Chest CT has a potential role in the diagnosis, detection of complications, and prognostication of coronavirus disease 2019 (COVID-19). Implementation of appropriate precautionary safety measures, ...chest CT protocol optimization, and a standardized reporting system based on the pulmonary findings in this disease will enhance the clinical utility of chest CT. However, chest CT examinations may lead to both false-negative and false-positive results. Furthermore, the added value of chest CT in diagnostic decision making is dependent on several dynamic variables, most notably available resources (real-time reverse transcription-polymerase chain reaction RT-PCR tests, personal protective equipment, CT scanners, hospital and radiology personnel availability, and isolation room capacity) and the prevalence of both COVID-19 and other diseases with overlapping manifestations at chest CT. Chest CT is valuable to detect both alternative diagnoses and complications of COVID-19 (acute respiratory distress syndrome, pulmonary embolism, and heart failure), while its role for prognostication requires further investigation. The authors describe imaging and managing care of patients with COVID-19, with topics including
chest CT protocol,
chest CT findings of COVID-19 and its complications,
the diagnostic accuracy of chest CT and its role in diagnostic decision making and prognostication, and
reporting and communicating chest CT findings. The authors also review other specific topics, including the pathophysiology and clinical manifestations of COVID-19, the World Health Organization case definition, the value of performing RT-PCR tests, and the radiology department and personnel impact related to performing chest CT in COVID-19.
RSNA, 2020.
•All included studies had a case-control design, which may have resulted in overestimation of diagnostic accuracy.•Most MRI signs have overall high specificity but low sensitivity in diagnosing ...intracranial hypertension.•Transverse sinus stenosis appears to be the most useful sign, because it has high specificity and fairly high sensitivity.
To systematically review the potential value of MRI signs in the assessment of intracranial hypertension (IIH).
MEDLINE and Embase were systematically searched for original studies investigating the accuracy of MRI signs in diagnosing IIH. Methodologic quality of included studies was assessed. Sensitivity and specificity were pooled with a bivariate random-effects model.
Twenty-one studies, comprising a total of 724 patients with IIH, were included. All studies had a case-control design. "Empty" sella (11 studies), posterior displacement of pituitary stalk (2 studies), meningoceles (2 studies), posterior globe flattening (8 studies), optic nerve head protrusion (6 studies), optic nerve enhancement (3 studies), optic nerve sheath distension (12 studies), optic nerve tortuosity (7 studies), slit-like ventricles (4 studies), tight subarachnoid spaces (3 studies), and inferior position of cerebellar tonsils (4 studies) had pooled sensitivity ranging between 6.1% and 68.6%, and pooled specificity ranging between 84.0% and 99.2%. Transverse sinus stenosis (8 studies) had pooled sensitivity of 84.4%; (95% CI: 65.9–93.9%) and pooled specificity of 94.9% (95% CI: 91.7–96.9%).
"Empty" sella, posterior pituitary stalk displacement, meningoceles, posterior globe flattening, optic nerve head protrusion, optic nerve enhancement, optic nerve sheath distension, optic nerve tortuosity, slit-like ventricles, tight subarachnoid spaces, and inferior position of cerebellar tonsils have overall high specificity but low sensitivity. Transverse sinus stenosis appears to be the most useful sign, because it has high specificity and fairly high sensitivity.
Background
The yield of whole‐body MRI for preventive health screening is currently not completely clear.
Purpose
To systematically review the prevalence of whole‐body MRI findings in asymptomatic ...subjects.
Study Type
Systematic review and meta‐analysis.
Subjects
MEDLINE and Embase were searched for original studies reporting whole‐body MRI findings in asymptomatic adults without known disease, syndrome, or genetic mutation. Twelve studies, comprising 5373 asymptomatic subjects, were included.
Field Strength/Sequence
1.5T or 3.0T, whole‐body MRI.
Assessment
The whole‐body MRI literature findings were extracted and reviewed by two radiologists in consensus for designation as either critical or indeterminate incidental finding.
Statistical Tests
Data were pooled using a random effects model on the assumption that most subjects had ≤1 critical or indeterminate incidental finding. Heterogeneity was assessed by the I2 statistic.
Results
Pooled prevalences of critical and indeterminate incidental findings together and separately were 32.1% (95% confidence interval CI: 18.3%, 50.1%), 13.4% (95% CI: 9.0%, 19.5%), and 13.9% (95% CI: 5.4%, 31.3%), respectively. There was substantial between‐study heterogeneity (I2 = 95.6–99.1). Pooled prevalence of critical and indeterminate incidental findings together was significantly higher in studies that included (cardio)vascular and/or colon MRI compared with studies that did not (49.7% 95% CI, 26.7%, 72.9% vs. 23.0% 95% CI, 5.5%, 60.3%, P < 0.001). Pooled proportion of reported verified critical and indeterminate incidental findings was 12.6% (95% CI: 3.2%, 38.8%). Six studies reported false‐positive findings, yielding a pooled proportion of 16.0% (95% CI: 1.9%, 65.8%). None of the included studies reported long‐term (>5‐year) verification of negative findings. Only one study reported false‐negative findings, with a proportion of 2.0%.
Data Conclusion
Prevalence of critical and indeterminate incidental whole‐body MRI findings in asymptomatic subjects is overall substantial and with variability dependent to some degree on the protocol. Verification data are lacking. The proportion of false‐positive findings appears to be substantial.
Level of Evidence: 4
Technical Efficacy: Stage 3
J. Magn. Reson. Imaging 2019;50:1489–1503.
The aim of this study was to systematically review and meta-analyze published data on the diagnostic performance of combined 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography ...(FDG-PET/CT) in the detection of primary tumors in patients with cancer of unknown primary (CUP). A systematic search for relevant studies was performed of the PubMed/MEDLINE and Embase databases. Methodological quality of the included studies was assessed. Reported detection rates, sensitivities and specificities were meta-analyzed. Subgroup analyses were performed if results of individual studies were heterogeneous. The 11 included studies, comprising a total sample size of 433 patients with CUP, had moderate methodological quality. Overall primary tumor detection rate, pooled sensitivity and specificity of FDG-PET/CT were 37%, 84% (95% CI 78–88%) and 84% (95% CI 78–89%), respectively. Sensitivity was heterogeneous across studies (P = 0.0001), whereas specificity was homogeneous across studies (P = 0.2114). Completeness of diagnostic workup before FDG-PET/CT, location of metastases of unknown primary, administration of CT contrast agents, type of FDG-PET/CT images evaluated and way of FDG-PET/CT review did not significantly influence diagnostic performance. In conclusion, FDG-PET/CT can be a useful method for unknown primary tumor detection. Future studies are required to prove the assumed advantage of FDG-PET/CT over FDG-PET alone and to further explore causes of heterogeneity.
Objective
To determine the anticipated contribution of recently published medical imaging literature, including artificial intelligence (AI), on the workload of diagnostic radiologists.
Methods
This ...study included a random sample of 440 medical imaging studies published in 2019. The direct contribution of each study to patient care and its effect on the workload of diagnostic radiologists (i.e., number of examinations performed per time unit) was assessed. Separate analyses were done for an academic tertiary care center and a non-academic general teaching hospital.
Results
In the academic tertiary care center setting, 65.0% (286/440) of studies could directly contribute to patient care, of which 48.3% (138/286) would increase workload, 46.2% (132/286) would not change workload, 4.5% (13/286) would decrease workload, and 1.0% (3/286) had an unclear effect on workload. In the non-academic general teaching hospital setting, 63.0% (277/240) of studies could directly contribute to patient care, of which 48.7% (135/277) would increase workload, 46.2% (128/277) would not change workload, 4.3% (12/277) would decrease workload, and 0.7% (2/277) had an unclear effect on workload. Studies with AI as primary research area were significantly associated with an increased workload (
p
< 0.001), with an odds ratio (OR) of 10.64 (95% confidence interval (CI) 3.25–34.80) in the academic tertiary care center setting and an OR of 10.45 (95% CI 3.19–34.21) in the non-academic general teaching hospital setting.
Conclusions
Recently published medical imaging studies often add value to radiological patient care. However, they likely increase the overall workload of diagnostic radiologists, and this particularly applies to AI studies.
Objective
To investigate the view of clinicians on diagnostic radiology and its future.
Methods
Corresponding authors who published in the
New England Journal of Medicine
and the
Lancet
between 2010 ...and 2022 were asked to participate in a survey about diagnostic radiology and its future.
Results
The 331 participating clinicians gave a median score of 9 on a 0–10 point scale to the value of medical imaging in improving patient-relevant outcomes. 40.6%, 15.1%, 18.9%, and 9.5% of clinicians indicated to interpret more than half of radiography, ultrasonography, CT, and MRI examinations completely by themselves, without consulting a radiologist or reading the radiology report. Two hundred eighty-nine clinicians (87.3%) expected an increase in medical imaging utilization in the coming 10 years, whereas 9 clinicians (2.7%) expected a decrease. The need for diagnostic radiologists in the coming 10 years was expected to increase by 162 clinicians (48.9%), to remain stable by 85 clinicians (25.7%), and to decrease by 47 clinicians (14.2%). Two hundred clinicians (60.4%) expected that artificial intelligence (AI) will not make diagnostic radiologists redundant in the coming 10 years, whereas 54 clinicians (16.3%) thought the opposite.
Conclusion
Clinicians who published in the
New England Journal of Medicine
or the
Lancet
attribute high value to medical imaging. They generally need radiologists for cross-sectional imaging interpretation, but for a considerable proportion of radiographs, their service is not required. Most expect medical imaging utilization and the need for diagnostic radiologists to increase in the foreseeable future, and do not expect AI to make radiologists redundant.
Clinical relevance statement
The views of clinicians on radiology and its future may be used to determine how radiology should be practiced and be further developed.
Key Points
• Clinicians generally regard medical imaging as high-value care and expect to use more medical imaging in the future.
• Clinicians mainly need radiologists for cross-sectional imaging interpretation while they interpret a substantial proportion of radiographs completely by themselves.
• The majority of clinicians expects that the need for diagnostic radiologists will not decrease (half of them even expect that we need more) and does not believe that AI will replace radiologists.
Chest CT may be used for the diagnosis of coronavirus disease 2019 (COVID-19), but clear scientific evidence is lacking. Therefore, we systematically reviewed and meta-analyzed the chest CT imaging ...signature of COVID-19.
What is the chest CT imaging signature of COVID-19 infection?
A systematic literature search was performed for original studies on chest CT imaging findings in patients with COVID-19. Methodologic quality of studies was evaluated. Pooled prevalence of chest CT imaging findings were calculated with the use of a random effects model in case of between-study heterogeneity (predefined as I
≥50); otherwise, a fixed effects model was used.
Twenty-eight studies were included. The median number of patients with COVID-19 per study was 124 (range, 50-476), comprising a total of 3,466 patients. Median prevalence of symptomatic patients was 99% (range, >76.3%-100%). Twenty-seven of the studies (96%) had a retrospective design. Methodologic quality concerns were present with either risk of or actual referral bias (13 studies), patient spectrum bias (eight studies), disease progression bias (26 studies), observer variability bias (27 studies), and test review bias (14 studies). Pooled prevalence was 10.6% for normal chest CT imaging findings. Pooled prevalences were 90.0% for posterior predilection, 81.0% for ground-glass opacity, 75.8% for bilateral abnormalities, 73.1% for left lower lobe involvement, 72.9% for vascular thickening, and 72.2% for right lower lobe involvement. Pooled prevalences were 5.2% for pleural effusion, 5.1% for lymphadenopathy, 4.1% for airway secretions/tree-in-bud sign, 3.6% for central lesion distribution, 2.7% for pericardial effusion, and 0.7% for cavitation/cystic changes. Pooled prevalences of other CT imaging findings ranged between 10.5% and 63.2%.
Studies on chest CT imaging findings in COVID-19 suffer from methodologic quality concerns. More high-quality research is necessary to establish diagnostic CT criteria for COVID-19. Based on the available evidence that requires cautious interpretation, several chest CT imaging findings appear to be suggestive of COVID-19, but normal chest CT imaging findings do not exclude COVID-19, not even in symptomatic patients.
Purpose
To investigate, in a meta-analysis, the frequency of pulmonary embolism (PE) in patients with COVID-19 and whether D-dimer assessment may be useful to select patients for computed tomography ...pulmonary angiography (CTPA).
Methods
A systematic literature search was performed for original studies which reported the frequency of PE on CTPA in patients with COVID-19. The frequency of PE, the location of PE, and the standardized mean difference (SMD) of D-dimer levels between patients with and without PE were pooled by random effects models.
Results
Seventy-one studies were included. Pooled frequencies of PE in patients with COVID-19 at the emergency department (ED), general wards, and intensive care unit (ICU) were 17.9% (95% CI: 12.0–23.8%), 23.9% (95% CI: 15.2–32.7%), and 48.6% (95% CI: 41.0–56.1%), respectively. PE was more commonly located in peripheral than in main pulmonary arteries (pooled frequency of 65.3% 95% CI: 60.0–70.1% vs. 32.9% 95% CI: 26.7–39.0%; OR = 3.540 95% CI: 2.308–5.431%). Patients with PE had significantly higher D-dimer levels (pooled SMD of 1.096 95% CI, 0.844–1.349). D-dimer cutoff levels which have been used to identify patients with PE varied between 1000 and 4800 μg/L.
Conclusion
The frequency of PE in patients with COVID-19 is highest in the ICU, followed by general wards and the ED. PE in COVID-19 is more commonly located in peripheral than in central pulmonary arteries, which suggests local thrombosis to play a major role. D-dimer assessment may help to select patients with COVID-19 for CTPA, using D-dimer cutoff levels of at least 1000 μg/L.
Key Points
•
The frequency of PE in patients with COVID-19 is highest in the ICU, followed by general wards and the ED.
•
PE in COVID-19 is more commonly located in peripheral than in central pulmonary arteries.
•
D-dimer levels are significantly higher in patients with COVID-19 who have PE.
Abstract Purpose To systematically review and meta-analyze the proportion of false-positive lesions at interim and end-of-treatment18 F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) ...in lymphoma using biopsy as reference standard. Materials and Methods Medline was searched for original studies. Methodological quality of included studies was evaluated, and results were meta-analytically summarized using random effects (in case of interstudy heterogeneity I2 ≤ 50%) or fixed effects (in case of no interstudy heterogeneity I2 > 50%). Results Eleven studies, comprising 139 patients who underwent biopsy of an FDG-avid lesion during or after completion of antilymphoma treatment, were included. Overall methodological quality was moderate. The proportion of false-positive results among all biopsied FDG-avid lesions at PET performed during of after completion of treatment ranged between 7.7% and 90.5% (the vast majority was due to inflammatory changes), with a weighted summary proportion (random effects, I2 = 75.7%) of 55.7% (95% confidence interval CI: 32.6-76.6%). There were no available studies on interim FDG-PET in Hodgkin lymphoma. The pooled summary false-positive proportions were 83.0% (95% CI: 72.0%-90.2%) for interim FDG-PET in non-Hodgkin lymphoma (fixed effects, I2 = 27.7%), 23.1% (95% CI: 4.7%-64.5%) for end-of-treatment FDG-PET in Hodgkin lymphoma (random effects; I2 = 67.1%), and 31.5% (95% CI: 3.9%-83.9%) for end-of-treatment FDG-PET in non-Hodgkin lymphoma (random effects, I2 = 68.3%). Conclusion Both interim and end-of-treatment FDG-PET scans in patients with lymphoma suffer from a very high number of false-positive FDG-avid lesions. This finding, in combination with the previously reported high number of false-negative FGD-PET scans for residual disease detection, suggests that the role of interim and end-of-treatment FDG-PET should be reconsidered.
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