News | Magnetic Resonance Imaging (MRI) | January 15, 2021

Imaging of Ballistic Wounds, Bullet Composition and Implications for MRI Safety

MRI of Nonferromagnetic Ballistics Suspended in Gelatin. 

MRI of Nonferromagnetic Ballistics Suspended in Gelatin. Scout (A), T1-weighted spin-echo (SE) (B), T2-weighted SE (C), T2-weighted gradient-recalled echo (GRE) (TR/TE, 500/10; D), and T2-weighted GRE (TR/TE, 700/30; E) MR images show jacket hollow point .45 automatic Colt pistol bullet (Corbon) (1), solid lead .45 Long Colt bullet (Winchester) (2), full metal jacket (FMJ) automatic Colt pistol bullet (Winchester) (3), 5.56-mm FMJ bullet (Federal Ammunition) (4), #7 lead shotgun pellet (Winchester) (5), and 5-mm lead air gun pellet (Sheridan) (6). On all sequences, metallic artifact is minimal. Although metallic artifact increases or blooms with increased TR/TE in GRE images (D and E), amount of surrounding distortion is still minimal.

Recommendations for MRI are in bold. MRI conditional indicates imaging is safe at 1.5 T. Ferromagnetic precautions indicate risk-benefit analysis is required before proceeding with MRI.

Proposed Algorithm for Triage of Patients With Embedded Ballistic Projectiles Who Need to Undergo MRI Examination. Recommendations for MRI are in bold. MRI conditional indicates imaging is safe at 1.5 T. Ferromagnetic precautions indicate risk-benefit analysis is required before proceeding with MRI.

January 15, 2021 — According to an article in ARRS’ American Journal of Roentgenology (AJR), because patients with ballistic embedded fragments are frequently denied magnetic resonance imaging (MRI) (due to indeterminate bullet composition sans shell casings), radiography and computed tomography (CT) can be used to identify nonferromagnetic projectiles that are safe for MRI.

“Commercially available handgun and shotgun ammunition representing projectiles commonly encountered in a clinical setting was fired into ballistic gelatin as a surrogate for human tissue,” explained first author Arthur J. Fountain from the department of radiology and imaging sciences at Emory University.

After obtaining radiographs and CT images of these gelatin blocks, Fountain and colleagues then obtained MR images of unfired bullets suspended in gelatin blocks using T1- and T2-weighted sequences. Magnetic attractive force, rotational torque, and heating effects of unfired bullets were assessed at 1.5 T.

Based upon debris trail and primary projectile deformation, the team separated the fired bullets into two groups: ferromagnetic and nonferromagnetic. Although ferromagnetic bullets showed mild torque forces and marked imaging artifacts at 1.5 T, nonferromagnetic bullets did not exhibit these effects.

Importantly, heating above the Food and Drug Administration limit of 2°C was not observed in any of the projectiles tested.

Additionally, the authors of this AJR article presented a triage algorithm for patients with retained ballistic fragments. “In particular,” Fountain et al. described, “a projectile that leaves a metallic debris trail from entry to final position or has been appreciably deformed is of copper, copper-alloy, or lead composition with a partial jacketed configuration or represents lead shotgun shot and does not pose a significant risk for imaging at 1.5 T or less, regardless of when the injury occurred.”

“Nonferromagnetic ballistic projectiles do not undergo movement or heating during MRI, and the imaging modality can be performed when medically necessary without undue risk and with limited artifact susceptibility on the resulting images, even when the projectile is in or near a vital structure,” the authors concluded.

For more information: arrs.org

Related Content

Brazilian researchers found that the higher the lung ultrasound score the greater the risk of ICU admission, intubation and death. Image courtesy of Julio Alencar

Brazilian researchers found that the higher the lung ultrasound score the greater the risk of ICU admission, intubation and death. Image courtesy of Julio Alencar

News | Coronavirus (COVID-19) | February 11, 2021
February 11, 2021 — ...
Unhealthy lifestyles, various diseases, stress, and aging can all contribute to an imbalance between the production of ROS and the body's ability to reduce and eliminate them. The resulting excessive levels of ROS cause "oxidative stress".

Unhealthy lifestyles, various diseases, stress, and aging can all contribute to an imbalance between the production of ROS and the body's ability to reduce and eliminate them. The resulting excessive levels of ROS cause "oxidative stress". Graphic courtesy of National Institutes for Quantum and Radiological Science and Technology

News | Magnetic Resonance Imaging (MRI) | February 10, 2021
February 10, 2021 — Oxygen is essential for human life, but within the body, certain biological environmental conditi
 Nuance Communications, Inc. announced the acquisition of Saykara, Inc., a like-minded startup focused on developing a mobile AI assistant to automate clinical documentation for physicians. The acquisition underscores Nuance's ongoing expansion of market and technical leadership in conversational artificial intelligence (AI) and ambient clinical intelligence (ACI) solutions that reduce clinician burnout, enhance patient experiences, and improve overall health system financial integrity.
News | Artificial Intelligence | February 08, 2021
February 8, 2021 — ...
Phase III clinical trial of men with a clinical suspicion of prostate cancer finds MRI with targeted biopsies to be more accurate at diagnosis and less intrusive than current standard
News | Magnetic Resonance Imaging (MRI) | February 08, 2021
February 8, 2021 — The results of a Phase III randomized clinical trial have shown that when it comes to detecting cl
Materialise engineers coordinated the development of a surgical plan and created an on-screen 3D model based on CT-scans.

Materialise engineers coordinated the development of a surgical plan and created an on-screen 3D model based on CT-scans.

Feature | Medical 3-D Printing | February 03, 2021
Three-dimensional technologies, developed by Materialise
Volpara Health, a health technology software company whose integrated breast care platform assists in the delivery of personalized patient care, announced the acquisition of CRA Health, LLC, a breast cancer risk assessment company spinoff from Massachusetts General Hospital — a Harvard Medical School teaching hospital.

Getty Images

News | Breast Imaging | February 02, 2021
February 2, 2021 — Volpara Health, a health technology software company whose integrated...