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R Passariello

Publications and source records attributed to R Passariello.

At least 37 records · Page 2Linked to original sources
PubMed2002

Multiphase multislice spiral CT for liver assessment: optimization in cirrhotic patients.

PURPOSE: The aim of our study was to optimize a multiphase study protocol with double arterial phase acquisition in a patient population with cirrhosis using a multislice spiral CT scanner. MATERIAL AND METHODS: Thirteen patients (10 males, 3 females, mean age 58 years) with known cirrhosis were selected for the study. All examinations were performed with a multislice spiral CT scanner (Somatom Plus 4 Volume Zoom; Siemens, Erlangen, Germany). Images were acquired using the following parameters: slice collimation, 2.5 mm; slice thickness, 3.0 mm; table feed, 10.8 mm/sec; mAs, 165; kVp, 120. Four scans of the hepatic parenchyma were obtained after the administration of contrast material. The first pass (early arterial phase) was acquired in a cranio-caudal direction; the second pass (late arterial phase) was acquired in a caudo-cranial direction. Early and late arterial phases were obtained during a single breath-hold of 24 sec. The third pass (portal-venous phase) was acquired with a 60-sec delay time after contrast material injection. The fourth pass (equilibrium phase) was obtained with a 180-sec delay time. Optimal delay time to start CT acquisition was assessed by means of injecting a 20-ml minibolus of contrast material and by performing serial dynamic scans every two sec at the level of the hepatic hilum. The time of peak aortic enhancement was used as the start time for the early arterial phase. Attenuation values of aorta, portal vein, and liver parenchyma were calculated in all the acquisitions. CT data from the early arterial phase were used to produce three-dimensional angiographic images of the hepatic and mesenteric circulation. RESULTS: The enhancement of liver parenchyma progressively increased from pre-contrast phase to portal-venous and equilibrium phases. The highest difference in attenuation values between aorta and hepatic parenchyma was observed during the second acquisition (early arterial phase, 247.78+/-106.29 HU) rather than during the third acquisition (late arterial phase, 185.72+/-109.23 HU); this difference was statistically significant (p<0.01). DISCUSSION: Results from our study emphasize the potential of multiphase acquisition in the evaluation of cirrhotic patients; in particular, the use of an early arterial phase is useful for studying the hepatic and mesenteric vascular anatomy, whereas the late arterial and the portal-venous phases are of paramount importance for adequate evaluation of liver parenchyma and focal lesions. Further studies are needed to evaluate whether the benefits deriving from double arterial phase acquisition would justify the increase in cost and patient radiation exposure.

Contrast Media↗
PubMed2002

Esophagogram and CT vs endoscopic and surgical specimens in the diagnosis of esophageal carcinoma.

PURPOSE: Aim of our study was to assess the accuracy of diagnostic imaging in establishing site, morphology and size of the neoplasm comparing surgical specimens or endoscopic examination with esophagograms and CT in patients with esophageal cancer. CT accuracy in defining TNM staging was also evaluated. MATERIAL AND METHODS: From 1993 to 2000 we examined 39 patients with esophageal cancer: 30 males (77%) and 9 females (23%), age range 41-85 years. All patients underwent esophagogram, digestive endoscopy, and chest and abdominal CT. In 22 patients who underwent surgery, we evaluated the correlation between diagnostic imaging and surgical specimens. Patients were divided into 3 groups on the basis of discrepancy between pathological and radiological measurements: =/<1 cm (considered as no discrepancy); 1 to 3 cm; > 3 cm. RESULTS: Esophagogram identified neoplasm in 38 patients out of 39, while CT identified neoplasm in all patients. Location and morphology of the neoplasm established at endoscopy were confirmed in all patients. Lesion length measured at esophagogram corresponded to length of surgical specimens in 13 of the 22 surgically treated patients (59%). In this group there was a dominance of polypoid and stenotic tumor forms. In the remaining 9 cases there was a dominance of ulcerative tumor forms. CT measurement corresponded in 7 patients (32%) with a dominance of polypoid and stenotic tumor forms. T staging performed with CT corresponded to surgical specimens in 12 patients (54%, T3-T4). N staging correlated in 19 patients (86%). CT identified distant metastases in 6 patients (27%). DISCUSSION AND CONCLUSIONS: Our study proves a high sensitivity of esophagogram and CT in the diagnosis of esophageal carcinoma. Esophagogram presented a higher accuracy in establishing tumor length (59% of cases, as compared to CT 32%). Tumor morphology influenced the accuracy of the esophagogram, and highest accuracy was obtained in polypoid and stenotic tumors. T staging performed with CT corresponded to surgical specimens in advanced stages (T3-T4), while accuracy was poorer in smaller superficial lesions (T1-T2) due to the inability of CT to differentiate the layers of the esophageal wall. N understaging in 14% of cases did not modify surgical management. CT presented a high sensitivity in the identification of loco-regional lymph nodes and identified distant metastases in 6 patients. In conclusion, these techniques are accurate and non-invasive and their role in establishing the correct management is therefore important.

Adult↗
PubMed2002

Magnetic Resonance Imaging of the anal canal using high resolution sequences and phased array coil: visualization of anal sphincter complex.

PURPOSE: To assess the normal anatomy of the anal sphincter complex using high-resolution MR imaging with phased -array coil. MATERIAL AND METHODS: Twenty patients, 13 males and 7 females, ranging in age between 27 and 56 years underwent MRI evaluation of the pelvic region, using a superconductive 1.5 T magnet (maximum gradient strength, 25 mT/m; minimum rise time 600 microseconds, equipped with phased-array coil. High-resolution T2-weighted Turbo Spin Echo sequences (TR, 4055 ms; TE, 132 ms; matrix 390x512; in-plane resolution, 0.67x0.57 mm) were acquired on multiple axial, sagittal and coronal planes. Images were reviewed by two experienced gastrointestinal radiologists in order to evaluate the normal anal sphincter complex. RESULTS: Optimal image quality of the anal sphincter complex was obtained in all cases. Different muscular layers were observed between the upper and lower aspects of the anal canal. In the lower part of the anal canal, internal and external sphincter muscles could be observed; in the upper part, puborectal and internal sphincter muscles were depicted. Good visualization of intersphincteric space, levator ani muscle and ischioanal space was also obtained in all cases. CONCLUSIONS: High-resolution MR images with phased-array coil provide optimal depiction of the anal canal and the anal sphincter complex.

Adult↗
PubMed2001

Multislice spiral computed tomography angiography of mesenteric arteries.

The introduction of multislice technology has improved and expanded the clinical applications of computed tomography angiography (CTA), and it is now possible to detect subtle vascular abnormalities. We optimised a high resolution CTA protocol to study the anatomy of mesenteric arteries with a multislice spiral CT scanner. We showed that multislice CTA produces images of high quality, with excellent anatomical visualisation of the main mesenteric trunks, and small collateral vessels. CTA may facilitate the diagnosis of vascular diseases, such as chronic mesenteric ischaemia, as well as acute disorders such as gastrointestinal bleeding.

Adult↗
PubMed2001

Multislice CT colonography: technical developments.

The introduction of multislice spiral computed tomography (CT) offers increased spatial resolution along the longitudinal axis, resulting in improved image quality, and dramatically reduced acquisition times, with the capability of examining large anatomic regions in a single breath hold. Dedicated protocols are still under optimization to reduce radiation exposure and to take full advantage of the new technology. This article presents a review of the literature; the impact of multislice CT on virtual colonoscopy is also discussed.

Colon↗
PubMed2001

[Diffusion-weighted echo-planar sequences for the evaluation of the upper abdomen: technique optimization].

PURPOSE: To optimize the technique for the evaluation of molecular diffusion in the abdomen. MATERIAL AND METHODS: Fifteen healthy volunteers, 6 males and 9 females, ranging in age between 24 and 31 years underwent an MRI evaluation of the upper abdomen, using a superconductive 1.5T magnet (maximum gradient strength, 25 mT/m; minimum rise time 600 ms), equipped with phased array abdominal multicoil. Diffusion study was performed with a single-shot Inversion Recovery Spin-Echo Echo-planar sequence (IR-SE-EPI) with the following parameters: TR = infinite; TE=101 ms; matrix 128 yen 128; receiver bandwidth 2080 Hz/pixel; slices: n.20; slice thickness: 8 mm; acquisition time: 5.41 s. For diffusion weighting the following b values were employed: b=30 mm/s2, b=300 mm/s2 e b=500 mm/s2. Both qualitative and quantitative (calculation of linear regression analysis and of apparent diffusion coefficient) image analysis was performed. RESULTS: Image quality was graded as diagnostic in all the cases. Image quality decreased with the increase of b values: at low b values, the anatomy of upper abdominal organs was easily recognized, whereas, at high b values, the same organs could not be adequately assessed unless the images were compared with those obtained with low b values. Magnetic susceptibility artifacts were observed in all the cases; no significant chemical-shift artifacts were observed as the fat saturation pre-pulse was employed. Quantitative analysis demonstrated an apparent diffusion coefficient of 1.58 s/mm2 for the liver, 1.61 s/mm2 for the spleen and 5,14 s/mm2 for the gallbladder. A statistically significant difference (p<0.001) was observed between parenchymatous organs (liver and spleen) and gallbladder, presenting as a stationary fluid. CONCLUSIONS: Diffusion-weighted MR sequences may be implemented for abdominal studies, but the optimization of same parameters is slightly different compared with neuroradiologic applications. The potential applications are interesting above all as regards the characterization of focal liver lesions. Further developments are awaited in both sequence optimization (greater stability and lower sensitivity to magnetic susceptibility artifacts) and data analysis, with more complex algorithms able to better quantify the real diffusion coefficient.

Abdomen↗
PubMed2001

[Role of color Doppler US in the evaluation of renal transplant].

AIM: To assess the role of Ultrasound (US), US Color Doppler (CD) and Power Doppler (PD) in the diagnosis and in the follow-up of renal graft pathology by evaluating morphological and functional features of the vasculature and comparing these to other clinical parameters. MATERIAL AND METHODS: From January 1990 to June 2000, four hundred and thirty-six renal allograft recipients (mean age 45 years) underwent periodical US, CD and PD (mean follow-up 48 months) to evaluate morphology and perfusion of the graft. Resistive index (RI) and pulsatility index (PI) were measured in order to monitor flow variations from the renal to the arcuate arteries. PD was used mainly to study the morphology of the cortical vessels. The examinations were performed on an Esaote Biomedica AU-4/5 (Genoa, Italy) using a convex 3.5 MHz probe and a linear 7.5 MHz probe. On the basis of clinical data the patients were divided into 3 groups: A) Normal, B) Acute graft dysfunction, C) Chronic allograft nephropathy. In 87 patients (20%) percutaneous biopsy or FNAB was performed. RI and PI mean values +/-SD were calculated and compared to the other diagnostic parameters considered: serum creatinine level, US morphology, CD and PD vascularization. Finally RI and PI for each group were compared using the t -test in order to determine the statistical significance of the correlation between these indices and the patients clinical conditions. RESULTS: The 436 patients were divided as follows: Group A) 170 patients (39%); Group B) 105 patients (24%); Group C) 161 patients (37%). Urological and surgical complications were ruled out in all patients. RI and PI showed a similar trend exceeding cut-off values in Group B) and C) with highest peaks in Group B. Statistical analysis demonstrated the efficacy of this method in the differentiation between normal and pathological grafts, but there was a reduced statistical difference between the two pathological groups. Histological analysis performed on 87 patients (20%) showed good correlation with RI. DISCUSSION AND CONCLUSIONS: CD is a non-invasive diagnostic method which provides flow-metric quantitative parameters for the hemodynamic assessment of the renal transplant. These values present a certain sensitivity but are not specific of renal graft dysfunction, as there is no reliable differentiation between acute rejection and other parenchymal pathologies. During the follow-up, RI and PI have no predictive value. RI variations from renal artery to cortical vessels (hylum-cortical ratio) show a good correlation with the clinical evolution of the transplant. The evaluation of RI and PI can generally be limited to renal and interlobar arteries as arcuate sampling is necessary only when the hylum-cortical ratio shows reduction or inversion. Integration of clinical and instrumental diagnoses can reduce the number of biopsies.

Acute Disease↗
PubMed2001

[Bifid median nerve in the carpal tunnel: integrated imaging].

PURPOSE: Carpal Tunnel Syndrome (CTS) is a neuropathy caused by compression of the median nerve at the level of the wrist, which is caused by different pathologic conditions. In some cases it has been associated with anatomic variations of the median nerve, mainly with the early duplication of the nerve inside the carpal tunnel (III Group of Lanz). The treatment of CTS is mainly surgical consisting in decompression by transection of the transverse carpal ligament, which is better performed by endoscopic release. The aim of our study was to evaluate the possibility to detect this anatomic variant by integrated imaging and assess the value of this information for planning treatment. MATERIAL AND METHODS: We report 6 cases of bifid median nerve examined by Ultrasonography (US) using mechanic sectorial and linear array transducers operating at 10 to 13 MHz, and by MR imaging using 0.2 T equipment. RESULTS: In all cases US transverse scans showed two adjacent oval formations with a structure similar to that of the median nerve. CONCLUSIONS. MR imaging confirmed the sonographic findings in all cases. All patients underwent open surgical treatment by decompression of the median nerve; in all cases an early duplicated median nerve was confirmed.

Carpal Tunnel Syndrome↗
PubMed2001

[Multislice spiral CT angiography in the evaluation of the anatomy of splanchnic vessels: preliminary experience].

PURPOSE: The aim of this study was to optimize the protocol for multislice spiral CT angiography and to assess the ability of the technique to detect the anatomy of splanchnic vessels, using volume rendering as reconstruction algorithm. MATERIAL AND METHODS: The anatomy of splanchnic vessels was studied in 19 patients (11 men, 8 women, age range 38-83 years) undergoing CT of the abdomen and pelvis. All examinations were performed with a multislice spiral CT scanner (Somatom Plus 4 Volume Zoom; Siemens, Erlangen, Germany) using the following parameters: collimation, 1 mm; slice width, 1 mm; table feed, 8 mm/sec; reconstruction interval, 1 mm; mAs, 120; kVp, 120. Before the study, the patients received 800 ml of water as oral contrast agent to opacify the stomach and small bowel. A nonionic contrast medium (130-140 ml; Xenetix 350, Guerbet, Aulnay-Sous-Bois, France) was infused intravenously at a rate of 3-5 ml/sec. Two scans of the abdomen and pelvis were obtained at 20-25 sec (arterial phase) and 60-65 sec (venous phase) after starting contrast medium injection. Image elaboration was performed using Vitrea 2.2 (Vital Images; Minneapolis, Minn., USA), a software with volume-rendering capabilities. RESULTS: All major arterial (celiac trunk, superior mesenteric artery, and inferior mesenteric artery) and venous (portal vein, superior mesenteric vein, inferior mesenteric vein, and splenic vein) vessels could be evaluated with excellent detail in all patients. Side branches, including small collaterals, could also be easily visualized. Volume rendered images always provided better understanding of the 3D anatomic relationships among splanchnic vessels and surrounding organs. DISCUSSION AND CONCLUSIONS: Multislice spiral CT angiography allows for optimal depiction of the anatomy of splanchnic vessels. It can be anticipated that the clinical applications of this imaging modality in the study of splanchnic vessels will be greatly expanded. However, further studies are necessary to rigorously compare the results of multislice spiral CT angiography with conventional angiography in terms of diagnostic accuracy.

Adult↗
PubMed2000

Computed tomography of the small bowel in adult celiac disease: the jejunoileal fold pattern reversal.

The aim of this retrospective study was to establish whether the distinctive intestinal fold pattern of celiac disease (CD), known by barium studies as jejunoileal fold pattern reversal (JFPR) may be recognized at CT. The number of intestinal folds per 2.5 cm, seen at CT, were counted in the jejunum and in the ileum of 22 adult patients with CD and compared with the folds of 30 consecutive subjects in whom an intestinal disease had been excluded. The results were submitted to statistical analysis by Student's t-test. In the control group the number of folds per 2.5 cm were 4.88 (SD +/- 0.78) in the jejunum and 2.84 ( +/- 0.62) in the ileum; in the CD group the number of folds were 2.42 ( +/- 1.61) in the jejunum and 5.11 ( +/- 1.24) in the ileum. There was a statistically significant difference in the number of jejunal and ileal folds between the CD patients and the control group (in both cases p < 0.001). The JFPR was seen in 15 patients with CD (68.2 %) but in none of the controls. Our study shows that JFPR is not a normal finding and can be demonstrated by CT in the majority of patients with CD.

Adult↗
PubMed2000

Contrast-enhanced color Doppler US in malignant portal vein thrombosis.

PURPOSE: To assess the role of contrast-enhanced color Doppler US in the differential diagnosis of benign and malignant portal vein thrombosis. MATERIAL AND METHODS: Fifty-six patients with portal vein thrombosis underwent color and power Doppler US examination before and after i.v. injection of galactose-palmitic acid suspension. The criterion for diagnosing the presence and extension of thrombosis was the lack of visualization of portal vein flow in a segment of the portal vein. The criterion for diagnosing malignant portal vein thrombosis was the detection of pulsatile arterial flow, either hepatopetal or hepatofugal, in the thrombus. The US data were correlated with the types of portal vein thrombosis. RESULTS: Among the 56 patients, there were 40 benign and 16 malignant portal thromboses. Unenhanced Doppler US detected continuous blood flow in 24 benign thromboses and pulsatile in 3 malignant thromboses. No flow, either continuous or pulsatile, was detected in 16 cases with benign thrombosis and in 13 cases with malignant thrombosis. Contrast-enhanced Doppler US allowed to assess pulsatile flow in 15 cases with malignant thrombosis (94%). The use of pulsatile flow as diagnostic criterion of malignant thrombosis yielded a sensitivity of 57% and a specificity of 95% with conventional Doppler US, whereas contrast-enhanced US achieved a sensitivity of 94% and a specificity of 100%. CONCLUSION: Contrast-enhanced Doppler US is a reliable diagnostic tool for assessing malignant portal vein thrombosis.

Aged↗
PubMed2000

Evaluation of bifid median nerve with sonography and MR imaging.

Bifid median nerve is an anatomic variation that may be associated with carpal tunnel syndrome. It is important for the surgeon to be aware of the existence of this condition preoperatively in order to plan the carpal tunnel release. We report the correlation between ultrasonographic findings and magnetic resonance imaging results in six patients with bifid median nerve, selected from a population of 294 patients with carpal tunnel syndrome, who were studied by ultrasonography using a high frequency transducer. Sonography showed two structures inside the carpal tunnel with the same pattern as the median nerve in all six patients. Magnetic resonance imaging confirmed the sonographic findings. The patients underwent open surgery, and a bifid median nerve was found. In conclusion, bifid median nerve is an anatomic variant that can be demonstrated ultrasonographically. It is important to be aware of this anomaly when planning carpal tunnel release surgery.

Adolescent↗
PubMed2000

[Role of color Doppler echography in the visualization of perianal fistulae with injections of physiologic solutions].

PURPOSE: To prove the diagnostic value of color Doppler US in the evaluation of perianal external fistulae, using an endocavitary probe and a saline solution injection, in order to show the location of the fistulae, their extension, possible secondary tracts, residual abscesses and the relationship with adjacent tissues. MATERIAL AND METHODS: From October 1999 to December 1999, thirty-five consecutive patients (21 males and 14 females, mean age 47.5) affected with Crohn's disease were examined prospectively. These patients presented postoperative recurring external perianal fistulae. From this first group, 10 patients (6 males and 4 females, mean age 45) were selected as the external fistula was open. A biplanar transrectal 7.5 MHz probe was used for the examination. First the external opening of the fistula was cannulated with a soft plastic catheter. Then the probe, covered with a lubricated condom filled with US gel, was introduced into the anal canal (males) or the vagina (females). An initial gray-scale US study was performed. Finally the color-box was positioned on the tract, the Pulse Repetition Frequency (PRF) adjusted and the saline solution introduced. The study was completed with axial and linear scans. RESULTS: The mean examination duration was 31 minutes. Only two patients found the examination annoying because of partial anorectal stricture. The wall layers and their thickness were clearly located and distinguished. Gray-scale US showed the local anatomy in all patients. In 4 patients it depicted the primary fistula as a thin hypoecoic line (40%, three intersphinteric and one transphinteric). Color Doppler US detected the fistula in all patients (100%, seven intersphinteric and three transphinteric). Moreover it showed 2 small secondary tracts in 2 patients. No abscesses were found at the time of the examination. In the patients who underwent a second operation, surgical findings showed a good correlation (90-100%) with color Doppler findings. DISCUSSION AND CONCLUSIONS: This study demonstrated a greater diagnostic value of endosonography with color Doppler and saline solution injection as compared to conventional gray-scale endosonography in the evaluation of fistulae. Since this technique is also cost-effective and well tolerated by most patients we conclude that at present it makes an important diagnostic tool in the preoperative assessment of perianal fistulae.

Adult↗
PubMed2000

European projects in radiological data bases for telemedicine and teaching.

Aim of this study is to describe the main characteristics of the European projects IAEVA II and HERMES whose principal objective is to render the already functioning computer systems more efficient. The medical environment is in continuous need of faster and better ways of communication, particularly in a radiological context, and this work therefore presents the above projects mainly from a radiological point of view.

Computer Communication Networks↗
PubMed2000

[Optimization of the technique of virtual colonoscopy using a multislice spiral computerized tomography].

PURPOSE: To optimize scanning parameters for virtual colonoscopy utilizing a multislice Helical CT scanner in an in vitro study (using a homemade colonic phantom) and in a preliminary clinical study. MATERIAL AND METHODS: A colonic phantom was built using a plastic tube and 12 plastiline polyps were placed inside. The colonic phantom was studied with a multislice Helical CT scanner. Axial images were obtained with the phantom parallel to the long axis of the moving table (in order to simulate the evaluation of ascending and descending colon): oblique images were acquired with the phantom at 45 degrees relative to the long axis of the moving table (in order to simulate the evaluation of sigmoid colon and colonic flexures). Four different scanning protocols were tested: 1) slice collimation, 5 mm; slice width, 7 mm; table speed, 25 mm; reconstruction index, 5 mm; 2) slice collimation, 2.5 mm; slice width, 3 mm; table speed, 15 mm; reconstruction index, 3 mm; 3) slice collimation, 1 mm; slice width, 1.25 mm; table speed, 5 mm; reconstruction index, 1 mm; 4) slice collimation, 1 mm; slice width, 1.25 mm; table speed, 4 mm; reconstruction index, 1 mm. Quantitative analysis consisted in evaluation of the number of identified polyps and polyp size along the longitudinal axis. Qualitative analysis consisted in the evaluation of image artifacts and quality of 3D reconstructed images (step artifacts and polyp geometry distortion). This preliminary clinical study was performed in 12 patients (7 men and 5 women) who underwent multislice Helical CT colonography. We selected patients with clinical indications for conventional colonoscopy or after unsuccessful conventional colonoscopy. RESULTS: Multislice Helical CT colonography was 100% sensitive in the detection of all polyps and in all scanning protocols. With oblique scans, only a 3-mm polyp was missed during protocol 1 (sensitivity: 92%). Polyp geometry distortion was observed on longitudinal reconstructions, whereas no distortion was seen on axial images. Image quality was graded as optimal for protocols 2, 3, and 4; protocol 1 was graded as good on transverse scans and as poor on oblique scans. In our preliminary clinical study, two colonic carcinomas and three polyps were identified. CONCLUSIONS: At present, the introduction of multislice technology in virtual colonoscopy permits to improve spatial resolution and image definition. The actual clinical advantage, in terms of increased diagnostic accuracy, needs further investigation in larger clinical studies.

Artifacts↗
PubMed1999

MRI of the biliary and pancreatic ducts.

Magnetic resonance Cholangiopancreatography (MRCP) is a non-invasive imaging technique able to provide projectional images of the bile ducts. Different sequences, using both breath-hold and non-breath-hold acquisition techniques, have been employed in order to obtain MRCP images. The authors discuss technical aspects, considering both three-dimensional non-breath-hold techniques and two-dimensional breath-hold, multi-slice and thick slab sequences. Clinical applications of MRCP are evaluated, presenting data from both the literature and personal experience. The main indication for MRCP study is represented by the evaluation of common bile duct obstruction, with the aim of assessing the presence of the obstruction (accuracy 85-100%) and, subsequently, its level (accuracy 91-100%) and its cause. The utility of associating conventional MR images to MRCP in malignant strictures, in order to characterize and stage the malignant lesion, is also discussed. Finally, data are presented regarding the indications and the utility of MR-pancreatography in the evaluation of patients with pancreatic duct anomalies and chronic pancreatitis.

Bile Duct Diseases↗