Medical imaging devices often use automated processing that creates and displays a self-normalized image. When improperly executed, normalization can misrepresent information or result in an ...inaccurate analysis. In the case of diagnostic imaging, a false positive in the absence of disease, or a negative finding when disease is present, can produce a detrimental experience for the patient and diminish their health prospects and prognosis. In many clinical settings, a medical technical specialist is trained to operate an imaging device without sufficient background information or understanding of the fundamental theory and processes involved in image creation and signal processing. Here, we describe a user-friendly image processing algorithm that mitigates user bias and allows for true signal to be distinguished from background. For proof-of-principle, we used antibody-targeted molecular imaging of colorectal cancer (CRC) in a mouse model, expressing human MUC1 at tumor sites. Lesion detection was performed using targeted magnetic resonance imaging (MRI) of hyperpolarized silicon particles. Resulting images containing high background and artifacts were then subjected to individualized image post-processing and comparative analysis. Post-acquisition image processing allowed for co-registration of the targeted silicon signal with the anatomical proton magnetic resonance (MR) image. This new methodology allows users to calibrate a set of images, acquired with MRI, and reliably locate CRC tumors in the lower gastrointestinal tract of living mice. The method is expected to be generally useful for distinguishing true signal from background for other cancer types, improving the reliability of diagnostic MRI.
Silicon‐based micro and nanoparticles are ideally suited for use as biomedical imaging agents because of their biocompatibility, biodegradability, and simple surface chemistry that facilitates drug ...loading and targeting. A method to hyperpolarize silicon particles using dynamic nuclear polarization (DNP), which increases magnetic resonance (MR) imaging signals by several orders‐of‐magnitude through enhanced nuclear spin alignment, was developed to allow silicon particles to function as contrast agents for in vivo magnetic resonance imaging. In this review, we describe the application of the DNP technique to silicon particles and nanoparticles for background‐free real‐time molecular MR imaging. This review provides a summary of the state‐of‐the‐science in silicon particle hyperpolarization with a detailed protocol for hyperpolarizing silicon particles. This information will foster awareness and spur interest in this emerging area of nanoimaging and provide a path to new developments and discoveries to further advance the field.
This article is categorized under:
Diagnostic Tools > In Vivo Nanodiagnostics and Imaging
Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease
Therapeutic Approaches and Drug Discovery > Emerging Technologies
Hyperpolarized silicon MRI as a platform imaging technology for nanomedicine.
Background:
Few specific risk factors are known for shoulder injury in professional pitchers. New pitch-tracking data allow for risk stratification based on advanced metrics.
Purpose/Hypothesis:
The ...purpose of this study was to determine the association between shoulder injury, pitch frequency, and pitch metrics (velocity, total break, break angle, and spin rate) for the 4-seam fastball, curveball, and slider. We hypothesized that more frequent use of the 4-seam fastball would be associated with shoulder injury.
Study Design:
Case-control study; Level of evidence, 3.
Methods:
The Major League Baseball (MLB) database was queried for pitchers who had been placed on the injury list (IL) with a shoulder injury between 2015 and 2019. Injured pitchers were matched 1:1 with controls (pitchers not on the IL with a shoulder injury during the study period), based on age (±1 year), history of ulnar collateral ligament reconstruction, position (starter vs reliever), and pitches thrown during the injury season (±500). Pitch frequency, velocity, horizontal break, vertical break, total break, and spin rate for the season were collected from the Baseball Savant website for the 4-seam fastball, curveball, and slider. Univariate analysis was used to determine group differences for individual variables. Multiple logistic regression was performed to determine odds ratios (ORs) for shoulder injury associated with pitch frequency, velocity, total break, break angle, and spin rate. Covariates included age, position, ulnar collateral ligament reconstruction status, expected weighted on-base average, and total pitches thrown.
Results:
Overall, 233 injured pitchers were evaluated. The most common reason for IL placement was inflammation (78/233; 33.5%) followed by strain or sprain (61/233; 26.2%). Increased total pitch break was associated with an increased risk of shoulder injury for the 4-seam fastball (OR, 1.340 95% confidence interval (CI), 1.199-1.509; P < .001) and slider (OR, 1.360 95% CI, 1.206-1.554; P < .001). For the slider, a decreased spin rate (OR = 0.998 95% CI, 0.997-0.999; P = .026) and a more vertical break angle (OR = 1.170 95% CI: 1.073-1.278; P = .004) were associated with increased risk of injury.
Conclusion:
Increased pitch break of the 4-seam fastball and slider was associated positively with shoulder injury in MLB pitchers. These findings add to the understanding of throwing injury and ability to detect risk using ball-tracking technology.
Porous silicon nanoparticles have recently garnered attention as potentially-promising biomedical platforms for drug delivery and medical diagnostics. Here, we demonstrate porous silicon ...nanoparticles as contrast agents for
Si magnetic resonance imaging. Size-controlled porous silicon nanoparticles were synthesized by magnesiothermic reduction of silica nanoparticles and were surface activated for further functionalization. Particles were hyperpolarized via dynamic nuclear polarization to enhance their
Si MR signals; the particles demonstrated long
Si spin-lattice relaxation (T
) times (∼25 mins), which suggests potential applicability for medical imaging. Furthermore,
Si hyperpolarization levels were sufficient to allow
Si MRI in phantoms. These results underscore the potential of porous silicon nanoparticles that, when combined with hyperpolarized magnetic resonance imaging, can be a powerful theragnostic deep tissue imaging platform to interrogate various biomolecular processes in vivo.
Porous silicon nanoparticles have recently garnered attention as potentially‐promising biomedical platforms for drug delivery and medical diagnostics. Here, we demonstrate porous silicon ...nanoparticles as contrast agents for 29Si magnetic resonance imaging. Size‐controlled porous silicon nanoparticles were synthesized by magnesiothermic reduction of silica nanoparticles and were surface activated for further functionalization. Particles were hyperpolarized via dynamic nuclear polarization to enhance their 29Si MR signals; the particles demonstrated long 29Si spin‐lattice relaxation (T1) times (∼25 mins), which suggests potential applicability for medical imaging. Furthermore, 29Si hyperpolarization levels were sufficient to allow 29Si MRI in phantoms. These results underscore the potential of porous silicon nanoparticles that, when combined with hyperpolarized magnetic resonance imaging, can be a powerful theragnostic deep tissue imaging platform to interrogate various biomolecular processes in vivo.
Size‐controlled porous silicon nanoparticles are synthesized and hyperpolarized via DNP technique to enhance their 29Si magnetic resonance signals. The particles exhibit long 29Si T1 times (∼25 mins) and could therefore have potential applications in medical imaging.
The ulnar collateral ligament is commonly injured in overhead throwing athletes, particularly baseball pitchers. Pitch movement (break) is a critical aspect to pitching performance. The primary ...purpose of this study was to determine the changes in pitch velocity, pitch break, angle of break, and pitch performance metrics before and after ulnar collateral ligament reconstruction (UCLR) in Major League Baseball (MLB) pitchers. The secondary purpose was to determine changes in pitch performance metrics before and after UCLR. We hypothesized that pitch break and pitch performance metrics would be unchanged following UCLR.
This is a retrospective case series study of pitchers who had undergone primary UCLR between 2008 and 2014. Velocity, horizontal movement (Hmov), and vertical movement (Vmov) of each pitch were collected from PITCHf/x for each pitcher 12-24 months before surgery, 12-24 months after surgery, and 24-36 months after surgery. Overall break was calculated by taking the Pythagorean sum of Hmov and Vmov. Angle of break was determined by taking the inverse tangent of Vmov divided by Hmov. Repeated measures ANCOVA was performed to determine differences in pitch velocity, movement, angle of movement, and performance metrics between pre- and postoperative timeframes. Performance metrics included balls, strikes, swings, fouls, swings and misses, ground balls, line drives, pop ups, fly balls, and home runs. Covariates included age at surgery, time from MLB debut to surgery, innings pitched as starter, innings pitched as reliver, and total pitches thrown.
In a cohort of 46 pitchers who underwent UCLR between 2008 and 2014, pitch velocity, movement, and angle were not significantly changed with respect to pre- or postoperative timeframes. In addition, postoperative timeframes had clinically insignificant differences in pitch performance metrics.
Pitch break and performance metrics are not significantly affected for pitchers who return after UCLR.
Medical imaging devices often use automated processing that creates and displays a self-normalized image. When improperly executed, normalization can misrepresent information or result in an ...inaccurate analysis. In the case of diagnostic imaging, a false positive in the absence of disease, or a negative finding when disease is present, can produce a detrimental experience for the patient and diminish their health prospects and prognosis. In many clinical settings, a medical technical specialist is trained to operate an imaging device without sufficient background information or understanding of the fundamental theory and processes involved in image creation and signal processing. Here, we describe a user-friendly image processing algorithm that mitigates user bias and allows for true signal to be distinguished from background. For proof-of-principle, we used antibody-targeted molecular imaging of colorectal cancer (CRC) in a mouse model, expressing human MUC1 at tumor sites. Lesion detection was performed using targeted magnetic resonance imaging (MRI) of hyperpolarized silicon particles. Resulting images containing high background and artifacts were then subjected to individualized image post-processing and comparative analysis. Post-acquisition image processing allowed for co-registration of the targeted silicon signal with the anatomical proton magnetic resonance (MR) image. This new methodology allows users to calibrate a set of images, acquired with MRI, and reliably locate CRC tumors in the lower gastrointestinal tract of living mice. The method is expected to be generally useful for distinguishing true signal from background for other cancer types, improving the reliability of diagnostic MRI.
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