Novel illuminoss photodynamic bone stabilization system: normal and post-operative complication imaging findings in the emergency setting.

The mainstay orthopedic surgical technique for fracture fixation involves metal plates, screws, and rods. While these methods are effective, they exhibit high rates of complications within specific populations, particularly among patients with pathologic and insufficiency fractures. IlluminOss represents a novel photodynamic bone stabilization system, approved for use in multiple countries, that serves as an alternative to traditional fracture fixation approaches for patients experiencing pathologic, traumatic, and fragility fractures. Despite the initial success of the system in fostering fracture healing, no study has comprehensively examined the radiological attributes of the IlluminOss Stabilization system thus far. The emergency radiologist is often the first point of imaging identification and interpretation for patients presenting with suspected postoperative complications, requiring evolving knowledge of both expected and atypical appearances for novel surgical implants. This manuscript's objective is to delve into the design and clinical application of IlluminOss, scrutinize relevant normal imaging findings across various modalities, and delineate potential complications associated with the IlluminOss Stabilization system for traumatic, pathologic, and fragility fractures that are increasingly encountered in the emergency department setting.

Computer Tomography Angiography of Peripheral Vascular Injuries.

Peripheral vascular injuries are a rare finding in the setting of trauma but an important source of morbidity and mortality when present. Fast and accurate diagnosis followed by rapid repair of vascular injuries are important for achieving the best clinical outcomes. The advancements in computer tomography (CT) and decades of experience in vascular imaging have allowed radiologists to become important contributors for the diagnosis and characterization of peripheral vascular injury. We review the epidemiology of peripheral vascular injuries, indications for imaging, ways to optimize CT technique, imaging findings, and common challenges for accurate diagnosis of such injuries.

Diagnostic performance of triple-contrast versus single-contrast multi-detector computed tomography for the evaluation of penetrating bowel injury.

PURPOSE: Selecting groups of low-risk penetrating trauma patients to forego laparotomy can be challenging. The presence of bowel injury may prevent non-operative management. Optimal CT technique to detect bowel injury related to penetrating injury is controversial. Our goal is to compare the diagnostic performance of triple-contrast (oral, rectal, and IV) against IV contrast-only CT, for the detection of bowel injury from penetrating abdominopelvic trauma, using surgical diagnosis as the reference standard. METHODS: Nine hundred ninety-seven patients who underwent CT for penetrating torso trauma at a single institution between 2009 and 2016 in our HIPPA-compliant and institutional review board-approved retrospective cohort study. A total of 143 patients, including 15 females and 123 males underwent a pre-operative CT, followed by exploratory laparotomy. Of these, 56 patients received triple-contrast CT. CT examinations were independently reviewed by two radiologists, blinded to surgical outcome and clinical presentation. Results were stratified by contrast type and injury mechanism and were compared based upon diagnostic performance indicators of sensitivity, specificity, negative predictive value, and positive predictive value. Area under the receiving operating characteristics curves were analyzed for determination of diagnostic accuracy. RESULTS: Bowel injury was present in 45 out of 143 patients (10 on triple-contrast group and 35 on IV contrast-only group). Specificity and accuracy were higher with triple-contrast CT (98% specific, 97-99% accurate) compared to IV contrast-only CT (66% specific, 78-79% accurate). Sensitivity was highest with IV contrast-only CT (91% sensitive) compared with triple-contrast CT (75% sensitive), although this difference was not statistically significant. Triple-contrast technique increased diagnostic accuracy for both radiologists regardless of mechanism of injury. CONCLUSION: In our retrospective single-institution cohort study, triple-contrast MDCT had greater accuracy, specificity, and positive predictive values when compared to IV contrast-only CT in evaluating for bowel injury from penetrating wounds.

MRI of Emergent Intracranial Infections and Their Complications.

Acute intracranial infections of the central nervous system and skull base are uncommon but time sensitive diagnoses that may present to the emergency department. As symptoms are frequently nonspecific or lack typical features of an infectious process, a high index of suspicion is required to confidently make the diagnosis, and imaging may not only serve as the first clue to an intracranial infection, but is often necessary to completely characterize the disease process and exclude any confounding conditions. Although computed tomography is typically the initial imaging modality for many of these patients, magnetic resonance imaging offers greater sensitivity and specificity in diagnosing intracranial infections, characterizing the full extent of infection, and identifying potential complications. The aim of this article is to serve as a review of the typical and most important imaging manifestations of these infections that can be encountered in the emergent setting.

Spine MRI: A Review of Commonly Encountered Emergent Conditions.

Over the last 2 decades, the proliferation of magnetic resonance imaging (MRI) availability and continuous improvements in acquisition speeds have led to significantly increased MRI utilization across the health care system, and MRI studies are increasingly ordered in the emergent setting. Depending on the clinical presentation, MRI can yield vital diagnostic information not detectable with other imaging modalities. The aim of this text is to report on the up-to-date indications for MRI of the spine in the ED, and review the various MRI appearances of commonly encountered acute spine pathology, including traumatic injuries, acute non traumatic myelopathy, infection, neoplasia, degenerative disc disease, and postoperative complications. Imaging review will focus on the aspects of the disease process that are not readily resolved with other modalities.

Evaluation of penetrating abdominal and pelvic trauma.

Penetrating abdominal trauma comprises a wide variety of injuries that will manifest themselves at imaging depending on the distinct mechanism of injury. The use of computed tomography (CT) for hemodynamically stable victims of penetrating torso trauma continues to increase in clinical practice allowing more patients to undergo initial selective non-surgical management. High diagnostic accuracy in this setting helps patients avoid unnecessary surgical intervention and ultimately reduce morbidity, mortality and associated medical costs. This review will present the evidence and the controversies surrounding the imaging of patients with penetrating abdominopelvic injuries. Available protocols, current MDCT technique controversies, organ-specific injuries, and key MDCT findings requiring intervention in patients with penetrating abdominal and pelvic trauma are presented. In the hemodynamically stable patient, the radiologist will play a key role in the triage of these patients to operative or nonoperative management.

Imaging evaluation of diaphragmatic injuries: Improving interpretation accuracy.

Diaphragmatic Injuries (DIs) remain a challenging diagnosis with potential catastrophic delayed complications. A high degree of suspicion in every case of severe blunt thoracoabdominal trauma or penetrating thoracoabdominal injury is essential. This review will present the evidence and controversies on this topic providing a practical tutorial for radiologists hoping to improve their interpretive accuracy for both blunt and penetrating DIs. The imaging signs of diaphragmatic injuries will be explained with emphasis on multidetector CT. Diagnostic pitfalls, available protocols and other issues will be presented.

Extensor Tendon Entrapment on Computed Tomography Imaging of Distal Radius Fractures.

Objective To examine the association between distal radius fractures and tendon entrapment identified on computed tomography (CT) imaging. Patients and Methods After Institutional Review Board approval, we retrospectively reviewed distal radius fractures that underwent CT imaging from an electronic database between January 2006 to February 2018 at a single level 1 hospital trauma center. We categorized all distal radial fractures according to the AO-OTA (AO Foundation/Orthopaedic Trauma Association) classification. Distal upper extremity tendons were assessed for entrapment. Fisher's exact test was used for statistical analysis with significance at p < 0.05. Results A total of 183 distal radius fractures were identified in 179 patients. A total of 16 fractures (13 males and 3 females) were associated with tendon entrapment. Mechanism of injury included falls ( n = 7), motor vehicle accidents ( n = 6), dog bites ( n = 2), and gunshot wound ( n = 1). Entrapped tendons were limited to the extensor compartment and included the extensor pollicis longus (EPL; n = 11), extensor pollicis brevis ( n = 1), extensor carpi ulnaris ( n = 1), extensor carpi radialis longus ( n = 1), and extensor digitorum communis ( n = 2). The most commonly associated AO-OTA fracture pattern with tendon entrapment was complete articular radial fractures (2R3C; 69%), eight of which were simple articular with metaphyseal multifragmentary fractures (2R3C2). Of the distal radius fractures, 81% were associated with additional ulnar fractures of varying severity and displacement. Conclusion Approximately 8.7% of distal radius fractures were retrospectively identified to have tendon entrapment compared with a previously reported incidence of 1.3%. Wrist surgeons and radiologists should have higher suspicion for tendon entrapment and carefully review preoperative CT imaging for tendon entrapment in distal radius fractures especially if there is an intra-articular, multifragmentary injury pattern. Wrist surgeons and radiologists should also have increased suspicion for EPL tendon entrapments given its high incidence in association with distal radius fractures. Level of Evidence This is a Level III, retrospective cross-sectional study.

Automatic Detection of Prostate Tumor Habitats using Diffusion MRI.

A procedure for identification of optimal Apparent Diffusion Coefficient (ADC) thresholds for automatic delineation of prostatic lesions with restricted diffusion at differing risk for cancer was developed. The relationship between the size of the identified Volumes of Interest (VOIs) and Gleason Score (GS) was evaluated. Patients with multiparametric (mp)MRI, acquired prior to radical prostatectomy (RP) (n = 18), mpMRI-ultrasound fused (MRI-US) (n = 21) or template biopsies (n = 139) were analyzed. A search algorithm, spanning ADC thresholds in 50 µm2/s increments, determined VOIs that were matched to RP tumor nodules. Three ADC thresholds for both peripheral zone (PZ) and transition zone (TZ) were identified for estimation of VOIs at low, intermediate, and high risk of prostate cancer. The determined ADC thresholds for low, intermediate and high risk in PZ/TZ were: 900/800; 1100/850; and 1300/1050 µm2/s. The correlation coefficients between the size of the high/intermediate/low risk VOIs and GS in the three cohorts were 0.771/0.778/0.369, 0.561/0.457/0.355 and 0.423/0.441/0.36 (p < 0.05). Low risk VOIs mapped all RP lesions; area under the curve (AUC) for intermediate risk VOIs to discriminate GS6 vs GS ≥ 7 was 0.852; for high risk VOIs to discriminate GS6,7 vs GS ≥ 8 was 0.952. In conclusion, the automatically delineated volumes in the prostate with restricted diffusion were found to strongly correlate with cancer aggressiveness.

Blunt Craniocervical Trauma: Does the Patient Have a Cerebral Vascular Injury?

Blunt cerebrovascular injury involves injury to the carotid and/or vertebral arteries sustained via generalized multitrauma or directed blunt craniocervical trauma. Stroke remains the most consequential outcome. Timely diagnosis and initiation of treatment before the development of neurologic complications has a well-established role in decreasing morbidity and mortality. This article presents evidence and controversies surrounding the optimization of diagnostic imaging for suspected blunt cerebrovascular injury. Discussion centers on the increasing reliance on multidetector computed tomography angiography for screening, considering relevant clinical criteria for determining screening. Imaging protocols, imaging findings, injury grading, pearls, and pitfalls are discussed.

Intra-Aortic Balloon Pump Simulating Thoracic Aortic Dissection.

We present a 70-year-old woman who had an intra-aortic balloon pump (IABP) in its deflated state in the aorta during a computed tomography angiogram scan. The scan was performed to assess for aortic dissection. The deflated IABP created a curvilinear filling defect in the aortic lumen that suggested an intimal flap. Herein, we described the finding and suggest key features that can help distinguish between this intra-aortic device and a true dissection. This distinction between the device and aortic dissection is not only important because of the potential pitfall of a false positive diagnosis but also because an IABP itself can lead to an aortic dissection and therefore its computed tomography features should be recognized in both its inflated and deflated state.

Multidetector CT of Midfacial Fractures: Classification Systems, Principles of Reduction, and Common Complications.

The advent of titanium hardware, which provides firm three-dimensional positional control, and the exquisite bone detail afforded by multidetector computed tomography (CT) have spurred the evolution of subunit-specific midfacial fracture management principles. The structural, diagnostic, and therapeutic complexity of the individual midfacial subunits, including the nose, the naso-orbito-ethmoidal region, the internal orbits, the zygomaticomaxillary complex, and the maxillary occlusion-bearing segment, are not adequately reflected in the Le Fort classification system, which provides only a general framework and has become less relevant in contemporary practice. The purpose of this article is to facilitate the involvement of radiologists in the delivery of individualized multidisciplinary care to adults who have sustained blunt trauma and have midfacial fractures by providing a clinically relevant review of the role of multidetector CT in the management of each midfacial subunit. Surgically relevant anatomic structures, search patterns, critical CT findings and their management implications, contemporary classification systems, and common posttraumatic and postoperative complications are emphasized. ©RSNA, 2018.

Automatic Detection and Quantitative DCE-MRI Scoring of Prostate Cancer Aggressiveness.

PURPOSE: To develop a robust and clinically applicable automated method for analyzing Dynamic Contrast Enhanced (DCE-) MRI of the prostate as a guide for targeted biopsies and treatments. MATERIALS AND METHODS: An unsupervised pattern recognition (PR) method was used to analyze prostate DCE-MRI from 71 sequential radiotherapy patients. Identified regions of interest (ROIs) with increased perfusion were assigned either to the peripheral (PZ) or transition zone (TZ). Six quantitative features, associated with the washin and washout part of the weighted average DCE curve from the ROI, were calculated. The associations between the assigned DCE-scores and Gleason Score (GS) were investigated. A heatmap of tumor aggressiveness covering the entire prostate was generated and validated with histopathology from MRI-ultrasound fused (MRI-US) targeted biopsies. RESULTS: The volumes of the PR-identified ROI's were significantly correlated with the highest GS from the biopsy session for each patient. Following normalization (and only after normalization) with gluteus maximus muscle's DCE signal, the quantitative features in PZ were significantly correlated with GS. These correlations straightened in subset of patients with available MRI-US biopsies when GS from the individual biopsies were used. Area under the receiver operating characteristics curve for discrimination between indolent vs aggressive cancer for the significant quantitative features reached 0.88-0.95. When DCE-scores were calculated in normal appearing tissues, the features were highly discriminative for cancer vs no cancer both in PZ and TZ. The generated heatmap of tumor aggressiveness coincided with the location and GS of the MRI-US biopsies. CONCLUSION: A quantitative approach for DCE-MRI analysis was developed. The resultant map of aggressiveness correlated well with tumor location and GS and is applicable for integration in radiotherapy/radiology imaging software for clinical translation.

Multidetector CT of Mandibular Fractures, Reductions, and Complications: A Clinically Relevant Primer for the Radiologist.

After the nasal bones, the mandible is the second most common site of facial fractures, and mandibular fractures frequently require open reduction. In the trauma injury setting, multidetector computed tomography (CT) has become the cornerstone imaging modality for determining the most appropriate treatment management, fixation method, and surgical approach. Multidetector CT is also used to assess the adequacy of the reduction and evaluate potential complications in the postoperative period. For successful restoration of the mandible's form and function, as well as management of posttraumatic and postoperative complications, reconstructive surgeons are required to have a detailed understanding of mandibular biomechanics, occlusion, and anatomy. To provide added value in the diagnosis, treatment planning, and follow-up of mandibular fractures, radiologists should be aware of these concepts. Knowledge of the techniques commonly used to achieve occlusal and anatomic reduction and of the rationale behind the range of available treatment options for different injury patterns-from isolated and nondisplaced fractures to multisite and comminuted fractures-also is essential. This article focuses on the use of multidetector CT for pre- and postoperative evaluation of mandibular fractures and outlines fundamental concepts of diagnosis and management-beginning with an explanation of common fracture patterns and their biomechanical underpinnings, and followed by a review of the common postoperative appearances of these fractures after semirigid and rigid fixation procedures. Specific considerations regarding fractures in different regions of the tooth-bearing and non-tooth-bearing mandible and the unique issues pertaining to the edentulous atrophic mandible are reviewed, and key features that distinguish major from minor complications are described. (©)RSNA, 2016.