Multisystem Assessment of the Imaging Manifestations of Coagulopathy in Hospitalized Patients With Coronavirus Disease (COVID-19).

BACKGROUND. Coronavirus disease (COVID-19) is known to be associated with a distinct form of coagulopathy. OBJECTIVE. The purpose of this study was to describe the imaging manifestations of COVID-19-associated coagulopathy across anatomic sites and modalities in hospitalized patients and to identify clinical variables associated with positive imaging findings. METHODS. We conducted a retrospective review of consecutive adult patients with COVID-19 admitted to our hospital over a 3-week period. Data on patient demographics, hematologic values, cross-sectional imaging examinations, and clinical outcomes (death and intubation) were collected. Imaging was reviewed for manifestations of coagulopathy. Multivariable logistic regression analyses were performed to assess associations of patient demographics, hematologic markers, and outcomes with the need for imaging and imaging manifestations of coagulopathy. RESULTS. Of 308 hospitalized patients with COVID-19, 142 (46%) underwent 332 cross-sectional imaging examinations. Of these, 37 (26%) had imaging results positive for coagulopathy. The most common imaging manifestations of coagulopathy were pulmonary embolus (n = 21) on contrast-enhanced CT or CTA, thrombus in the upper- or lower-extremity veins (n = 13) on Doppler ultrasound, end-organ infarction in the bowel (n = 4) and kidney (n = 4) on contrast-enhanced CT, and thrombus or parenchymal infarction in the brain (n = 2) on contrast-enhanced CTA or MRI with MRA. Among patients with imaging results positive for coagulopathy, eight (22%) had multisite involvement. Thrombi were multifocal in four of five patients with positive upper-extremity and three of eight patients with positive lower-extremity examination results and involved superficial veins, deep veins, or both. In multivariable analysis, intubation (p < .001) and prolonged prothrombin time (p = .04) were significantly associated with undergoing imaging. No patient variable was significantly associated with imaging results positive for coagulopathy (p > .05). CONCLUSION. Imaging commonly shows manifestations of coagulopathy in hospitalized patients with COVID-19. Over one-fifth of patients with such manifestations show multisite involvement. Clinical variables poorly predict which patients have positive imaging results, indicating a complementary role of imaging in detecting COVID-19-associated coagulopathy. CLINICAL IMPACT. In patients with COVID-19 with suspected systemic coagulopathy, pulmonary CTA, extremity Doppler ultrasound, contrast-enhanced abdominal CT, and contrast-enhanced brain MRI and MRA may all be appropriate in the absence of imaging contraindications.

Automated assessment of COVID-19 pulmonary disease severity on chest radiographs using convolutional Siamese neural networks.

Purpose To develop an automated measure of COVID-19 pulmonary disease severity on chest radiographs (CXRs), for longitudinal disease evaluation and clinical risk stratification. Materials and Methods A convolutional Siamese neural network-based algorithm was trained to output a measure of pulmonary disease severity on anterior-posterior CXRs (pulmonary x-ray severity (PXS) score), using weakly-supervised pretraining on ~160,000 images from CheXpert and transfer learning on 314 CXRs from patients with COVID-19. The algorithm was evaluated on internal and external test sets from different hospitals, containing 154 and 113 CXRs respectively. The PXS score was correlated with a radiographic severity score independently assigned by two thoracic radiologists and one in-training radiologist. For 92 internal test set patients with follow-up CXRs, the change in PXS score was compared to radiologist assessments of change. The association between PXS score and subsequent intubation or death was assessed. Results The PXS score correlated with the radiographic pulmonary disease severity score assigned to CXRs in the COVID-19 internal and external test sets (ρ=0.84 and ρ=0.78 respectively). The direction of change in PXS score in follow-up CXRs agreed with radiologist assessment (ρ=0.74). In patients not intubated on the admission CXR, the PXS score predicted subsequent intubation or death within three days of hospital admission (area under the receiver operator characteristic curve=0.80 (95%CI 0.75-0.85)). Conclusion A Siamese neural network-based severity score automatically measures COVID-19 pulmonary disease severity in chest radiographs, which can be scaled and rapidly deployed for clinical triage and workflow optimization.

Automated Assessment and Tracking of COVID-19 Pulmonary Disease Severity on Chest Radiographs using Convolutional Siamese Neural Networks.

PURPOSE: To develop an automated measure of COVID-19 pulmonary disease severity on chest radiographs (CXRs), for longitudinal disease tracking and outcome prediction. MATERIALS AND METHODS: A convolutional Siamese neural network-based algorithm was trained to output a measure of pulmonary disease severity on CXRs (pulmonary x-ray severity (PXS) score), using weakly-supervised pretraining on ∼160,000 anterior-posterior images from CheXpert and transfer learning on 314 frontal CXRs from COVID-19 patients. The algorithm was evaluated on internal and external test sets from different hospitals (154 and 113 CXRs respectively). PXS scores were correlated with radiographic severity scores independently assigned by two thoracic radiologists and one in-training radiologist (Pearson r). For 92 internal test set patients with follow-up CXRs, PXS score change was compared to radiologist assessments of change (Spearman ρ). The association between PXS score and subsequent intubation or death was assessed. Bootstrap 95% confidence intervals (CI) were calculated. RESULTS: PXS scores correlated with radiographic pulmonary disease severity scores assigned to CXRs in the internal and external test sets (r=0.86 (95%CI 0.80-0.90) and r=0.86 (95%CI 0.79-0.90) respectively). The direction of change in PXS score in follow-up CXRs agreed with radiologist assessment (ρ=0.74 (95%CI 0.63-0.81)). In patients not intubated on the admission CXR, the PXS score predicted subsequent intubation or death within three days of hospital admission (area under the receiver operating characteristic curve=0.80 (95%CI 0.75-0.85)). CONCLUSION: A Siamese neural network-based severity score automatically measures radiographic COVID-19 pulmonary disease severity, which can be used to track disease change and predict subsequent intubation or death.

FDG-PET for Assessment of Endometrial and Vulvar Cancer.

Fluorodeoxyglucose positron emission tomography computed tomography (FDG-PET/CT) provides a comprehensive whole body evaluation in patients with endometrial and vulvar cancer. Here, we discuss the role of FDG-PET/CT in defining the disease extent in patients presenting with these cancers. Detection of lymph node and distant metastases has implications for staging, treatment planning, and patient prognosis. Procedures for image acquisition and interpretation for optimum accuracy and essential elements that should be included in the PET-CT report are described. Common imaging pitfalls are presented and illustrated with examples.

Immune-related tumour response assessment criteria: a comprehensive review.

Growing emphasis on precision medicine in oncology has led to increasing use of targeted therapies that encompass a spectrum of drug classes including angiogenesis inhibitors, immune modulators, signal transduction inhibitors, DNA damage modulators, hormonal agents etc. Immune therapeutic drugs constitute a unique group among the novel therapeutic agents that are transforming cancer treatment, and their use is rising. The imaging manifestations in patients on immune therapies appear to be distinct from those typically seen with conventional cytotoxic therapies. Patients on immune therapies may demonstrate a delayed response, transient tumour enlargement followed by shrinkage, stable size, or initial appearance of new lesions followed by stability or response. These newer patterns of response to treatment have rendered conventional criteria such as World Health Organization and response evaluation criteria in solid tumours suboptimal in monitoring changes in tumour burden. As a consequence, newer imaging response criteria such as immune-related response evaluation criteria in solid tumours and immune-related response criteria are being implemented in many trials to effectively monitor patients on immune therapies. In this review, we discuss the traditional and new imaging response criteria for evaluation of solid tumours, review the outcomes of various articles which compared traditional criteria with the new immune-related criteria and discuss pseudo-progression and immune-related adverse events.

Body CT scanning in young adults: examination indications, patient outcomes, and risk of radiation-induced cancer.

PURPOSE: To quantify patient outcome and predicted cancer risk from body computed tomography (CT) in young adults and identify common indications for the imaging examination. MATERIALS AND METHODS: This retrospective multicenter study was HIPAA compliant and approved by the institutional review boards of three institutions, with waiver of informed consent. The Research Patient Data Registry containing patient medical and billing records of three university-affiliated hospitals in a single metropolitan area was queried for patients 18-35 years old with a social security record who underwent chest or abdominopelvic CT from 2003 to 2007. Patients were analyzed according to body part imaged and scanning frequency. Mortality status and follow-up interval were recorded. The Biologic Effects of Ionizing Radiation VII method was used to calculate expected cancer incidence and death. Examination indication was determined with associated ICD-9 diagnostic code; 95% confidence intervals for percentages were calculated, and the binomial test was used to compare the difference between percentages. RESULTS: In 21 945 patients, 16 851 chest and 24 112 abdominopelvic CT scans were obtained. During the average 5.5-year (± 0.1 [standard deviation]) follow-up, 7.1% (575 of 8057) of chest CT patients and 3.9% (546 of 13 888) of abdominal CT patients had died. In comparison, the predicted risk of dying from CT-induced cancer was 0.1% (five of 8057, P < .01) and 0.1% (eight of 12 472, P < .01), respectively. The most common examination indications were cancer and trauma for chest CT and abdominal pain, trauma, and cancer for abdominopelvic CT. Among patients without a cancer diagnosis in whom only one or two scans were obtained, mortality and predicted risk of radiation-induced cancer death were 3.6% (215 of 5914) and 0.05% (three of 5914, P < .01) for chest CT and 1.9% (219 of 11 291) and 0.1% (six of 11 291, P < .01) for abdominopelvic CT. CONCLUSION: Among young adults undergoing body CT, risk of death from underlying morbidity is more than an order of magnitude greater than death from long-term radiation-induced cancer.

When does a radiologist's recommendation for follow-up result in high-cost imaging?

PURPOSE: To measure the proportion of high-cost imaging generated by a radiologist's recommendation and to identify the imaging findings resulting in follow-up. MATERIALS AND METHODS: This retrospective HIPAA-compliant study had institutional review board approval, with waiver of informed consent. A recommended examination was defined as one performed within a single episode of care (defined as fewer than 60 days after the initial imaging) following a radiologist's recommendation in a prior examination report. Chest and abdominal computed tomography (CT), brain and lumbar spine magnetic resonance (MR) imaging, and body positron emission tomography were included for analysis. From a database of all radiology examinations (approximately 200,000) at one institution over a 6-month period, a computerized search identified all high-cost examinations that were preceded by an examination containing a radiologist recommendation. Medical records were reviewed to verify accuracy of the recommending-recommended examination pairs and to determine the reason for the radiologist's recommendation. For proportions, 95% confidence intervals were calculated. RESULTS: Overall, 1558 of 29,232 (5.3%) high-cost examinations followed a radiologist's recommendation. Chest CT was the high-cost examination most often resulting from a radiologist's recommendation (878 of 9331, 9.4%), followed by abdominal CT (390 of 10,258, 3.8%) and brain MR imaging (222 of 6436, 3.4%). The examination types with the highest numbers of follow-up examinations were chest radiography (n=431), chest CT (n=410), abdominal CT (n=214), and abdominal ultrasonography (n=120). The most common findings resulting in follow-up were pulmonary nodules or masses (559 of 1558, 35.9%), other pulmonary abnormalities (150 of 1558, 9.6%), adenopathy (103 of 1558, 6.6%), renal lesions (101 of 1558, 6.5%), and negative examination findings (101 of 1558, 6.5%). CONCLUSION: Radiologists' recommendations account for only a small proportion of outpatient high-cost imaging examinations. Pulmonary nodule follow-up is the most common cause for radiologist-generated examinations.

ACR Appropriateness Criteria® assessment of gravid cervix.

It is well recognized that preterm birth is the leading cause of perinatal mortality and morbidity. There is a significant association between cervix length and preterm birth risk. Most authorities consider a cervical length <3 cm as the lower limit of normal. A cervical length >3 cm has a high negative predictive value for delivery less than 34 weeks. A cervical length of <15 mm is moderately predictive (∼ 70%) of preterm birth within 48 hours. Cervical length is normally distributed and should remain relatively constant until the third trimester. Transabdominal US is the least reliable method of cervical length assessment. The most reliable method of documenting cervical length is transvaginal ultrasound (TVUS). Transperineal US is an alternative for imaging if TVUS is contraindicated, such as with premature rupture of membranes. However, the resolution is decreased compared to TVUS. Short cervix length is the single most important predictive finding for premature delivery. This observation should prompt consultation for high risk obstetrical care and consideration of other management options such as cerclage or activity restriction.The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed biennially by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging.

Malignant tumors of the female pelvic floor: self-assessment module.

The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of malignant tumors of the female pelvic floor and the imaging features that determine therapy.

MRI and PET/CT for triaging stage IB clinically operable cervical cancer to appropriate therapy: decision analysis to assess patient outcomes.

OBJECTIVE: We evaluated the ability of pretreatment MRI and PET/CT to improve outcomes for patients with clinically staged International Federation of Gynecology and Obstetrics (FIGO) IB cervical cancer. MATERIALS AND METHODS: We developed a decision-analytic model to predict outcomes for a hypothetical patient cohort with FIGO IB cervical cancer who underwent pretreatment MRI, PET/CT, MRI and PET/CT, or no further imaging (direct pursuance of surgery). The model incorporated imaging performance, underlying parametrial extension and lymph node involvement, surgery and chemoradiation treatment options, and survival penalties from incorrect assessment of disease extent. Three outcomes were compared: 5-year overall survival, percentage of patients receiving correct primary therapy, and percentage of patients spared "trimodality therapy" (surgery followed by chemoradiation). Sensitivity analysis was performed to assess the effects of model uncertainty on outcomes. RESULTS: The preferred imaging strategy depended on the outcome studied. Five-year overall survival was comparable across strategies but was highest with the no-imaging strategy (92.37%) and with PET/CT (92.36%) and lowest with MRI (92.30%). Triage to correct primary therapy was highest with PET/CT (89.27%) and lowest with MRI (68.21%). Avoidance of trimodality therapy was highest with combined MRI and PET/CT (95.01%) and lowest with the no-imaging strategy (82.32%). Results were somewhat sensitive to imaging test performance characteristics but stable across most parameter ranges tested. CONCLUSION: Pretreatment imaging of FIGO IB cervical cancer patients can optimize triage to appropriate therapy. Although imaging does not appear to improve survival, PET/CT maximizes patient triage to correct therapy, and combined MRI and PET/CT spares the most patients unnecessary trimodality therapy.

Algorithmic workup of abnormal vaginal bleeding with endovaginal sonography and sonohysterography: self-assessment module.

The educational objectives for this self-assessment module on endovaginal sonography and sonohysterography are for the participant to exercise, self-assess, and improve his or her understanding of the imaging evaluation of abnormal vaginal bleeding and to gain familiarity with the algorithm for the workup for endometrial disorders.

Does radiologist recommendation for follow-up with the same imaging modality contribute substantially to high-cost imaging volume?

PURPOSE: To retrospectively measure repeat rates for high-cost imaging studies, determining their causes and trends, and the impact of radiologist recommendations for a repeat examination on imaging volume. MATERIALS AND METHODS: This HIPAA-compliant study had institutional review board approval, with waiver of informed consent. Repeat examination was defined as a same-modality examination performed in the same patient within 0 days to 7 months of a first examination. From a database of all radiology examinations (>2.9 million) at one institution from May 1996 to June 2003, a computerized search identified head, spine, chest, and abdominal computed tomographic (CT), brain and spine magnetic resonance (MR) imaging, pelvic ultrasonography (US), and nuclear cardiology examinations with a prior examination of the same type within 7 months. Examination pairs were subdivided into studies repeated at less than 2 weeks, between 2 weeks and 2 months, or between 2 and 7 months. Automated classification of radiology reports revealed whether a repeat examination from June 2002 to June 2003 had been preceded by a radiologist recommendation on the prior report. Trends over time were analyzed with linear regression, and 95% confidence intervals were calculated. RESULTS: Between July 2002 and June 2003, 31 111 of 100 335 examinations (31%) were repeat examinations. Body CT (9057 of 20 177 [45%] chest and 8319 of 22 438 [37%] abdomen) and brain imaging (6823 of 18 378 [37%] CT and 3427 of 11 455 [30%] MR imaging) represented the highest repeat categories. Among five high-cost, high-volume imaging examinations, 6426 of 85 014 (8%) followed a report with a radiologist recommendation. Most common indications for examination repetition were neurologic surveillance within 2 weeks and cancer follow-up at 2-7 months. From 1997 to mid-2003, MR imaging and CT repeat rates increased (0.71% per year [P < .01] and 1.87% per year [P < .01], respectively). CONCLUSION: Repeat examinations account for nearly one-third of high-cost radiology examinations and represent an increasing proportion of such examinations. Most repeat examinations are initiated clinically without a recommendation by a radiologist.