SIRM-SIN-AIOM: appropriateness criteria for evaluation and prevention of renal damage in the patient undergoing contrast medium examinations-consensus statements from Italian College of Radiology (SIRM), Italian College of Nephrology (SIN) and Italian Association of Medical Oncology (AIOM).

The increasing number of examinations and interventional radiological procedures that require the administration of contrast medium (CM) in patients at risk for advanced age and/or comorbidities highlights the problem of CM-induced renal toxicity. A multidisciplinary group consisting of specialists of different disciplines-radiologists, nephrologists and oncologists, members of the respective Italian Scientific Societies-agreed to draw up this position paper, to assist clinicians increasingly facing the challenges posed by CM-related renal dysfunction in their daily clinical practice.The major risk factor for acute renal failure following CM administration (post-CM AKI) is the preexistence of renal failure, particularly when associated with diabetes, heart failure or cancer.In accordance with the recent guidelines ESUR, the present document reaffirms the importance of renal risk assessment through the evaluation of the renal function (eGFR) measured on serum creatinine and defines the renal risk cutoff when the eGFR is < 30 ml/min/1.73 m2 for procedures with intravenous (i.v.) or intra-arterial (i.a.) administration of CM with renal contact at the second passage (i.e., after CM dilution with the passage into the pulmonary circulation).The cutoff of renal risk is considered an eGFR < 45 ml/min/1.73 m2 in patients undergoing i.a. administration with first-pass renal contact (CM injected directly into the renal arteries or in the arterial district upstream of the renal circulation) or in particularly unstable patients such as those admitted to the ICU.Intravenous hydration using either saline or Na bicarbonate solution before and after CM administration represents the most effective preventive measure in patients at risk of post-CM AKI. In the case of urgency, the infusion of 1.4% sodium bicarbonate pre- and post-CM may be more appropriate than the administration of saline.In cancer patients undergoing computed tomography, pre- and post-CM hydration should be performed when the eGFR is < 30 ml/min/1.73 m2 and it is also advisable to maintain a 5 to 7 days interval with respect to the administration of cisplatin and to wait 14 days before administering zoledronic acid.In patients with more severe renal risk (i.e., with eGFR < 20 ml/min/1.73 m2), particularly if undergoing cardiological interventional procedures, the prevention of post-CM AKI should be implemented through an internal protocol shared between the specialists who treat the patient.In magnetic resonance imaging (MRI) using gadolinium CM, there is a lower risk of AKI than with iodinated CM, particularly if doses < 0.1 mmol/kg body weight are used and in patients with eGFR > 30 ml/min/1.73 m2. Dialysis after MRI is indicated only in patients already undergoing chronic dialysis treatment to reduce the potential risk of systemic nephrogenic fibrosis.

SIRM-SIAAIC consensus, an Italian document on management of patients at risk of hypersensitivity reactions to contrast media.

Hypersensitivity reactions (HRs) to contrast media (CM) can be distinguished in immune-mediated (including allergic reactions) and non-immune-mediated reactions, even if clinical manifestations could be similar. Such manifestations range from mild skin eruptions to severe anaphylaxis, making it important for radiologists to know how to identify and manage them. A panel of experts from the Società Italiana di Radiologia Medica e Interventistica (SIRM) and the Società Italiana di Allergologia, Asma e Immunologia Clinica (SIAAIC) provided a consensus document on the management of patients who must undergo radiological investigations with CM. Consensus topics included: the risk stratification of patients, the identification of the culprit CM and of a safe alternative by an allergy workup, as well as the use of premedication and the correct procedure to safely perform an elective (i.e., scheduled) or urgent examination. The most important recommendations are: (1) in all patients, a thorough medical history must be taken by the prescribing physician and/or the radiologist to identify at-risk patients; (2) in patients with hypersensitivity reactions to CM, the radiologist must consider an alternative, non-contrast imaging study with a comparable diagnostic value, or prescribe a different investigation with another class of CM; (3) if such options are not feasible, the radiologist must address at-risk patients to a reference centre for an allergy evaluation; (4) if timely referral to an allergist is not viable, it is recommended to use a CM other than the responsible one, taking into account cross-reactivity patterns; in the case of patients with histories of severe reactions, the presence of an anesthesiologist is also recommended and a premedication is suggested.

Quantitative analysis of contrast-enhanced ultrasonography of the bowel wall can predict disease activity in inflammatory bowel disease.

PURPOSE: To evaluate the accuracy of quantitative analysis of bowel wall enhancement in inflammatory bowel disease (IBD) with contrast enhanced ultrasound (CEUS) by comparing the results with vascular density in a biopsy sample from the same area of the intestinal tract, and to determine the usefulness of this analysis for the prediction of disease activity. MATERIALS AND METHODS: This prospective study was approved by our institute's ethics committee and all patients gave written informed consent. We enrolled 33 consecutive adult patients undergoing colonoscopy and biopsy for IBD. All patients underwent CEUS and the results were quantitatively analyzed. Vessel count per high-power field on biopsy specimens was compared with colonoscopy, baseline ultrasonography, and CEUS findings, and with analysis of peak intensity, time to peak, regional blood volume, mean transit time, and regional blood flow. Results in patients with high and low vascular density were compared using Fisher's test, t-test, Pearson's correlation test, and receiver operating characteristic curve (ROC) analysis. Cutoff values were determined using ROC analysis, and sensitivity and specificity were calculated. RESULTS: High vascular density (>265 vessels per field) on histological examination was significantly correlated with active disease on colonoscopy, baseline ultrasonography, and CEUS (p<.0001). Quantitative analysis showed a higher enhancement peak, a shorter time to peak enhancement, a higher regional blood flow and regional blood volume in patients with high vascular density than in those with low vascular density. Cutoff values to distinguish between active and inactive disease were identified for peak enhancement (>40.5%), and regional blood flow (>54.8 ml/min). CONCLUSION: Quantitative analysis of CEUS data correlates with disease activity as determined by vascular density. Quantitative parameters of CEUS can be used to predict active disease with high sensitivity and specificity.

Contrast enhanced ultrasound: Should it play a role in immediate evaluation of liver tumors following thermal ablation?

PURPOSE: To compare the accuracy of immediate CEUS with results of 24-h CEUS and MDCT in early evaluation of liver tumors following thermal ablation, using the combined results of a 3 month follow-up MDCT and CEUS as a reference standard. SUBJECTS AND METHODS: From our database, we selected patients who underwent a thermal ablation immediately followed by CEUS (within 5-10min) between February 2009 and February 2011. There were 92 patients (median age 73 years), two of whom had repeat ablation during the study period for a total of 94 tumors. Sixty tumors were treated with radiofrequency and 34 with microwave ablation. All patients underwent CEUS and CT examinations at 24h. For patients with more than one treated tumor in the same session, the lesion imaged post-procedural and at 24-h with CEUS in all vascular phases was selected. All measurements of the necrotic zone, as an avascular zone, were performed during the portal-venous phase. Immediate post-procedural CEUS and 24h CEUS and MDCT were blindly reviewed by two radiologists. One radiologist blindly reviewed the follow-up imaging. The mean diameters of the necrotic zone at post-procedural CEUS, and CEUS and MDCT at 24h were compared and diagnostic accuracy to detect residual tumor calculated for each index tests compared to 3-months follow-up imaging. RESULTS: The mean diameter of the necrotic zone was: 29±9mm at post-procedural CEUS, 34±10mm at 24h CEUS and 35±11mm at 24h MDCT. Mean diameter of the necrotic zone was significantly smaller at post-procedural CEUS compared to either CEUS or MDCT at 24h (p<0.001 for all). With a 95% confidence interval, the sensitivity was 25% (11-47%) for immediate CEUS, 20% (8-42%) for CEUS at 24-h, and 40% (22-61%) for CT at 24-h. Specificity was 96% (89-99%) for immediate CEUS, 97% (91-99%) for CEUS at 24-h, and 97% (91-99%) for CT at 24-h. CONCLUSIONS: Diagnostic accuracy of post-procedural CEUS in early evaluation of liver tumors following thermal ablation is comparable to both CEUS and MDCT performed at 24h. Therefore, post-procedural CEUS can be used to detect and retreat residual viable tissue in the same ablation session.

Economic assessment of contrast-enhanced ultrasonography for evaluation of focal liver lesions: a multicentre Italian experience.

BACKGROUND: The aim of this study was to evaluate the clinical and economic consequences of the introduction of contrast-enhanced ultrasonography (CEUS) into the diagnostic clinical algorithm for the characterization of incidental focal liver lesions (FLLs). METHODS: This prospective study enrolled 485 subjects at three hospitals in Italy. Two diagnostic algorithms were utilized: (1) a classic patient work-up, which included baseline US followed by a CT or MR examination, and (2) a new patient management scheme in which, following the baseline US, a CEUS examination was performed. For each pathway, both direct and indirect health costs for the National Health System (NHS) at two of the three hospitals involved in the study were calculated. Clinical outcome was measured in terms of number of cases correctly diagnosed, using contrast-enhanced CT/contrast-enhanced MR as the reference standard. RESULTS: CEUS correctly differentiated (benign vs. malignant) 559 of 575 lesions (97.2%), with a sensitivity of 98.1% and a specificity of 95.7%. Histological characterization was correct in 502 of 575 lesions (87%) with a sensitivity of 90.5% and a specificity of 85.4%. In terms of cost, the conventional diagnostic algorithm incurred for the NHS a total cost of Euro 134.576,60 vs. Euro 55.674,30 with CEUS, for a saving of Euro 78.902 (Euro 162 per patient). For the hospitals, the total cost was Euro 147.045 without CEUS vs Euro 61.979 with CEUS, for a saving of Euro 85.065,96 or Euro 175,39 per patient. CONCLUSION: The routine use of CEUS for the characterization of FLLs provides significant cost savings, both for the NHS and for the hospital.

Characterization of focal liver lesions with a new ultrasound contrast agent using continuous low acoustic power imaging: comparison with contrast enhanced spiral CT.

PURPOSE: To evaluate the concordance of the enhancement patterns of a new ultrasound contrast agent (SonoVue) with those obtained with dual-phase contrast-enhanced spiral CT (CE-CT) in the characterization of focal liver lesions (FLLs). MATERIALS AND METHODS: Sixty-two patients with focal liver lesions discovered at ultrasound and also studied with CECT underwent contrast-enhanced ultrasound using continuous low acoustic power imaging after receiving a 2.4 ml bolus of the new US contrast agent SonoVue, consisting of a dispersion of sulphur hexafluoride microbubbles. The examinations were made using ATL HDI-5000, Acuson SEQUOIA and Aloka 5500 Prosound ultrasound systems with 5.2 MHz curved-array probes. The concordance between US and CE-CT images was evaluated on site by two radiologists blinded to CT RESULTS: The FLLs were assessed in the arterial (20 s after CM injection), portal (after 45-60 s) and late (after 120 s) phases for: 1) presence/absence of enhancement 2) distribution of enhancement (homogenous or target distribution, centripetal or centrifugal flow, and other), 3) qualitative enhancement pattern (hyperechoic, hypoechoic, or isoechoic) versus normal liver parenchyma. RESULTS: The concordance between SonoVue-enhanced US and CE-CT was 85%. Moreover during portal venous phase with CEUS it was possible to differentiate between malignancy or benignity of 91% of lesions. CONCLUSIONS: The preliminary data obtained in this study suggest that continuous low acoustic power imaging and contrast-enhanced US show similar results to CT in contrast distribution and contrast enhancement patterns.