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P Pavone

Publications and source records attributed to P Pavone.

At least 91 records · Page 5Linked to original sources
PubMed1997

[MR cholangiopancreatography: technique, indications and clinical results].

INTRODUCTION: MR cholangiopancreatography (MRCP) is a new noninvasive imaging technique for the study of biliopancreatic disorders, providing projectional images of the biliary tree and pancreatic duct without any contrast agent. MATERIAL AND METHODS: We used different sequences, with both breath-hold and nonbreath-hold techniques, to acquire MRCP images, first based on GE and then on FSE sequences. FSE images provide higher SNR and are less susceptible to artifacts (metal objects, motion and blood flow artifacts). At the Department of Radiology of the University of Rome La Sapienza, we acquired MRCP images with non breath-hold, 3D fat-suppressed TSE sequences (TR = 3000-2000, TE 700, turbo factor 128) optimized on a .5T magnet with 15 mT/m gradients. No patient preparation or sedation was required, although antiperistaltic drugs and oral administration of tap water were preferred. Four hundred and thirty patients were examined, all of them with an indication to conventional cholangiography. RESULTS: MRCP depicted the whole common bile duct and the first-order intrahepatic branches in all the normal cases. Its accuracy in identifying biliary obstruction level and site was 100%, versus 94.6% in characterizing its cause. MRCP had 96.3% diagnostic accuracy in choledocholithiasis, with some false positives and false negatives caused by: 1) small stones missed on MIP reconstructions; 2) signal loss due to complete CBD obstruction by stones; 3) pneumobilia; 4) differential diagnosis between small stones and air bubbles. The main role of MRCP in benign strictures is to provide a detailed map of the biliary tract for better treatment planning. In particular, MRCP is extremely useful in hepaticojejunostomy patients, where ERC is not indicated because of postoperative anatomical changes. Both conventional MRI and MRCP are important in malignant strictures to identify the lesion and to characterize and stage it. Finally, MR pancreatography is very useful to follow up chronic pancreatitis patients because it shows Wirsung duct strictures and dilatations, intraductal filling defects and, in some cases, the communication between the pseudocyst and the pancreatic duct. CONCLUSIONS: MRCP combined with conventional MRI can completely replace CT and ERCP in bilio-pancreatic disorders.

Adult↗
PubMed1996

MR cholangiopancreatography (MRCP) at 0.5 T: technique optimisation and preliminary results.

The aim of our study was to evaluate the feasibility of MR cholangiopancreatography (MRCP) at 0.5 T. To our knowledge no previous studies of MRCP have been performed at mid-field strength. Thirty-one patients with dilated biliary systems were examined with three-dimensional MRCP. All patients were studied with a 0.5 T superconducting magnet. A three-dimensional turbo spin-echo (TSE) sequence was acquired (TR = 5000 ms, TE = 244 ms, echo train length = 45; acquisition time = 14 min 10 s). Coronal images were post-processed with the MIP algorithm. Recently, the parameters have been optimised (TR = 3000 ms, TE = 700 ms, echo train length = 128), reducing the acquisition time to 3 min. Endoscopic retrograde cholangiopancreatography (ERCP) was performed in 26 cases; 5 patients underwent percutaneous transhepatic cholangiography PTC. MRCP and ERCP images were evaluated by an experienced radiologist and an endoscopist. MRCP of diagnostic quality was acquired in all patients. Choledocholithiasis was correctly evaluated by MRCP in 12 of 12 patients, compared with 11 correct diagnoses by ERCP. The presence and the level of the stricture were accurately shown in 16 of 16 patients with MRCP and in 13 of 16 patients with ERCP. The peripheral biliary tree above the obstruction and pancreatic duct were better evaluated by MRCP in all cases. In 3 of 3 patients who had undergone bilio-enteric surgery, a correct evaluation of the site of the anastomosis was possible with MRCP. It is concluded that MRCP performed at mid-field strength allows good visualisation of the dilated biliary system. Excellent results have been obtained on comparison with ERCP. MRCP performed at mid-field strength could have the same clinical value as high field strength MRCP.

Adult↗
PubMed1996

An integrated approach to senology education: combination of a hypermedia program with a multimedia archive.

The aim of this work was to demonstrate the computerized system on senology, which combines a hypermedia application to a multimedia didactical archive, integrated with a radiological information system. These applications have been developed on Macintosh computers using the softwares Supercard and 4th Dimension. The hypermedia application deals with basic principles of anatomy as well as the radiologic semeiology and pathology through different imaging techniques in order to illustrate basic principles. Thus, students can modify their learning pathways and the timing as they wish. Limitations are related to time consumption in preparing the programs and technical difficulties in expanding them. Multimedia archive allows to classify a large number of difficult and uncommon clinical cases, creating an easily updatable teaching file in digital format which considerably improves access to stored image data, also reducing loss of films and film degradation. From initial experiences we conclude that these systems are valid devices in information and up to date for physicians dedicated to the study of breast pathology.

Breast↗
PubMed1996

Radiology information and image management system: new approach to PACS with hypermedia capabilities of personal computers.

A system for archiving patient data and images was developed, installed, and evaluated in a radiology department. The system was developed with a relational database program for use with commercially available computers linked with an Ethernet network. The main options of the system are those of a conventional radiology information system: scheduling, registration, examination execution, reporting, archives and statistics, and system administration. However, the main feature of the system is the image archiving capability. Images are associated with patient records after capture by direct acquisition of the video signal or by scanning. Only relevant pathologic images are archived and a commonly employed compression algorithm is used, reducing the total memory requirement for each case to 200-600 kbytes. The diagnosis is still made by reading the original images. The low-resolution images stored in the system have an important role in teaching and consultation and as a first-line archive. Good results have been obtained with this system, which is used by medical and nonmedical staff without any special training.

Humans↗
PubMed1996

[Magnetic resonance pyelography: optimization of the technic and the preliminary results].

Magnetic resonance pyelography (MRP) is a new noninvasive method which demonstrates dilated urinary tracts with no need of contrast agent injection. This study was aimed at technique optimization, using new fast sequences with high intrinsic contrast, to demonstrate the urinary tract in obstructive uropathy patients. Twelve consecutive patients and 4 healthy volunteers were included in this prospective study; all the exams were performed with a high gradient power 0.5-T unit using T2- weighted turbo SE sequences, acquired three-dimensionally on the coronal plane. Obstructive uropathy was caused in 9 patients by neoplastic lesions, in 2 by postoperative strictures and in 1 by inflammatory tissue. In all patients MRP depicted the dilated urinary tract optimally, with good morphological detailing and the accurate assessment of both level and cause of obstruction. In the healthy volunteers, the absence of dilatation did not permit the complete visualization of the urinary tract. To conclude, MRP is a new technique which permits high-quality imaging of the urinary tract. Further studies are needed to assess its actual potentials and clinical role.

Adult↗
PubMed1996

[Lithiasis of the common bile duct: the role of cholangiography and magnetic resonance].

The aim of our study was to evaluate the sensitivity, specificity and diagnostic accuracy of Magnetic Resonance Cholangiography (MR-CP) in patients with suspected choledocholithiasis. Sixty-two patients (mean age: 56.3 years) previously submitted to US, were examined with MRCP. MR exams were performed with an 0.5 T superconductive magnet (Gyroscan T5-II; Philips, Medical System, Best, NL) and a body coil. 3D-TSE sequences (TR/TE/ETL = 5.000/244/45 ms) were acquired, with 14 min 10 sec acquisition time. In the last 21 patients, acquisition time was reduced down to 3 min, by optimizing the parameters as follows: TR/TE/ETL = 3.000/700/128 ms. The images, obtained on the coronal plane, were then reconstructed with the MIP algorithm. MRCP images were studied both as MIP reconstructions and as single slices. The diagnosis was always compared with endoscopic or percutaneous findings. MRCP images were of diagnostic quality in all cases, with 91.7% sensitivity, 100% specificity and 96.8% diagnostic accuracy. MRCP had 100% positive predictive value and 95% negative predictive value. In conclusion, this technique is extremely useful to examine the patients with obstructive jaundice secondary to lithiasis.

Adult↗
PubMed1996

[Breast scintigraphy with technetium 99m sestamibi, as support to radiologic methods in the study of breast lesions].

Our study was aimed at investigating the efficacy of scintigraphy with 99mTc-Sestamibi (MIBI) as a support to mammography and US in the diagnosis and staging of breast cancer. Twenty-seven women with breast lesions were examined: the masses, detected at mammography and US, ranged in diameter 0.7 to 2.5 cm; mass features suggested a benign lesion in 5 patients, a malignant lesion in 9 patients and a questionable diagnosis in 13 patients. 99mTc-MIBI scintigraphic images were analyzed blind by two observers and the pattern was considered positive when tracer uptake was demonstrated at the lesion. In neoplastic lesions, tracer uptake was looked for also in the axilla. All the patients were submitted to surgery and, in case of malignancy, lymphadenectomy was also performed. MIBI scintigraphy was negative in 14/16 benign lesions and positive in 9/11 malignant lesions. Tracer uptake in the axilla was observed in 3 of 5 patients with nodal involvement. Scintigraphy had 82% sensitivity, 87% specificity and 85% accuracy in the diagnosis of breast cancers.

Adult↗
PubMed1996

[Computed tomography patterns in patients treated with laparoscopic Nissen fundoplication for gastroesophageal reflux].

This work was aimed at investigating the CT anatomy in patients submitted to Nissen's fundoplication. Forty patients (mean age: 61 years) with peptic esophagitis (9 patients), refractory gastroesophageal (GE) reflux (11 patients) and hiatal hernia (20 patients) were examined. CT studies were performed with a third generation unit (CT Pace, General Electric, USA) with the patients in the prone position, after Gastrovison (Schering) and barium paste administration. In 34 patients, CT demonstrated surgery-related anatomical changes, such as the presence of a soft tissue mass at the distal third of the esophagus. In 4 patients, functional incompetence of the fundoplication (3 patients) and a recurrent hyatal hernia (1 patient) were demonstrated. In conclusion, CT studies performed with a dedicated technique permitted the accurate assessment of the anatomy of the GE junction after Nissen's fundoplication. In our study, CT demonstrated the presence of postoperative fluid collections and specific signs related to fundoplication incompetence. Our results suggest a possible application of CT to the postoperative follow-up of the patients submitted to Nissen's fundoplication, with a complementary role that of to endoscopy and functional exams.

Adult↗
PubMed1996

[Magnetic resonance angiography of the portal vein in liver transplant recipients].

This work was aimed at investigating the diagnostic accuracy of Magnetic Resonance Angiography (MRA) in the study of the portal vein in liver transplant recipients. Ten patients (7 men and 3 women; mean age: 45 years) were examined 7-180 days after transplantation. The indications to liver transplant follow: post-infective active chronic hepatitis (4 patients), post-alcoholic chronic hepatitis (2 patients), HCC (2 patients), sclerosing cholangitis (1 patient) and primary biliary cirrhosis (1 patient). MRA images were acquired with the 2D TOF technique (TR 50 ms, TE 6.9 ms; FA 30 degrees, 40 slices; 6-mm thickness with 1-mm overlapping; 2 averages; 7.06 TA; matrix: 192 x 256). Axial scans were reconstructed with the MIP technique. Phase contrast sequences with retrospective cardiac triggering were also acquired for flow quantitation (TR/TE/FA: 26/9.3/20 degrees; FOV 150; matrix: 96 x 128; 4 averages, VENC = 20 cm/s). MRA yielded good quality images of the anatomy of the main portal vein and of the bifurcation in all cases, while a signal loss was observed in the peripheral branches. In all cases, the anastomosis could be studied at the portal vein. On MIP reconstructed images, the anastomosis appeared as a relative stenosis (4), while on 2D images it appeared as a small hypodense area on the vessel margin, because of the slight paramagnetic effect of the vascular suture. No thrombi were depicted in any patient and flow was hepatopetal in all cases. In conclusion, MRA is a useful tool for portal system studies in liver transplant recipients, because it permits the panoramic depiction of the portal system and the quantitation of flow (10).

Female↗