Spectrum of opportunistic fungal lung co-infections in COVID-19: What the radiologist needs to know.

Fungal lung co-infections associated with COVID-19 may occur in severely ill patients or those with underlying co-morbidities, and immunosuppression. The most common invasive fungal infections are caused by aspergillosis, mucormycosis, pneumocystis, cryptococcus, and candida. Radiologists integrate the clinical disease features with the CT pattern-based approach and play a crucial role in identifying these co-infections in COVID-19 to assist clinicians to make a confident diagnosis, initiate treatment and prevent complications.

[Spectrum of opportunistic fungal lung co-infections in COVID-19: What the radiologist needs to know]. / Espectro de coinfecciones pulmonares fúngicas oportunistas en COVID-19: lo que el radiólogo debe saber.

Fungal lung co-infections associated with COVID-19 may occur in severely ill patients or those with underlying co-morbidities, and immunosuppression. The most common invasive fungal infections are caused by aspergillosis, mucormycosis, pneumocystis, cryptococcus, and candida. Radiologists integrate the clinical disease features with the CT pattern-based approach and play a crucial role in identifying these co-infections in COVID-19 to assist clinicians to make a confident diagnosis, initiate treatment and prevent complications.

Canadian Association of Radiologists Guidance on Contrast-Associated Acute Kidney Injury.

Purpose: Iodinated contrast media is one of the most frequently administered pharmaceuticals. In Canada, over 5.4 million computed tomography (CT) examinations were performed in 2019, of which 50% were contrast enhanced. Acute kidney injury (AKI) occurring after iodinated contrast administration was historically considered a common iatrogenic complication which was managed by screening patients, prophylactic strategies, and follow-up evaluation of renal function. The Canadian Association of Radiologists (CAR) initially published guidelines on the prevention of contrast induced nephropathy in 2007, with an update in 2012. However, new developments in the field have led to the availability of safer contrast agents and changes in clinical practice, prompting a complete revision of the earlier recommendations. Information sources: Published literature, including clinical trials, retrospective cohort series, review articles, and case reports, along with expert opinions from radiologists and nephrologists across Canada. Methods: The leadership of the CAR formed a working group of radiologists and nephrologists with expertise in contrast administration and patient management related to contrast-associated AKI. We conducted a comprehensive review of the published literature to evaluate the evidence about contrast as a cause of AKI, and to inform evidence-based recommendations. Based on the available literature, the working group developed consensus recommendations. Key Findings: The working group developed 21 recommendations, on screening, choice of iodinated contrast media, prophylaxis, medication considerations, and post contrast administration management. The key changes from the 2012 guidelines were (1) Simplification of screening to a simple questionnaire, and not delaying emergent examinations due to a need for creatinine measurements (2) Prophylaxis considerations only for patients with estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m2 (3) Not recommending the routine discontinuation of any drugs to decrease risk of AKI, except metformin when eGFR is less than 30 mL/min/1.73 m2 and (4) Not requiring routine follow up serum creatinine measurements post iodinated contrast administration. Limitations: We did not conduct a formal systematic review or meta-analysis. We did not evaluate our specific suggestions in the clinical environment. Implications: Given the importance of iodinated contrast media use in diagnosis and management, and the low risk of AKI after contrast use, these guidelines aim to streamline the processes around iodinated contrast use in most clinical settings. As newer evidence arises that may change or add to the recommendations provided, the working group will revise these guidelines.

Justification: Les agents de contraste iodés (ACI) sont parmi les produits pharmaceutiques les plus fréquemment administrés. Au Canada, plus de 5,4 millions d'examens de tomodensitométrie (TDM) ont été réalisés en 2019, dont 50 % ont été faits avec un ACI. L'insuffisance rénale aiguë (IRA) survenant après l'administration d'un ACI était historiquement considérée comme une complication iatrogénique fréquente qui était prise en charge par le dépistage des patients, des stratégies prophylactiques et une évaluation de suivi de la fonction rénale. L'Association canadienne des radiologistes (CAR) a publié des lignes directrices pour la prévention de la néphropathie induite par les agents de contraste en 2007 et une mise à jour en 2012. De nouveaux développements sur le terrain ont toutefois mené à la disponibilité d'agents de contraste plus sécuritaires et à des changements dans la pratique clinique, ce qui a entraîné une révision complète des recommandations antérieures. Sources: La littérature publiée, y compris les essais cliniques, les séries de cohortes rétrospectives, les articles-synthèse et les rapports de cas, de même que les opinions d'experts de radiologistes et de néphrologues de partout au Canada. Méthodologie: La direction de la CAR a formé un groupe de travail composé de radiologues et de néphrologues ayant une expertise dans l'administration d'ACI et la gestion de patients atteints d'IRA survenant après l'administration d'un ACI. Le groupe a procédé à une revue complète de la littérature publiée afin d'évaluer les données probantes sur les ACI comme cause de l'IRA et de formuler des recommandations en fonction de celles-ci. Le groupe de travail a élaboré des recommandations consensuelles en se fondant sur la documentation disponible. Principaux résultats: Le groupe de travail a élaboré 21 recommandations sur le dépistage, le choix des agents de contraste iodés, la prophylaxie, les considérations relatives aux médicaments et la gestion post-administration de l'ACI. Les principaux changements par rapport aux lignes directrices de 2012 étaient : (1) de simplifier le dépistage à un simple questionnaire et de ne pas retarder les examens émergents en raison du besoin de mesurer la créatinine; (2) d'avoir des considérations prophylactiques uniquement pour les patients dont le débit de filtration glomérulaire estimé (DFGe) est inférieur à 30 mL/min/1,73 m2; (3) de ne pas recommander l'arrêt des médicaments visant à réduire le risque d'IRA, comme c'est normalement le cas, sauf la metformine lorsque le DFGe est inférieur à 30 mL/min/1,73 m2 et; (4) ne pas demander de mesures de suivi de routine de la créatinine sérique après administration d'un agent de contraste iodé. Limites: Le groupe n'a pas procédé à une revue formelle et systématique de la littérature sur le sujet ni à une méta-analyse. Les suggestions n'ont pas été évaluées dans un environnement clinique. Conclusion: Compte tenu de l'importance des agents de contraste iodés dans le diagnostic et la prise en charge des patients, et du faible risque d'IRA encouru après leur administration, ces recommandations ne visent qu'à simplifier les processus relatifs à l'utilisation des ACI dans la plupart des milieux cliniques. Le groupe de travail révisera ces lignes directrices au fur et à mesure que des éléments de preuve plus récents seront ajoutés aux recommandations fournies.

Canadian Association of Radiologists Guidance on Contrast Associated Acute Kidney Injury.

Iodinated contrast media (ICM) is one of the most frequently administered pharmaceuticals. In Canada, over 5.4 million computed tomography (CT) examinations were performed in 2019, of which 50% were contrast enhanced. Acute kidney injury (AKI) occurring after ICM administration was historically considered a common iatrogenic complication which was managed by screening patients, prophylactic strategies, and follow up evaluation of renal function. The Canadian Association of Radiologists (CAR) initially published guidelines on the prevention of contrast induced nephropathy in 2007, with an update in 2012. However, new developments in the field have led to the availability of safer contrast agents and changes in clinical practice, prompting a complete revision of the earlier recommendations. This revised guidance document was developed by a multidisciplinary CAR Working Group of radiologists and nephrologists, and summarizes changes in practice related to contrast administration, screening, and risk stratification since the last guideline. It reviews the scientific evidence for contrast associated AKI and provides consensus-based recommendations for its prevention and management in the Canadian healthcare context. This article is a joint publication in the Canadian Association of Radiologists Journal and Canadian Journal of Kidney Health and Disease, intended to inform both communities of practice.

Utility of MRCP in surveillance of primary sclerosing cholangitis associated hepatobiliary malignancy: 15 year experience at a single institution in Ontario, Canada.

OBJECTIVE: Magnetic resonance cholangiopancreatography (MRCP) is used for the surveillance of primary sclerosing cholangitis (PSC) and its associated complications. The time interval gap for subsequent follow-up MRCP is variable depending on clinical practice patterns, therefore this study was done to assess the MRCP follow-up strategy used in our institution for screening PSC-associated hepatobiliary malignancies. MATERIALS AND METHODS: This retrospective observational cohort included MRCP studies in adult patients, with clinical and radiological diagnosis of PSC over the past 15-year period between January 1, 2003 to December 31, 2018. The study population was grouped based on the presence and absence of PSC-associated malignancy. The frequency of MRCP follow-up was compared between the groups to look for MRI ordering trends in surveillance for PSC-associated complications. RESULTS: The overall median interval follow-up with MRCP was 14 months. The median follow-up interval in cases with PSC-associated malignancy was 6.0 months, compared to 13.1 months in the PSC group without malignancy (p 0.013). During the study period, the PSC-associated malignancy group had a median number of 7.5 scans, while the no malignancy group had a median number of 4 scans. Three patients (3/10, 30%) developed hepatobiliary malignancies within the first year of clinical diagnosis of PSC. The most common malignancy associated with PSC was cholangiocarcinoma (4.6%,7/10). Other PSC-associated malignancies included carcinoma gallbladder (1.3%,2/10), and hepatocellular carcinoma (0.6%,1/10). The median age of PSC associated malignancies was 56 (IQR 15) and higher compared to median age of PSC group without malignancies 46 (IQR 25.5), p 0.035. CONCLUSION: The median interval for subsequent follow-up MRCP in our study cohort was 14 months. One-third of PSC-associated hepato-biliary malignancies developed within the first year of clinical diagnosis of PSC, and the risk of PSC-associated hepato-biliary malignancy is constant after the first year.

Electronic Consultation Between Primary Care Providers and Radiologists.

OBJECTIVE. The purpose of this study was to assess the use of an electronic consultation platform to connect primary care providers and radiologists and provide opportunities for valuable consultation regarding diagnostic imaging in patients, as well as to identify opportunities for targeted education surrounding high-yield radiology topics. MATERIALS AND METHODS. A retrospective review was performed of consultations conducted using the electronic platform from September 2012 to January 2017. Consultations were classified by subspecialty (neuroradiology, thoracic, abdominal, musculoskeletal, or pediatric radiology), question type (workup, surveillance, education, specialist referral query, discharge, or other), anatomy, and pathology. Feedback surveys were completed by primary care providers after each consultation to evaluate timeliness, value, and impact on patient care. RESULTS. A total of 302 consultations were reviewed. Subspecialty breakdown was as follows: abdominal, 94/302 (31%); neuroradiology, 74/302 (25%); musculoskeletal, 61/302 (20%); thoracic, 56/302 (19%); and pediatric, 17/302 (6%). The majority of consultations pertained to patient workup (112/302 [37%]), surveillance of imaging findings (95/302 [31%]), and provider education (48/302 [16%]). Cystic lesions (38/302 [13%]), pain (24/302 [8%]), and bone lesions (21/302 [7%]) were the most queried conditions. Patient management was altered in 167 cases (55%), and unnecessary testing was avoided in 84 (28%). Providers rated the perceived value of the electronic consultation system as excellent in 227 cases (75%). CONCLUSION. The electronic consultation system allowed primary care providers to easily consult with radiologists, was perceived as high value by primary care providers, resulted in altered patient management, and avoided unnecessary imaging tests. We identified follow-up imaging of cystic lesions and imaging workup of pain in patients as opportunities for continuing medical education for primary care providers.

Editorial on "Diagnostic Efficacy of Contrast-Enhanced MRI in Detecting Residual or Recurrent Hepatocellular Carcinoma After Transarterial Chemoembolization: A Systematic Review and Meta-analysis".

LEVEL OF EVIDENCE: 5 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;52:1029-1030.

Can CT and MR Shape and Textural Features Differentiate Benign Versus Malignant Pleural Lesions?

RATIONALE AND OBJECTIVES: The study aimed to identify a radiomic approach based on CT and or magnetic resonance (MR) features (shape and texture) that may help differentiate benign versus malignant pleural lesions, and to assess if the radiomic model may improve confidence and accuracy of radiologists with different subspecialty backgrounds. MATERIALS AND METHODS: Twenty-nine patients with pleural lesions studied on both contrast-enhanced CT and MR imaging were reviewed retrospectively. Three texture and three shape features were extracted. Combinations of features were used to generate logistic regression models using histopathology as outcome. Two thoracic and two abdominal radiologists evaluated their degree of confidence in malignancy. Diagnostic accuracy of radiologists was determined using contingency tables. Cohen's kappa coefficient was used to assess inter-reader agreement. Using optimal threshold criteria, sensitivity, specificity, and accuracy of each feature and combination of features were obtained and compared to the accuracy and confidence of radiologists. RESULTS: The CT model that best discriminated malignant from benign lesions revealed an AUCCT = 0.92 ± 0.05 (P < 0.0001). The most discriminative MR model showed an AUCMR = 0.87 ± 0.09 (P < 0.0001). The CT model was compared to the diagnostic confidence of all radiologists and the model outperformed both abdominal radiologists (P < 0.002), whereas the top discriminative MR model outperformed one of the abdominal radiologists (P = 0.02). The most discriminative MR model was more accurate than one abdominal (P = 0.04) and one thoracic radiologist (P = 0.02). CONCLUSION: Quantitative textural and shape analysis may help distinguish malignant from benign lesions. A radiomics-based approach may increase diagnostic confidence of abdominal radiologists on CT and MR and may potentially improve radiologists' accuracy in the assessment of pleural lesions characterized by MR.

Pancreatic Neuroendocrine Tumors Complicated by Sinistral Portal Hypertension: Insights into Pathogenesis.

Purpose: To investigate the association between pancreatic neuroendocrine tumors (panNETs) and sinistral portal hypertension (SPH) and provide insights into the pathogenesis. Methods: A retrospective review of panNETs was conducted from our institution for 12 years. Medical imaging findings were analyzed to determine any association with splenic vein thrombosis (SVT) at diagnosis. The cases were further selected based on the criteria for SPH, namely, (1) presence of SVT, (2) gastric varices, (3) patent portal vein, and (4) normal liver function tests. Results: There were 61 patients with panNETs and 8 (8/61) had SVT and gastric varices at diagnosis. Four (4/8) met the strict criteria for SPH while the other four had more conventional portal hypertension. The four with SPH had large tumors located in the tail with splenic vein invasion and three of four presented with bleeding gastric varices. All four patients underwent surgical resection. Mean follow-up was 8.5 years and the hematemesis never recurred. The other four patients (four of eight) with gastric varices had unresectable disease and all died after a mean survival of 29 months. Conclusion: PanNETs appear to be more commonly associated with SVT and SPH compared with other tumors. This could be related to their relatively indolent nature and their intrinsic vascularity. From a surgical viewpoint, the decision to operate depends on many factors including but not limited to the size/stage, grade, and functionality of the tumor and comorbidities. These considerations notwithstanding, the association between panNETs and SPH suggests that there is benefit in timely resection of panNETs located in the tail.

Utilization of pre-operative imaging for colon cancer: A population-based study.

OBJECTIVE: To assess the use of pre-operative imaging for colon cancer and to identify factors associated with utilization in routine clinical practice. METHODS: This population-based, retrospective cohort study used a random sample of 25% of colon cancer patients treated with surgery in the province of Ontario (2002-2008). Pre-operative imaging (<16 weeks from surgery) of the chest, abdomen-pelvis was identified. Modified poisson regression was used to analyze factors associated with practice patterns. RESULTS: Of the 7,249 included patients, 48% had pre-operative imaging (CT abdomen and imaging of the chest) in keeping with guideline recommendations. The rate of guideline concordant pre-operative imaging increased over time: 64% in the most recent study period (2006-2008) versus 31% (2002-2004); P < 0.001. Variables associated with use of chest imaging: Age, co-morbidity, surgeon volume, and geographic region; no association with gender, hospital volume, or socio-economic status. Variables associated with use of abdomen imaging: Hospital volume and geographic region; no association with age, gender, comorbidity, socio-economic status, or surgeon volume. CONCLUSION: In clinical practice, the majority of patients were not receiving pre-operative imaging that was in line with clinical practice guidelines; however, use increased over time indicating a possible association with dissemination of clinical practice guidelines. J. Surg. Oncol. 2017;115:202-207. © 2016 Wiley Periodicals, Inc.

CT in adults: systematic review and meta-analysis of interpretation discrepancy rates.

PURPOSE: To use meta-analysis to determine the discrepancy rate when interpreting computed tomography (CT) studies performed in adult patients and to determine whether discrepancy rate differs on the basis of body region or level of radiologist training. MATERIALS AND METHODS: MEDLINE and EMBASE were searched from 1946 to June 2012 by using the combination "radiology AND (error OR peer review)." Two reviewers independently selected studies that met the inclusion criteria and extracted study data. Total and major discrepancy rates were investigated with a random-effects meta-analysis, and subgroups were compared by using the χ(2) Q statistic. Subgroup analyses were performed on the basis of the level of training of the initial radiologist and the body system scanned. RESULTS: Fifty-eight studies met the inclusion criteria (388 123 CT examinations). The pooled total discrepancy rate was 7.7% (95% confidence interval [CI]: 5.6%, 10.3%), and the major discrepancy rate was 2.4% (95% CI: 1.7%, 3.2%). The pooled major discrepancy rate was comparable for staff (2.9%; 95% CI: 1.2%, 6.7%) and residents (2.2%; 95% CI: 1.7%, 2.9%) (Q = 0.92, P = .633). The pooled major discrepancy rates for head CT (0.8%; 95% CI: 0.4%, 1.6%) and spine CT (0.7%; 95% CI: 0.2%, 2.7%) were lower than those for chest CT (2.8%; 95% CI: 1.5%, 5.4%) and abdominal CT (2.6%; 95% CI: 1.0%, 6.7%) (Q = 8.28, P = .041). Lack of blinding of the reference radiologist to the initial report was associated with a lower major discrepancy rate (2.0%; 95% CI: 1.4%, 2.7%; 43 studies) than when blinding was present (12.1%; 95% CI: 4.4%, 29.4%; five studies) (Q = 10.65, P = .001). CONCLUSION: Potentially useful reference ranges were identified in the subgroup analyses on the basis of body region scanned at adult CT. However, considerable heterogeneity that is only partially explained by subgroup analysis signifies that further research is necessary--particularly regarding the question of blinding of the reference radiologist.

Complication rates and effectiveness of uterine artery embolization in the treatment of symptomatic leiomyomas: a systematic review and meta-analysis.

OBJECTIVE: The purpose of this meta-analysis was to determine the rates of major complications, other associated adverse events, reintervention, and clinical improvement from studies reporting complications of uterine artery embolization (UAE) for the treatment of symptomatic leiomyomas. MATERIALS AND METHODS: PubMed, Medline, Embase, and Cochrane databases were searched for publications on the treatment of leiomyomas by UAE. Data pertaining to study characteristics, numbers of complications, symptomatic improvement, and reinterventions were collected by two readers. Pooled event rates were calculated using a random effects method. RESULTS: Fifty-four study populations met the inclusion criteria, yielding a total of 8159 patients. There were no reported deaths. Major complications occurred at a rate of 2.9% (95% CI, 2.2-3.8%). The rate of hysterectomy for resolution of a complication from UAE was 0.7% (0.5-0.9%), and the rate of readmission was 2.7% (1.9-3.7%). Multiple other specific complications were recorded including leiomyoma tissue passage (4.7% [3.9-5.7%]), deep venous thrombosis or pulmonary embolism (0.2% [0.2-0.4%]), and permanent amenorrhea (3.9% [2.7-5.3%]). Reintervention rates including repeat UAE, myomectomy, or hysterectomy calculated per patient-year occurred at 5.3% (4.2-6.4%) with follow-up ranging from 0.25 to 5 years. Clinical symptomatic improvement ranged from 78% to 90%, with follow-up ranging from 0.25 to 2 years. CONCLUSION: Symptomatic uterine leiomyoma treatment by UAE is an effective procedure with a low rate of major complications supporting its use as an alternative to hysterectomy.

Computed tomography (CT) bone segmentation of an ancient Egyptian mummy: a comparison of automated and semiautomated threshold and dual-energy techniques.

Dual-energy computed tomography (CT) enables 3-dimensional,noninvasive, and nondestructive imaging with material separation. Dual-energy CT is generally used to segment hydrated tissues within the clinical context. We apply dual-energy CT to an ancient Egyptian mummy and present several techniques designed to separate bone from desiccated tissue and resin. Automated and semiautomated dual-energy CT techniques are compared to manual segmentation and thresholding-based techniques. Semiautomated techniques enable substantial reductions in operator time compared to manual segmentation.

Percutaneous image-guided biopsy of the spleen: systematic review and meta-analysis of the complication rate and diagnostic accuracy.

PURPOSE: To use meta-analysis to determine the complication rate and diagnostic accuracy of image-guided percutaneous needle biopsy of the spleen. MATERIALS AND METHODS: Several electronic databases were searched through July 2010 without language restrictions. Two reviewers independently selected studies that met the inclusion criteria for the diagnostic accuracy and complication rate arms of the study. Study data were independently extracted by the two reviewers. The primary 2 × 2 data were investigated with a random-effects meta-analysis of sensitivity and specificity. The complication rate data were investigated with a random-effects meta-analysis; sensitivity analysis of complication rate, excluding needles larger than 18 gauge, was performed. RESULTS: Four studies met the inclusion criteria for the diagnostic accuracy arm (639 patients), and nine met the inclusion criteria for the complication rate arm (741 patients). The meta-analysis showed a pooled sensitivity of 87.0% (95% confidence interval [CI]: 80.7%, 91.4%) and specificity of 96.4% (95% CI: 81.4%, 99.4%). The pooled major complication rate was 2.2% (95% CI: 0.8%, 5.6%). Sensitivity analysis with the removal of biopsies performed with needles larger than 18 gauge showed a major complication rate of 1.3% (95% CI: 0.6%, 2.5%). The most commonly encountered complications were hemorrhage followed by pain. CONCLUSION: Image-guided percutaneous biopsy of the spleen demonstrates high diagnostic accuracy and a major complication rate, for needles 18 gauge or smaller, that is similar to that reported for the liver and kidney. This technique should be considered a favorable alternative to splenectomy.

A Case of Appendiceal Adenocarcinoma with Clinical Benefit from FOLFOX and Bevacizumab.

A 44-year-old woman presented with lower abdominal pain and bilateral ovarian masses on ultrasound. Exploratory laparotomy revealed extensive peritoneal and intra-abdominal disease and an abnormal appendix. Bilateral salpingo-oophorectomy, infracolic omentectomy, ileocolic resection and primary anastomosis were performed. Final pathology revealed a primary appendiceal adenocarcinoma, poorly differentiated, of signet ring cell type. CT scan postoperatively revealed gross residual disease. The patient was treated with FOLFOX chemotherapy combined with bevacizumab. Repeat CT scan showed a decrease in residual disease and the patient clinically improved. After her treatment has been continued for 13 months, she remains clinically well and her CT scan shows sustained disease stability. Disseminated appendiceal carcinoma is generally considered to be refractory to 5-FU-based chemotherapy and, to our knowledge, this is the first reported case of a patient with appendiceal adenocarcinoma demonstrating clinical benefit and sustained stability of disease with combination chemotherapy plus bevacizumab.