Francesco Fraioli

Pancreatic carcinoma: The role of high-resolution multislice spiral CT in the diagnosis and assessment of resectability

Abstract. The purpose of our study was to evaluate multislice computed tomography (MSCT) in the assessment of patients with clinical, laboratory, and US suspicion of pancreatic neoplasm, and to evaluate resectability status. Forty-six patients with a suspected pancreatic tumor underwent MSCT. After a preliminary precontrast survey, a postcontrast scan was performed in the arterial and portal venous phase with the following protocol: 4×1-mm collimation; 1.25- and 5-mm slice thickness width, respectively, and 1- and 5-mm reconstruction interval. In all patients pathological correlation was obtained. The evaluation of all images provided a diagnosis in 44 patients, with a sensitivity, specificity, and accuracy of 97, 80, and 96%, respectively. The MSCT correctly provided a diagnosis of unresectability with sensitivity of 96%, specificity of 86%, and accuracy of 93%. Evaluation of 1-mm slices demonstrated 83 of the 91 liver metastases found at surgery; conversely, the 5-mm slices detected only 76 of these lesions. Infiltration of peripancreatic major vessels was demonstrated, and was confirmed at surgery in 18 patients. High-resolution MSCT improves prediction of resectability in patients with suspected pancreatic carcinoma. Parenchymal and vascular information can be achieved with a single MSCT examination.

Whole-Tumor Perfusion CT in Patients with Advanced Lung Adenocarcinoma Treated with Conventional and Antiangiogenetic Chemotherapy: Initial Experience

PURPOSE To determine whether wide-volume perfusion computed tomography (CT) performed with a new generation scanner can allow evaluation of the effects of chemotherapy combined with antiangiogenetic treatment on the whole tumor mass in patients with locally advanced lung adenocarcinoma and to determine if changes in CT numbers correlate with the response to therapy as assessed by conventional response evaluation criteria in solid tumors (RECIST). MATERIALS AND METHODS Forty-five patients with unresectable lung adenocarcinoma underwent perfusion CT before and 40 and 90 days after chemotherapy and antiangiogenetic treatment. RECIST measurements and calculations of blood flow, blood volume, time to peak, and permeability were performed by two independent blinded radiologists. Pearson correlation coefficient was used to assess the correlation between baseline CT numbers. Baseline and follow-up perfusion parameters of the neoplastic lesions were tested overall for statistically significant differences by using the repeated-measures analysis of variance and then were also compared on the basis of the therapy response assessed according to the RECIST criteria. RESULTS Pearson correlation coefficient showed a significant correlation between baseline values of blood flow and blood volume (ρ = 0.48; P = .001), time to peak and permeability (ρ = 0.31; P = .04), time to peak and blood flow (ρ = -0.66; P < .001), and time to peak and blood volume (ρ = -0.39; P = .007). Blood flow, blood volume, and permeability values were higher in responding patients than in the other patients, with a significant difference at second follow-up for blood flow (P = .0001), blood volume (P = .02), and permeability (P = .0001); time to peak was higher in nonresponding patients (P = .012). CONCLUSION Perfusion CT imaging may allow evaluation of lung cancer angiogenesis demonstrating alterations in vascularity following treatment.

Long-term follow-up after bronchoscopic lung volume reduction in patients with emphysema

Bronchoscopic lung volume reduction (BLVR) is a novel emphysema therapy. We evaluated long-term outcome in patients with heterogeneous emphysema undergoing BLVR with one-way valves. 40 patients undergoing unilateral BLVR entered our study. Pre-operative mean forced expiratory volume in 1 s (FEV1) was 0.88 L·s−1 (23%), total lung capacity was 7.45 L (121%), intrathoracic gas volume was 6 L (174%), residual volume (RV) was 5.2 L (232%), and the 6-min walk test (6MWT) was 286 m. All patients required supplemental oxygen; the Medical Research Council (MRC) dyspnoea score was 3.9. High-resolution computed tomography (HRCT) results were reviewed to assess the presence of interlobar fissures. 33 patients had a follow-up of >12 months (median 32 months). 37.5% of the patients had visible interlobar fissures. 40% of the patients died during follow-up. Three patients were transplanted and one underwent lung volume reduction surgery. Supplemental oxygen, FEV1, RV, 6MWT and MRC score showed a statistically significant improvement (p≤0.0001, p=0.004, p=0.03, p=0.003 and p<0.0001, respectively). Patients with visible fissures had a functional advantage. BLVR is feasible and safe. Long-term sustained improvements can be achieved. HRCT-visible interlobar fissures are a favourable prognostic factor.

Multidetector–row CT angiography of renal artery stenosis in 50 consecutive patients: prospective interobserver comparison with DSA

Purpose.The purpose of this study was to establish the diagnostic value of multidetector–row computed tomography (MDCT) angiography compared with digital subtraction angiography (DSA) for detection and quantification of both main and accessory renal artery stenosis in patients with secondary hypertension.Materials and methods.Fifty consecutive patients scheduled for DSA were considered candidates for MDCT angiography. In all patients, MDCT angiography of the abdominal aorta was performed before DSA. For the purpose of interpretation, the arteries were separately interpreted either with DSA or MDCT angiography in order to provide qualitative and quantitative information. For qualitative evaluation, one experienced reader graded the opacification of renal arteries as excellent, good or poor; for quantitative evaluation, MDCT and DSA were independently evaluated for the number of renal arteries and the presence, location and degree of stenosis in random order by three readers. On the basis of consensus readings, calculations of sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) for detection of degree of stenosis were made by using DSA findings as the standard of reference. Interobserver variability was also assessed.Results.With regard to qualitative analysis, arterial enhancement was considered excellent in 39 patients and good in 11. For quantitative analysis, 73 arteries were classified as normal with DSA. Although 72 of these were also classified as normal with CT angiography, one was overestimated by one grade; at DSA, 16 arteries were classified as moderately stenotic; in two arteries, there was an overestimation of one grade. Perfect correlation was achieved for the diagnosis of occlusion. In two patients, all three readers detected multiple severe stenoses on both modalities, with a “string–of–beads” appearance typical of fibromuscular dysplasia. Accessory arteries were correctly identified as such by all three readers on either DSA or MDCT. Levels of sensitivity, specificity and accuracy regarding degree of stenosis were 100%, 98.6% and 96.9%, respectively, with PPV and NPV of 97.6% and 100%, respectively. When we considered significant arterial stenosis (50%–100% luminal narrowing), sensitivity, specificity and accuracy were 100%, 97.3% and 97.8%, respectively, with a PPV and NPV of 98.2% and 97.8%, respectively. For all observers, interobserver agreement was almost perfect (k=0.81–1) for both MDCT and DSA, with a k value between 0.82 and 0.95.Conclusions.MDCT angiography is very accurate and robust, even for the assessment of renal artery stenosis, and has the potential to become a viable substitute, in most cases, for diagnostic catheter–based DSA.

MDCT of the abdominal aorta: basics, technical improvements, and clinical applications

ConclusionMultiple diagnostic techniques have been proposed for the evaluation of the abdominal aorta and iliac arteries so as to avoid the use of DSA.The development of MDCT has improved the assessment of the aorta and its branches allowing increasingly faster acquisition of thin sections. The increasing speed of the acquisition requires more attentive administration of iodinated contrast agent, at higher flow rates and with higher iodine concentration so that a homogeneous enhancement throughout the acquisition is achieved. Compared to other techniques, MDCT angiography has several advantages related to transverse data acquisition and the possibility of performing multiplanar interactive reconstructions. Furthermore, the rapid diffusion of MDCT scanners worldwide, not followed by the diffusion of high-field-strenght MR systems, enable to perform high quality MR angiography, has allowed an increasing number of CT angiography examinations to be performed.There are two major limitations of MDCT angiography in the evaluation of patients with peripheral arterial disease: the use of ionizing radiation and iodinated contrast agents. Regarding the radiation issue, it has been recently noted that it is not that important in older individuals who are the typical patients with peripheral arteriopathy, and that the radiation dose, compared with that of DSA, is significantly lower. Furthermore, as shown in other areas, it might be possible to reduce the radiation dose to the patient by optimizing the acquisition protocol. Concerning the use of iodinated contrast agents, it must be noted that several patients present with poor renal function and cannot tolerate administration of a possibly nephrotoxic agent; nevertheless, the nephrotoxicity of nonionic contrast agents has been significantly reduced as compared with ionic contrast agents and their administration can be considered safe and well tolerated, even in high-risk populations. Furthermore, the amount of iodinated contrast agent needed for MDCT angiography is significantly lower than that of single-slice spiral CT angiography, and the further increase in speed of new multidetector-row CTs will allow the use of even smaller amounts.

Cardiopulmonary exercise testing (CPET) in pulmonary emphysema.

In patients affected by chronic obstructive pulmonary disease (COPD), cardiopulmonary response to exercise was never related to the severity of emphysema (E) measured by high resolution computed tomography (HRCT). Sixteen patients (age=65±8 yrs; FEV(1)=54±18%pred; RV=160±28%pred) with moderate to severe E (quantified by lung HRCT as % voxels <-910 HU) were exercised on a cycle-ergometer to exhaustion. Oxygen uptake (V˙(O2)), carbon dioxide output (V˙(CO2)), ventilation (V˙(E)), tidal volume (V(T)), and end-tidal P(CO2) (PET(CO2)) derived variables were measured breath-by-breath. The % of E correlated with: (1) the ratio V(Tpeak) (r=0.74; p=0.001); (2) the V˙(E)/V˙(CO2) slope (r=-0.77; p=0.0004); (3) PET(CO2) values at peak exercise (r=0.80; p=0.0001). Also, the %E was strongly predicted by the following exercise equation: %E(EST) = 58.1 + 11.9 × ΔV˙(E)/V˙(CO2) (r=0.94; p<0.0001). A V(Tpeak)/FEV1 ratio>1 is typically observed in severe E patients; furthermore, the V˙(E)/V˙(CO2) slope and the PET(CO2peak) values decrease and increase respectively as more as the emphysema is severe.

Multidetector-row CT angiography of the infrarenal aortic and lower extremities arterial disease

Since its first clinical implementation in 1991, CT angiography with volumetric scanning has had a substantial impact in the field of non-invasive diagnostic imaging. Helical CT has experienced, over the past decade, a revolution of its technology improving X-ray tubes capabilities, gantry rotation and interpolation algorithm performances, and has challenged digital subtraction angiography (DSA) in the evaluation of many districts of the vascular system [2, 6]. Nevertheless, the greatest advance has been the introduction of multidetector-row computed tomography (MDCT) scanners that have profound implication for clinical CT scanning [1, 3]. Currently capable of acquiring 16 channels of helical data simultaneously, MDCT scanners have substantially improved the quality and ease of performing angiographic studies, leading CT angiography to a robust method of volumetric vascular imaging. Based on the greatest incremental gain in scan speed since the development of helical CT, fundamental advantages of MDCT include substantially shorter acquisition times, but also acquisition of large volumes at high resolution (0.625, 1.25-mm effective thickness), with excellent visualization also of small branches, reducing the amount of iodinated contrast agent and improved threedimensional (3D) rendering with diminished artefacts. As CT angiography has become a mainstream examination in many radiology departments, a discussion of techniques toward optimizing CT angiography performed with MDCT scanners is important. An overview of clinical setting of peripheral arterial disease (PAD) and an elucidation of MDCT principles focused on optimizing peripheral vascular imaging is presented. A discussion of contrast medium administration strategies proceeds, with attention toward injection protocol and bolus timing. An outline of 3D visualization techniques is subsequently presented.

Quadruple-Phase MDCT of the Liver in Patients with Suspected Hepatocellular Carcinoma: Effect of Contrast Material Flow Rate

OBJECTIVE The purposes of this study were to evaluate the effect of contrast material flow rate (3 mL/sec vs 5 mL/sec) on the detection and visualization of hepatocellular carcinoma (HCC) with MDCT and the safety profile of iodixanol at different injection rates. SUBJECTS AND METHODS In a prospective, randomized multicenter trial, 97 patients (83 men and 14 women, with a mean age of 64 years) suspected of having HCC underwent quadruple-phase (double arterial, portal venous, delayed phase) 4-16-MDCT. Patients were randomized to receive iodixanol, 320 mg I/mL (1.5 mL/kg body weight), at a flow rate of 3 mL/sec (48 patients) or 5 mL/sec (49 patients). Qualitative (lesion detection, image quality) and quantitative (liver and aortic enhancement, tumor-liver contrast) analyses and safety assessment were performed. RESULTS Overall, 145 HCCs were detected in the 5 mL/sec group and 100 HCCs in the 3 mL/sec group (p < 0.05). More lesions equal to or less than 1 cm were detected at 5 mL/sec (33 vs 16 lesions). The late arterial phase showed significantly more lesions than the early, arterial phase (133 vs 100 and 96 vs 67 lesions, respectively, p < 0.0001). Hyperattenuating HCCs were better visualized in the late arterial phase at 5 mL/sec (excellent visualization: 54% vs 27%). Using a flow of 5 mL/sec did not increase the rate of patient discomfort or contrast media-related adverse events. Most discomfort in both groups was of mild intensity and there was no severe discomfort. CONCLUSION For detection of HCC with MDCT, a higher flow rate of 5 mL/sec is recommended. Visualization of hyperattenuating HCC is improved with no greater discomfort or adverse events.

Localization of pancreatic insulinomas with MR imaging at 0.5 T.

Objective: To determine the role of MR imaging in the localization of pancreatic insulinomas in patients with clinical and laboratory diagnosis of insulinproducing tumor. Material and Methods: Thirty-one patients presenting with signs and symptoms of pancreatic insulinomas were prospectively included in our study. Twenty-six patients underwent surgery, and pathologic specimens were examined: 5 patients, in whom the initial diagnosis of insulinoma was excluded, were also studied and then followed up. All patients were studied with a high gradient power 0.5 T magnet. Images were evaluated by 2 radiologists blinded to previous investigations, tests and results. Results: MR imaging correctly localized 24 of the 26 insulinomas (2 were false-negative and 1 false-positive) and was correctly negative in the 5 control patients. the interobserver agreement had a kappa value of 0.89. Conclusion: MR imaging was accurate in localizing pancreatic insulinomas and as a consequence, patients in our institution are now submitted to surgery directly after the MR examination. Invasive methods are considered only in cases in which, despite clear biochemical results, MR imaging has not demonstrated a pancreatic focal lesion.

Radial scars of the breast: Contrast-enhanced magnetic resonance mammography appearance

Abstract:  The purpose of this study was to evaluate the appearance of contrast‐enhanced magnetic resonance mammography (CE‐MRM) in patients with suspected radial scar on mammography. Thirty women with radial opacities or black star findings at mammography, preoperatively underwent CE‐MRM. Examinations were performed with a 1.5 T magnet with a bilateral surface coil using a FS T2‐weighted turbo spin echo (TSE) and three‐dimensional (3D) dynamic T1‐weighted fast low‐angle shot (FLASH) sequences. Criteria for lesion evaluation included morphologic patterns and signal intensity curves. Mammography and CE‐MRM findings were compared with pathologic findings. CE‐MRM suggested the presence of radial scar in 18 of 30 cases and the presence of malignancy in 11 of 30 cases; 1 lesion was classified as borderline. At surgery 22 radial scars (including 4 with associated ductal carcinoma in situ) and 8 carcinomas were detected. CE‐MRM provided a specificity of 89%, sensitivity of 83%, and accuracy of 87%. Differently from breast cancer, radial scars are nonenhancing at CE‐MRM. Nevertheless, the possibility of nonenhancing carcinomatous foci existing within radial scars implies that surgical excision should be performed in all cases.