Emanuele Scribano

Computed tomography halo sign in pulmonary nodules: frequency and diagnostic value.

On computed tomography (CT) scanning, a ground-glass opacity zone surrounding a pulmonary nodule has been named the computed tomography (CT) halo sign. To investigate the frequency and diagnostic value of the CT halo sign, the authors reviewed the CT examinations of 305 patients with proven diseases producing solitary or multiple nodules. The CT halo sign was seen in 22 patients (7%). Eleven patients had a solitary nodule; five patients had multiple nodules; and six patients had nodules associated with areas of pulmonary consolidation, or ground-glass opacity, or both. Solitary nodules were the result of bronchioloalveolar carcinoma (n = 5), tuberculoma (n = 2), squamous cell carcinoma, non-Hodgkin lymphoma, myxovirus infection, and metastasis (n = 1 each). Multiple nodules were the result of metastasis (n = 2), Kaposi sarcoma (n = 2), and Wegener granulomatosis (n = 1). Nodules associated with areas of consolidation or ground-glass opacity were the result of metastasis (n = 2), bronchioloalveolar carcinoma, bronchiolitis obliterans organizing pneumonia, eosinophilic pneumonia, and invasive pulmonary aspergillosis (n = 1 each). The data showed that the CT halo sign is a nonspecific finding. It is known that in immunocompromised patients the CT halo sign should suggest invasive pulmonary aspergillosis, Kaposi sarcoma, and lymphoproliferative pulmonary disorders. However, in immunocompetent patients, the authors found that a solitary nodule with the CT halo sign and pseudocavitations has a high likelihood of being a bronchioloalveolar carcinoma.

Harmonic US imaging of vesicoureteric reflux in children: usefulness of a second generation US contrast agent

Background: Contrast-enhanced voiding urosonography (VUS) is largely accepted both for the diagnosis and follow-up of vesicoureteric reflux (VUR) in children. Objective: To evaluate the usefulness of contrast-enhanced second-harmonic VUS in the diagnosis and grading of VUR, using a second-generation contrast agent. Materials and methods: Eighty consecutive children were prospectively studied with contrast-enhanced second-harmonic VUS. All children received a second-generation contrast medium, constituted by phospholipid-stabilized microbubbles of sulphur-hexafluoride (SonoVue, Bracco, Milan, Italy). US monitoring of the bladder, of the retrovesical space and of the kidneys was performed using, alternatively, both tissue-harmonic and contrast-harmonic modes. In those young boys where VUR was depicted at VUS, examination was completed with transperineal, sagittal urethral exploration during micturition. VUR was graded in five steps and diagnoses were compared with voiding cystourethrography (VCUG). Results: VUR was diagnosed in 52 reno-ureteral units with VUS. In 49 of these reno-ureteral units, VCUG confirmed the presence of VUR. In comparison to VUS, sensitivity and negative predictive value of VCUG were inferior. The grade of VUR detected at VUS was higher than that detected at VCUG in three units. In no case was the grade of VUR detected at VCUG higher than the one detected at VUS. The differences between VUS and VCUG in grading VUR were statistically significant (p=0.02). Imaging of the normal posterior urethra was skilfully demonstrated with US in 15 young boys with VUR. No statistically significant differences were found between tissue-harmonic and contrast-harmonic mode (p=0.102). Conclusions: Contrast-enhanced second-harmonic VUS is a sensitive and easy technique for the evaluation of VUR. A second-generation US contrast medium such as SonoVue, if available, should be the first choice as the dose required for one examination is much lower and consequently significant reduction of contrast agent cost is possible.

Muscle Fat Fraction in Neuromuscular Disorders: Dual-Echo Dual-Flip-Angle Spoiled Gradient-Recalled MR Imaging Technique for Quantification—A Feasibility Study

PURPOSE To prospectively evaluate the muscle fat fraction (MFF) measured with dual-echo dual-flip-angle spoiled gradient-recalled acquisition in the steady state (SPGR) magnetic resonance (MR) imaging technique by using muscle biopsy as the reference standard. MATERIALS AND METHODS After ethics approval, written informed consent from all patients was obtained. Twenty-seven consecutive patients, evaluated at the Neuromuscular Disorders Center with a possible diagnosis of neuromuscular disorder, were prospectively studied with MR imaging of the lower extremities to quantify muscle fatty infiltration by means of MFF calculation. Spin-density- and T1-weighted fast SPGR in-phase and opposed-phase dual-echo sequences were performed, respectively, with 20° and 80° flip angles. Round regions of interest were drawn by consensus on selected MR sections corresponding to anticipated biopsy sites. These were marked on the patients skin with a pen by using the infrared spider light of the system, and subsequent muscle biopsy was performed. MR images with regions of interest were stored on a secondary console where the MFF calculation was performed by another radiologist blinded to the biopsy results. MFFs calculated with dual-echo dual-flip-angle SPGR MR imaging and biopsy were compared by using a paired t test, Pearson correlation coefficient, and Bland-Altman plots. P value of < .05 was considered to indicate a statistically significant difference. RESULTS The mean MFFs obtained with dual-echo dual-flip-angle SPGR MR imaging and biopsy were 20.3% (range, 1.7%-45.1%) and 20.6% (range, 3%-46.1%), respectively. The mean difference, standard deviation of the difference, and t value were -0.3, 1.3, and -1.3 (P > .2), respectively. The Pearson correlation coefficient was 0.995; with the Bland-Altman method, all data points were within the ± 2 SDs limits of agreement. CONCLUSION The results show that dual-echo dual-flip-angle SPGR MR imaging technique provides reliable calculation of MFF, consistent with biopsy measurements.

Iodine quantification to distinguish clear cell from papillary renal cell carcinoma at dual-energy multidetector CT: a multireader diagnostic performance study.

PURPOSE To investigate whether dual-energy multidetector row computed tomographic (CT) imaging with iodine quantification is able to distinguish between clear cell and papillary renal cell carcinoma ( RCC renal cell carcinoma ) subtypes. MATERIALS AND METHODS In this retrospective, HIPAA-compliant, institutional review board-approved study, 88 patients (57 men, 31 women) with diagnosis of either clear cell or papillary RCC renal cell carcinoma at pathologic analysis, who underwent contrast material-enhanced dual-energy nephrographic phase study between December 2007 and June 2013, were included. Five readers, blinded to pathologic diagnosis, independently evaluated all cases by determining the lesion iodine concentration on color-coded iodine maps. The receiving operating characteristic curve analysis was adopted to estimate the optimal threshold for discriminating between clear cell and papillary RCC renal cell carcinoma , and results were validated by using a leave-one-out cross-validation. Interobserver agreement was assessed by using an intraclass correlation coefficient. The correlation between tumor iodine concentration and tumor grade was investigated. RESULTS A tumor iodine concentration of 0.9 mg/mL represented the optimal threshold to discriminate between clear cell and papillary RCC renal cell carcinoma , and it yielded the following: sensitivity, 98.2% (987 of 1005 [95% confidence interval: 97.7%, 98.7%]); specificity, 86.3% (272 of 315 [95% confidence interval: 85.0%, 87.7%]); positive predictive value, 95.8% (987 of 1030 [95% confidence interval: 95.0%, 96.6%]); negative predictive value, 93.7% (272 of 290 [95% confidence interval: 92.8%, 94.7%]); overall accuracy of 95.3% (1259 of 1320 [95% confidence interval: 94.6%, 96.2%]), with an area under the curve of 0.923 (95% confidence interval: 0.913, 0.933). An excellent agreement was found among the five readers in measured tumor iodine concentration (intraclass correlation coefficient, 0.9990 [95% confidence interval: 0. 9987, 0.9993). A significant correlation was found between tumor iodine concentration and tumor grade for both clear cell (τ = 0.85; P < .001) and papillary RCC renal cell carcinoma (τ = 0.53; P < .001). CONCLUSION Dual-energy multidetector CT with iodine quantification can be used to distinguish between clear cell and papillary RCC renal cell carcinoma , and it provides insights regarding the tumor grade.

Usefulness of power Doppler and contrast-enhanced sonography in the differentiation of hyperechoic renal masses

AbstractBackground: In a prospective study, we compared power Doppler with and without contrast medium in the depiction of vascularity for the characterization of hyperechoic renal lesions. Methods: Forty-one hyperechoic renal expansive lesions (29 benign, 12 malignant) in 32 patients were studied with power-Doppler ultrasonography before and after administration of an echo-enhancing agent (Levovist Schering AG, Berlin, Germany). Vascular architecture of the lesions was categorized into five different patterns. Results: Power Doppler ultrasonography showed vascular structures in 25 lesions. The study enhanced with Levovist showed vascularity in eight of 16 lesions not seen on the unenhanced study. The characterization of vascular patterns with unenhanced power Doppler ultrasonography improved diagnostic accuracy compared with gray-scale ultrasonography (59% vs. 32%). The combination of B mode and power Doppler produced even greater diagnostic accuracy (78%), independent of the administration of echo-enhancing agent. Levovist administration was useful in the differential diagnosis between pseudotumor and neoplasm. Conclusion: The use of songraphic contrast agent did not increase the diagnostic accuracy of power Doppler in the differential diagnosis of hyperechoic renal lesions but was advantageous for the characterization of suspected pseudomasses.

Dual-energy CT for detection of endoleaks after endovascular abdominal aneurysm repair: usefulness of colored iodine overlay.

OBJECTIVE The purpose of our study was to evaluate the value of dual-source dual-energy CT with colored iodine overlay for detection of endoleaks after endovascular abdominal aortic aneurysm repair. We also calculated the potential dose reduction by using a dual-energy CT single-phase protocol. SUBJECTS AND METHODS From November 2007 to November 2009, 74 patients underwent CT angiography 2-7 days after endovascular repair during single-energy unenhanced and dual-energy venous phases. By using dual-energy software, the iodine overlay was superimposed on venous phase images with different percentages ranging between 0 (virtual unenhanced images) and 50-75% to show the iodine in an orange color. Two blinded readers evaluated the data for diagnosis of endoleaks during standard unenhanced and venous phase images (session 1, standard of reference) and virtual unenhanced and venous phase images with colored iodine overlay images (session 2). We compared the effective dose radiation of a single-energy biphasic protocol with that of a single-phase dual-energy protocol. The diagnostic accuracy of session 2 was calculated. RESULTS The mean dual-energy effective dose was 7.27 mSv. By using a dual-energy single-phase protocol, we obtained a mean dose reduction of 28% with respect to a single-energy biphasic protocol. The diagnostic accuracy of session 2 was: 100% sensitivity, 100% specificity, 100% negative predictive value, and 100% positive predictive value. Statistically significant differences in the level of confidence for endoleak detection between the two sessions were found by reviewers for scores 3-5. CONCLUSION Dual-energy CT with colored iodine overlay is a useful diagnostic tool in endoleak detection. The use of a dual-energy single-phase study protocol will lower radiation exposure to patients.

Accuracy of contrast-enhanced dual-energy MDCT for the assessment of iodine uptake in renal lesions.

OBJECTIVE The objective of our study was to assess the accuracy of iodine-related attenuation and iodine quantification as imaging biomarkers of iodine uptake in renal lesions on a single-phase nephrographic image with dual-energy MDCT. MATERIALS AND METHODS Fifty-nine patients (41 men, 18 women; age range, 28-84 years) with 80 renal lesions underwent contrast-enhanced dual-energy CT during the nephrographic phase of enhancement. Renal lesions were characterized as enhancing or nonenhancing on color-coded iodine overlay maps using iodine-related attenuation (in Hounsfield units) and iodine quantification (in milligrams per milliliter). For iodine-related attenuation the iodine uptake thresholds of 15 and 20 HU were tested; a threshold of 0.5 mg/mL was used for iodine quantification. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of iodine-related attenuation and iodine quantification were calculated from chi-square tests of contingency with histopathology or imaging follow-up as the reference standard. The 95% CIs were calculated from binomial expression. Differences in sensitivity and specificity were assessed by means of McNemar analysis. RESULTS A significant difference in sensitivity and specificity was found between iodine-related attenuation with the thresholds of 15 HU (sensitivity, 91.4%; specificity, 93.3%; PPV, 91.4%; NPV, 93.3%) and 20 HU (sensitivity, 77.1%; specificity, 100%; PPV, 100%; NPV, 84.9%) (p = 0.008) and between iodine quantification (sensitivity, 100%; specificity, 97.7%; PPV, 97.2%; NPV, 100%) and iodine-related attenuation with a threshold of 20 HU (p = 0.004). No significant difference in sensitivity and specificity was found between iodine quantification and iodine-related attenuation with a threshold of 15 HU. CONCLUSION Contrast-enhanced dual-energy MDCT with iodine-related attenuation and iodine quantification allows accurate evaluation of iodine uptake in renal lesions on a single-phase nephrographic image.

The role of the ostiomeatal unit anatomic variations in inflammatory disease of the maxillary sinuses

OBJECTIVE The purpose of the study was to determine the correlation between bony anatomic variations of the ostiomeatal unit (OMU) and chronic maxillary sinusitis. The study was based on the hypothesis that the mucosal contact caused by the variations represents the critical factor in increasing the risk of maxillary sinusitis. MATERIALS AND METHODS Thin section high resolution computerised tomography (CT) examinations of the paranasal sinuses in 73 consecutive patients with 113 anatomic variations of the OMU were retrospectively reviewed. The following CT features were assessed: (1) Type of anatomic variations, (2) presence of a mucosal contact in the OMU and (3) presence of maxillary disease. Statistical evaluation was carried out using chi 2-test. RESULTS The following bony anatomic variations were found: Concha bullosa (67 cases), abnormalities of the uncinate process (18 cases), Hallers cells (24 cases) and large ethmoidal bulla (four cases). Only 52 of the 113 anatomic variations were associated with ipsilateral maxillary disease (mucosal thickening, mucous retention cysts, polyps, retained secretions). Of 113 variations, 44 caused a mucosal contact, 35 of these were associated with maxillary abnormalities, while in nine cases there were no pathologic changes. Of 69 variations, 17 did not cause mucosal contact (P < 0.05). CONCLUSION Our data shows that, in the presence of anatomic bony variations, a contact between the mucosal surface of the OMU is valuable in predicting the likelihood of a maxillary inflammatory disease.

Giant fibrovascular polyp of the esophagus : CT and MR findings

Abstract. We present a case of giant fibrovascular polyp of the esophagus with predominant fat contents. Both computed tomography (CT) and magnetic resonance imaging (MRI) findings of this rare tumor are reported. The employment of CT and MRI in the presurgical evaluation of fibrovascular esophageal polyp is suggested.

Potential role of colour-Doppler cystosonography with echocontrast in the screening and follow-up of vesicoureteral reflux.

Primary vesicoureteral reflux is a predisposing factor for urinary tract infections in children. The first‐choice technique for the diagnosis of vesicoureteral reflux is voiding cystourethrography, followed by cystoscintigraphy; cystoscintigraphy, however, has the advantage of only minor irradiation of the patient, but it does not allow the morphological evaluation of bladder and vesicoureteral reflux grading. Colour‐Doppler cystosonography with echocontrast is a recently introduced method for imaging vesicoureteral reflux. The aim of our study is to evaluate the role of colour‐Doppler cystosonography with echocontrast in the diagnosis of vesicoureteral reflux. Twenty children (11M, 9F) aged between 0.4 and 4.9 y underwent colour‐Doppler cystosonography using a diluted solution of Levovist® (Schering, Germany), after filling up the bladder with saline. In all patients, vesicoureteral reflux diagnosis and grading had been performed previously by voiding cystourethrography within 5 d from ultrasonography. Our data showed high accuracy in the detection of medium to severe vesicoureteral reflux (grades III‐V), confirmed by radiological features in 9/9 patients. Conversely, in the 11 patients with mild vesicoureteral reflux (grades I‐II), this technique showed extremely low sensitivity, allowing diagnosis in only four cases.