[From evidence to care sustainability: risk management by contrast agent in cancer patient. Experience in an italian teaching hospital]. / Dalle evidenze alla sostenibilità assistenziale: la gestione del rischio da mezzo di contrasto nel paziente oncologico. Esperienza in un centro universitario italiano.

The use of organo-iodinated contrast media (CM) in diagnostics and intervention has increased in the last 10 years. It is necessary to distinguish between the different types of contrast agent, primarily with respect to osmolarity: with low osmolarity the safety profile for the patient is higher. The risk of acute renal injury caused by contrast agent (PC-AKI) is however determined also by risk factors related to the patient. Particularly in main centers, it is advisable to have a standardized program in order to stratify patients with respect to risk, to define prevention strategies and the roles of the specialists involved. The experience described in this work consists in the application of an organizational model relating to CT, with a feasibility study of applying an evidence-based check-list in the clinical routine, as a tool to support clinical decisions (Clinical Decision Support System, CDSS) in the oncology field. A pilot evaluation was carried out on 54 patients belonging to the case series treated in a Teaching Hospital, in a day service regime with a diagnosis of solid tumor. The results of this evaluation led the working group to believe that the CDSS thus structured determines the possibility of overestimating the clinical risk of PC-AKI, and consequently to redefine the evaluation form. Experience has shown that it is not generally easy to immediately identify an algorithm useful for standardizing the management of clinically complex situations, such as PC-AKI prevention. The conduction of pilot evaluations can be a valid instrument of harmonization between the solidity of the references deriving from evidence based medicine and the tangibility of real world data. It is advisable to broaden the application of the CDSS more in a larger number of cases, as well as conduct a pre-post analysis relating to the clinical impact in terms of incidence from PC-AKI.

Comparison of iodinated contrast media for the assessment of atherosclerotic plaque attenuation values by CT coronary angiography: observations in an ex vivo model.

OBJECTIVE: To compare the influence of different iodinated contrast media with several dilutions on plaque attenuation in an ex vivo coronary model studied by multislice CT coronary angiography. METHODS: In six ex vivo left anterior descending coronary arteries immersed in oil, CT (slices/collimation 64×0.625 mm, temporal resolution 210 ms, pitch 0.2) was performed after intracoronary injection of a saline solution, and solutions of a dimeric isosmolar contrast medium (Iodixanol 320 mgI ml(-1)) and a monomeric high-iodinated contrast medium (Iomeprol 400 mgI ml(-1)) with dilutions of 1/80 (low concentration), 1/50 (medium concentration), 1/40 (high concentration) and 1/20 (very high concentration). Two radiologists drew regions of interest in the lumen and in calcified and non-calcified plaques for each solution. 29 cross-sections with non-calcified plaques and 32 cross-sections with calcified plaques were evaluated. RESULTS: Both contrast media showed different attenuation values within lumen and plaque (p<0.0001). The correlation between lumen and non-calcified plaque values was good (Iodixanol r=0.793, Iomeprol r=0.647). Clustered medium- and high-concentration solutions showed similar plaque attenuation values, signal-to-noise ratios (SNRs) (non-calcified plaque: medium solution SNR 31.3±15 vs 31.4±20, high solution SNR 39.4±17 vs 37.4±22; calcified plaque: medium solution SNR 305.2±133 vs 298.8±132, high solution SNR 323.9±138 vs 293±123) and derived contrast-to-noise ratios (p>0.05). CONCLUSION: Differently iodinated contrast media have a similar influence on plaque attenuation profiles. ADVANCES IN KNOWLEDGE: Since iodine load affects coronary plaque attenuation linearly, different contrast media may be equally employed for coronary atherosclerotic plaque imaging.

Clinical indications for cardiac computed tomography. From the Working Group of the Cardiac Radiology Section of the Italian Society of Medical Radiology (SIRM).

Cardiac computed tomography (CCT) has grown as a useful means in different clinical contexts. Technological development has progressively extended the indications for CCT while reducing the required radiation dose. Even today there is little documentation from the main international scientific societies describing the proper use and clinical indications of CCT; in particular, there are no complete guidelines. This document reflects the position of the Working Group of the Cardiac Radiology Section of the Italian Society of Radiology concerning the indications for CCT.

ECG-gated multidetector computed tomography for the assessment of the postoperative ascending aorta.

PURPOSE: This study was undertaken to define the role of electrocardiographically (ECG)-gated multidetector computed tomography (MDCT) in the assessment of the postoperative ascending aorta. MATERIALS AND METHODS: From November 2006 to June 2007, 21 patients, [11 men, ten women; age +/- standard deviation (SD): 62.7+/-10.8 years] with a history of ascending aorta replacement underwent ECG-gated MDCT and were prospectively included in our study. Ascending aorta replacement had been performed with different surgical techniques: Bentall-De Bono (four patients, 19%), Tirone-David (five patients, 23%), and modified Tirone-David with creation of aortic neosinuses (12 patients, 57%). Two patients were excluded from MDCT evaluation because they failed to fulfil the inclusion criteria. Transthoracic echocardiography was used as the reference standard. All patients provided informed consent. RESULTS: In all patients, ECG-gated MDCT provided a clear depiction of the aortic annulus, aortic root and ascending aorta, enabling accurate measurements in all cases. The aortic valve area (3.4+/-0.2 cm(2)), the diameter of the sinotubular junction (31.6+/-1.8 mm), the diameter of the neosinuses in the case of modified Tirone-David procedures (37.3+/-2.1 mm) and the distance between the cusps and the graft wall during systole (3.1+/-0.7 mm) fell within standard ranges and showed a good correlation (r=0.89) with the values obtained with transthoracic echocardiography. CONCLUSIONS: MDCT is currently considered a compulsory diagnostic step in patients with suspected or known aortic pathology. MDCT is a reliable technique for anatomical and functional assessment of the postoperative aortic root and provides cardiac surgeons with new and detailed information, enabling them to formulate a prognostic opinion regarding the outcome of the surgical procedure.

Assessment of left main coronary artery atherosclerotic burden using 64-slice CT coronary angiography: correlation between dimensions and presence of plaques.

PURPOSE: The aim of this study was to correlate left main (LM) coronary artery dimensions with the presence of atherosclerosis by multidetector-row computed tomography (MDCT) coronary angiography (CA) and to assess coronary atherosclerotic plaques with a semiquantitative method. MATERIALS AND METHODS: Sixty-two consecutive patients (41 men, mean age 60+/-11) with suspected coronary artery disease underwent 64-MDCT coronary angiography. LM dimensions (length, ostial and bifurcation diameters), quantitative [location, Hounsfield unit (HU) attenuation] and qualitative (composition, shape) analysis of plaques within the LM were performed. All patients underwent conventional CA. RESULTS: Thirty patients (mean age 55+/-10) without plaques in the LM presented the following average dimensions: length 10.6+/-6.1 mm, ostial diameter 5.5+/-0.7 mm, bifurcation diameter 4.9+/-0.9 mm. LM plaques (n=36) were detected in 32 patients (mean age 64+/-10) with the following LM average dimensions: length 11.3+/-4.0 mm, ostial diameter 6.0+/-1.2 mm and bifurcation diameter 6.0+/-1.2 mm. Plaques were calcified (40%, mean attenuation 742+/-191 HU), mixed (43%, mean attenuation 387+/-94 HU) or noncalcified (17%, mean attenuation 56+/-14 HU) and were frequently eccentric (77%). Age was significantly different in the two groups (p<0.05). LM diameters of patients with plaques were improved (p<0.05). A moderate correlation was found between the LM bifurcation diameter and the corresponding plaque area (r=0.56). Significant conventional CA lesions of the LM were present in just three patients (5%). CONCLUSIONS: Increased LM diameters are associated with the presence of atherosclerosis. MDCT CA indicates relevant features of LM atherosclerotic burden, as rupture and subsequent thrombosis of vulnerable plaques may develop from lesions characterised as nonsignificant at conventional CA.

Diagnostic accuracy of 64-slice CT in the assessment of coronary stents.

PURPOSE: The purpose of this study was to assess the diagnostic accuracy of 64-slice computed tomography (64-CT) coronary angiography in the detection of coronary in-stent restenosis. MATERIALS AND METHODS: Ninety-five patients (72 men and 23 women, mean age 58+/-8 years) with previous percutaneous coronary intervention with stenting and suspected restenosis underwent 64-CT (Sensation 64, Siemens). The mean time between stent deployment and 64-CT was 6.1+/-4.2 months. The scan parameters were: slices 32 x 2, individual detector width 0.6 mm, rotation time 0.33 s, feed 3.84 mm/rotation, 120 kV, 900 mAs. After the intravenous administration of iodinated contrast material (Iomeprol 400 mgI/ml, Iomeron, Bracco) and a bolus chaser (40 ml of saline), the scan was completed in <12 s. All coronary segments with a stent were assessed on 64-CT by two observers in consensus and judged as: patent, with intimal hyperplasia (lumen reduction of <50%), with in-stent restenosis (> or =50%), or with in-stent occlusion (100%). The consensus reading was compared with conventional coronary angiography. RESULTS: Four patients were excluded because of insufficient image quality. In the remaining 91, we assessed 102 stents (31 RCA; 10 LM; 54 LAD; 7 CX). In 14 (13.7%) stents, in-stent restenosis (n=8) or in-stent occlusion (n=6) was found. Intimal hyperplasia was detected in 11 (10.8%) stents. The sensitivity and negative predictive value of 64-CT for in-stent occlusion were 100% and 100%, respectively, whereas for all stenoses, >50% they were 92.9% and 98.7%, respectively. CONCLUSIONS: We found that 64-CT has a high diagnostic accuracy for the detection of in-stent restenosis in a selected patient population.

Three-dimensional quantitative assessment of lung parenchyma in cystic fibrosis: preliminary results.

PURPOSE: The aim of this study was to assess the feasibility of three-dimensional (3D) reconstructions and quantitative analysis of the volume of each component of the lung with cystic fibrosis (CF). MATERIALS AND METHODS: Twenty-two patients with CF (mean age 17+/-8 years) were included in the study. The patients underwent an unenhanced single-slice spiral computed tomography (CT) chest scan with the following parameters: collimation 3 mm, table feed 6 mm x rot(-1), reconstruction interval 1 mm, soft tissue reconstruction kernel. Four image data sets were obtained: native axial slices, cine-mode display, virtual bronchographic volume-rendered images with algorithm for tissue transition display and virtual endoluminal views. The lungs were segmented manually from the hilum to the visceral pleura on the axial images, and the entire lung volume was calculated. A histogram was generated representing the fractional volume of tissues, the density of which was within a preset range. A curve was then obtained from the histogram. RESULTS: Native axial images and cine-mode display allowed complete evaluation of lung volumes. Virtual bronchography allowed a better assessment of the distribution of bronchiectasis. Virtual bronchoscopy was limited by the fact that it visualised only the surface, without differentiating mucus from the bronchial wall. Manual segmentation and generation of density-volume curves required 41+/-7 min for each lung. Three curve patterns were identified depending on disease severity. CONCLUSIONS: Volume-density analysis of lungs with CF is feasible. Its main advantage is that image analysis is not analogical, as the assessment is not performed using scoring systems or similar ordinal scales. This technique cannot differentiate acute from chronic findings, and the predictive value of the curve should be assessed.

Non-invasive assessment of coronary artery stent patency with multislice CT: preliminary experience.

PURPOSE: To evaluate the diagnostic accuracy of multislice computed tomography coronary angiography (MSCT-CA) in the detection of in-stent restenosis. MATERIALS AND METHODS: Forty-two patients (33 male, 9 female, mean age 58+/-8 years) previously subjected to percutaneous implantation of coronary stent with suspected in-stent restenosis, underwent a 16-row MSCT (Sensation 16, Siemens) examination. The average time between stent implantation and MSCT-CA was 7.4+/-5.3 months. The following scan parameters were used: collimation 16x0.75 mm, rotation time 0.42 s, feed 3.0 mm/rot., kV 120, mAs 500. After administration of iodinated contrast material (Iomeprol 400 mgI/ml, 100 ml at 4 ml/s) and bolus chaser (40 ml of saline at 4 ml/s) the scan was completed in <20 s. All segments with a stent were assessed by two observers in consensus and were graded according to the following scheme: patent stent, in-stent intimal hyperplasia (IIH) (lumen reduction <50%), in-stent restenosis (ISR) (=/>50%), in-stent occlusion (ISO) (100%). Consensus reading was compared with coronary angiography. RESULTS: Forty-seven stents were assessed (16 in the right coronary artery; 4 in the left main; 22 in the left anterior descending; 5 in the circumflex). In 7 (17%) stents there was ISR (3) or ISO (4), and in 4 (10%) stents there was IIH. The sensitivity and negative predictive values for the detection of ISO were 80% and 98%, respectively, while for the detection of ISR+ISO they were 50% and 89%, respectively. CONCLUSIONS: Although the results are encouraging, the follow-up of stent patency with MSCT-CA does not show a diagnostic accuracy suitable for clinical implementation.

Small renal masses: assessment of lesion characterization and vascularity on dynamic contrast-enhanced MR imaging with fat suppression.

OBJECTIVE: The aim of our study was to characterize renal lesions equal to or smaller than 3.0 cm using dynamic contrast-enhanced MR imaging with fat suppression by means of quantitative analysis of signal intensity. MATERIALS AND METHODS: We retrospectively reviewed the MR imaging examinations of 35 patients (20 with renal cell carcinoma, eight with angiomyolipoma, and seven with complicated cysts) who were studied with spin-echo and dynamic fat-suppressed gradient-recalled echo MR sequences, before and after the administration of gadopentetate dimeglumine. Every 30 sec after contrast injection, we measured the lesion percentage of enhancement and the ratio of contrast (lesion-renal cortex signal intensity difference) to noise. RESULTS: Ten renal cell carcinomas were classified as hypervascular (enhancement greater than that of renal cortex) and 10 as hypovascular. The percentage of enhancement of hypervascular carcinomas was similar to that of renal cortex until 150 sec and greater in the late sequences (180-210 sec, p < 0.01). Hypovascular carcinomas had a lower percentage of enhancement than hypervascular carcinomas (60-210 sec, p < 0.005). Angiomyolipomas, after an early enhancement peak, showed values similar to those of hypovascular carcinomas. Complicated cysts had very low enhancement (p < 0.001). The baseline contrast-to-noise ratio was negative for all lesions (hypointensity with respect to renal cortex). After gadolinium injection, the contrast-to-noise ratio of hypervascular carcinomas rose, becoming positive after 150 sec. Until 60 sec, the contrast-to-noise ratio of hypovascular carcinomas declined slightly, whereas that of angiomyolipomas and cysts fell sharply; then the three curves remained stable (60-210 sec, p < 0.05 for all matches except angiomyolipomas versus cysts). CONCLUSION: Quantitative analysis of signal intensity variations during dynamic contrast-enhanced MR imaging with fat suppression can be useful in the characterization of small renal lesions.

[The assessment of skin tumors with magnetic resonance with high resolution and a paramagnetic contrast medium]. / Valutazione dei tumori cutanei con Risonanza Magnetica con elevata risoluzione e mezzo di contrasto paramagnetico.

INTRODUCTION: The technologic improvement of surface coils in MRI has allowed better visualization of the skin and thus permitted the clinical use of this technique in dermatology. MRI allows to assess the depth and extent of skin tumors and to detect any malignant transformation. The MR differentiation between benign and malignant skin lesions relies on morphological criteria which however do not have an absolute diagnostic value. We investigated the role of paramagnetic contrast agents in the differentiation between benign and malignant skin lesions. MATERIAL AND METHODS: Forty-one patients, 33 with benign and 8 with malignant skin tumors, were submitted to MRI. All the examinations were performed with a 1.5 T superconductive unit, with a 2.5 cm surface coil. Axial T1- and T2-weighted SE images were acquired with 2 mm slice thickness. Paramagnetic contrast material was administered to all patients. The signal intensity of the skin lesions was calculated before and after paramagnetic contrast agent administration positioning a region of interest. A percentage ratio of contrast enhancement was calculated to quantify contrast agent uptake and the relative values were compared between benign and malignant lesions. A qualitative analysis was also performed rating the contrast enhancement of each lesion as high, intermediate, or absent. RESULTS: The quantitative analysis showed a statistically significant difference (p < .5) between the contrast enhancement values of benign and malignant lesions. In particular, malignancies had values ranging 117.3 (+/- 28.7) to 125 (+/- 32.4), while benign lesions had -20.6 to 99.8 (+/- 21.1). Conversely, no difference in contrast enhancement was found at qualitative analysis. CONCLUSIONS: MRI is a promising tool for characterizing skin tumors. Our preliminary results should be confirmed on larger series of patients with the use of high temporal resolution imaging sequences.

[Stener lesions: ultrasonography assessment in 12 cases]. / Lesione di Stener: valutazione ecografica in 12 casi.

We investigated the ultrasonographic (US) features of Stener injury and thus the role of US in the diagnosis of this condition. Stener injuries are characterized by the tear of the cubital ligament system of the first metacarpophalangeal joint during hyperabduction. This condition may be associated with the displacement of the ligament proximal stump above the thumb adductor muscle. We examined 12 patients (9 men and 3 women) with a clinical diagnosis of joint instability due to hyperabduction of the first metacarpophalangeal joint. All the US exams were performed with a linear probe (7.5-10 MHz); a 13-MHz probe was also used in 7 patients. All the patients were submitted to radiography in the standard projections, to detect associated bone injuries. US allowed the identification of a round lesion surrounded by a hypoechoic halo, between the distal edge of the dorsal interosseous muscle of the first finger and the first metacarpal bone (the proper Stener injury) in 4/12 patients. In contrast, no typical sign was shown in the other 8 patients. US results were then compared with surgical findings. The diagnosis of proper Stener injury was surgically confirmed in 4 patients. Only 2 patients with clinical signs of thumb instability, who were negative for Stener injuries at US, were submitted to surgery which demonstrated the ligament tear responsible for joint instability, but ruled out the displacement. To conclude, US must be integrated with clinical signs because this imaging method accurately shows complete tears with displaced proximal stump of the cubital ligament.