Computed Tomography Coronary Angiography on a Detector-Based Spectral Computed Tomography Platform: Evaluation of Patients With Coronary Artery Disease Reporting and Data System Score of 3 and Higher.

PURPOSE: Computed tomography (CT) coronary angiography performed on a detector-based spectral scanner helps more closely approximate severity of stenosis with nuclear medicine and cardiac catheterization tests compared with single-energy CT (SECT) in patients with an original CAD-RADS score of 3 and higher. METHODS: This retrospective trial was conducted between January 2017 and December 2019 and included 52 patients with a CAD-RADS score of 3 and higher. Two reading sessions were performed 6 weeks apart. The first reading session was performed using only conventional images and the second reading session was performed using spectral results. Detector-based spectral CT CAD-RADS scores were compared with cardiac stress test and/or cardiac catheterization results for final characterization of stenosis in 41 segments from 32 patients. The mean CAD-RADS score was calculated for both the conventional images and spectral images. RESULTS: The CAD-RADS score for SECT and the score for spectral CT for the 41 segments were compared. Available associated stress test and/or cardiac catheterization results were also compared with CAD-RADS scores. In 51% (21/41), a diagnosis concordant with best practices results was achieved with the help of spectral CT results. A mean CAD-RADS score of 3.56 was obtained using spectral results, compared with 3.93 using conventional images. A 2-tailed paired t test determined the difference to be significant with a P value of 0.007. CONCLUSIONS: Computed tomography coronary angiography is feasible on a detector-based spectral CT scanner and can improve diagnostic confidence over SECT angiography in patients with an original CAD-RADS score of 3 and higher.

Unusual complication of late presentation deceleration aortic injury.

A 50-year-old patient presented with a stroke. An ascending aortic mass noted by computed tomography was attached to the aortic wall and was found to be thrombus at surgery. Pathologic examination revealed an intraluminal thrombus attached to a focal segment of intimal fragmentation. Sectioning of the aortic wall revealed what were findings consistent with what would be noted with a previously unrecognized traumatic ascending aortic deceleration injury. To our knowledge, this is the first case of a late presentation of deceleration aortic injury, presenting with a thrombus within the ascending aorta.

Online conferencing software in radiology: Recent trends and utility.

Videoconferencing platforms have recently gained wide attention due to the COVID-19 pandemic, both within and outside of the medical community. This article reviews various applications of online meeting technology to the radiologic community, not only in response to the recent pandemic but also thereafter. Various platform features are outlined and discussed, specifically with respect to collaboration, training, and patient care. Platforms reviewed are GoToMeeting, Microsoft Teams, Skype, WebEx, and Zoom.

Diagnosis in a snap: a pilot study using Snapchat in radiologic didactics.

PURPOSE: To evaluate Snapchat, an image-based social media platform, as a tool for emergency radiologic didactics comparing image interpretation on mobile devices with conventional analysis on a classroom screen. MATERIALS AND METHODS: Seven radiology residents (4 juniors, 3 seniors;4 males, 3 females; 28.4 years old, ± 1.7 years) were shown 5 emergent radiologic cases using Snapchat and 5 cases of similar content and duration on a classroom projector over 4 weeks. All images depicted diagnoses requiring immediate communication to ordering physicians. Performance was scored 0-2 (0 = complete miss, 1 = major finding, but missed the diagnosis, 2 = correct diagnosis) by two attending radiologists in consensus. RESULTS: All residents performed better on Snapchat each week. In weeks 1-4, juniors scored 21/40 (52.5%), 23/40 (57.5%), 19/40 (47.5%), and 18/40 (45%) points using Snapchat compared with 13/40 (32.5%), 23/40 (57.5%), 14/40 (35%), and 13/40 (32.5%), respectively, each week by projector, while seniors scored 19/30 (63.3%), 21/30 (70%), 27/30 (90%), and 21/30 (70%) on Snapchat versus 16/30 (53.3%), 19/30 (63.3%), 20/30 (66.7%), and 20/30 (66.7%) on projector. Four-week totals showed juniors scoring 81/160 (50.6%) on Snapchat and 63/160 (39.4%) by projector compared with seniors scoring 88/120 (73.3%) and 75/120 (62.5%), respectively. Performance on Snapchat was statistically, significantly better than via projector during weeks 1 and 3 (p values 0.0019 and 0.0031). CONCLUSION: Radiology residents interpreting emergency cases via Snapchat showed higher accuracy compared with using a traditional classroom screen. This pilot study suggests that Snapchat may have a role in the digital radiologic classroom's evolution.

Social Media in Radiology: Overview and Usefulness of Online Professional #SoMe Profiles.

Social media is a ubiquitous part of society and used by many healthcare professionals, including radiologists. This article prepared by the 2019-2020 Radiology Research Alliance Social Media Task Force presents different uses and benefits of an online professional social media profile. Physician and healthcare-specific issues along with popular platforms such as LinkedIn, Facebook, Twitter, Instagram, and YouTube are used to explore topics including education, branding, research, mentorship, promotion, and leadership.

Radiologic chest CT findings from COVID-19 in Orleans Parish, Louisiana.

Orleans Parish in Louisiana is in the midst of an exponentially increasing number of patient admissions with COVID-19 and respiratory symptoms. Patients have been described having CT findings most consistent with an early-stage (<7 days from symptoms onset) or an advanced stage (8-14 days from symptoms onset). We describe and illustrate those early and advanced stage CT findings from patients with documented COVID-19 who have been admitted to University Medical Center in New Orleans, Louisiana.

Follow-up Recommendation Rates Associated With Spectral Detector Dual-Energy CT of the Abdomen and Pelvis: A Retrospective Comparison to Single-Energy CT.

BACKGROUND: Dual-energy CT image sets have many applications in abdominopelvic imaging but no demonstrated clinical effect. PURPOSE: To determine the effect of dual-energy CT iodine maps on abdominopelvic imaging follow-up recommendation rates. MATERIALS AND METHODS: Retrospective study of abdominopelvic CTs acquired from April 2017 through June 2018. CT reports were analyzed for radiologic follow-up recommendation and follow-up recommendation reason. Follow-up MRI reports were analyzed for benign or nonbenign diagnosis. CT scans with iodine maps (CTIMs) and conventional CT scans (CCTs) subgroups were compared using χ2 testing. RESULTS: In all, 3,221 abdominopelvic CT scans of 2,401 patients (1,326 men, 1,075 women, mean age 54.1 years) were analyzed; 1,423 were CTIMs and 1,798 were CCTs. Follow-up recommendation rates were not significantly different for CTIMs and CCTs (19.5% and 21.4%, respectively, P = .19). Follow-up recommendations because of incomplete diagnosis were significantly lower in CTIMs (9.1%) than in CCTs (11.9%, P = .01). Follow-up recommendations for MRI and PET/CT were significantly lower in CTIMs (9.6%) than CCTs (13.0%, P = .003). Follow-up MRI outcomes (n = 111) were not different between CTIMs (61.2% benign) and CCTs (59.6%, P = .87). CONCLUSION: Dual-energy CT iodine maps are associated with decreased follow-up examinations because of incomplete diagnosis and decreased recommendations for follow-up MRI, suggesting that abdominopelvic iodine maps may benefit patient care and decrease institutional cost.

Dual-energy CT in the obese: a preliminary retrospective review to evaluate quality and feasibility of the single-source dual-detector implementation.

PURPOSE: To determine the feasibility of performing dual-energy CT with a single-source spectral detector system in obese patients. MATERIALS AND METHODS: Retrospective, IRB-approved review of 28 patients weighing ≥ 270 lbs (122 kg) who underwent CT of the abdomen on a single-source spectral detector system was performed. Two blinded, independent radiologists rated relative preference between conventional CT images taken at 120 kVp (CCT120) and monoenergetic 70 keV equivalent (MonoE70) as well as iodine map image quality in the spleen, pancreas, kidneys, and liver. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared between conventional CT and MonoE70 images and correlated with body habitus markers of weight, height, and abdominal diameter. RESULTS: MonoE70 images were preferred by radiologists 100% of the time (1-sample t test, p < 0.0001) over conventional CCT120 images. Noise was significantly lower; SNR and CNR were significantly higher in MonoE70 images than in CCT120 images (paired t tests, p < 0.0001). Mean iodine map rating (scale 1-5) was 4.54 ± 0.58, denoting near homogenous and complete iodine mapping through the spleen, pancreas, kidneys, and liver for the majority of patients. Body habitus markers were not significantly correlated with image preference score; noise; MonoE70 SNR; MonoE70 CNR; change in noise, SNR, or CNR from CCT120 to MonoE70, or iodine map quality; ordinal and linear regression, p = 0.2547, p = 0.6837, p = 0.1888, p = 0.5489, p = 0.9830, p = 0.8849, p = 0.8741, p = 0.1522, respectively. CONCLUSION: The single-source spectral detector implementation of dual-energy CT provides viable, high-quality imaging for obese patients.

On-Site 3-Dimensional Printing and Preoperative Adaptation Decrease Operative Time for Mandibular Fracture Repair.

PURPOSE: The purpose of this study was to compare the intraoperative time and operating room costs between patients with mandibular fractures treated with traditional adaptation and fixation and patients treated with preadapted plates created with on-site 3-dimensionally printed models. PATIENTS AND METHODS: We designed a prospective comparative cohort study for patients with mandibular fractures. The control group received traditional open reduction and internal fixation of their mandibular fractures. For the patients in the experimental group, a 3-dimensional (3D) model of the fractured mandible was made using an on-site 3D printer. The model then underwent osteotomy, if needed, and the plate was adapted to the model, submitted to sterilization, and implanted in the patient. The primary outcome variable was intraoperative plating time, and the secondary outcome variable was operating room cost. The groups were compared by the Wilcoxon signed rank test. RESULTS: The 38 patients included in the study had a mean age of 39.6 years, and male patients comprised 81.6%. The mean time for intraoperative plate adaptation was 22.8 ± 2.1 minutes in the control group and 6.9 ± 0.3 minutes in the experimental, 3D printed group (P < .0001). In the experimental group, 4 patients (21%) required a single intraoperative corrective bend. The calculated average cost per patient based on the average operating costs at our institution was $2,306.45 in the control group and $698.00 in the experimental group. CONCLUSIONS: This study shows that the use of 3D printers for fabrication of models to prebend maxillofacial reconstruction plates is associated with decreased operating room time and costs. Using an on-site 3D printer requires minor start-up and use costs and results in a significant reduction in operating room time, which remains one of the most expensive aspects of facial trauma care.

Atypical Presentation of Extramedullary Plasmacytoma.

BACKGROUND: Plasmacytomas are monoclonal proliferations of plasma cells that typically affect the intramedullary axial skeleton. Imaging findings of an extramedullary plasmacytoma on radiograph and computed tomography can be nonspecific and can resemble other entities such as lymphoma, metastases, chondrosarcomas, or giant cell tumors. CASE REPORT: A 60-year-old female with a medical history of partial complex seizures, hypertension, diabetes, glaucoma, and hyperlipidemia presented with complaints of superficial abdominal pain associated with erythema and swelling for 3 weeks. Computed tomography of her abdomen at time of presentation revealed a 5.8 × 2.7-cm irregularly marginated soft-tissue density just below the umbilicus with an adjacent defect in the midline rectus abdominis. The final pathologic diagnosis was extramedullary plasmacytoma. Treatment during the next year included local radiation, systemic chemotherapy, and an autologous peripheral blood stem cell transplant. Three years after initial diagnosis, the patient presented to the emergency department, and testing revealed new plasmacytomas. The decision was made to proceed with palliative care. CONCLUSION: This case is a unique example of a patient with an extramedullary plasmacytoma with no diagnostic signs of multiple myeloma.

Logistics of Three-dimensional Printing: Primer for Radiologists.

The Association of University Radiologists Radiology Research Alliance Task Force on three-dimensional (3D) printing presents a review of the logistic considerations for establishing a clinical service using this new technology, specifically focused on implications for radiology. Specific topics include printer selection for 3D printing, software selection, creating a 3D model for printing, providing a 3D printing service, research directions, and opportunities for radiologists to be involved in 3D printing. A thorough understanding of the technology and its capabilities is necessary as the field of 3D printing continues to grow. Radiologists are in the unique position to guide this emerging technology and its use in the clinical arena.

Left Atrium Measurements via Computed Tomography Pulmonary Angiogram as a Predictor of Diastolic Dysfunction.

PURPOSE: Left atrium (LA) enlargement on echocardiography may be an indicator of diastolic dysfunction (DD). It is not well known if computed tomography pulmonary angiography (CTPA) can detect DD. METHODS: A total of 127 patients who underwent both CTPA and echo within 48 hours were analyzed retrospectively. Left atrium diameters from CTPA were correlated with echo and evaluated against degrees of DD. Computed tomography pulmonary angiography pulmonary artery (PA)/aorta ratio was analyzed as a tool to detect pulmonary hypertension. RESULTS: There were 42% of patients who had DD. There was a strong correlation between LA size on CTPA and echo (r = 0.78). An LA greater than 4.0 cm gave a sensitivity of 68.1% and specificity of 73.9% for DD detection. A PA/aorta cutoff greater than 0.84 yielded a sensitivity of 84% and specificity of 33% for pulmonary hypertension. CONCLUSIONS: Computed tomography pulmonary angiography measurements of LA and PA/aorta ratio correlate strongly with equivalent findings on echo. We suggest that LA and PA/aorta measurements be included on chest CTPA reports.

Cardiac magnetic resonance imaging in peripartum cardiomyopathy.

BACKGROUND: Peripartum cardiomyopathy (PPCM) is a rare life-threatening condition of unclear etiology. Data on the use of cardiac magnetic resonance (CMR) imaging to characterize PPCM are limited. This study was done to assess the role of CMR imaging for the diagnosis and prognostication of patients with PPCM. METHODS: Medical records of a tertiary medical center were screened for PPCM patients with CMR imaging done within the past 5 years (2006-2011). Images were reviewed by 2 expert radiologists (blinded to clinical data) using cine sequences for chamber function and size, T2-weighted images for the determination of edema (T2-ratio), and late gadolinium enhancement (LGE) sequences for myocardial tissue characterization. RESULTS: Ten PPCM patients (aged 28 ± 6 years, 90% African American) had a total of 15 CMR examinations: 4 in the acute phase (within 7 days of diagnosis) and 11 during follow-up (median, 12 months; range, 1-72 months). Left ventricular ejection fraction was decreased in all 4 initial scans. Elevated T2 ratio (>2) seen in 1 patient decreased on follow-up imaging. LGE was seen in 1 of the 4 acute-phase scans and in 4 of the 11 follow-up phase scans. These 4 patients had multiple readmissions because of heart failure exacerbations and persistently low left ventricular ejection fraction on subsequent echocardiograms. CONCLUSIONS: LGE seems to be associated with a poor prognosis in the setting of PPCM. CMR imaging seems to have promising practical implications in the diagnosis and prognostication of PPCM patients.

MR imaging of the acute abdomen and pelvis: acute appendicitis and beyond.

Acute abdominal and pelvic processes account for more than half of all surgical procedures performed in the emergency setting. Rapid and accurate diagnosis in the emergency department is essential for the appropriate management of these acute conditions. Magnetic resonance (MR) imaging is an attractive modality for diagnostic imaging in patients for whom the risks of radiation or the potential nephrotoxicity of iodinated contrast agents is a major concern, such as pregnant and pediatric patients. MR imaging is most useful for evaluating pregnant patients with acute lower abdominal pain believed to have an extra-uterine cause, such as appendicitis or ovarian torsion. Other patients with other conditions commonly seen in the emergency setting may be better evaluated with another cross-sectional imaging modality. Imaging protocols should be adapted to the constraints of acute illness, with emphasis placed on minimizing the duration of image acquisition, and should include strategies to decrease motion-related artifacts. A prudent approach is to select the imaging modalities that can best depict a particular subset of clinical conditions to help narrow the differential diagnosis. Disadvantages of MR imaging include its high cost, the limited availability of MR imaging systems and trained radiologists, and the incompatibility of MR imaging systems and the equipment used for intensive care and monitoring of patient status.

Magnetic resonance imaging of the gastrointestinal tract.

Comprehensive bowel examination results from the combined use of T2-weighted single-shot and breath hold T1-weighted gradient echo, minus/plus fat suppression, and gadolinium-enhanced 3D gradient echo (3D VIBE, T1 FAME, 3D THRIVE). Gadolinium-enhanced imaging should be performed dynamically, but the venous 60- to 90-second delayed phase images with fat suppression are generally the most valuable. Removal of fat signal for detection of enhancing normal and abnormal structures is critical. Newly available True-FISP (FIESTA, BFFE) sequences obtained in the 2D form can be very helpful in delineation of bowel wall pathology and overall bowel anatomy, particularly when combined with a water-based intraluminal distending agent. Advantages include rapid acquisition, high signal-to-noise, and motion insensitivity. Generalized protocol for comprehensive evaluation of the entire abdomen and pelvis can be used for the following bowel indications: type and severity of inflammatory bowel disease (IBD); identifying enteric abscesses and fistulae; preoperative staging of malignant neoplasms, including rectal carcinoma; differentiating postoperative and radiation therapy changes from recurrent carcinoma; follow-up evaluation of metastases response to localized ablative or systemic chemotherapy. For improved visualization of bowel wall in dedicated examinations, bowel distension should be achieved using either orally or rectally delivered contrast agents to produce either bright or dark lumen. We have found 2D True-FISP without fat suppression superior to 3D True-FISP and to single-shot echo-train sequences to provide a T2-weighted image of bowel morphology. Strengths include: performed without fat suppression results in the very dark bowel wall being sandwiched between intermediate high signal fat adjacent to bowel serosa, and very high lumen signal from water-distending agent; 2D True-FISP provides motion insensitivity that is lost if 3D is used; True-FISP produces better edge sharpness than single-shot echo-train, higher contrast, and resists flow void artifacts commonly seen with single-shot echo-train imaging combined with a water distending agent. Drawbacks of this technique include: artifacts related to extreme sensitivity to field inhomogeneity, including air-soft tissue interfaces at the patient skin surface, and from retained bowel gas; retained bowel gas is dark against dark bowel wall, impairing bowel wall assessment; and True-FISP does not provide sensitivity for edema, which is superior on single-shot echo-train imaging. Small/large bowel indications for MRI include: inflammatory bowel disease, infectious disease including abscess evaluation or for appendicitis, inflammatory conditions including ischemia, and partial obstruction, malnutrition, and neoplasm search.

MR imaging of the liver.

MR imaging is establishing a role as a primary diagnostic technique, with increasing evidence showing MR imaging to have advantages over CT regarding diagnostic sensitivity and specificity for many pathologies of solid organs, bile and pancreatic ducts, bowel, peritoneum, and retroperitoneum. In addition, there are increasing concerns regarding the risks of radiation and iodinated contrast associated with CT imaging of the abdomen. The incidence of contrast-induced nephropathy associated with iodinated contrast used for CT scanning is difficult to ascertain because reporting is spurious and variable in interpretation.

Approach to abdominal imaging at 1.5 Tesla and optimization at 3 Tesla.

This article reviews fundamental principles and sequence techniques that have been used successfully for imaging diseases of the abdomen and pelvis at 1.5 Tesla. This article also introduces concepts and the specific alteration of sequence parameters for optimization of abdominal-pelvic imaging at 3 Tesla.

MR imaging of diffuse liver diseases.

This article discusses MR imaging sequences that are used for the evaluation of diffuse liver diseases, including processes that lead to abnormal lipid metabolization, iron de-position disease, and perfusion abnormalities.