Multidetector CT of Laryngeal Injuries: Principles of Injury Recognition.

Blunt laryngeal trauma is associated with high morbidity and mortality. However, owing to their relatively rare occurrence, laryngeal injuries may be missed or underdiagnosed. Even subtle abnormalities at multidetector CT may correspond to significant functional abnormalities. It is important to understand normal CT laryngeal anatomy and develop a systematic review of the cervical soft tissues and laryngeal skeleton in patients who undergo screening CT cervical spine or other neck examinations in the setting of trauma, such as CT angiography. Multidetector CT findings of the normal larynx are reviewed, and blunt laryngeal injuries including soft-tissue edema, hematoma, mucosal lacerations, cartilage fracture, cricoarytenoid dislocation, and vocal fold paralysis are presented. The radiologist plays an important role in diagnosis and may be the first to identify laryngeal injuries that are not evident at physical examination. This article reviews normal laryngeal anatomy, presents various blunt laryngeal injuries at multidetector CT with case examples, discusses the role of multidetector CT in acute management, and describes pitfalls of diagnosis. ©RSNA, 2019.

Thinking beyond pannus: a review of retro-odontoid pseudotumor due to rheumatoid and non-rheumatoid etiologies.

Retro-odontoid pseudotumor, or mass-like retro-odontoid soft tissue thickening, is an uncommon but important imaging finding that may be associated with rheumatoid arthritis, crystal deposition diseases, as well as non-inflammatory conditions such as cervical degenerative changes and mechanical alterations. Retro-odontoid pseudotumor is commonly associated with atlantoaxial microinstability or subluxation. MRI and CT have an important role in the detection and diagnosis of retro-odontoid pseudotumor. However, due to a wide range of imaging characteristics and ambiguous etiology, it is a frequently misunderstood entity. The purpose of this article is to review relevant anatomy of the craniocervical junction; describe various imaging appearances, pathophysiology and histology in both rheumatoid and non-rheumatoid etiologies; and discuss differential diagnosis of retro-odontoid pseudotumor in order to help guide clinical management.

Color postprocessing of conventional CT images: preliminary results in assessment of nondisplaced proximal femoral fractures.

PURPOSE: The purpose of this study was to demonstrate the diagnostic performance and effect on reader confidence of a custom computed tomography (CT) color postprocessing algorithm for assessment of nondisplaced proximal femoral fractures. MATERIALS AND METHODS: Four radiologists, including two PGY-3 radiology residents and two emergency radiologists, independently interpreted 30 CT examinations of the hip and/or pelvis performed for trauma, consisting of a total of 15 cases positive for nondisplaced hip fracture and 15 age and sex-matched controls. Images were reviewed first with conventional CT images and after at least 8 weeks, all images were reviewed again with the addition of coronal color postprocessed images. Sensitivity and specificity were compared with McNemar's test, and diagnostic confidence was compared with paired t tests. RESULTS: There was no significant difference in diagnostic performance between conventional and postprocessed images, although there was nominally increased sensitivity and decreased specificity with the postprocessed images: for all readers, the sensitivity and specificity for conventional images was 88.3 and 95.0%, compared to 93.3% (p = 0.25) and 88.3% (p = 0.14) for postprocessed images. Three of four readers (including both attending radiologists) reported an increase in confidence with postprocessed images for cases negative for fracture (10-point confidence scale of 7.25 for conventional images, compared to 8.2 for postprocessed images for all readers, p = 0.0053). There was no difference in diagnostic confidence for cases positive for fracture. CONCLUSIONS: A custom color CT postprocessing algorithm did not demonstrate a significant difference in diagnostic performance for assessment of nondisplaced proximal femoral fractures within the limitations of a relatively small sample size; however, postprocessing increases confidence of experienced readers in cases negative for fracture.

Association Between CT Angiogram Collaterals and CT Perfusion in the Interventional Management of Stroke III Trial.

BACKGROUND AND PURPOSE: Collateral flow can determine ischemic core and tissue at risk. Using the Interventional Management of Stroke (IMS) III trial data, we explored the relationship between computed tomography angiogram (CTA) collateral status and CT perfusion (CTP) parameters. METHODS: Baseline CTA collaterals were trichotomized as good, intermediate, and poor, and CTP studies were analyzed to quantify ischemic core, tissue at risk, and mismatch ratios. Kruskal-Wallis and Spearman tests were used to measure the strength of association and correlation between CTA collaterals and CTP parameters. RESULTS: A total of 95 patients had diagnostic CTP studies in the IMS III trial. Of these, 53 patients had M1/M2 middle cerebral artery±intracranial internal carotid artery occlusion, where baseline CTA collateral grading was performed. CTA collaterals were associated with smaller CTP measured ischemic core volume (P=0.0078) and higher mismatch (P=0.0004). There was moderate negative correlation between collaterals and core (rs=-0.45; 95% confidence interval, -0.64 to -0.20) and moderate positive correlation between collaterals and mismatch (rs=0.53; 95% confidence interval, 0.29-0.71). CONCLUSION: Better collaterals were associated with smaller ischemic core and higher mismatch in the IMS III trial. Collateral assessment and perfusion imaging identify the same biological construct about ischemic tissue sustenance.

Endovascular Thrombolysis in the Management of Iliofemoral Thrombosis in Children: A Multi-Institutional Experience.

PURPOSE: To evaluate technical feasibility, complications, and clinical outcomes of endovascular thrombolysis for iliofemoral thrombosis at two tertiary-care children's hospitals. MATERIALS AND METHODS: Institutional review board-approved retrospective review from March 2003 through June 2013 showed that venous thrombolysis for iliofemoral thrombosis was performed in 57 children (64 limbs) with a median age of 16.1 years (mean age, 14.5 y; range, 1.0-17.8 y). Techniques included catheter-directed thrombolysis (CDT), percutaneous mechanical thrombectomy (PMT), and pharmacomechanical catheter-directed thrombolysis (PCDT) with adjunctive angioplasty and/or stent placement. Villalta and modified Villalta scales were applied retrospectively to follow-up data to assess postthrombotic syndrome (PTS). RESULTS: Technical success (≥ 50% thrombolysis) rate was 93.7%: grade III (100%) in 19 limbs, grade II (50%-99%) in 41 limbs, and grade I (< 50%) in four limbs. Techniques included CDT with PCDT (32.8%) or PMT (35.9%), CDT alone (26.6%), PCDT alone (4.7%) or with adjunctive angioplasty (54.7%), and stent placement (6.3%). Mean duration of CDT was 36.5 hours (range, 2.9-89.6 h). There was one major complication (1.8%) of bleeding requiring transfusion. Minor complications (ie, bleeding) occurred in seven patients (12.2%). Median follow-up was 1.5 years (range, 30 d to 7 y). Seven patients underwent repeat thrombolysis for recurrent thrombosis. The PTS rate was 59.3% per modified Villalta scale but only 2.1% per Villalta scale. CONCLUSIONS: Endovascular thrombolysis is technically feasible and safe for iliofemoral thrombosis in children. Variable results were seen with two scales to assess PTS, suggesting an acute need for standardization of outcome measurement in children.

Youthful memory capacity in old brains: anatomic and genetic clues from the Northwestern SuperAging Project.

The Northwestern University SuperAging Project recruits community dwellers over the age of 80 who have unusually high performance on tests of episodic memory. In a previous report, a small cohort of SuperAgers was found to have higher cortical thickness on structural MRI than a group of age-matched but cognitively average peers. SuperAgers also displayed a patch of ACC where cortical thickness was higher than in 50- to 60-year-old younger cognitively healthy adults. In additional analyses, some SuperAgers had unusually low densities of age-related Alzheimer pathology and unusually high numbers of von Economo neurons in the anterior cingulate gyrus. SuperAgers were also found to have a lower frequency of the ɛ4 allele of apolipoprotein E than the general population. These preliminary results show that above-average memory capacity can be encountered in advanced age. They also offer clues to potential biological factors that may promote resistance to age-related involutional changes in the structure and function of the brain.

Exacerbation of Inequities in Use of Diagnostic Radiology During the Early Stages of Reopening After COVID-19.

OBJECTIVE: Assess diagnostic radiology examination utilization and associated social determinants of health during the early stages of reopening after state-mandated shutdown of nonurgent services because of coronavirus disease 2019 (COVID-19). METHODS: This institutional review board-approved, retrospective study assessed all patients with diagnostic radiology examinations performed at an academic medical center with eight affiliated outpatient facilities before (January 1, 2020, to March 8, 2020) and after (June 7, 2020, to July 15, 2020) the COVID-19 shutdown. Examinations during the shut down (March 9, 2020, to June 6, 2020) were excluded. Patient-specific factors (eg, race, ethnicity), imaging modalities, and care settings were extracted from the Research Data Warehouse. Primary outcome was the number of diagnostic radiology examinations per day compared pre- and post-COVID-19 shutdown. Univariate analysis and multivariable logistic regression determined features associated with completing an examination. RESULTS: Despite resumption of nonurgent services, marked decrease in radiology examination utilization persisted in all care settings post-COVID-19 shutdown (869 examinations per day preshutdown [59,080 examinations in 68 days] versus 502 examinations per day postshutdown [19,594 examinations in 39 days]), with more significantly decreased odds ratios for having examinations in inpatient and outpatient settings versus in the emergency department. Inequities worsened, with patients from communities with high rates of poverty, unemployment, and chronic disease having significantly lower odds of undergoing radiology examinations post-COVID-19 shutdown. Patients of Asian race and Hispanic ethnicity had significantly lower odds ratios for having examinations post-COVID-19 shutdown compared with White and non-Hispanic patients, respectively. DISCUSSION: The COVID-19 pandemic has exacerbated known pre-existing inequities in diagnostic radiology utilization. Resources should be allocated to address subgroups of patients who may be less likely to receive necessary diagnostic radiology examinations, potentially leading to compromised patient safety and quality of care.

Quantifying Impact of Disruption to Radiology Education During the COVID-19 Pandemic and Implications for Future Training.

PURPOSE: The aim of this study was to assess the impact on radiology resident education due to the COVID-19 pandemic in order to inform future educational planning. METHODS: During a 10-week study period from March 16 to May 22, 2020, changes to educational block-weeks (BW) of first through fourth year residents (R1-4) were documented as disrupted in the setting of the COVID-19 pandemic. The first 5 weeks and the second 5 weeks were evaluated separately for temporal differences. Overall and mean disrupted BW per resident were documented. Wilcoxon rank-sum tests were used to assess pairwise differences between classes with Bonferroni-adjusted P-values, as well as differences in the early versus later phase of the pandemic. RESULTS: Of 373 BW, 56.6% were assigned to virtual curriculum, 39.4% radiology clinical duties, 2.9% illness, and 1.1% reassignment. Scheduling intervention affected 6.2 ± 2.3 (range 1-10) mean BW per resident over the 10-week study period. The R3 class experienced the largest disruption, greater than the R2 classes, and statistically significantly more than the R1 and R4 classes (both P < 0.05). The second half of the pandemic caused statistically significantly more schedule disruptions than the first half (P = 0.009). DISCUSSION: The impact of COVID-19 pandemic varied by residency class year, with the largest disruption of the R3 class and the least disruption of the R4 class. To optimize future educational opportunities, shifting to a competency-based education paradigm may help to achieve proficiency without extending the length of the training program.

Beyond business as usual: Radiology residency educational response to the COVID-2019 pandemic.

The COVID-19 pandemic has disrupted standard hospital operations and diagnostic radiology resident education at academic medical centers across the country. Deferment of elective surgeries and procedures coupled with a shift of resources toward increased inpatient clinical needs for the care of COVID-19 patients has resulted in substantially decreased imaging examinations at many institutions. Additionally, both infection control and risk mitigation measures have resulted in minimal on-site staffing of both trainees and staff radiologists at many institutions. As a result, residents have been placed in nonstandard learning environments, including working from home, engaging in a virtual curriculum, and participating in training sessions in preparation for potential reassignment to other patient care settings. Typically, for residents to gain the necessary knowledge, skills, and experience to practice independently upon graduation, radiology training programs must provide an optimal balance between resident education and clinical obligations. We describe our experience adapting to the challenges in educational interruptions and clinical work reassignments of 41 interventional and diagnostic radiology residents at a large academic center. We highlight opportunities for collaboration and teamwork in creatively adjusting and planning for the short and long-term impact of the pandemic on resident education. This experience shows how the residency educational paradigm was shifted during a pandemic and can serve as a template to address future disruptions.

Radiology Workload Changes During the COVID-19 Pandemic: Implications for Staff Redeployment.

RATIONALE AND OBJECTIVES: Quantify changes in total and by-subspecialty radiology workload due to deferring nonurgent services during the initial COVID-19 pandemic, and describe operational strategies implemented due to shifts in priority. MATERIALS AND METHODS: This retrospective, Institutional Review Board-exempt, study was performed between February 3, 2020 and April 19, 2020 at a large academic medical center. During March 9-15 (intervention period), nonurgent outpatient service deferments began. Five-week periods pre- (baseline) and postintervention (COVID) were defined. Primary outcomes were radiology volume (reports per day) overall and in 11 subspecialty divisions. Linear regression assessed relationship between baseline vs. COVID volumes stratified by division. Secondary outcomes included changes in relative value units (RVUs), inpatient and outpatient volumes. RESULTS: There were 62,791 baseline reports vs. 23,369 during COVID; a 60% overall precipitous volume decrease (p < 0.001). Mean volume decrease pre- and during-COVID was significant (p < 0.001) amongst all individual divisions. Mean volume decrease differed amongst divisions: Interventional Radiology experienced least disruption (29% volume decrease), 7 divisions experienced 40%-60% decreases, and Musculoskeletal, Breast, and Cardiovascular imaging experienced >75% volume decrease. Total RVUs decreased 60% (71,186 baseline; 28,476 COVID). Both outpatient and inpatient report volumes decreased; 72% (41,115 baseline; 11,326 COVID) and 43% (12,626 baseline vs. 6,845 COVID), respectively. In labor pool tracking data, 21.8% (162/744) total radiology employees were reassigned to other hospital duties during the intervention period. CONCLUSION: Precipitous radiology workload reductions impacted subspecialty divisions with marked variation. Data-driven operational decisions during COVID-19 assisted workflow and staffing assignment changes. Ongoing adjustments will be needed as healthcare systems transition operations to a "new normal."

Atlanto-axial Pannus in Patients with and without Rheumatoid Arthritis.

OBJECTIVE: Pannus formation in the atlanto-axial joint is a well-recognized complication of rheumatoid arthritis (RA). Occasionally, atlanto-axial pannus is reported when patients without a history of RA undergo magnetic resonance imaging (MRI) of the cervical spine. We sought to further characterize these patients. METHODS: The Partners HealthCare Research Patient Data Registry was free-text searched for "atlanto-axial" AND "pannus" in cervical spine MRI reports from 2001 to 2015. Cases with MRI reports describing pannus were reviewed. Clinical data were extracted by chart review in cases with confirmed atlanto-axial pannus (n = 105). RESULTS: Twenty-nine patients (27.6%) had RA, all of whom except one carried this diagnosis at the time of the MRI scan. Only 1 of 77 patients without a history of RA was subsequently diagnosed with RA (1.3%, 95% CI 0.1-7.0%, median followup 3.6 yrs). Non-RA patients were significantly older (median age 79 vs 63 yrs, p < 0.0001), less frequently female (55% vs 86%, p = 0.0032), and more likely to have undergone prior cervical spine surgery (18% vs 0%, p = 0.016) compared with RA patients. Thirty-four non-RA patients (44.7%) either had a clinical diagnosis of calcium pyrophosphate dihydrate disease (CPPD) or imaging evidence for tissue calcification. There were no significant differences in age or sex between the CPPD subgroup and other non-RA patients. Twenty-eight patients (26.7%) underwent cervical spine surgery. CONCLUSION: Patients without RA diagnosis and incidental atlanto-axial pannus on cervical spine MRI are unlikely to have previously unrecognized RA. Degenerative disease and tissue calcification may contribute to pannus formation in these patients.

Addressing the challenges of sleeve gastrectomy in end-stage renal disease: Analysis of 100 consecutive renal failure patients.

BACKGROUND: While previous studies have demonstrated short-term efficacy of laparoscopic sleeve gastrectomy in candidates awaiting renal transplantation, the combination of morbid obesity and end-stage renal disease presents unique challenges to perioperative care. We demonstrate how increasing experience and the development of postoperative care guidelines can improve outcomes in this high-risk population. METHODS: Single-center medical records were reviewed for renal transplantation candidates undergoing laparoscopic sleeve gastrectomy between 2011 and 2015 by a single surgeon. Postoperative care protocols were established and continually refined throughout the study period, including a multidisciplinary approach to inpatient management and hospital discharge planning. The first 100 laparoscopic sleeve gastrectomy patients were included and divided into 4 equal cohorts based on case sequence. RESULTS: Compared with the first 25 patients undergoing laparoscopic sleeve gastrectomy, the last 25 patients had shorter operative times (97.8 ± 27.9 min vs 124.2 ± 33.6 min), lower estimated blood loss (6.6 ± 20.8 mL vs 34.0 ± 38.1 mL), and shorter hospital duration of stay (1.7 ± 2.1 days vs 2.9 ± 0.7 days) (P < .01 each). Readmission rates, complications, and 1-year mortality did not differ significantly. CONCLUSION: Increasing experience and the development of clinical care guidelines in this high-risk population is associated with reduced health care resource utilization and improved perioperative outcomes.