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Objective: To correlate contrast-enhanced ultrasound (CEUS) findings of hepatic focal nodular hyperplasia (FNH) with lesion size, depth and liver echogenicity and to compare CEUS with baseline US.Methods: Two radiologists evaluated baseline US and CEUS examinations of 92 FNHs (mean size: 3.1 +/- 1.7 cm) in 71 patients (59 women and 12 men) to detect the "spoke-wheel" sign, central scar and feeding vessel. The FNHs were grouped and analysed by dimension, depth and liver echogenicity.Results: At least one sign could be detected at CEUS in 27 out of 36 (75%) FNHs larger than 3 cm and in 17 out of 56 (30%) FNH measuring 3 cm or less (p < 0.0001). No statistically significant differences were noted between lesion depth or liver echogenicity and detection rate of these signs at CEUS (p > 0.05) as well as between CEUS or baseline US/CD with regard to lesion size, depth or liver echogenicity (p > 0.05).Conclusion: The detection rate of the central scar and spoke-wheel sign in FNH at CEUS is strongly dependent on lesion size and CEUS can confidently diagnose most FNHs larger than 3 cm. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the study was to compare the coronary artery calcium score (CACS) and computed tomography coronary angiography (CTCA) for the assessment of non-obstructive/obstructive coronary artery disease (CAD) in high-risk asymptomatic subjects.Methods: Two hundred and thirteen consecutive asymptomatic subjects (113 male; mean age 53.6 +/- 12.4 years) with more than one risk factor and an inconclusive or unfeasible non-invasive stress test result underwent CACS and CTCA in an outpatient setting. All patients underwent conventional coronary angiography (CAG). Data from CACS (threshold for positive image: Agatston score 1/100/1,000) and CTCA were compared with CAG regarding the degree of CAD (non-obstructive/obstructive; or=50% lumen reduction).Results: The mean calcium score was 151 +/- 403 and the prevalence of obstructive CAD was 17% (8% one-vessel and 10% two-vessel disease). Per-patient sensitivity, specificity, positive and negative predictive values of CACS were: 97%, 75%, 45%, and 100%, respectively (Agatston >or=1); 73%, 90%, 60%, and 94%, respectively (Agatston >or=100); 30%, 98%, 79%, and 87%, respectively (Agatston >or=1,000). Per-patient values for CTCA were 100%, 98%, 97%, and 100%, respectively (p < 0.05). CTCA detected 65% prevalence of all CAD (48% non-obstructive), while CACS detected 37% prevalence of all CAD (21% non-obstructive) (p < 0.05).Conclusion: CACS proved inadequate for the detection of obstructive and non-obstructive CAD compared with CTCA. CTCA has a high diagnostic accuracy for the detection of non-obstructive and obstructive CAD in high-risk asymptomatic patients with inconclusive or unfeasible stress test results. [ABSTRACT FROM AUTHOR]

This was a prospective, multicenter study designed to evaluate the utility of MDCT in the diagnosis of coronary artery disease (CAD) in patients scheduled for elective coronary angiography (CA) using different MDCT systems from different manufacturers. Twenty national sites prospectively enrolled 367 patients between July 2004 and June 2006. Computed tomography (CT) was performed using a standardized/optimized scan protocol for each type of MDCT system (> or =16 slices) and compared with quantitative CA performed within 2 weeks of MDCT. A total of 284 patients (81%) were studied by 16-slice MDCT systems, while 66 patients (19%) by 64-slice MDCT scanners. The primary analysis was on-site/off-site evaluation of the negative predictive value (NPV) on a per-patient basis. Secondary analyses included on-site evaluation on a per-artery and per-segment basis. On-site evaluation included 327 patients (CAD prevalence 58%). NPV, positive predictive value (PPV), sensitivity, specificity, and diagnostic accuracy (DA) were 0.91 (95% CI 0.85-0.95), 0.91 (95% CI 0.86-0.95), 0.94 (95% CI 0.89-0.97), 0.88 (95% CI 0.81-0.93), and 0.91 (95% CI 0.88-0.94), respectively. Off-site analysis included 295 patients (CAD prevalence 56%). NPV, PPV, sensitivity, specificity, and DA were 0.73 (95% CI 0.65-0.79), 0.93 (95% CI 0.87-0.97), 0.73 (95% CI 0.65-0.79), 0.93 (95% CI 0.87-0.97), and 0.82 (95% CI 0.77-0.86), respectively. The results of this study demonstrate the utility of MDCT in excluding significant CAD even when conducted by centers with varying degrees of expertise and using different MDCT machines. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the added diagnostic value of contrast-enhanced US (CEUS) combined with 64-row multidetector CT (CT) in the assessment of hepatocellular nodule vascularity in patients with liver cirrhosis. One hundred and six cirrhotic patients (68 male, 38 female; mean age +/- SD, 70 +/- 7 years) with 121 biopsy-proven hepatocellular nodules (72 hepatocellular carcinomas, 10 dysplastic and 15 regenerative nodules, 12 hemangiomas, and 12 other benignancies) detected during US surveillance were prospectively recruited. Each nodule was scanned by CEUS during the arterial (10-40 s), portal venous (45-90 s), and delayed sinusoidal phase (from 100 s after microbubble injection to microbubble disappearance). Nodule vascularity at CEUS, CT, and combined CEUS/CT was evaluated side-by-side by two independent blinded readers who classified nodules as benign or malignant according to reference diagnostic criteria. The combined assessment of CEUS/CT provided higher sensitivity (97%, both readers) than did separate assessment of CEUS (88% reader 1; 87% reader 2) and CT (74% reader 1; 71% reader 2; P < 0.05), while no change in specificity was provided by combined analysis. The combined assessment of hepatocellular nodule vascularity at CT and CEUS improved sensitivity in the diagnosis of malignancy in patients with liver cirrhosis. [ABSTRACT FROM AUTHOR]

The aim of our study was to assess the prevalence of variants and anomalies of the coronary artery tree in patients who underwent 64-slice computed tomography coronary angiography (CT-CA) for suspected or known coronary artery disease. A total of 543 patients (389 male, mean age 60.5 +/- 10.9) were reviewed for coronary artery variants and anomalies including post-processing tools. The majority of segments were identified according to the American Heart Association scheme. The coronary dominance pattern results were: right, 86.6%; left, 9.2%; balanced, 4.2%. The left main coronary artery had a mean length of 112 +/- 55 mm. The intermediate branch was present in the 21.9%. A variable number of diagonals (one, 25%; two, 49.7%; more than two, 24%; none, 1.3%) and marginals (one, 35.2%; two, 46.2%; more than two, 18%; none, 0.6%) was visualized. Furthermore, CT-CA may visualize smaller branches such as the conus branch artery (98%), the sinus node artery (91.6%), and the septal branches (93%). Single or associated coronary anomalies occurred in 18.4% of the patients, with the following distribution: 43 anomalies of origin and course, 68 intrinsic anomalies (59 myocardial bridging, nine aneurisms), three fistulas. In conclusion, 64-slice CT-CA provides optimal visualization of the variable and complex anatomy of coronary arteries because of the improved isotropic spatial resolution and flexible post-processing tool. [ABSTRACT FROM AUTHOR]

Objectives: The Liver Imaging Reporting and Data System algorithm allows category downgrade in the presence of ancillary features (AFs) favoring benignity, even in observations categorized as LR-5. This study aims to assess the role of AFs favoring benignity in LR-5 observations and their impact on category downgrade., Methods: This study included high-risk patients with at least one LR-5 observation imaged with gadoxetate disodium MRI. Three readers with different experience levels independently evaluated the presence of AFs favoring malignancy (not hepatocellular carcinoma (HCC) in particular and HCC in particular) and AFs favoring benignity. Category downgrade was considered possible in the presence of ≥ 1 AF favoring benignity and no AF favoring malignancy. Correlation between observations size and number of AFs was assessed using Spearman's rank correlation coefficient. Cohen's kappa (k) test was used to assess inter-reader agreement., Results: The final study cohort included 162 LR-5 (mean size: 23 ± 16 mm) in 119 patients. AFs favoring benignity were reported in 9 (5.6%), 20 (12.3%), and 10 (6.2%) LR-5 observations by reader 1, reader 2, and reader 3, respectively. Hepatobiliary phase isointensity was observed in 6 (3.7%), 2 (1.2%), and 7 (4.3%) observations, respectively. Category downgrade was considered possible in only one (0.6%) observation by reader 1 and reader 3. There was a significant correlation between observation size and number of AFs favoring malignancy (p < 0.001), not HCC in particular (p ≤ 0.010), and favoring HCC in particular (p < 0.001). Inter-reader agreement of AFs favoring benignity was poor to moderate (k range: - 0.01, 0.43)., Conclusions: AFs favoring benignity are not uncommon in LR-5 observations, but category downgrade is exceptional., Key Points: • Ancillary features favoring benignity are encountered in 5.6-12.3% of observations categorized as LR-5. • Category downgrade of LR-5 observations is very rare (0.6% of observations) in the presence of AFs favoring benignity due to the high prevalence (98-99%) of ancillary features favoring malignancy in LR-5 observations. • The inter-reader agreement of ancillary features favoring benignity is poor to moderate (k range: - 0.01, 0.43) in readers with different levels of experience., (© 2021. European Society of Radiology.)

Objective: The aim of this study was (1) to investigate the application of texture analysis of choline PET/CT images in prostate cancer (PCa) patients and (2) to propose a machine-learning radiomics model able to select PET features predictive of disease progression in PCa patients with a same high-risk class at restaging., Material and Methods: Ninety-four high-risk PCa patients who underwent restaging Cho-PET/CT were analyzed. Follow-up data were recorded for a minimum of 13 months after the PET/CT scan. PET images were imported in LIFEx toolbox to extract 51 features from each lesion. A statistical system based on correlation matrix and point-biserial-correlation coefficient has been implemented for features reduction and selection, while Discriminant analysis (DA) was used as a method for features classification in a whole sample and sub-groups for primary tumor or local relapse (T), nodal disease (N), and metastatic disease (M)., Results: In the whole group, 2 feature (HISTO&#95;Entropy&#95;log10; HISTO&#95;Energy&#95;Uniformity) results were able to discriminate the occurrence of disease progression at follow-up, obtaining the best performance in DA classification (sensitivity 47.1%, specificity 76.5%, positive predictive value (PPV) 46.7%, and accuracy 67.6%). In the sub-group analysis, the best performance in DA classification for T was obtained by selecting 3 features (SUVmin; SHAPE&#95;Sphericity; GLCM&#95;Correlation) with a sensitivity of 91.6%, specificity 84.1%, PPV 79.1%, and accuracy 87%; for N by selecting 2 features (HISTO = &#95;Energy Uniformity; GLZLM&#95;SZLGE) with a sensitivity of 68.1%, specificity 91.4%, PPV 83%, and accuracy 82.6%; and for M by selecting 2 features (HISTO&#95;Entropy&#95;log10 - HISTO&#95;Entropy&#95;log2) with a sensitivity 64.4%, specificity 74.6%, PPV 40.6%, and accuracy 72.5%., Conclusion: This machine learning model demonstrated to be feasible and useful to select Cho-PET features for T, N, and M with valuable association with high-risk PCa patients' outcomes., Key Points: • Artificial intelligence applications are feasible and useful to select Cho-PET features. • Our model demonstrated the presence of specific features for T, N, and M with valuable association with high-risk PCa patients' outcomes. • Further prospective studies are necessary to confirm our results and to develop the application of artificial intelligence in PET imaging of PCa.

Objectives: To assess the intraoperative neuroimaging findings in patients treated with transcranial MR-guided focused ultrasound (tcMRgFUS) thalamotomy using 1.5T equipment in comparison with the 48-h follow-up., Methods: Fifty prospectively enrolled patients undergoing unilateral tcMRgFUS thalamotomy for either medication-refractory essential tremor (n = 39) or Parkinson tremor (n = 11) were included. Two radiologists evaluated the presence and size of concentric lesional zones (zone I, zone II, and zone III) on 2D T2-weighted sequences acquired intraoperatively after the last high-energy sonication and at 48 h. Sonication parameters including number of sonications, delivered energy, and treatment temperatures were also recorded. Differences in lesion pattern and size were assessed using the McNemar test and paired t test, respectively., Results: Zones I, II, and III were visualized in 34 (68%), 50 (100%), and 44 (88%) patients, and 31 (62%), 50 (100%), and 45 (90%) patients after the last high-energy sonication for R1 and R2, respectively. All three concentric zones were visualized intraoperatively in 56-58% of cases. Zone I was significantly more commonly visualized at 48 h (p < 0.001). Diameter of zones I and II and the thickness of zone III significantly increased at 48 h (p < 0.001). Diameters of zones I and II measured intraoperatively demonstrated significant correlation with thermal map temperatures (p ≤ 0.001). Maximum temperature significantly correlated with zone III thickness at 48 h. A threshold of 60.5° had a sensitivity of 56.5-66.7% and a specificity of 70.5-75.5% for thickness > 6 mm at 48 h., Conclusions: Intraoperative imaging may accurately detect typical lesional findings, before completing the treatment. These imaging characteristics significantly correlate with sonication parameters and 48-h follow-up., Key Points: • Intraoperative T2-weighted images allow the visualization of the zone I (coagulation necrosis) in most of the treated patients, while zone II (cytotoxic edema) is always detected. • Lesion size depicted with intraoperative transcranial MRgFUS imaging correlates well with procedure parameters. • Intraoperative transcranial MRgFUS imaging may have a significant added value for treating physicians.

Background: Lacrimal gland (LG) involvement in patients with Graves ophthalmopathy (GO) has been considered as a potential cause of the associated GO symptoms and different studies demonstrated the LG involvement in patients with GO than healthy controls. The aim of this study was to evaluate LG involvement, through measurement of its herniation, using a magnetic resonance imaging (MRI) index, in patients with different GO activities., Methods: Thirty-two consecutive Caucasian patients affected by GO were enrolled and grouped in group A (16 with inactive GO, CAS < 3) and B (16 with active GO, CAS ≥ 3) according to their GO activity. All patients underwent clinical-endocrinological assessment, a complete ocular evaluation, and orbital MRI examination., Results: No difference was found between the hormonal parameters, thyroid ultrasound-derived parameters, and thyroid-stimulating hormone (TSH) receptor (TSH-R) antibodies (TRAb) levels in group B and those in group A. The LG herniation (LGH) measurement evaluated by MRI was significantly higher in group B for both right (10.1 (7.3-17) vs. 7 (0-3.4) mm; p = 0.004) and left (8.5 (6.6-13) vs. 5.8 (0-12) mm; p = 0.026) eye than group A. A positive correlation was found between TRAb and LGH herniation (Rho 0.462, p = 0.009)., Conclusions: Measurement of LGH seems to be a good marker of the disease and GO activity., Key Points: • Lacrimal gland herniation is a simple index related to disease activity • Lacrimal gland herniation is correlated to TRAb levels • Lacrimal gland evaluation could be useful to differentiate active from inactive Graves ophthalmopathy in an early stage of disease.

Objectives: The purpose of our retrospective review of prospectively acquired Whole Body Magnetic Resonance (WB-MRI) scans was to assess the incidence of osteonecrosis in patients who received different chemotherapies., Methods: We evaluated the WB-MRI scans performed on 42 patients with Hodgkin Lymphoma treated by three chemotherapy regimens (6ABVD, 2ABVD + 4BEACOPP, 2ABVD + 8BEACOPP), excluding patients with the main risk factors for osteonecrosis., Results: Six out of seven patients (86 %) who received eight BEACOPP and one out of five patients (20 %) treated by four BEACOPP presented osteonecrosis, with a statistically significant difference of frequency between the two groups of patients (p < 0.05); no injury has been reported in patients treated by only ABVD. Among a total of 48 osteonecrotic lesions observed, 48 % were detected in the knee; multifocal osteonecrosis were detected in six out of seven patients (86 %)., Conclusions: The development of osteonecrosis is strictly related to the chemotherapy protocol adopted and the number of cycles received, with a strong correlation between the dose of corticosteroids included in the BEACOPP scheme and this complication. WB-MRI can be considered as a helpful tool that allows detecting earlier osteonecrotic lesions in patients treated with corticosteroids., Key Points: • Osteonecrosis is a possible complication of patients with Lymphoma treated by chemotherapy. • Osteonecrosis is related to the corticosteroids included within the BEACOPP protocol. • WB-MRI allows detecting osteonecrotic lesions in patients treated with corticosteroids.

Objectives: Aortic distensibility and pulse-wave velocity (PWV) are under investigation as parameters by which to evaluate the indication for ascending aorta (AA) replacement. The maximum rate of systolic distension (MRSD) was proposed as a new index of aortic elasticity. The aim of this study was to assess the role of aortic elasticity parameters to predict AA growth rates in patients with AA dilation (AAD)., Methods: Magnetic resonance imaging (MRI) was performed annually in 65 patients with AA dilation (median follow-up 17 months; 25-75th percentile; range 12-30 months). A significant increase in AA diameter was defined as a ≥2-mm increase., Results: An increase in AA diameter was found in 42 (68 %) patients (AAD+ group) and absent in 20. Median increase was 0.16 (25-75th percentile; range 0.32-0.7) mm/month. The AAD+ group had a lower MRSD (4.6 ± 2.2 vs 7.4 ± 2.0, p < 0.001) but the same PWV and distensibility. MRSD showed 93.7 % specificity and 75.6 % sensitivity for prediction of increase. Patients with MRSD ≤ 6 had lower progression-free survival times (p < 0.002). After a follow-up of 4.1 years, patients who underwent surgical therapy had lower MRSD and distensibility than others., Conclusions: MRSD is an index of aorta elastic properties and is a valuable predictor for progression in AAD., Key Points: • MRI-derived parameters of aortic wall elasticity predict progression of ascending aorta dilation. • Maximal rate of systolic distension (MRSD) was the best predictor of progression. • Patients with MRSD ≤ 6 had lower progression-free survival (PFS) times. • Patients who underwent surgical therapy had lower MRSD and distensibility. • MRI-derived parameters identify patients with fast progression of Ascending Aorta Dilation.

Computed tomography coronary angiography (CTCA) has reached very high standards both in terms of diagnostic performance and radiation dose reduction. This commentary follows a report on CTCA using less than 0.1 mSv in selected patients. This is an extraordinary accomplishment, both for technology and for medicine. The difficult task is now to implement this tool in clinical practice so it can play the best possible role. CTCA can improve diagnostic pathways, can save money for healthcare systems and could even improve pharmacological therapy. All of this may happen, but it will require the combined effort of all the experienced operators in this field, including the referring clinicians. In times of financial constraint, CTCA may also help to restrict ineffective medical expenses.

We assessed the effect of intra-coronary attenuation on diagnostic accuracy using 64-slice computed tomography coronary angiography (CT-CA). We enrolled 170 patients with suspected coronary artery disease who underwent conventional coronary angiography (CA) and 64-slice CT-CA (100 ml of Iomeprol 400 mg I/ml at 4 ml/s). The study population was divided into two groups (85 patients each based on median attenuation of 326 HU) based on mean arterial attenuation; group 1 with low attenuation and group 2 with high attenuation. Diagnostic accuracy for the detection of significant coronary artery stenosis was determined for both groups using CA as reference standard. Overall, 163 significant stenoses were detected in 1,030 assessable coronary artery segments in group 1 compared with 160 significant stenoses in 1,020 assessable segments in group 2. The average intra-coronary attenuation was significantly (P < 0.05) higher for group 2 (388 +/- 46 HU) compared with group 1 (291 +/- 33 HU). The corresponding sensitivity and specificity values for detection of significant coronary artery stenosis were higher for group 2 (96.3% and 97.6%, respectively) than for group 1 (82.8% and 93.2%, respectively) and were more marked in distal coronary segments than in proximal segments. Higher intra-coronary attenuation on CT-CA results in greater diagnostic accuracy for detection of coronary artery stenosis.

Attenuation variability (measured in Hounsfield Units, HU) of human coronary plaques using multislice computed tomography (MSCT) was evaluated in an ex vivo model with increasing convolution kernels. MSCT was performed in seven ex vivo left coronary arteries sunk into oil followingthe instillation of saline (1/infinity) and a 1/50 solution of contrast material (400 mgI/ml iomeprol). Scan parameters were: slices/collimation, 16/0.75 mm; rotation time, 375 ms. Four convolution kernels were used: b30f-smooth, b36f-medium smooth, b46f-medium and b60f-sharp. An experienced radiologist scored for the presence of plaques and measured the attenuation in lumen, calcified and noncalcified plaques and the surrounding oil. The results were compared by the ANOVA test and correlated with Pearson's test. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. The mean attenuation values were significantly different between the four filters (p < 0.0001) in each structure with both solutions. After clustering for the filter, all of the noncalcified plaque values (20.8 +/- 39.1, 14.2 +/- 35.8, 14.0 +/- 32.0, 3.2 +/- 32.4 HU with saline; 74.7 +/- 66.6, 68.2 +/- 63.3, 66.3 +/- 66.5, 48.5 +/- 60.0 HU in contrast solution) were significantly different, with the exception of the pair b36f-b46f, for which a moderate-high correlation was generally found. Improved SNRs and CNRs were achieved by b30f and b46f. The use of different convolution filters significantly modifief the attenuation values, while sharper filtering increased the calcified plaque attenuation and reduced the noncalcified plaque attenuation.

The objective of this study was to assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) to characterize hypoechoic focal hepatic lesions (HFHL) in fatty liver (FL). A study group of 105 patients with FL and 105 HFHLs (52 malignant and 53 benign) underwent CEUS after SonoVue administration. Two blinded readers independently reviewed baseline ultrasound (US) and CEUS scans and classified each lesion as malignant or benign on a five-point scale of confidence, and recorded whether further imaging work-up was needed. Sensitivity, specificity, areas under the receiver operating characteristic (ROC) curve (A (z)), and interobserver agreement were calculated. We observed that the diagnostic confidence improved after reviewing CEUS scans for both readers (A (z)=0.706 and 0.999 and A (z)=0.665 and 0.990 at baseline US and CEUS, respectively; p<0.0001). Inter-reader agreement increased (weighted k=0.748 at baseline US vs. 0.882 at CEUS). For both readers, after CEUS, the occurrence of correctly characterized lesions increased (from 27/105 [27.5%] to 94/105 [89.5%], and from 19/105 [18.1%] to 93/105 [88.6%], respectively; p<0.0001) and the need for further imaging decreased (from 93/105 [88.6%] to 26/105 [24.8%], and from 96/105 [91.4%] to 40/105 [38.1%], respectively; p<0.0001). We conclude that CEUS improves the diagnostic performance of radiologists in the characterization of HFHLs in FL and reduces the need for further imaging work-up.

The composition of an atherosclerotic lesion, rather than solely the degree of stenosis, is considered to be an important determinant of acute coronary events. Whereas until recently only invasive techniques have been able to provide clues about plaque composition with consistent reproducibility, several recent studies have revealed the potential of multislice computed tomography (MSCT) for noninvasive plaque imaging. Coronary MSCT has the potential to detect coronary plaques and to characterize their composition based on the X-ray attenuating features of each structure. MSCT may also reveal the total plaque burden (calcified and noncalcified components) for individual patients with coronary atherosclerosis. However, several parameters (i.e. lumen attenuation, convolution filtering, body mass index of the patient, and contrast to noise ratio of the images) are able to modify the attenuation values that are used to define the composition of coronary plaques. The detection of vulnerable plaques will require more sophisticated scanners combined with newer software applications able to provide quantitative information. The aim of this article is to discuss the potential benefits and limitations of MSCT in coronary plaque imaging.

To assess the feasibility of contrast-enhanced ultrasound (CEUS) of the thyroid gland and to evaluate the potential of this method for characterising solitary thyroid nodules.18 patients affected by solitary thyroid nodules (size range: 0.6 to 3.6 cm; mean: 1.8 cm) confirmed by surgery (nine papillary carcinomas, four follicular carcinomas, three hyperplasias, one follicular adenoma and one Plummer's adenoma) underwent pulse inversion US at low M.I. (0.06 to 0.08) after i.v. injection of a 2.4-mL bolus of SonoVue. Baseline echogenicity and the dynamic enhancement pattern of each nodule, in comparison with adjacent thyroid parenchyma, were assessed. Signal intensity values on grey-scale images were also calculated at baseline, 30 s, 60 s and 120 s after SonoVue administration. Following administration of SonoVue, malignant nodules showed absent (4 out of 13), faint dotted (4 out of 13) and diffuse (5 out of 13) contrast enhancement, in this last case inhomogeneous (4 out of 5 cases) or homogeneous (1 out of 5). Benign nodules showed diffuse contrast enhancement, both homogeneous (3 out of 5) and heterogeneous (2 out of 5). Quantitative data have confirmed subjective findings, but CEUS never modified precontrast analysis. CEUS of thyroid gland is a feasible technique, but overlapping findings seem to limit the potential of this technique in the characterization of thyroid nodules.

Three-dimensional reconstructions represent a visual-based tool for illustrating the basis of three-dimensional post-processing such as interpolation, ray-casting, segmentation, percentage classification, gradient calculation, shading and illumination. The knowledge of the optimal scanning and reconstruction parameters facilitates the use of three-dimensional reconstruction techniques in clinical practise. The aim of this article is to explain the principles of multidimensional image processing in a pictorial way and the advantages and limitations of the different possibilities of 3D visualisation.

The prevalence of benign focal liver lesions (BFLL) is high both in the general population and in patients with known malignancies. The gray-scale ultrasound (US) technique is usually the first-line imaging modality used in the radiological workup of such lesions, but unfortunately it lacks specificity. Furthermore, Doppler examination may often be unsatisfactory owing to motion artefacts, or when small or deeply located lesions are evaluated. Recently, microbubble-based contrast agents used in combination with gray-scale US techniques, which are very sensitive to nonlinear behavior of microbubbles, have led to a better depiction of both microvasculature and macrovasculature of focal hepatic masses, thus improving the reliability of using US in the assessment of liver tumors. This review illustrates the spectrum of enhancement patterns of BFLL on contrast-enhanced ultrasonography with SonoVue, a second-generation microbubble-based contrast agent.

Assessment of attenuation (measured in Hounsfield units, HU) of human coronary plaques was performed using multislice computed tomography (MSCT) in an ex vivo model. In three ex vivo specimens of left coronary arteries in oil, MSCT was performed after intracoronary injection of four solutions of contrast material (400 mgI/ml iomeprol). The four solutions were diluted as follows: 1/infinity, 1/200, 1/80, and 1/20. All scans were performed with the following parameters: slices/collimation 16/0.75 mm, rotation time 375 ms. Each specimen was scored for the presence of atherosclerotic plaques. In each plaque the attenuation was measured in four regions of interest for lumen, plaque (non-calcified thickening of the vessel wall), calcium, and surrounding (oil surrounding the vessel). The results were compared with a one-way analysis of variance test and were correlated with Pearson's test. There were no significant differences in the attenuation of calcium and oil in the four solutions. The mean attenuation in the four solutions for lumen (35+/-10, 91+/-7, 246+/-18, 511+/-89 HU) and plaque (22+/-22, 50+/-26, 107+/-36, 152+/-67 HU) was significantly different between each decreasing dilution (p<0.001). The mean attenuation of lumen and plaque of coronary plaques showed high correlation, while the values were significantly different (r=0.73; p<0.001). Intracoronary attenuation modifies significantly the attenuation of plaques assessed with MSCT.

The objective of this study was to describe the spectrum of contrast-enhancement patterns of hepatic haemangiomas undetermined at grey-scale ultrasound (US) on SonoVue-enhanced pulse-inversion (PI) US. Twenty patients (11 women, nine men) with 35 haemangiomas (size range: 1-7 cm; mean: 3.1 cm) undetermined at baseline US underwent PI at low M.I. (0.05-0.08) after i.v. injection of SonoVue. All haemangiomas were confirmed by typical helical computed tomography (CT) and/or magnetic resonance imaging (MRI) findings. US examinations were videotaped and then reviewed by two experienced radiologists blinded to the final diagnosis. Readers evaluated by consensus the baseline echogenicity and the dynamic enhancement pattern of each lesion, in comparison with adjacent liver parenchyma. After administration of SonoVue, 31/35 (88%) haemangiomas showed peripheral hyperechoic nodules in the arterial phase, followed by progressive centripetal fill-in, which was complete in 25/35 cases and incomplete in 6/35 cases. Three out of 35 (9%) haemangiomas showed rapid and complete fill-in in the arterial phase, which persisted in the portal and delayed phases. Finally, 1/35 haemangiomas (3%) showed a rim of arterial contrast enhancement with progressive and complete centripetal fill-in in portal-venous and delayed phases. In conclusion, PI after the administration of SonoVue enabled the depiction of typical contrast-enhancement patterns in haemangiomas undetermined at baseline US.

The aim of this study was to describe gray-scale appearance of liver parenchyma and focal nodular hyperplasia (FNH) by pulse inversion (PI) ultrasound (US) at baseline and after contrast agent administration in patients with normal and fatty liver. Sixteen consecutive patients (12 women, 4 men) with 29 previously diagnosed FNHs (15 of 29 located in normal liver and 14 of 29 in fatty liver) underwent PI US before and after SH U 508A (Levovist) injection. Signal intensity values were measured within the FNHs and the adjacent liver parenchyma in selected images. Baseline echogenicity of fatty liver was higher (15.19 +/- 2.90 dB +/- SD) than normal liver (10.91 +/- 3.15 dB +/- SD; p<0.001). After Levovist administration, normal livers (7 of 16) showed a statistically significant increase of echogenicity (16.59 +/- 3.81 dB +/- SD; p<0.001) in comparison with fatty livers (9 of 16; 15.75 +/- 3.12 dB +/- SD). The FNHs located in normal liver showed baseline echogenicity higher (12.29 +/- 3.22 dB +/- SD) than that of FNHs arising in fatty liver (7.06 +/- 2.43 dB +/- SD; p<0.001). After Levovist administration, FNHs located in normal liver showed a statistically significant increase of echogenicity (25.30 +/- 4.62 dB +/- SD) in comparison with FNHs located in fatty liver (13.58 +/- 3.54 dB +/- SD; p<0.001); the latter always showed mean values of echogenicity lower than surrounding liver parenchyma. In our series decreased contrast-enhancement pattern of both fatty liver and FNHs located in fatty liver was the most prominent finding when Levovist is administered. Contrast washout was a distinctive feature of FNH arising from the fatty liver.

Computed tomography is an accurate method of identifying the various types of abdominal wall hernias, especially if they are clinically occult, and of distinguishing them from other diseases such as hematomas, abscesses and neoplasia. In this study we examined the CT images of 94 patients affected by abdominal wall hernias observed over a period of 6 years. Computed tomography clearly demonstrates the anatomical site of the hernial sac, the content and any occlusive bowel complications due to incarceration or strangulation. Clinical diagnosis of external hernias is particularly difficult in obese patients or in those with laparotic scars. In these cases abdominal imaging is essential for a correct preoperative diagnosis and to determine the most effective treatment.