Fulvio Stacul

Contrast medium extravasation injury: guidelines for prevention and management.

Abstract. Extravasation of contrast material is a well-recognized complication of contrast-enhanced imaging studies. The management of this complication is contentious; therefore, the Contrast Media Safety Committee of The European Society of Urogenital Radiology decided to review the literature and issue guidelines. A comprehensive literature search was carried out. The resulting report was discussed at the 8th European Symposium on Urogenital Radiology in Genoa, Italy. Automated power injection may result in extravasation of large volumes and may or can lead to severe tissue damage. Infants, young children and unconscious and debilitated patients are particularly at risk of extravasation during contrast media injection. Fortunately, most extravasations result in minimal swelling or erythema, with no long-term sequelae; however, severe skin necrosis and ulceration may occur. Large volumes of high osmolar contrast media are known to induce significant tissue damage. Compartment syndrome may be seen associated with extravasation of large volumes. Conservative management is often adequate, but in serious cases the advice of a plastic surgeon is recommended. Based on the review simple guidelines for prophylaxis and management of contrast medium extravasation injuries are proposed.

Effects of a dimeric vs a monomeric nonionic contrast medium on renal function in patients with mild to moderate renal insufficiency: a double-blind, randomized clinical trial.

Abstract. The efficacy and safety of nonionic dimeric contrast media in subjects with impaired renal function is largely unknown. The present study was aimed at determining the risk of tubular nephrotoxicity in patients with mild to moderate renal insufficiency who underwent intravenous urography (IVU) with the nonionic dimeric contrast agent iodixanol (Visipaque, Nycomed Imaging, Oslo, Norway). In a double-blind protocol 64 patients (55 males; mean age 68.3 years) with serum creatinine between 135 and 265 μmol/l who were to undergo IVU were randomized to receive iodixanol (a nonionic dimer) or iopromide (a nonionic monomer), 600 mg I/kg b. w. Renal function was evaluated before and 1 h, 6 h, 24 h, 48 h and 7 days after IVU with analysis of serum creatinine, urinary enzymes alanylaminopeptidase and N-acetyl-β-glucosaminidase, and urinary microproteins α-1-microglobulin and albumin. Renal function remained stable in both contrast medium groups during the follow-up period. No statistically significant differences were observed between the monomer and the dimer in terms of urinary enzyme and microprotein excretion or serum creatinine. Transient radiocontrast-induced nephropathy developed in 1 patient who had received iodixanol. The administration of the nonionic dimeric contrast medium iodixanol, or of the nonionic monomer iopromide, entailed a low nephrotoxic potential in patients with mild to moderate renal insufficiency undergoing excretory urography.

Present-day imaging of patients with renal colic.

Abstract In the past decade alternatives to urography have been proposed for the study of patients with renal colic. In 1992 it was suggested to replace urography with KUB and ultrasonography. In 1993 the combination of KUB and ultrasonography followed by urography in unresolved cases was proposed and, in 1995, it was suggested to replace urography with unenhanced helical CT (UHCT). This article illustrates the contribution of UHCT to the study of patients with renal colic and analyses advantages and shortcomings of the technique compared with other diagnostic approaches. Diagnostics of the patient with renal colic is based on the detection of direct and indirect signs which allow identification of not only the calculus, with a sensitivity of 94–100 % and accuracy of 93–98 % according different authors, but also other signs that can serve to guide patient management and evaluate long-term prognosis. Unenhanced helical CT has the capability to detect extraurinary abnormalities which present with flank pain and mimic renal colic. The examination technique affects the quality of the images and therefore diagnostic accuracy as well as the dose to the patient. With regard to setting parameters, the choice of thickness and table feed should be guided by numerous factors. Multiplanar reconstruction is indicated in the study of the entire ureter course to identify the exact site of the calcification for the urologist to perform an evaluation similar to that obtained by urography. Many authors consider UHCT to be a valuable tool for suggesting the best therapeutic approach. Among these there are also urologists. The evaluation is based on the stone detection, its size and level in the urinary tract. Cost analysis shows that the cost of UHCT is equal to or inferior to the cost of urography. With regard to the dose, different data are reported in the literature. A high pitch (more than 1.5) and a thin collimation (3-mm thickness) are good compromise between quality and dose which can be compared to the dose of normal urography. What is to be done if helical CT is not available? If helical CT is not available, plain film plus ultrasonography should be considered. This approach does not solve all the cases; in unresolved cases urography is indicated. It should also be noted that US has a good sensitivity in detecting other conditions such as biliary lithiasis, acute pancreatitis, acute appendicitis and abdomino-pelvic masses which are responsible for pain that mimics renal colic. In conclusion, IVU should not have any more the priority in investigating the patients with renal colic. Helical CT should be the first choice in imaging a patient with renal colic. If this technique is not available, plain film and ultrasonography should be considered adding urography in unresolved cases.

Ultrasonography and Plain Film Versus Intravenous urography in ureteric colic

Urography (IVU) is considered the best first investigation in patients with suspected ureteric colic, but recently ultrasonography (US), combined with a plain film of the abdomen (KUB), has been suggested as an alternative. We have undertaken a prospective study to see if this approach can be used in an Emergency Department by radiologists with different amounts of ultrasound experience. Some 180 patients with suspected ureteric colic presenting to the Emergency Department over an 8-month period were studied. They had a plain abdominal film (KUB) and US examination of the kidneys, ureters and bladder following hydration. Some 120 patients subsequently underwent IVU at a mean interval of 3.5 days after the ultrasound examination. Of these, 15 patients passed a stone before their IVU. Of the remaining 105 patients, 44 had an IVU positive for stone and 61 had a negative IVU. Fifty of the 60 patients who did not have an IVU had clinical follow-up and 31 had ultrasound. Our findings in this prospective study suggest that in the hydrated patient the combination of KUB plus US is a sensitive but not very specific screening test (sensitivity 95%, specificity 67%). Because of the high negative predictive value of KUB plus US (95%), urography is not likely to be helpful when KUB plus US are negative. Urography is indicated only if KUB plus US findings are equivocal or if intervention is necessary. If we had used KUB plus US alone as the first test in our patients, urography would have been unnecessary in approximately 60%. Twenty per cent of our patients passed a stone in the first 48 h.

Cost analysis of different protocols for imaging a patient with acute flank pain.

Abstract. The aim of this study was to analyse the costs of different diagnostic approaches to patients with acute flank pain. Four different diagnostic approaches were considered: (a) spiral CT without contrast medium (CM); (b) plain film, ultrasonography (US) and intravenous urography (IVU) – the latter procedure is used in our department in cases still unsolved following the former investigations (28 % in our experience); (c) plain film, US and spiral CT without CM (as an alternative to IVU in 28 % of cases); and (d) IVU. The cost of each procedure in a university hospital was calculated, following analysis of the differential costs of each investigation (equipment, depreciation and maintenance costs, related materials and services, radiologists, radiographers, nurses) and their common costs (auxiliary personnel and indirect internal costs). Finally, we calculated the full cost of each procedure and applied it to the different diagnostic approaches. The full cost of each approach was: (a) spiral CT without CM = 74 Euro; (b) plain film, US and IVU (28 %) = 66.89 Euro; (c) plain film, US and spiral CT without CM (28 %) = 64.93 Euro; (d) IVU = 80.90 Euro. Intravenous urography alone or in unsolved cases is not to be considered because it provides higher costs and worse diagnostic results, whereas X-ray dose to patient is almost equal between IVU and spiral CT. Spiral CT integrated to plain film and US in unsolved cases could be preferred because of lower cost and dose to patient, though reaching a diagnostic conclusion may take longer than an immediate spiral CT.

Radiofrequency Ablation Compared to Surgery for the Treatment of Benign Thyroid Nodules

Objective. Benign thyroid nodules are a common occurrence whose only remedy, in case of symptoms, has always been surgery until the advent of new techniques, such as radiofrequency ablation (RFA). This study aimed at evaluating RFA efficacy, tolerability, and costs and comparing them to hemithyroidectomy for the treatment of benign thyroid nodules. Design and Methods. 37 patients who underwent RFA were retrospectively compared to 74 patients surgically treated, either in a standard inpatient or in a short-stay surgical regimen. Efficacy, tolerability, and costs were compared. The contribution of final pathology was also taken into account. Results. RFA reduced nodular volume by 70% after 12 months and it was an effective method for treating nodule-related clinical problems, but it was not as effective as surgery for the treatment of hot nodules. RFA and surgery were both safe, although RFA had less complications and pain was rare. RFA costed €1,661.50, surgery costed €4,556.30, and short-stay surgery costed €4,139.40 per patient. RFA, however, did not allow for any pathologic analysis of the nodules, which, in 6 patients who had undergone surgery (8%), revealed that the nodules harboured malignant cells. Conclusions. RFA might transform our approach to benign thyroid nodules.

Contrast-induced nephropathy in patients undergoing computed tomography (CONNECT) – a clinical problem in daily practice? A multicenter observational study

Background: Although several studies have examined contrast-induced nephropathy (CIN) following computed tomography (CT) procedures under closely controlled clinical trial conditions, less is known about the incidence of CIN (or its key predictive factors) in a “real world” clinical setting. Purpose: A multicenter, observational registry study was undertaken in Italian hospital radiology departments to retrospectively assess the incidence of CIN in at-risk patients undergoing iodixanol-enhanced CT procedures. Material and Methods: Each department used center-specific (nonstandardized) CT protocols. Data were available from 493 at-risk patients; most (76.4%) had 1 risk factor for CIN, 19.8% had 2, and 3.4% had 3. In all, 169 patients (34.3%) had reduced renal function (estimated glomerular filtration rate [eGFR] <60 ml/min/1.73m2). Prophylactic volume expansion was not used in 70.6% of the study population. Results: The overall incidence of CIN (defined as a ≥44.2 μmol/l [0.5 mg/dl] increase in serum creatinine from baseline 72 h postprocedure) was 2.6%; in the subpopulation of patients with renal impairment (with or without other risk factors), CIN incidence was 4.7%. Multivariate analysis identified renal insufficiency as the only risk factor predictive of CIN (relative risk, 3.850; 95% confidence interval, 1.200–12.348; P=0.023). Conclusion: In the clinical setting of hospital CT radiology practice, where guideline-recommended strategies for CIN prevention may not be consistently followed, use of the iso-osmolar agent iodixanol appears to be associated with a low incidence of CIN in at-risk patients.

Effects of iodinated contrast media on blood and endothelium

The aim of the study was to assess the effects of iodinated contrast media on blood components and endothelium based on experimental and clinical studies and to produce clinically relevant guidelines for reducing thrombotic and hematologic complications following the intravascular use of contrast media. A report was drafted after review of the literature and discussions among the members of the Contrast Media Safety Committee of the European Society of Urogenital Radiology. The final report was produced following discussion at the 12th European Symposium on Urogenital Radiology in Ljubljana, Slovenia (2005). Experimental data indicate that all iodinated contrast media produce an anticoagulant effect and that this effect is greater with ionic contrast media. Several of the in vitro and experimental in vivo studies on haematological effects of contrast media have not been confirmed by clinical studies. Low- or iso-osmolar contrast media should be used for diagnostic and interventional angiographic procedures, including phlebography. Meticulous angiographic technique is the most important factor for reducing the thrombotic complications associated with angiographic procedures. Drugs and interventional devices that decrease the risk of thromboembolic complications during interventional procedures minimize the importance of the effects of contrast media.

US, colour-Doppler US and fine-needle aspiration biopsy in the diagnosis of thyroid nodules

PurposeThe purpose of this study was to correlate the diagnosis of benign or malignant thyroid nodules obtained with grey-scale ultrasound (US) and colour-Doppler US with the cytological findings after US-guided fine-needle aspiration (FNA).Materials and methodsBetween January 2004 and June 2005, 516 thyroid nodules in 420 patients (181 solitary thyroid nodules and 239 multiple nodules) were prospectively evaluated with US, colour-Doppler US and US-guided FNA. The nodules were classified as sonographically benign, suspicious or malignant in accordance with established US criteria. Cytological findings were classified as inadequate, benign, indeterminate, suspicious or malignant. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of US and colour-Doppler US were evaluated using FNA as the reference procedure.ResultsThe sensitivity, specificity, PPV, NPV and overall accuracy values of grey-scale US were 46%, 73%, 34%, 82% and 67%, respectively, for solitary thyroid nodules and 35%, 72%, 14%, 90% and 68%, respectively, for multiple nodules. The evaluation of nodule vascularity with colour-Doppler US produced a slight increase in sensitivity but a slight reduction in specificity.ConclusionsThyroid nodules cannot be accurately characterised using grey-scale US or colour-Doppler US.RiassuntoObiettivoCorrelare la diagnosi ecografica ed eco-color Doppler di benignità o di malignità del nodulo tiroideo con i risultati della citologia dopo agoaspirazione ecoguidata.Materiali e metodiNel periodo tra gennaio 2004 e giugno 2005 sono stati valutati prospetticamente con ecografia, eco-color Doppler e agoaspirazione sotto guida ecografica 516 noduli tiroidei in 420 pazienti (181 pazienti portatori di un nodulo solitario e 239 pazienti con noduli multipli). I noduli sono stati classificati come ecograficamente benigni, sospetti o maligni utilizzando i criteri stabiliti in letteratura. I risultati della citologia sono stati classificati come inadeguati, benigni, indeterminati, sospetti, maligni. Sono stati calcolati i valori di sensibilità, specificità, valore predittivo positivo (VPP), valore predittivo negativo (VPN) e accuratezza diagnostica dell’ecografia e dell’ecografia associata a eco-color Doppler, utilizzando come indagine di riferimento la citologia.RisultatiNei pazienti con nodulo tiroideo solitario i valori di sensibilità, specificità, VPP, VPN e accuratezza diagnostica dell’ecografia in scala dei grigi sono risultati rispettivamente del 46%, 73%, 34%, 82% e 67%. Nei pazienti con multipli noduli i valori sono risultati rispettivamente del 35%, 72%, 14%, 90% e 68%. La valutazione della vascolarizzazione dei noduli al color Doppler ha portato ad un modesto aumento della sensibilità nella caratterizzazione dei noduli, ma ad una riduzione della specificità.ConclusioniL’ecografia e l’eco-color Doppler non consentono di caratterizzare accuratamente il nodulo tiroideo.

CT urography: The end of IVU?

A review of the literature on the diagnostic accuracy of multidetector computed tomography urography (MDCTU) and intravenous urography (IVU) reveals a lack of comparative studies. However, the available data indicate that MDCTU has a high diagnostic accuracy. MDCTU is also preferred by patients, as it does not require bowel preparation. Full acceptance of this technique by the urologist will depend on optimisation of the communication process with a careful selection of the images to be transmitted. MDCTU has a higher cost than IVU but allows some diagnostic algorithms to be simplified. The real concern potentially limiting the widespread use of MDCTU is its higher radiation dose when compared with IVU. Although low-dose protocols will soon be available, a substantial dose reduction can already be achieved by tailoring MDCTU to the clinical problem rather than using a standardised approach. Our analysis indicates that IVU will definitely lose any residual role it may still have. In our department, the last urographic procedure was performed in May 2006.RiassuntoL’analisi della letteratura sulla accuratezza diagnostica di uro-TC ed urografia mette in rilievo la scarsità di dati comparativi disponibili. Quanto finora disponibile sottolinea peraltro la notevole efficacia diagnostica dell’uro-TC. L’uro-TC è inoltre preferita dal paziente non necessitando di una preparazione intestinale. La sua piena accettazione da parte dell’urologo inviante dipenderà da una ottimizzazione del processo di comunicazione che passa attraverso una scelta attenta delle immagini da trasmettere. Sotto il profilo economico l’uro-TC presenta un costo superiore all’urografia, ma offre l’opportunità di ottenere consistenti vantaggi economici per la semplificazione di alcuni iter diagnostici. Il vero nodo che può limitare attualmente il ricorso all’uro-TC è rappresentato dalla dose di radiazioni più elevata che tale esame eroga rispetto all’urografia. Ci si sta avviando verso protocolli a bassa dose, ma già ora una riduzione consistente della dose si può ottenere modificando l’effettuazione dell’indagine in base al problema clinico. Tutte queste considerazioni fanno sì che l’urografia possa veder cancellato anche il limitato spazio che ha mantenuto negli ultimi anni. Nel nostro Istituto l’ultimo esame urografico è stato effettuato nel maggio 2006.