Imaging of Intimate Partner Violence, From the AJR Special Series on Emergency Radiology.

Intimate partner violence (IPV) is a highly prevalent public health issue with multiple adverse health effects. Radiologists are well suited to assessing a patient's likelihood of IPV. Recognition of common IPV injury mechanisms and resulting target and defensive injury patterns on imaging and understanding of differences between patients who have experienced IPV and those who have not with respect to use of imaging will aid radiologists in accurate IPV diagnosis. Target injuries often involve the face and neck as a result of blunt trauma or strangulation; defensive injuries often involve an extremity. Awareness of differences in injury patterns resulting from IPV-related and accidental trauma can aid radiologists in detecting a mismatch between the provided clinical history and imaging findings to support suspicion of IPV. Radiologists should consider all available current and prior imaging in assessing the likelihood of IPV; this process may be aided by machine learning methods. Even if correctly suspecting IPV on the basis of imaging, radiologists face challenges in acting on that suspicion, including appropriately documenting the findings, without compromising the patient's confidentiality and safety. However, through a multidisciplinary approach with appropriate support mechanisms, radiologists may serve as effective frontline physicians for raising suspicion of IPV.

Imaging Findings on Head Computed Tomography Scans in Victims of Intimate Partner Violence.

OBJECTIVE: The aim of the study is to analyze the imaging findings and injury patterns seen on head computed tomography (CT) examinations performed on survivors of intimate partner violence (IPV). METHODS: An institutional review board-approved retrospective analysis of 668 patients reporting IPV to our institution's violence intervention and prevention program between January 2013 and June 2018 identified 40 unique patients with radiological findings visible on head CT. All injuries visible on head CT were analyzed based on the anatomic location and injury type. Demographics, IPV screening at the time of injury, concomitant, prior, and subsequent injuries to the index head injury were also recorded. RESULTS: Our study cohort had 36 women and 4 men with a mean age at presentation of 43 ± 13 years (mean ± SD), 91 unique injuries with 57 (62.6%) isolated soft tissue injuries, 4 (3.2%) fractures, 13 (14.3%) intra-axial, and 17 (18.7%) extra-axial injuries. Soft tissue injuries and intra-axial injuries occurred most commonly in the frontal region (45.6% and 38.5%), followed by the parietal region (22.8% and 23.1%), while most extra-axial injuries were subdural hematomas (41.2%). Left-sided injuries accounted for 49% (45/91) with 29/91 right-sided (32%) and 17/91 bilateral (19%) injuries. The IPV screening occurred in 44% of injury visits (22/50). Concomitant injuries were seen in 14/50 injury visits (28%), most commonly being in the lower extremity (6/14, 42.9% [% of visits with concomitant injuries]) followed by the upper extremity (5/14, 35.7%), while 52% of visits (26/50) were preceded by prior injuries and 68% of events (34/50) were followed by subsequent injuries. CONCLUSIONS: Isolated soft tissue swelling is the most common manifestation of IPV on head CT scans with frontoparietal region being the most common site. Synchronous and metachronous injuries are frequent.

Facial injury patterns in victims of intimate partner violence.

PURPOSE: To evaluate the imaging findings of facial injuries in patients reporting intimate partner violence (IPV). METHODS: A retrospective review of radiology studies performed for 668 patients reporting IPV to our institution's violence prevention support program identified 96 patients with 152 facial injuries. Demographics, imaging findings, and clinical data obtained from a review of the electronic medical records (EMR) were analyzed to categorize injury patterns. RESULTS: The study cohort consisted of 93 women and 3 men with a mean age of 35 years (range 19-76; median 32). At the time of presentation, 57 (59.3%) patients reported IPV as the mechanism of injury. The most frequent site of injury was the midface, seen in 65 (67.7%) patients. The most common fracture sites were the nasal bones (45/152, 29.6%), followed by the mandible (17/152, 11.1%), and orbits (16/152, 10.5%). Left-sided injuries were more common (90/152; 59.2%). A vast majority of fractures (94.5%) showed minimal or no displacement. Over one-third of injuries (60/152, 39.4%) demonstrated only soft tissue swelling or hematoma without fracture. Associated injuries were seen most frequently in the upper extremity, occurring synchronously in 11 (11.4%) patients, and preceding the index facial injury in 20 (21%) patients. CONCLUSION: /advances in knowledge. The midface was the most frequent location of injury in victims of intimate partner violence, and the nasal bone was the most commonly fractured facial bone. Recognizing these injury patterns can help radiologists suspect IPV and prompt them to discuss the possibility of IPV with the clinical providers.

Radiological and clinical features of traumatic atlanto-occipital dislocation.

PURPOSE: We aimed to describe the findings of traumatic atlanto-occipital dislocation (AOD) on cervical spine CTs and differences leading to varying treatment of these patients. METHODS: We retrospectively identified 20 adult patients with AOD from cervical spine CTs demonstrating fracture or fracture dislocations over 19 years at 2 major trauma centers. Medical records were reviewed and craniovertebral junction (CVJ) metrics measured on CT. Intubation, Glasgow Coma Scale (GCS), additional injuries, occiput/atlas/axis fracture, concurrent atlantoaxial subluxation, vascular injury on CT angiography, and ligamentous injury on MRI were noted. RESULTS: Using the Traynelis Classification, eight patients had type 2 and eight patients type 3 AOD. Four of 5 patients who died within 14 days of CT had type 2 AOD. Three patients had medial/lateral AOD. Of the patients who survived initial injuries, a greater percentage who underwent surgical or halo fixation versus non-operatively treated patients had abnormal CVJ measurements including BDI (62.5% vs 0%), atlantoaxial subluxation (75% vs 14.3%), ligamentous injury (80% vs 66.7%), intubation (62.5% vs 28.6%), GCS<8 (62.5% vs 14.3%), and additional injuries (75% vs 71.4%) on presentation. MRI helped identify 2 cases of type 2 AOD and surgical decision making in 8 cases. CONCLUSIONS: Types 2 and 3 were the most common, and type 2 is the deadliest type of AOD. A greater proportion of patients who undergo surgical or halo fixation have abnormal CT/MR findings with neurologic impairment at presentation. MRI aided detection of potentially missed type 2 AOD and was critical for surgical decision making.

Traumatic cervical spine fracture patterns on CT: a retrospective analysis at a level 1 trauma center.

PURPOSE: The purpose of our study was to determine common acute traumatic cervical spine fracture patterns on CT cervical spine (CTCS). METHODS: We retrospectively reviewed 1091 CTCS positive for traumatic fractures performed over a 10-year period at a level 1 trauma center. Fractures were classified by vertebral level, laterality, and anatomic location (anterior/posterior arch, body, odontoid, pedicle, facet, lateral mass, lamina, spinous process, transverse foramina, and transverse processes). RESULTS: C2 was the most commonly fractured vertebra (38% of all studies), followed by C7 (32.4%). 48.7% of studies had upper cervical spine (C1 and/or C2) fractures. 39.7% of positive studies involved > 1 vertebral level. Conditioned on fractures at one cervical level, the probability of fracture was greatest at adjacent levels with a 50% chance of sustaining a C7 fracture with C6 fracture. However, 31.3% (136) of studies with multi-level fractures had non-contiguous fractures. The most common isolated vertebral process fracture was of the transverse process, seen in 89 (8.2%) studies at a single level, 27 (2.5%) studies at multiple levels. Subaxial spine vertebral process fractures outnumbered body fractures with progressive dominance of vertebral process fracture down the spine. CONCLUSION: C2 was the most commonly fractured vertebral level. Multi-level traumatic cervical spine fractures constituted 40% of our cohort, most commonly at C6/C7 and C1/C2. Although the conditional probability of concurrent fracture in studies with multi-level fractures was greatest in contiguous levels, nearly one-third of multi-level fractures involved non-contiguous fractures.

Fractional Flow Reserve Estimated at Coronary CT Angiography in Intermediate Lesions: Comparison of Diagnostic Accuracy of Different Methods to Determine Coronary Flow Distribution.

Purpose To compare the diagnostic accuracy of different computed tomographic (CT) fractional flow reserve (FFR) algorithms for vessels with intermediate stenosis. Materials and Methods This cross-sectional HIPAA-compliant and human research committee-approved study applied a four-step CT FFR algorithm in 61 patients (mean age, 69 years ± 10; age range, 29-89 years) with a lesion of intermediate-diameter stenosis (25%-69%) at CT angiography who underwent FFR measurement within 90 days. The per-lesion diagnostic performance of CT FFR was tested for three different approaches to estimate blood flow distribution for CT FFR calculation. The first two, the Murray law and the Huo-Kassab rule, used coronary anatomy; the third used contrast material opacification gradients. CT FFR algorithms and CT angiography percentage diameter stenosis (DS) measurements were compared by using the area under the receiver operating characteristic curve (AUC) to detect FFRs of 0.8 or lower. Results Twenty-five lesions (41%) had FFRs of 0.8 or lower. The AUC of CT FFR determination by using contrast material gradients (AUC = 0.953) was significantly higher than that of the Huo-Kassab (AUC = 0.882, P = .043) and Murray law models (AUC = 0.871, P = .033). All three AUCs were higher than that for 50% or greater DS at CT angiography (AUC = 0.596, P < .001). Correlation of CT FFR with FFR was highest for gradients (Spearman ρ = 0.80), followed by the Huo-Kassab rule (ρ = 0.68) and Murray law (ρ = 0.67) models. All CT FFR algorithms had small biases, ranging from -0.015 (Murray) to -0.049 (Huo-Kassab). Limits of agreement were narrowest for gradients (-0.182, 0.147), followed by the Huo-Kassab rule (-0.246, 0.149) and the Murray law (-0.285, 0.256) models. Conclusion Clinicians can perform CT FFR by using a four-step approach on site to accurately detect hemodynamically significant intermediate-stenosis lesions. Estimating blood flow distribution by using coronary contrast opacification variations may improve CT FFR accuracy. © RSNA, 2017 Online supplemental material is available for this article.

Utility and reproducibility of 3-dimensional printed models in pre-operative planning of complex thoracic tumors.

BACKGROUND AND OBJECTIVES: 3D-printed models are increasingly used for surgical planning. We assessed the utility, accuracy, and reproducibility of 3D printing to assist visualization of complex thoracic tumors for surgical planning. METHODS: Models were created from pre-operative images for three patients using a standard radiology 3D workstation. Operating surgeons assessed model utility using the Gillespie scale (1 = inferior to 4 = superior), and accuracy compared to intraoperative findings. Model variability was assessed for one patient for whom two models were created independently. The models were compared subjectively by surgeons and quantitatively based on overlap of depicted tissues, and differences in tumor volume and proximity to tissues. RESULTS: Models were superior to imaging and 3D visualization for surgical planning (mean score = 3.4), particularly for determining surgical approach (score = 4) and resectability (score = 3.7). Model accuracy was good to excellent. In the two models created for one patient, tissue volumes overlapped by >86.5%, and tumor volume and area of tissues ≤1 mm to the tumor differed by <15% and <1.8 cm2 , respectively. Surgeons considered these differences to have negligible effect on surgical planning. CONCLUSION: 3D printing assists surgical planning for complex thoracic tumors. Models can be created by radiologists using routine practice tools with sufficient accuracy and clinically negligible variability.

Update on the Role of Imaging in Detection of Intimate Partner Violence.

Intimate partner violence (IPV) is a major public health problem with adverse health and mental consequences. Patient- and clinician-related barriers to screening include underreporting, misattribution of IPV to other causes, and patients not seeking help or facing social stigmas and discrimination. Radiology may help overcome these barriers through objective imaging evaluation, noting mismatches between image findings and provided clinical history. Recognizing injury patterns specific to IPV on imaging aids early identification and intervention even when the patient is not forthcoming. This article examines the ways radiologists have adapted to meet an ever-increasing demand for diagnosis and reporting of IPV.

Significance of Right-to-Left Ventricular Ratio as a Quantitative Computed Tomography Biomarker in Patients With Negative Computed Tomography Pulmonary Angiograms.

PURPOSE: The purpose of our study was to determine if the ratio of right-to-left ventricular diameter (RV/LV ratio) on computed tomography (CT) pulmonary angiograms (CTPA) is predictive of 90-day mortality in patients without pulmonary embolism (PE). MATERIALS AND METHODS: This Institutional Review Board-approved single-institution retrospective study was performed on patients who underwent CTPA in the emergency or inpatient setting over a 1-year period. Right and left ventricular diameters were measured and RV/LV ratios calculated for patients without acute PE. Ratios greater than or equal to 0.9 were considered abnormal. Univariate analysis was performed for the outcome of death within 90 days of CT. Multivariable analysis was also performed to control for age, sex, and lung disease. RESULTS: Of the 423 patients included in the study, 55 patients died within 90 days of CT. An RV/LV ratio ≥0.9 was predictive of 90-day mortality: of the 226 patients with RV/LV ≥0.9, 42 (18.6%) died within 90 days, compared with 13 of 197 patients without abnormal ratio (6.6%), with odds ratio (OR) of 3.23 (95% confidence interval [CI]: 1.68-6.22; P<0.01). In multivariate analysis, RV/LV ratio had an OR of 5.19 per unit increase (95%CI: 1.06-25.42; P=0.04); age had an OR of 1.04 per year increase (95% CI: 1.01-1.06; P<0.01). CONCLUSION: Increased RV/LV ratio is a negative prognostic factor even in patients without acute PE and may be a useful CT biomarker to include in radiology reports for all patients undergoing CTPA.

The transluminal attenuation gradient in coronary CT angiography for the detection of hemodynamically significant disease: can all arteries be treated equally?

OBJECTIVE: Results of the use of the transluminal attenuation gradient (TAG) at coronary CT angiography (CCTA) to predict hemodynamically significant disease vary widely. This study tested whether diagnostic performance of TAG to predict fractional flow reserve (FFR) ≤ 0.8 is improved when applied separately to subsets of coronary arteries that carry similar physiological flow. METHODS: 28 patients with 64 × 0.5 mm CCTA and invasive FFR in ≥1 major coronary artery were retrospectively evaluated. Two readers assessed TAG in each artery. The receiver operating characteristic (ROC) area under the curve (AUC) was used to assess the diagnostic performance of TAG to detect hemodynamically significant disease following a clinical use rule [negative: FFR > 0.8 or ≤ 25% diameter stenosis (DS) at invasive catheter angiography; positive: FFR ≤ 0.8 or ≥ 90% DS at invasive catheter angiography]. ROC AUC was compared for all arteries pooled together, vs separately for arteries carrying similar physiological flow (Group 1: all left anterior descending plus right-dominant left circumflex; Group 2: right-dominant RCA plus left/co-dominant left circumflex). RESULTS: Of the 84 arteries, 30 had FFR measurements, 30 had ≤25% DS and 13 had ≥90% DS. 11 arteries with 26-89% DS and no FFR measurement were excluded. TAG interobserver reproducibility was excellent (Pearson r = 0.954, Bland-Altman bias: 0.224 Hounsfield unit cm-1). ROC AUC to detect hemodynamically significant disease was higher when considering arteries separately (Group 1 AUC = 0.841, p = 0.039; Group 2 AUC = 0.840, p = 0.188), than when pooling all arteries together (AUC = 0.661). CONCLUSION: Incorporating information on the physiology of coronary flow via the particular vessel interrogated and coronary dominance may improve the accuracy of TAG, a simple measurement that can be quickly performed at the time of CCTA interpretation to detect hemodynamically significant stenosis in individual coronary arteries. Advances in knowledge: The interpretation of TAG may benefit by incorporating information regarding which coronary artery is being interrogated.

Diagnostic performance of a Lattice Boltzmann-based method for CT-based fractional flow reserve.

AIMS: Fractional flow reserve (FFR) estimated from coronary computed tomography angiography (CT-FFR) offers non-invasive detection of lesion-specific ischaemia. We aimed to develop and validate a fast CT-FFR algorithm utilising the Lattice Boltzmann method for blood flow simulation (LBM CT-FFR). METHODS AND RESULTS: Sixty-four patients with clinically indicated CTA and invasive FFR measurement from three institutions were retrospectively analysed. CT-FFR was performed using an onsite tool interfacing with a commercial Lattice Boltzmann fluid dynamics cloud-based platform. Diagnostic accuracy of LBM CT-FFR ≤0.8 and percent diameter stenosis >50% by CTA to detect invasive FFR ≤0.8 were compared using area under the receiver operating characteristic curve (AUC). Sixty patients successfully underwent LBM CT-FFR analysis; 29 of 73 lesions in 69 vessels had invasive FFR ≤0.8. Total time to perform LBM CT-FFR was 40±10 min. Compared to invasive FFR, LBM CT-FFR had good correlation (r=0.64), small bias (0.009) and good limits of agreement (-0.223 to 0.206). The AUC of LBM CT-FFR (AUC=0.894, 95% confidence interval [CI]: 0.792-0.996) was significantly higher than CTA (AUC=0.685, 95% CI: 0.576-0.794) to detect FFR ≤0.8 (p=0.0021). Per-lesion specificity, sensitivity, and accuracy of LBM CT-FFR were 97.7%, 79.3%, and 90.4%, respectively. CONCLUSIONS: LBM CT-FFR has very good diagnostic accuracy to detect lesion-specific ischaemia (FFR ≤0.8) and can be performed in less than one hour.

Medical 3D printing: methods to standardize terminology and report trends.

BACKGROUND: Medical 3D printing is expanding exponentially, with tremendous potential yet to be realized in nearly all facets of medicine. Unfortunately, multiple informal subdomain-specific isolated terminological 'silos' where disparate terminology is used for similar concepts are also arising as rapidly. It is imperative to formalize the foundational terminology at this early stage to facilitate future knowledge integration, collaborative research, and appropriate reimbursement. The purpose of this work is to develop objective, literature-based consensus-building methodology for the medical 3D printing domain to support expert consensus. RESULTS: We first quantitatively survey the temporal, conceptual, and geographic diversity of all existing published applications within medical 3D printing literature and establish the existence of self-isolating research clusters. We then demonstrate an automated objective methodology to aid in establishing a terminological consensus for the field based on objective analysis of the existing literature. The resultant analysis provides a rich overview of the 3D printing literature, including publication statistics and trends globally, chronologically, technologically, and within each major medical discipline. The proposed methodology is used to objectively establish the dominance of the term "3D printing" to represent a collection of technologies that produce physical models in the medical setting. We demonstrate that specific domains do not use this term in line with objective consensus and call for its universal adoption. CONCLUSION: Our methodology can be applied to the entirety of medical 3D printing literature to obtain a complete, validated, and objective set of recommended and synonymous definitions to aid expert bodies in building ontological consensus.

Preoperative planning and tracheal stent design in thoracic surgery: a primer for the 2017 Radiological Society of North America (RSNA) hands-on course in 3D printing.

In this work, we provide specific clinical examples to demonstrate basic practical techniques involved in image segmentation, computer-aided design, and 3D printing. A step-by-step approach using United States Food and Drug Administration cleared software is provided to enhance surgical intervention in a patient with a complex superior sulcus tumor. Furthermore, patient-specific device creation is demonstrated using dedicated computer-aided design software. Relevant anatomy for these tasks is obtained from CT Digital Imaging and Communications in Medicine images, leading to the generation of 3D printable files and delivery of these files to a 3D printer.

Two alternating motor programs drive navigation in Drosophila larva.

When placed on a temperature gradient, a Drosophila larva navigates away from excessive cold or heat by regulating the size, frequency, and direction of reorientation maneuvers between successive periods of forward movement. Forward movement is driven by peristalsis waves that travel from tail to head. During each reorientation maneuver, the larva pauses and sweeps its head from side to side until it picks a new direction for forward movement. Here, we characterized the motor programs that underlie the initiation, execution, and completion of reorientation maneuvers by measuring body segment dynamics of freely moving larvae with fluorescent muscle fibers as they were exposed to temporal changes in temperature. We find that reorientation maneuvers are characterized by highly stereotyped spatiotemporal patterns of segment dynamics. Reorientation maneuvers are initiated with head sweeping movement driven by asymmetric contraction of a portion of anterior body segments. The larva attains a new direction for forward movement after head sweeping movement by using peristalsis waves that gradually push posterior body segments out of alignment with the tail (i.e., the previous direction of forward movement) into alignment with the head. Thus, reorientation maneuvers during thermotaxis are carried out by two alternating motor programs: (1) peristalsis for driving forward movement and (2) asymmetric contraction of anterior body segments for driving head sweeping movement.