Diagnosing the acute abdomen during a global contrast shortage: a single centre experience.

BACKGROUND: The COVID-19 pandemic led to a global shortage of iodinated contrast media (ICM) in early 2022. ICM is used in more than half of the computed tomography of the abdomen and pelvis (CTAP) performed to diagnose an acute abdomen (AA). In response to the shortage, the RANZCR published contrast-conserving recommendations. This study aimed to compare AA diagnostic outcomes of non-contrast CTs performed before and during the shortage. METHODS: A single-centre retrospective observational cohort study of all adult patients presenting with an AA who underwent a CTAP was conducted during the contrast shortage period from May to July 2022. The pre-shortage control comparison group was from January to March 2022; key demographics, imaging modality indication and diagnostic outcomes were collected and analysed using SPSS v27. RESULTS: Nine hundred and sixty-two cases met the inclusion criteria, of which n = 502, 52.2% were in the shortage period group. There was a significant increase of 464% in the number of non-contrast CTAPs performed during the shortage period (P < 0.001). For the six AA pathologies, only n = 3, 1.8% of non-contrast CTAPs had equivocal findings requiring further imaging with a contrast CTAP. Of the total CTs performed, n = 464, 48.2% were negative. CONCLUSION: This study showed that when non-contrast CTs are selected appropriately, they appear to be non-inferior to contrast-enhanced CTAPs in diagnosing acute appendicitis, colitis, diverticulitis, hernia, collection, and obstruction. This study highlights the need for further research into utilizing non-contrast scans for assessing the AA to minimize contrast-associated complications.

Lessons from the contrast dye shortage during COVID-19: A narrative review.

The sudden contrast dye shortage, precipitated by a temporary forced closure of healthcare plant, has limited the supply of iodinated contrast media to Australia. Furthering the impact of the coronavirus disease 2019 pandemic, this new crisis has increased burden on the radiology system. Lessons from the strategies applied during the shortage should be used as building blocks as safeguards for the future. A pragmatic approach to education and training is required in an ever-changing environment. Our relationships between medical specialties and manufacturers are paramount to maintaining an effective workflow. An ongoing commitment to a strong workforce will be the backbone to overcome another challenge in these uncertain times.

Shortage of iodinated contrast media: Status and possible chances - A systematic review.

PURPOSE: Covid-19 related lockdowns have resulted in a shortage of iodinated contrast media (ICM) in 2022. Health care providers have reacted with implementing conservation strategies to stay operational without compromising patient care. Although articles describing the implemented Interventions have been published, possible chances of the shortage have not yet been mentioned in the literature. METHODS: We conducted a literature search in PubMed and Google Scholar, and analysed the background, interventions, and possible benefits of low-dose ICM regimens. RESULTS: We included 22 articles dealing with "ICM shortage" for the analysis. The delivery bottlenecks in the USA and Australia led to two different countermeasures, 1. reduction of the number of contrast-enhanced image-guided examinations and 2. reduction of the (single) ICM dose. Interventions from both groups have resulted in significant reduction of ICM usage; however, group 1 has contributed more to overall ICM reduction. As benefit of the ICM reduction, we revealed an increased safety for patients at risk (e.g. hypersensitivity reactions, contrast-induced acute kidney injury, thyroid toxic effects). CONCLUSION: The ICM shortage of 2022 has forced health care providers to implement conservation strategies to stay operational. Although there were already proposals for dose reduction before the corona pandemic and the associated supply bottlenecks, this situation led to the use of a reduced amount of contrast agent on a large scale. This presents a good opportunity to reconsider protocols and the use of contrast-enhanced imaging in general for future practice as it offers chances and advantages regarding costs, environmental impact, and patient safety.

Differential renal proteomics analysis in a novel rat model of iodinated contrast-induced acute kidney injury.

Contrast-induced acute kidney injury (CI-AKI), which occurs after the use of iodinated contrast media, has become the third leading cause of hospital-acquired acute kidney injury (AKI). It is associated with prolonged hospitalization and increased risks of end-stage renal disease and mortality. The pathogenesis of CI-AKI is unclear and effective treatments are lacking. By comparing different post-nephrectomy times and dehydration times, we constructed a new, short-course CI-AKI model using dehydration for 24 h two weeks after unilateral nephrectomy. We found that the low-osmolality contrast media iohexol caused more severe renal function decline, renal morphological damage, and mitochondrial ultrastructural alterations compared to the iso-osmolality contrast media iodixanol. The shotgun proteomics based on Tandem Mass Tag (TMT) was used to conduct proteomics research on renal tissue in the new CI-AKI model, and 604 distinct proteins were identified, mainly involving complement and coagulation cascade, COVID-19, PPAR signalling pathway, mineral absorption, cholesterol metabolism, ferroptosis, staphylococcus aureus infection, systemic lupus erythematosus, folate biosynthesis, and proximal tubule bicarbonate reclamation. Then, using parallel reaction monitoring (PRM), we validate 16 candidate proteins, of which five were novel candidates (Serpina1, Apoa1, F2, Plg, Hrg) previously unrelated to AKI and associated with an acute response as well as fibrinolysis. The pathway analysis and 16 candidate proteins may help to discover new mechanisms in the pathogenesis of CI-AKI, allowing for early diagnosis and outcome prediction.

Short-term outcome of late gadolinium changes detected on cardiovascular magnetic resonance imaging following coronavirus disease 2019 Pfizer/BioNTech vaccine-related myocarditis in adolescents.

BACKGROUND: Rare cases of cardiac inflammation following vaccination for severe acute respiratory coronavirus 2 (SARS-CoV-2) have been reported. OBJECTIVE: To study paediatric patients with clinical findings of acute inflammation post coronavirus disease 2019 (COVID-19) Pfizer/BioNTech vaccination using cardiovascular magnetic resonance imaging (MRI) in acute and subacute phases. MATERIALS AND METHODS: We enrolled adolescents younger than 18 years who presented at one of two institutions between July 2021 and August 2022 with clinical and laboratory findings of acute myocarditis shortly following COVID-19 Pfizer/BioNTech vaccination. They all underwent cardiovascular MRI using the institutional myocarditis protocol. RESULTS: Five adolescents (four boys) underwent eight scans between 3 days and 109 days (mean 49 days) after the onset of symptoms following COVID-19 vaccination. Myocardial oedema appeared on short tau inversion recovery (STIR) T2-weighted images in three adolescents at presentation (3-12 days after symptom onset). In these children, the myocardial oedema/acute inflammation had resolved at follow-up cardiovascular MRI (53-68 days after first MRI). However, in all three adolescents, a persistent area of late gadolinium enhancement was evident at follow-up, suggesting post-myocarditic fibrosis. One adolescent scanned only once, 66 days after being symptomatic, had no acute inflammation but persistent fibrotic changes. This last adolescent, who underwent the first scan 109 days after symptom onset, had findings compatible with an episode of previous myocarditis, with mild ongoing regional myocardial oedema/inflammation. CONCLUSION: This study on post-vaccine myocarditis demonstrates residual lesions with persistent areas of late gadolinium enhancement/myocardial fibrosis with ongoing myocardial oedema after resolution of the initial myocardial oedema a few weeks after Pfizer/BioNTech vaccination. There is an urgent need to recognise and fully investigate the outcome of post-vaccination myocarditis.

Cardiac MRI Findings in COVID-19 Vaccine-Related Myocarditis: A Pooled Analysis of 468 Patients.

Understanding the pattern and severity of myocarditis caused by the coronavirus disease 2019 (COVID-19) vaccine is imperative for improving the care of the patients, and cardiac evaluation by MRI plays a key role in this regard. Our systematic review and meta-analysis aimed to summarize cardiac MRI findings in COVID-19 vaccine-related myocarditis. We performed a comprehensive systematic review of literature in PubMed, Scopus, and Google Scholar databases using key terms covering COVID-19 vaccine, myocarditis, and cardiac MRI. Individual-level patient data (IPD) and aggregated-level data (AD) studies were pooled through a two-stage analysis method. For this purpose, all IPD were first gathered into a single data set and reduced to AD, and then this AD (from IPD studies) was pooled with existing AD (from the AD studies) using fixed/random effect models. I² was used to assess the degree of heterogeneity, and the prespecified level of statistical significance (P value for heterogeneity) was <0.1. Based on meta-analysis of 102 studies (n = 468 patients), 79% (95% confidence interval [CI]: 54%-97%) of patients fulfilled Lake Louise criteria (LLC) for diagnosis of myocarditis. Cardiac MRI abnormalities included elevated T2 in 72% (95% CI: 50%-90%), myocardial late gadolinium enhancement (LGE) in 93% (95% CI: 83%-99%; nearly all with a subepicardial and/or midwall pattern), impaired left ventricular ejection fraction (LVEF) (<50%) in 4% (95% CI: 1.0%-9.0%). Moreover, elevated T1 and extracellular volume fraction (ECV) (>30), reported only by some IPD studies, were detected in 74.5% (76/102) and 32% (16/50) of patients, respectively. In conclusion, our findings may suggest that over two-thirds of patients with clinically suspected myocarditis following COVID-19 vaccination meet the LLC. COVID-19 vaccine-associated myocarditis may show a similar pattern compared to other acute myocarditis entities. Notably, preserved LVEF is probably a common finding in these patients. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 3.

Incidence of Contrast-Associated Acute Kidney Injury in Renal-Competent COVID-19 Patients Undergoing Computed Chest Angiography.

PURPOSE: COVID-19 infection poses a significant risk of both renal injury and pulmonary embolism, producing a clinical challenge, as the criterion standard examination for pulmonary embolism, computed tomography angiography (CTA), requires the use of nephrotoxic iodinated contrast agents.Our investigation evaluated whether symptomatic COVID-19-positive patients without laboratory evidence of renal impairment are at increased risk for developing contrast-associated acute kidney injury (CA-AKI). METHOD: All COVID-19-positive patients undergoing noncontrast chest computed tomography and CTA at an apex tertiary medical center between March 1 and December 10, 2020, were retrospectively evaluated. A total of 258 renal-competent (estimated glomerular filtration rate >30) patients with baseline and 48- to 72-hour postexamination creatinine measurements were identified and analyzed for incidence of acute kidney injury (AKI) meeting the criteria for CA-AKI. RESULTS: Twenty-five of 191 patients undergoing CTA (13.1%) and 9 of the 67 undergoing noncontrast computed tomography (13.4%) experienced creatinine increases meeting the criteria for CA-AKI. Univariate and multivariate analyses accounting for known AKI risk factors revealed no correlation between iodinated contrast administration and the incidence AKI meeting the criteria for CA-AKI (univariable odds ratio, 0.97 [95% confidence interval, 0.43-2.20]; multivariable odds ratio, 0.97 [95% confidence interval, 0.40-2.36]). CONCLUSIONS: Renal-competent COVID-19 patients undergoing chest CTA may not have an increased risk of AKI. Additional studies are needed to confirm this preliminary finding.

Follow-up cardiac magnetic resonance in children with vaccine-associated myocarditis.

Myocarditis is a rare complication of the COVID-19 mRNA vaccine. We previously reported a case series of 15 adolescents with vaccine-associated myocarditis, 87% of whom had abnormalities on initial cardiac magnetic resonance (CMR), including late gadolinium enhancement (LGE) in 80%. We performed follow-up CMRs to determine the trajectory of myocardial recovery and better understand the natural history of vaccine-associated myocarditis. Case series of patients age < 19 years admitted to Boston Children's Hospital with acute vaccine-associated myocarditis following the BNT162b2 vaccine who had abnormal CMR at the time of initial presentation, and underwent follow-up testing. CMR assessment included left ventricular (LV) ejection fraction, T2-weighted myocardial imaging, LV global native T1, LV global T2, extracellular volume (ECV), and late gadolinium enhancement (LGE). Ten patients (9 male, median age 15 years) with vaccine-associated myocarditis underwent follow-up CMR at a median of 92 days (range 76-119) after hospital discharge. LGE was persistent in 80% of patients, though improved from prior in all cases. Two patients (20%) had abnormal LV global T1 at presentation, which normalized on follow-up. ECV decreased between acute presentation and follow-up in 6/10 patients; it remained elevated at follow-up in 1 patient and borderline in 3 patients. CONCLUSION: CMR performed ~3 months after admission for COVID-19 vaccine-associated myocarditis showed improvement of LGE in all patients, but persistent in the majority. Follow-up CMR 6-12 months after acute episode should be considered to better understand the long-term cardiac risks. WHAT IS KNOWN: • Myocarditis is a rare side effect of COVID-19 mRNA vaccine. •Late gadolinium enhancement is present on most cardiac magnetic resonance at the time of acute presentation. WHAT IS NEW: •Late gadolinium enhancement improved on all repeat cardiac magnetic resonance at 3-month follow-up. •Most patients still had a small amount of late gadolinium enhancement, the clinical significance of which is yet to be determined.

Negative effects of iodine-based contrast agent on renal function in patients with moderate reduced renal function hospitalized for COVID-19.

BACKGROUND: Kidney disease and renal failure are associated with hospital deaths in patients with COVID - 19. We aimed to test if contrast enhancement affects short-term renal function in hospitalized COVID - 19 patients. METHODS: Plasma creatinine (P-creatinine) was measured on the day of computed tomography (CT) and 24 h, 48 h, and 4-10 days after CT. Contrast-enhanced (n = 142) and unenhanced (n = 24) groups were subdivided, based on estimated glomerular filtration rates (eGFR), > 60 and ≤ 60 ml/min/1.73 m2. Contrast-induced acute renal failure (CI-AKI) was defined as ≥27 µmol/L increase or a > 50% rise in P-creatinine from CT or initiation of renal replacement therapy during follow-up. Patients with renal replacement therapy were studied separately. We evaluated factors associated with a > 50% rise in P-creatinine at 48 h and at 4-10 days after contrast-enhanced CT. RESULTS: Median P-creatinine at 24-48 h and days 4-10 post-CT in patients with eGFR> 60 and eGFR≥30-60 in contrast-enhanced and unenhanced groups did not differ from basal values. CI-AKI was observed at 48 h and at 4-10 days post contrast administration in 24 and 36% (n = 5/14) of patients with eGFR≥30-60. Corresponding figures in the eGFR> 60 contrast-enhanced CT group were 5 and 5% respectively, (p < 0.037 and p < 0.001, Pearson χ2 test). In the former group, four of the five patients died within 30 days. Odds ratio analysis showed that an eGFR≥30-60 and 30-day mortality were associated with CK-AKI both at 48 h and 4-10 days after contrast-enhanced CT. CONCLUSION: Patients with COVID - 19 and eGFR≥30-60 had a high frequency of CK-AKI at 48 h and at 4-10 days after contrast administration, which was associated with increased 30-day mortality. For patients with eGFR≥30-60, we recommend strict indications are practiced for contrast-enhanced CT. Contrast-enhanced CT had a modest effect in patients with eGFR> 60.

Contrast­induced acute kidney injury in COVID-19 patients.

METHODS: Forty-two COVID-19 patients who underwent emergency PCI due to the diagnosis of acute coronary syndrome were included in the study. Mean age was 63±14.76 and males accounted for 81 % (34/42). Contrast-induced acute kidney injury (CI-AKI) was defined as absolute increase in serum creatinine level by 0.3 mg/dL above baseline within 48 hours of contrast exposure. Patients were divided into two groups according to CI-AKI development following coronary angiography. RESULTS: CI-AKI developed in 33.3 % (14/42) of the patients. Pre-procedure e-GFR (p=0.028), serum albumin levels (p=0.021), and ejection fraction (p=0.039) were lower in the CI-AKI group. Whereas the platelet/lymphocyte ratio was significantly lower in the non-CI-AKI group (p=0.010). CONCLUSIONS: Our study results demonstrated that patients suffering from COVID-19 had a high risk of CI-AKI development following coronary angiography (Tab. 1, Ref. 36).

[Assessment of the influence of different factors on the risk of the development of a new coronavirus infection in patients with contrast induced acute kidney injury].

AIM: The main aim of our study was to assess the role of risk factors in patients with previous contrast induced acute kidney injury (CI-AKI) on a probability of a development of the new coronavirus infection. MATERIALS AND METHODS: Our study includes 65 patients with the history of CI-AKI after coronary angiography from 2013 to 2017 years; 10 of them had a new coronavirus infection, which had developed before November 2020. CI-AKI was defined as an increase of 25% or more, or an absolute increase of 0.5 mg/dl or more in serum creatinine from baseline value, assessed at 48 hours following the administration of the contrast. The primary endpoint was the development of a new coronavirus infection. RESULTS: We found statistically significant difference in the prevalence of the allergic reaction to iodine (р=0.0178) between non-COVID and COVID-patients group. Also, there were statistically significant differences in the secondary endpoints: renal replacement therapy (р=0.0178) and repeated percutaneous coronary intervention in the last year (р=0.0112) were more common among patients with coronavirus. The difference in the prevalence of arterial hypertension was near to statistical significance (р=0.0882). CONCLUSION: COVID-patients with CI-AKI had more allergic reactions to iodine than non-COVID patients. The trend of more common arterial hypertension between COVID-patients was found in our research. There were not any statistical significant differences in other risk factors. There were statistically significant difference in the secondary endpoints such as repeated percutaneous coronary intervention and renal replacement therapy. Other endpoints didnt show a statistically significant difference.

Iodine allergy: Common misperceptions.

PURPOSE: The current evidence regarding iodine-containing compounds and iodine allergy cross-reactivity is reviewed. SUMMARY: Iodine is an essential human nutrient found in the thyroid gland. It is used in the synthesis of the thyroid hormones thyroxine and triiodothyroxine. Patients who report having adverse reactions to iodine-containing substances are often labelled as having an "iodine allergy," which can result in delays in care or patients being denied essential iodinated contrast media (ICM) or other iodine-containing drugs. A literature review was conducted to evaluate the evidence regarding iodine allergy and iodine-containing drugs. Of 435 articles considered potentially appropriate for full review (plus 12 additional articles included on the basis of references from the eligible articles), 113 could not be obtained. After exclusion of 353 articles that did not meet all inclusion criteria, the remaining 81 articles were included in the review. The results of the literature review indicated that iodine has not been shown to be the allergen responsible for allergic reactions to iodinated contrast media, amiodarone, povidone-iodine, and other iodine-containing compounds. CONCLUSION: There is a lack of evidence to support cross-reactivity between iodine-containing compounds in so called iodine-allergic individuals.