recently, the low-intensity Cerenkov light emitted by tissues as a byproduct of the IR–biostructure interaction has been suggested as an effective internal light source that can trigger phototherapy and guide radiotherapy dosimetry using Cerenkov imaging. This review also provides an overview of in vitro and in vivo studies regarding the use of Cerenkov radiation produced by X-rays or radionucleotides and combined with nanoparticles as a hybrid method to induce enhanced photothermal and photodynamic therapies.

Միկրոալիքային ճառագայթման հետ շփում ունեցող զինծառայողների կենսաբանական տարիքի և ծերացման տեմպի հարցի շուրջ / On the issue of biological age and the aging rate of the military personnel exposed to microwave radiation

The 21st century is characterized by the rapid development of radio­electronics, which has brought on and continues to bring on a natural increase in the number of people exposed to ultrahigh-frequency electromagnetic radiation during the production, testing, operation and repair of generators of such radiation. They have become extensively exploited in military affairs, meteorology, navigation, space and other scientific research. The problem becomes even more urgent due to the widespread use of equipment operating with the use of non-ionizing radiation in everyday life. For that reason, the problem of the impact of such radiation on the human body becomes urgent, depending on the time of exposure (the length of professional exposure to radiation). Currently, it has been established that the biological age and the aging rate are integral criteria for assessing the state of the human body working under the influence of a number of physical and chemical factors caused by microwave radiation. The study is targeted at developing scientifically substantiated preventive measures aimed at preserving the health and working capacity of this group of people. In this regard, the authors studied the aging rates of individuals (100 persons aged 18-27), professionally exposed to microwaves of non-thermal intensity. In the course of the study, changes in the value of biological age and the aging rate were analyzed depending on the calendar age and professional experience. The data obtained revealed the following patterns: slowing down of aging, which, apparently, could be considered as body response to microwave exposure; variations in the indicators of biological age and the aging rate, taking into account professional experience, which may indicate a certain process of adaptive restructuring of the body going on against the background of age-related changes and prolonged professional activity. In these individuals the so-called type of “health accumulation” is recorded. Based on the results of the study, specific recommendations have been developed to improve the health of people who are professionally exposed to non-thermal non-ionizing ultra-high-frequency electromagnetic radiation. «HAIKAKAN BANAK» DEFENSE-ACADEMIC JOURNAL 2023 © All Rights Reserved

Abstract P3-02-04: Prediction of breast cancer response to neoadjuvant chemotherapy in different biological breast cancer subtypes using diffuse optical tomography

Abstract Background: Optical-based imaging modalities play an important role in assessing breast tissue composition by measuring optical property contrast from endogenous chromophores. The advantages of optical techniques are the use of non-ionizing radiation, ease of use, and relatively low cost. The primary objective of this study is to examine changes in optically derived parameters (i.e., deoxy-hemoglobin concentration, ctHHb) from different breast cancer subtypes under neoadjuvant chemotherapy (NAC), and correlate with tumor pathologic complete response (pCR). Methods: This retrospective study evaluated 89 tumors in total divided into three distinct subtypes: HR+/HER2- (n=34), HER2+ (n=27), and TNBC (n=28). All patients were imaged at baseline, before starting NAC (TP0), and two weeks after receiving one cycle of taxane-based chemotherapy (TP1). HER2+ breast cancer patients also received HER2-target therapy. pCR was defined as complete absence of invasive carcinoma in the breast and lymph node(s) (ypT0/is ypN0 Mx) at the time of surgery. Whole breast volume was imaged by a diffuse optical tomography breast imaging system (DOTBIS) using low-intensity near-infrared light. ctHHb tumor volume concentration was normalized by the non-affected health tissue ctHHb mean value (ctHHbN). For each molecular subgroup, we conducted an independent-samples t-test to determine if there was a difference in ctHHbN levels at TP1 compared to TP0 between patients with a pCR and non-pCR. Significance was assumed at a confidence interval of 95% (α = 0.05). Results: In total, 69 patients were imaged with DOTIBS at both time points, TP0 and TP1. HR+/HER2-, TNBC and HER2+ accounted for 32% (n=23), 37% (n=22) and 30% (n=22), respectively. The ratio between ctHHbN levels measured at TP1 and TP0 was statistically significantly lower in the pCR group than non-pCR for the HER2+ and HR+/HER2- molecular subgroups, Table 1. Conclusion: Aligned to the current practices in breast cancer management based on the characterization of breast cancer subtypes, our work evaluated changes in DOTBIS optically derived features and pCR status for different subtypes. We observed that ctHHbN levels change after two weeks of NAC and these changes are modifiable according to pCR status and are dependent on immunophenotype. Table 1.Ratio between ctHHbN levels measured at TP1 and TP0 between pCR and non-pCR according to different molecular subtypes.Molecular SubtypepCR (mean ± SD )non-pCR (mean ± SD )p-valueHR+/HER2- (n=23)0.77 ± 0.22 (n=6)1.14 ± 0.24 (n=17).01HER2+ (n=24)0.74 ± 0.30 (n=15)1.54 ± 0.98 (n=9).04TNBC (n=22)0.96 ± 0.38 (n=4)1.29 ± 0.37 (n=18).18Bold values indicate statistical significance at p<.05 level. Citation Format: Mirella L Altoe, Kevin M Kalinsky, Hua Guo, Hanina Hibshoosh, Mariella Tejada, Katherine D Crew, Melissa K Accordino, Meghna S Trivedi, Alessandro Marone, Hyun K Kim, Andreas H Hielscher, Dawn L Hershman. Prediction of breast cancer response to neoadjuvant chemotherapy in different biological breast cancer subtypes using diffuse optical tomography [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-02-04.

Optoacoustic imaging of the skin.

Optoacoustic (OA, photoacoustic) imaging capitalizes on the synergistic combination of light excitation and ultrasound detection to empower biological and clinical investigations with rich optical contrast while effectively bridging the gap between micro and macroscopic imaging realms. State-of-the-art OA embodiments consistently provide images at micron-scale resolution through superficial tissue layers by means of focused illumination that can be smoothly exchanged for acoustic-resolution images at diffuse light depths of several millimetres to centimetres via ultrasound beamforming or tomographic reconstruction. Taken together, this unique multi-scale imaging capacity opens unprecedented capabilities for high-resolution in vivo interrogations of the skin at scalable depths. Moreover, diverse anatomical and functional information is retrieved via dynamic mapping of endogenous chromophores such as haemoglobin, melanin, lipids, collagen, water and others. This, along with the use of non-ionizing radiation, facilitates a clinical translation of the OA modalities. We review recent progress in OA imaging of the skin in preclinical and clinical studies exploiting the rich contrast provided by endogenous substances in tissues. The imaging capabilities of existing approaches are discussed in the context of initial translational studies on skin cancer, inflammatory skin diseases, wounds and other conditions.

Alterations in haematological parameters of multiple <i>in-utero</i> insonated rabbits (<i>Oryctolagus cuniculus</i>)

The fact that ultrasound is generally perceived as a safe imaging modality due to its use of non-ionizing radiation encouraged its increasing use in the diagnosis of cyesis in Veterinary practice. Ultrasound heating during obstetric scans has the potential of increasing body temperature via absorption. The study was conducted to determine the effect of multiple prenatal ultrasounds scanning on haematological parameters of rabbit fetuses. The research involves in vivo experimental model using 16 pregnant does and exposing them to ultrasound for average of 5 minutes at day 7, 12, 15, 20, 25, 27 and 29 of gestation. They were divided into two groups as insonated and control, the restrain and scanning procedures were mimicked on the group of does that were not scanned (positive control). Upon parturition, blood samples were collected from the kits via jugular venesection into ethylene diamine tetra acetic acid containing tubes for haematology. There was a significant reduction (p < 0.05) of red blood cell count and haemoglobin concentration of insonated group. Values of packed cell volume and platelet were lower but not significant (p > 0.05) in insonated as against the control while a non-significant slight increase in total white blood cell count was seen in the control. Therefore, ultrasound heating from multiple in-utero exposure can possibly cause alterations in haematological values in Rabbits.
 Keywords: Fetus, Haematology, Insonation, In-utero, Rabbit, Ultrasound

Accuracy of the three-dimensional 3D Doppler over conventional 2D ultrasound in the diagnosis of morbid adherent placenta (MAP)

Background: Two-dimensional ultrasound [2D] is in routine use in nearly most of the hospitals and many physician clinics as it offers a lot of benefits compared to other medical imaging techniques. Ultrasonography offers unique qualities including real-time imaging, physiologic measurement, use of non-ionizing radiation and no known bio-effects in the diagnostic range, while being non-invasive. Sonographic image quality has increasingly benefited from sophisticated computer technology.Aim of the Work: Is to evaluate the diagnostic accuracy of three-dimensional (3D) power Doppler over conventional 2D Doppler in diagnosis of morbidly adherent placenta in patients with one or more previous cesarean section diagnosed as placenta previa.Patients and Methods: The present study was carried out at Ain-Shams University Maternity Hospital. Women approached were recruited from Special Care Center of the fetus. After proper counseling, all women who were chosen for enrollment agreed to participate. The total number of pregnant women enrolled in the study was 120 women.Results: In the following analysis, intraoperative and placental histopathology findings were considered as golden standard test when compared to the 2D and 3D uterine ultrasonography amongst the 120 studied cases.Conclusion: The current study suggested that 3D power Doppler modality had a better screening capability for the prediction of the sequel of morbid placentation; namely, difficult placental delivery, considerable intraoperative blood loss, need for caesarean hysterectomy and bladder injury in women with placenta previa prior to cesarean (by its higher sensitivity and negative predictive value (NPV) and its lower false negative rates) when compared to the 2D ultrasound

ICNIRP Statement on Diagnostic Devices Using Non-ionizing Radiation: Existing Regulations and Potential Health Risks.

Use of non-ionizing radiation (NIR) for diagnostic purposes allows non-invasive assessment of the structure and function of the human body and is widely employed in medical care. ICNIRP has published previous statements about the protection of patients during medical magnetic resonance imaging (MRI), but diagnostic methods using other forms of NIR have not been considered. This statement reviews the range of diagnostic NIR devices currently used in clinical settings; documents the relevant regulations and policies covering patients and health care workers; reviews the evidence around potential health risks to patients and health care workers exposed to diagnostic NIR; and identifies situations of high NIR exposure from diagnostic devices in which patients or health care workers might not be adequately protected by current regulations. Diagnostic technologies were classified by the types of NIR that they employ. The aim was to describe the techniques in terms of general device categories which may encompass more specific devices or techniques with similar scientific principles. Relevant legally-binding regulations for protection of patients and workers and organizations responsible for those regulations were summarized. Review of the epidemiological evidence concerning health risks associated with exposure to diagnostic NIR highlighted a lack of data on potential risks to the fetus exposed to MRI during the first trimester, and on long-term health risks in workers exposed to MRI. Most of the relevant epidemiological evidence that is currently available relates to MRI or ultrasound. Exposure limits are needed for exposures from diagnostic technologies using optical radiation within the body. There is a lack of data regarding risk of congenital malformations following exposure to ultrasound in utero in the first trimester and also about the possible health effects of interactions between ultrasound and contrast media.

Current artefacts in cardiac and chest magnetic resonance imaging: tips and tricks.

Currently MRI is extensively used for the evaluation of cardiovascular and thoracic disorders because of the well-established advantages that include use of non-ionizing radiation, good contrast and high spatial resolution. Despite the advantages of this technique, numerous categories of artefacts are frequently encountered. They may be related to the scanner hardware or software functionalities, environmental factors or the human body itself. In particular, some artefacts may be exacerbated with high-field-strength MR machines (e.g. 3 T). Cardiac imaging poses specific challenges with respect to breath-holding and cardiac motion. In addition, new cardiac MR-conditional devices may also be responsible for peculiar artefacts. The image quality may thus be impaired and give rise to a misdiagnosis. Knowledge of acquisition and reconstruction techniques is required to understand and recognize the nature of these artefacts. This article will focus on the origin and appearance of the most common artefacts encountered in cardiac and chest MRI along with possible correcting methods to avoid or reduce them.

Abstract B45: Optical spectroscopy of tumor oxygenation and metabolism in preclinical head and neck tumors that fail radiation therapy

Abstract The purpose of this study was to determine the role of tumor metabolism and its relationship with tumor oxygenation in driving radiation resistance in head and neck cancer. The use of anatomical endpoints for therapy planning and the evaluation of response to radiation therapy in head and neck squamous cell carcinomas (HNSCC) is problematic because patients who do not respond favorably are losing critical time when alternate interventions could be attempted earlier. The use of a radiolabeled isotope severely limits the frequency of positron emission tomography (PET) of glycolytic demand and therefore the availability of immediate response to therapy. Although radiation-induced reoxygenation is a biomarker of tumor cell kill, radiation-induced reoxygenation can also lead to increased production of reactive oxygen species (ROS) that stabilize hypoxia-inducible factor (HIF-1). The transcription factor, hypoxia-inducible factor (HIF-1) and its downstream targets play an important role in the switch to aerobic glycolysis or metabolism of glucose to lactate under well-oxygenated conditions. Aerobic glycolysis confers tumors with a growth advantage, reduces the production of toxic free radicals by diverting energy production away from the mitochondria, and creates an acidic environment conducive for invasion and metastasis. Thus, it is important to measure both tumor glycolytic demand and oxygenation to determine whether re-oxygenation after radiation is accompanied by decreased glycolytic demand signaling cell death, or increased glycolytic demand signaling potential treatment failure. The use of non-ionizing radiation and the low cost of optical imaging allow measurements of these functional biomarkers several times after commencement of therapy and have the potential to significantly improve treatment outcome. We have developed fiber-based diffuse optical spectroscopy for simultaneously quantifying vascular oxygenation (SO2) and glycolytic demand in solid tumors in vivo. Glycolytic demand was measured using a fluorescent glucose analog, 2-[N-(7-nitrobenz-2-oxa-1,3-diaxol-4-yl)amino]-2-deoxyglucose (2-NBDG). Quantification of label-free SO2 and 2-NBDG-fluorescence-based glycolytic demand 60 minutes after administration of the tracer (2-NBDG60) was performed using computational models of light-tissue interaction. In a pilot radiation study, a group of 10 mice was injected subcutaneously with FaDu head and neck cancer cells. Once tumor size reached 200 mm3, they were exposed to a 5-day dose of radiotherapy (1 dose/day; 7.5Gy/day) using a biological small animal X-ray irradiator (X-Rad320). In addition to pre-radiation baseline measurements of SO2 and 2-NBDG60, we also measured both parameters every other day during radiation (Days 1, 3, and 5) and for 10 days following the end of radiation. Total of 8 mice showed tumor recurrence after elimination of the primary tumor. Wide variability was observed in both recurrence and location after radiation. Mice that failed therapy showed improved oxygenation as well as increased glycolytic demand relative to local control mice as early as day 4 after commencing radiation. Mice that responded completely to radiation (no recurrence up to 90 days post treatment) showed similar trends in improved SO2 as the tumor was cured coupled with decreasing glycolytic demand. Our results illustrate the potential of optical measurements to provide valuable information about the metabolic status of tumors in vivo, with important implications for early cancer prognosis. Our future efforts will focus on a larger mouse cohort, identifying the specific role of HIF-1 in mediating treatment failure, and expanding the technology to measure larger areas of the tumor. Citation Format: Narasimhan Rajaram, Helen A. Murphy, Nimmi Ramanujam. Optical spectroscopy of tumor oxygenation and metabolism in preclinical head and neck tumors that fail radiation therapy. [abstract]. In: Proceedings of the AACR Special Conference: Metabolism and Cancer; Jun 7-10, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(1_Suppl):Abstract nr B45.

Application of nuclear magnetic resonance in medicine and its influence on the quality of life and work environment

This work describes the application of nuclear magnetic resonance (NMR) in medicine and its influence on the work and life environment. Nuclear magnetic resonance, a powerful research tool, is based on the physical principle that cores of certain atoms (in this case hydrogen) can absorb or emit radiofrequency waves when placed in a magnetic field. This method is used for making high quality section pictures of the inside of the human body; in addition, it shows high sensitivity in revealing cancer, its position and its relation to the surrounding tissue. It is characterised by the use of non-ionizing radiation and a strong magnetic field, and, as explored by now, it does not have harmful effects on the human body. Therefore, it is completely noninvasive, comfortable and safe for patients as well for medical workers.

Ultraviolet phototherapy for cutaneous diseases: a concise review.

Phototherapy is the use of non-ionizing radiation, primarily in the ultraviolet spectrum, to treat disease. In dermatology, ultraviolet (UV) phototherapy remains an established, lower cost, and often preferred option for many common skin conditions, despite the introduction of newer potent biologics. This article introduces a principal therapeutic modality in the treatment of psoriasis, atopic dermatitis (eczema), vitiligo, and morphea among other diseases where oral manifestations may be present, providing basic information about the use of UVA, UVB, and PUVA. Practical considerations and side effects of phototherapy are described. Phototherapy is an effective treatment for many illnesses and carries a relatively benign side-effect profile.

Photoacoustic-based nanomedicine for cancer diagnosis and therapy

Photoacoustic imaging is the latest promising diagnostic modality that has various advantages such as high spatial resolution, deep penetration depth, and use of non-ionizing radiation. It also employs a non-invasive imaging technique and optically functionalized imaging. The goal of this study was to develop a nanomedicine for simultaneous cancer therapy and diagnosis based on photoacoustic imaging. Human serum albumin nanoparticles loaded with melanin and paclitaxel (HMP-NPs) were developed using the desolvation technique. The photoacoustic-based diagnostic and chemotherapeutic properties of HMP-NPs were evaluated through in vitro and in vivo experiments. The size and zeta potential of the HMP-NPs were found to be 192.8±21.11nm and −22.2±4.39mV, respectively. In in vitro experiments, HMP-NPs produced increased photoacoustic signal intensity because of the loaded melanin and decreased cellular viability because of the encapsulated paclitaxel, compared to the free human serum albumin nanoparticles (the control). In vivo experiments showed that the HMP-NPs efficiently accumulated inside the tumor, resulting in the enhanced photoacoustic signal intensity in the tumor site, compared to the normal tissues. The in vivo chemotherapy study demonstrated that HMP-NPs had the capability to treat cancer for an extended period. In conclusion, HMP-NPs were simultaneously capable of photoacoustic diagnostic and chemotherapy against cancer.

Comparative Analysis of AnisotropicDiffusion and Non Local Meanson Ultrasound Images

Applications of Ultrasound in examining physical health of patient are continuously expanding over last few decades. Ultrasound imaging has assisted doctors in the diagnosis of medical health of patient in obstetrics, cardiology, gynaecology, musculoskeletal, urology and others. It has proved to be very promising and considerably advantageous over other imaging methods because of its features like non-invasive nature, use of non-ionizing radiation, portability, rapidity in performance, ease and cheap availability, real time imaging capability, high patient acceptability. Despite many advantages, it suffers from Speckle noise which results in affecting image resolution and contrast making an adverse impact on the diagnostic capability of the imaging modality. In this paper, we attempt to remove speckle noise from musculoskeletal ultrasound image for shoulder application using Anisotropic Diffusion and Non-Local Means (NLM) method. The quantitative analysis of the result is done using measurement indexes such as peak signal to noise ratio (PSNR), signal to noise ratio (SNR) and root mean square error (RMSE), whereas, visual inspection is carried out for qualitative analysis.

Prenatal ultrasound heating impacts on fluctuations in haematological analysis of Oryctolagus cuniculus.

Prenatal Ultrasound (US) is commonly used as a routine procedure on pregnant women. It is generally perceived as a safe procedure due to the use of non-ionizing radiation. However, the neurotoxicity of diagnostic prenatal US was detected to have a correlation with high susceptibility to early developing fetus. This research involved in vivo experimental model by using 3(rd) trimester pregnant Oryctolagus cuniculus and exposing them to US exposures for 30, 60, and 90 minutes at their gestational day (GD) 28-29. The output power and intensities, spatial peak temporal average intensity (ISPTA) of US were varied from 0.4 to 0.7 W and 0.13 to 0.19 W/cm(2) respectively were tested initially in free-field, water. Haematological analysis was carried out to detect any changes in blood constituents. Statistically significant differences were detected in red blood cell (RBC) count (P<0.001), haemoglobin (Hb) concentration (P<0.001) and also platelet (PLT) count (P<0.001) in newborn of Oryctolagus cuniculus. These findings indicate the possibility of US heating in causing defects on studied animal.

Abstract CN08-01: Expediting clinical translation of optical molecular imaging techniques in oncology and its role in preventive medicine

Abstract In recent years, significant progress has been made in both optical imaging systems and fluorescent contrast agents for clinical applications. NIRF imaging with a free-floating imaging device mounted on the ceiling of the operating theatre or on a microscope articulating arm during surgery for cancer will enable visualization of tumor delineation, locoregional metastases, remnant disease as well as e.g. tumor-containing lymph nodes. Hereby, the surgeon can both detect (diagnostic) and excise (therapeutic) malignant tissue and possible residual disease at the same time. The use of NIRF optical imaging has a range of advantages. Most prominent among these is the fact that it is very safe technology, simple to operate, fast, high resolution (as low as 1 mm), relatively inexpensive and makes use of non-ionizing radiation. Based on the above, it is clear that intra-operative imaging is on the verge of entering standard clinical practice for surgery. Not only the imaging system but also the availability of clinical grade tumor-targeted probes is of the utmost importance for a successful introduction into clinical practice. This talk will give an overview of the current concepts and future perspectives of intraoperative fluorescence image-guided surgery using non-targeted and targeted optical contrast agents for the first-time ever used in patients with ovarian cancer and the anticipated developments within the next 5 years. It will become clear that agencies like the FDA and EMA will play a major role in bringing this technology into the clinic and the necessity of standardization of methodology when applied in multinational multicenter studies. Moreover, the role of optical molecular imaging as a screening instrument in preventive medicine will be outlined. Citation Format: Gooitzen M. van Dam. Expediting clinical translation of optical molecular imaging techniques in oncology and its role in preventive medicine. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr CN08-01.

MR-gesteuerte Schmerztherapie: Prinzipien und klinische Applikationen

X-ray fluoroscopy and computed tomography are frequently used to perform percutaneous interventions in pain therapy. The development of MR-compatible therapy needles now allows these interventions to be performed under MR imaging guidance. MR-guided interventions may be performed using most clinical MR scanners; however, systems with an open configuration are advantageous. Multiplanar pre- and intra-procedural MR imaging provides the interventionalist with essential information, such as evaluation of anatomy and pathology, as well as the planning of the procedure and monitoring of fluid distribution without the use of contrast agents. With the use of non-ionizing radiation, interventional MR imaging is especially suited for the treatment of children and young adults as well as for serial injection therapy. For spinal MR interventions, passive needle visualization is an easily achievable and reliable method. The resulting needle artifact is influenced by several factors such as the alloy of the needle, the strength of the static magnetic field, the sequence type, the spatial orientation of the therapy needle as well as the echo time and may further be optimized during the intervention by alteration of the last three factors. Fast acquisition techniques and image processing allow for continuous, near real-time MR imaging (so-called MR fluoroscopy) and interactive needle navigations, comparable to X-ray fluoroscopy and CT fluoroscopy. The purpose of this review is to illustrate and discuss general concepts of interventional MR imaging. A spectrum of interventional MR imaging procedures in spinal pain therapy is described and illustrated, including procedures such as lumbar facet joint injections, sacroiliac joint injections, lumbar spinal nerve root infiltrations and drug delivery to the lumbar sympathetic chain.

Diffuse optical imaging and spectroscopy for cancer

Visible light and near infrared light interact with biological tissue by absorption and scattering. Diffuse optical imaging and spectroscopy reconstructs tissue physiologic parameters based on noninvasive measurement of tissue optical properties. This technology can be used to differentiate physiologic and molecular signatures of both malignant and benign tissues, as they relate to the area of cancer research. Major advantages are the use of non-ionizing radiation, real-time continuous data acquisition, low cost, and portability. Limitations include low spatial resolution and limited reproducibility. This paper reviews the currently available state-of-the-art technologies for diffuse optical imaging and spectroscopy and their applications in cancer research.

Contrast echocardiography for myocardial perfusion imaging using intravenous agents: progress and promises.

This article is a convenient overview to assist the interested echocardiographist towards acquiring his own experience in the field of myocardial perfusion imaging using intravenous contrast agents. This goal is now pursued in many centres, since contrast echo holds the advantages of cardiac ultrasound (non-invasiveness, high spatial and temporal resolution, wide availability, use of non-ionizing radiation), and because a variety of transpulmonary agents-together with a spectrum of imaging modalities-are becoming available. Many technical considerations need to be addressed for optimal myocardial perfusion imaging: characteristics of the contrast medium (air-filled or perfluorocarbon filled and/or encapsulated agents), modality of administration (bolus injection or continuous infusion) and interaction between microbubbles and ultrasound (dependency on power output). Moreover, intermittent harmonic imaging, intermittent harmonic power Doppler, pulse inversion and amplitude modulation imaging have all been developed to enhance microbubble detection over myocardial tissue. These new acquisition modalities also yield specific artifacts impacting on myocardial perfusion assessment. Finally, acute myocardial infarction and chronic ischaemic heart disease (at baseline and during stress) are the most studied clinical models for perfusion imaging with contrast echo, and are reviewed in this article. Perfusion imaging with intravenous contrast agents has never been as close to widespread clinical use as it is today, but many methodological issues remain unsettled before the wish of the contrast echocardiographist comes true: that is, a cheap, user-friendly and widely available technology that would disclose new information in echocardiography.