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Purpose We evaluated the accuracy of magnetic resonance imaging in determining the size and shape of localized prostate cancer. Materials and Methods The subjects were 114 men who underwent multi-parametric magnetic resonance imaging before radical prostatectomy with patient specific mold processing of the specimen from 2013 to 2015. T2-weighted images were used to contour the prostate capsule and cancer suspicious regions of interest. The contours were used to design and 3-dimentional print custom molds, which permitted alignment of excised prostates with magnetic resonance imaging scans. Tumors were reconstructed in 3 dimensions from digitized whole mount sections. Tumors were then matched with regions of interest and the relative geometries were compared. Results Of the 222 tumors evident on whole mount sections 118 had been identified on magnetic resonance imaging. For the 118 regions of interest mean volume was 0.8 cc and the longest 3-dimensional diameter was 17 mm. However, for matched pathological tumors, of which most were Gleason score 3 + 4 or greater, mean volume was 2.5 cc and the longest 3-dimensional diameter was 28 mm. The median tumor had a 13.5 mm maximal extent beyond the magnetic resonance imaging contour and 80% of cancer volume from matched tumors was outside region of interest boundaries. Size estimation was most accurate in the axial plane and least accurate along the base-apex axis. Conclusions Magnetic resonance imaging consistently underestimates the size and extent of prostate tumors. Prostate cancer foci had an average diameter 11 mm longer and a volume 3 times greater than T2-weighted magnetic resonance imaging segmentations. These results may have important implications for the assessment and treatment of prostate cancer.

The application of THz to medical imaging is experiencing a surge in both interest and federal funding. A brief overview of the field is provided along with promising and emerging applications and ongoing research. THz imaging phenomenology is discussed and tradeoffs are identified. A THz medical imaging system, operating at ~525 GHz center frequency with ~125 GHz of response normalized bandwidth is introduced and details regarding principles of operation are provided. Two promising medical applications of THz imaging are presented: skin burns and cornea. For burns, images of second degree, partial thickness burns were obtained in rat models in vivo over an 8 hour period. These images clearly show the formation and progression of edema in and around the burn wound area. For cornea, experimental data measuring the hydration of ex vivo porcine cornea under drying is presented demonstrating utility in ophthalmologic applications.

To visualize intracoronary lesions in patients with different clinical expressions of coronary disease, we performed coronary angioscopy during coronary-artery bypass surgery in 10 patients with unstable angina and 10 patients with stable coronary disease. We examined a total of 32 vessels, using flexible fiberoptic angioscopes. Twenty-two vessels had no acute intimal lesion; three had complex plaques, six had thrombi, and one had both. Coronary angiography correctly identified the absence of complex plaque and thrombus in 22 vessels, but it detected only one of four complex plaques and one of seven thrombi. On angioscopy, none of the 17 arteries in the patients with stable coronary disease had either a complex plaque or thrombus. In the "offending" arteries of the patients with unstable angina, all three patients with accelerated angina had complex plaques and all seven with angina at rest had thrombi. We conclude that angioscopy frequently reveals complex plaques or thrombi not detected by coronary angiography. Our observations suggest that anginal syndromes that are refractory to medical treatment can be caused by unstable pathologic processes in the intima. Ulceration of plaques may increase the frequency and severity of effort angina, and the subsequent development of partially occlusive thrombi may cause unstable rest angina.

Abstract-Lesion composition plays a significant role in atherosclerotic lesion instability and rupture. Current clinical techniques cannot fully characterize lesion composition or accurately identify unstable lesions. This study investigates the use of time-resolved fluorescence spectroscopy for unstable atherosclerotic lesion diagnosis. The fluorescence of human coronary artery samples was induced with nitrogen laser and detected in the 360-to 510-nm wavelength range. The samples were sorted into 7 groups according to the AHA classification: normal wall and types I, II a (fatty streaks), III (preatheroma), IV (atheroma), V a (fibrous), and V b (calcified) lesions. Spectral intensities and time-dependent parameters [average lifetime f ; decay constants: 1 (fast-term), 2 (slow-term), A 1 (fast-term amplitude contribution)] derived from the time-resolved spectra of coronary samples were used for tissue characterization. We determined that a few intensity values at longer wavelengths (Ͼ430 nm) and time-dependent parameters at peak emission region (390 nm) discriminate between all types of arterial samples except between normal wall and type I lesions. The lipid-rich lesions (more unstable) can be discriminated from fibrous lesions (more stable) on the basis of time-dependent parameters (lifetime and fast-term decay). We inferred that features of lipid fluorescence are reflected on lipid-rich lesion emission. Our results demonstrate that analysis of the time-resolved spectra may be used to enhance the discrimination between different grades of atherosclerotic lesions and provide a means of discrimination between lipid-rich and fibrous lesions. Key Words: atherosclerosis Ⅲ lesion instability Ⅲ time-resolved laser-induced fluorescence Ⅲ spectroscopy R upture of coronary atherosclerotic lesions leads to the acute coronary syndromes of unstable angina, acute myocardial infarction, and ischemic sudden death. [1][2][3] Evidence suggests that lesion composition plays a crucial role in lesion instability and that lipid-rich lesions are more prone to rupture than fibrous lesions. [1][2][3] Current clinical techniques (angiography, angioscopy, ultrasound) are limited in their ability to characterize lesion composition and identify lipidrich lesions. 3 Various techniques are currently under study as potential new tools for identification of lipid-rich lesions (MRI, 4 near-infrared spectroscopy, 5 Raman spectroscopy 6 ) or markers of instability, such as macrophage activation in fibrous cap (local thermography 7 ).Several groups have investigated laser-induced fluorescence spectroscopy (LIFS) as a tool for analyzing plaque composition in the attempt to guide laser angioplasty and to evaluate the likelihood of restenosis. 8 -13 The research was carried out for both ex vivo 8 -12 and in vivo 12,13 conditions. These early studies have demonstrated the potential of LIFS to characterize a few types of atherosclerotic lesions (fibrous, atheromatous, calcified) and to discriminate those from the normal arterial wall. These studies,...

Robot-assisted minimally invasive surgery has gained widespread use over the past decade, but the technique is currently operated in the absence of haptic feedback during tissue manipulation. We have developed a complete tactile feedback system, consisting of a piezoresistive force sensor, control system, and pneumatic balloon tactile display, and mounted directly onto a da Vinci surgical robotic system. To evaluate the effect of tactile feedback on robotic manipulation, a group of novices (n = 16) and experts ( n = 4) were asked to perform three blocks of peg transfer tasks with the tactile feedback system in place. Force generated at the end-effectors was measured in all three blocks, but tactile feedback was active only during the middle block. All subjects used higher force when the feedback system was inactive. When active, subjects immediately used substantially less force and still maintained appropriate grip during the task. After the system was again turned off, grip force increased significantly to prefeedback levels. These results demonstrate that robotic manipulations without tactile feedback are done with more force than needed to grasp objects. Therefore, the addition of tactile feedback allows the surgeon to grasp with less force, and may improve control of the robotic system and handling of tissues and other objects.

Nanotechnology is the design and assembly of submicroscopic devices called nanoparticles, which are 1–100 nm in diameter. Nanomedicine is the application of nanotechnology for the diagnosis and treatment of human disease. Disease-specific receptors on the surface of cells provide useful targets for nanoparticles. Because nanoparticles can be engineered from components that (1) recognize disease at the cellular level, (2) are visible on imaging studies, and (3) deliver therapeutic compounds, nanotechnology is well suited for the diagnosis and treatment of a variety of diseases. Nanotechnology will enable earlier detection and treatment of diseases that are best treated in their initial stages, such as cancer. Advances in nanotechnology will also spur the discovery of new methods for delivery of therapeutic compounds, including genes and proteins, to diseased tissue. A myriad of nanostructured drugs with effective site-targeting can be developed by combining a diverse selection of targeting, diagnostic, and therapeutic components. Incorporating immune target specificity with nanostructures introduces a new type of treatment modality, nano-immunochemotherapy, for patients with cancer. In this review, we will discuss the development and potential applications of nanoscale platforms in medical diagnosis and treatment. To impact the care of patients with neurological diseases, advances in nanotechnology will require accelerated translation to the fields of brain mapping, CNS imaging, and nanoneurosurgery. Advances in nanoplatform, nano-imaging, and nano-drug delivery will drive the future development of nanomedicine, personalized medicine, and targeted therapy. We believe that the formation of a science, technology, medicine law–healthcare policy (STML) hub/center, which encourages collaboration among universities, medical centers, US government, industry, patient advocacy groups, charitable foundations, and philanthropists, could significantly facilitate such advancements and contribute to the translation of nanotechnology across medical disciplines.

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