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R Pozzi-Mucelli

Publications and source records attributed to R Pozzi-Mucelli.

At least 19 recordsLinked to original sources
PubMed2002

Usefulness of virtual endoscopic three-dimensional reconstructions of the middle ear.

This work uses a new programme for producing 3D radiological images acquired by means of CT which enables the internal surfaces of the examined structures to be visualized. This new method, which is able to navigate inside organs in a similar way to fibreoptic endoscopy, is known as virtual endoscopy. CT examinations of the temporal bone were carried out using spiral equipment and endoscopic 3D processing was carried out on a separate workstation equipped with a volume-rendering programme. Once the technical parameters necessary for obtaining a representation of the internal surfaces had been defined, a simulation of a virtual otoscopy was conducted by moving the virtual endoscope from the external auditory canal through the annulus to the tympanic cavity. The simulation can be obtained either by moving the endoscope by hand, using the mouse, or by defining a path along which the software automatically creates an endoscopic 3D reconstruction. The images thus obtained are projected sequentially to give a "movie" effect, i.e. a continuous progression of the endoscope. The average time required to conduct the procedure ranges from 20 to 30 min. A virtual endoscopic visualization of the middle ear was obtained which, in particular, generated images of the tympanic cavity with the ossicular chain. In our experience, virtual otoscopy shows the anatomy of the structures of the tympanic cavity in excellent detail and may be considered complementary to CT, providing useful images enabling better visual representation and understanding of this complex structure. Although clinical applications of the technique remain to be defined it may have a role to play in presurgical diagnostic evaluation of the ossicular chain, epitympanum and retrotympanum.

Ear, Middle↗
PubMed2001

Present-day imaging of patients with renal colic.

In the past decade alternatives to urography have been proposed for the study of patients with renal colic. In 1992 it was suggested to replace urography with KUB and ultrasonography. In 1993 the combination of KUB and ultrasonography followed by urography in unresolved cases was proposed and, in 1995, it was suggested to replace urography with unenhanced helical CT (UHCT). This article illustrates the contribution of UHCT to the study of patients with renal colic and analyses advantages and shortcomings of the technique compared with other diagnostic approaches. Diagnostics of the patient with renal colic is based on the detection of direct and indirect signs which allow identification of not only the calculus, with a sensitivity of 94-100% and accuracy of 93-98% according different authors, but also other signs that can serve to guide patient management and evaluate long-term prognosis. Unenhanced helical CT has the capability to detect extraurinary abnormalities which present with flank pain and mimic renal colic. The examination technique affects the quality of the images and therefore diagnostic accuracy as well as the dose to the patient. With regard to setting parameters, the choice of thickness and table feed should be guided by numerous factors. Multiplanar reconstruction is indicated in the study of the entire ureter course to identify the exact site of the calcification for the urologist to perform an evaluation similar to that obtained by urography. Many authors consider UHCT to be a valuable tool for suggesting the best therapeutic approach. Among these there are also urologists. The evaluation is based on the stone detection, its size and level in the urinary tract. Cost analysis shows that the cost of UHCT is equal to or inferior to the cost of urography. With regard to the dose, different data are reported in the literature. A high pitch (more than 1.5) and a thin collimation (3-mm thickness) are good compromise between quality and dose which can be compared to the dose of normal urography. What is to be done if helical CT is not available? If helical CT is not available, plain film plus ultrasonography should be considered. This approach does not solve all the cases; in unresolved cases urography is indicated. It should also be noted that US has a good sensitivity in detecting other conditions such as biliary lithiasis, acute pancreatitis, acute appendicitis and abdomino-pelvic masses which are responsible for pain that mimics renal colic. In conclusion, IVU should not have any more the priority in investigating the patients with renal colic. Helical CT should be the first choice in imaging a patient with renal colic. If this technique is not available, plain film and ultrasonography should be considered adding urography in unresolved cases.

Colic↗
PubMed1997

Delayed CT in acute renal infection.

CT scans of the kidneys obtained approximately 3 hours after contrast administration often reveal useful information in patients with renal infections. In this article, we discuss three main features of these delayed scans. Feature 1 shows a nephrogram replacing a variable portion of the low density areas present in the early enhanced phase. The nephrogram can be streaky, band-like, cone or horseshoe-shaped; Feature 2 exhibits a focal staining or a hyperdense rim surrounding microabscesses and macroabscesses; Feature 3, very rare, is characterized by hyperdense areas located far from the lesions detected on early scans. These features make it possible to better define the actual extent of infection and the presence of the edema, improving diagnostic confidence.

Acute Disease↗
PubMed1994

[Digital angiography and lipiodol computerized tomography in the anatomopathological framework of hepatocarcinoma].

The introduction of therapies other than conventional surgery of hepatocellular carcinoma (HCC) requires an accurate pathologic classification, which is important because it is well known that HCC may have multicentric growth. The Liver Cancer Study Group of Japan has proposed a classification dividing HCCs into three macroscopic forms from the pathologic point of view: nodular, massive and infiltrating HCCs. The nodular type is subdivided into four types: single nodular type, single nodular type with surrounding proliferation, multinodular fused type and multinodular type. Forty-six HCC patients were examined with Lipiodol Computed Tomography (LCT) to investigate the agreement between pathologic and imaging findings. LCT proved to be in close agreement with pathologic findings. Sixteen cases were classified as type I (single nodular type), 8 as type II (single nodular type with limited foci), 1 as type III (multinodular fused type), 18 as type IV (multiple nodular type with diffuse foci) and 3 cases as type V (massive form). No cases of infiltrative forms were observed in our series. Based on LCT findings, the capabilities of digital subtraction angiography (DSA) were studied in the pathologic classification of HCCs. DSA exhibited some limitations in the pathologic classification of HCCs in 5 of 16 patients with type I lesions. In these cases DSA suggested false-positive diagnoses because of regenerative nodules in cirrhotic liver in 3 cases and of daughter nodules (not confirmed at LCT) in 2 cases. In 7 of 8 patients with type II HCCs, DSA failed to show the daughter nodules surrounding the main nodule. In the 18 patients with multiple distant nodules (type IV), DSA was less sensitive in defining nodule number and site. In the massive form, the information obtained with LCT and DSA was comparable. In conclusion, LCT should be considered a basic examination in the study of HCC extent. Based on LCT findings, the most appropriate treatment can be selected, be it surgery, alcohol injection, or intraarterial chemoembolization.

Aged↗
PubMed1991

[The contribution of gadolinium to the magnetic resonance diagnosis of spondylodiscitis].

To determine the contribution of Gd-DTPA to the evaluation of vertebral infections 16 MR examinations with i.v. Gd-DTPA injection were performed on 12 patients with diagnosis of spondylodiscitis. All patients were examined with both SE T1- and SE T2-weighted sequences. The SE T1-weighted sequence was repeated following i.v. Gd-DTPA injection (0.1 nmol/kg). Signal intensities and visibility of the lesions were evaluated with MR. For each lesion the grade of visibility on SE T1-weighted sequence was compared with the grade of visibility on SE T2-weighted sequence. Moreover, for each study the information obtained by the combined evaluation of SE T1-weighted sequence without and with Gd-DTPA was compared with the information obtained by combined SE T1- and SE T2-weighted sequences. Gd-DTPA was useful in the evaluation of lesions of the discal space, showing in all cases an area of low signal intensity with peripheral enhancement; this finding allowed, in some cases, to differentiate mild spondylodiscitis from degenerative features. Gd-DTPA was also very useful in determining the extent of the disease: in comparison with MR study without contrast media, the combined evaluation of SE T1-weighted sequence without and with Gd-DTPA better showed the extent of the disease in 7/8 cases (88%).

Adult↗
PubMed1990

Problematic renal masses in ultrasonography and computed tomography.

The diagnosis of renal masses is based upon the contribution of ultrasonography (US) and computed tomography (CT), which enable the recognition of these lesions with high diagnostic accuracy. However, a number of diagnostic difficulties exist in the definition of the nature of the mass, both for cystic and solid lesions, and to a lesser extent in the identification of the mass. "Complicated" cystic masses, such as calcified cysts, hemorrhagic cysts, inflammatory cysts, abscesses, and cystic tumors may be difficult to diagnose with US and sometimes with CT. CT is helpful in most of these cases because it enables the evaluation of the calcifications and the density of the fluid content. CT is also helpful in cases of cystic tumors because it shows the enhancement of septae within the masses. Problems with solid masses are the identification of small renal tumors and the definition of the benign or malignant nature of the mass. Although both techniques enable the recognition of most tumors, even if small in diameter, they are still limited in defining the pathological structure of the tumor.

Humans↗
PubMed1990

[Magnetic resonance in the diagnosis of bone infections].

Skeletal infections represent a variety of clinical and pathological conditions in which both an early diagnosis and the precise evaluation of disease extent are very important in planning proper therapy. To determine MRI capabilities and limitations in the evaluation of skeletal infections 21 patients--12 with a clinical diagnosis of osteomyelitis of the lower limbs and 9 with a clinical diagnosis of spondyloscitis--were studied with this technique. All patients were examined with conventional X-rays; conventional tomography was performed in 3 cases, and CT in 6. Signal intensities and morphological aspects were then evaluated with MRI. MRI diagnoses were compared with surgical findings or clinical follow-up, after antibiotic therapy: 19 true-positives were observed, together with 1 true-negative, 1 false-positive, and no false-negatives. MRI findings were correlated with those of conventional radiology: MRI identified the lesions and their nature in 100% of cases, whereas conventional radiology did the same in 85% of cases; in 50% of cases only the latter was able to define the nature of the process. Four patients underwent MRI follow-up. MRI was highly sensitive in determining the presence of lesions in an early stage and in demonstrating lesion regression. Moreover, MRI was able to identify the complications occurring in some cases of osteomyelitis and spondyloscitis. In all cases MRI allowed the extent of the disease to be accurately determined and, in osteomyelitis of the lower limbs, it was extremely useful to differentiate soft-tissue infections from bone marrow involvement.

Adolescent↗
PubMed1990

[Magnetic resonance of the bone marrow].

Magnetic resonance imaging has opened new possibilities to current diagnostic radiology in the evaluation of bone marrow. In the past, bone marrow imaging was based on conventional radiology, nuclear medicine and computed tomography; they all exhibited some capabilities but also some limitations. Bone image on MR scans is due to bone marrow, with its different components of red and yellow marrow. Since red marrow is mostly liquid and yellow marrow contains large amounts of fat, the signal will vary, on T1-weighted images, according to their different proportions. There is a gradual change from red marrow to yellow marrow from birth to adulthood: this change determines the MR appearance of bone marrow, the different features of which should be known for a correct evaluation of pathologic findings. MRI is extremely effective in the evaluation of infiltrative disorders of bone marrow, such as leukemia, lymphoma, myeloma, primary and metastatic skeletal tumors, and infections. MRI allows depletive disorders of bone marrow and ischemic processes to be studied. Finally, MRI allows the non-invasive follow up of bone marrow pathologic conditions, thus representing a valid alternative to biopsy.

Bone Marrow↗
PubMed1989

[Comparative analysis of the technics of preoperative localization of the parathyroid glands].

Parathyroid surgery needs an appropriate diagnosis and a preoperative localization. We conducted a prospective study to compare the efficacy of 4 different imaging modalities in 17 patients: thallium-technetium subtraction scintigraphy, ultrasonography, computed tomography and arteriography. The sensitivity was: scintigraphy 58%, echotomography 86%, Tc 92% and arteriography only 33%. Neck exploration confirmed the imaging results. We found 15 cases of adenomas (2 cases of double adenoma) and 1 case of hyperplasia; in 1 patient, no lesions were found. We conclude that the association of such techniques appears to be the optimal strategy in about 100% of the patients.

Adenoma↗
PubMed1988

[Diagnostic imaging of renal tumors of small dimensions].

The incidence of small renal tumors (less than cm 3) has increased in the past few years. Reasons for the increased number of reports are related to the contribution of Sonography and Computed Tomography--which enable a greater number of kidneys to be examined and allow a more detailed study of renal parenchyma. In order to assess the diagnostic value and role of the various imaging techniques in this pathology, the authors reviewed all renal tumors observed between 1982 and 1987. Nineteen cases presented with the characteristics of small renal tumors with "solid" findings on both US and CT. Sixteen cases were histologically proven (15 adenocarcinomas, 1 oncocytoma). Three recent, unoperated, cases are included since their features are the same as in the other cases. Metastases and other kinds of tumors (i.e. angiomyolipomas) are not included in this series. Ivp was performed in 14/19 cases; US and CT were always performed. CT proved to be the most sensitive technique, being positive in all cases. Ivp was positive in 9/14 cases (64%) and US in 14/19 (73%). A significant increase in the number of small renal tumors detected was observed, mainly in 1985-1987. This increase is correlated with the increase in the total number of abdominal examinations which US and CT have made possible. Most patients were asymptomatic; in fact, 15/19 cases were incidentally discovered with US and CT of the upper abdomen. US and CT appear to give a substantial contribution to an early diagnosis of small renal tumors, which may have a significant impact on both surgery and prognosis.

Adenocarcinoma↗
PubMed1986

Impact of technology and technique on the performance of the intravenous D.S.A. of the carotid arteries.

Intravenous Digital Subtraction Angiography (i.v. D.S.A.) was performed at the carotid bifurcation level in 259 patients with clinical or physical findings of a Cerebrovascular Insufficiency (C.V.I.). The angiographic examinations have been performed during two different periods, basically differing for the technology of the digital equipment and for the technique used. The personal experience showed how these two factors are important in determining the quality of the image and therefore the accuracy of the i.v. studies. Images of good quality of the common and internal carotid arteries have been obtained in 73% and 54% of the cases of the first period and in 93% and 82% of the cases of the second period. The role of the i.v. D.S.A. in the management of the C.V.I. depends not only upon the quality of the images, but also upon the surgical policy and from the availability of ultrasounds.

Angiography↗
PubMed1986

[Contrast media in venous digital angiography: ionic or non-ionic?].

Nonionic contrast media (cm) are more and more widely employed in vascular radiology. These cm are the choice in some conventional arteriographies owing to their better tolerability. In intravenous digital subtraction angiography (DSA) the analysis of the personal material and of the literature allows to state that: the image quality with ionic and non ionic cm is similar; the tolerability of nonionic cm is slightly superior; the cardiac and renal toxicity of nonionic cm is slightly lower; reactions to nonionic cm take place with a lower frequency; the price of nonionic cm is considerably higher. Therefore nonionic cm seem to be slightly superior to ionic agents on the basis of these data and they should be theoretically preferred. The only doubt to their routine use in intravenous DSA is the high cost. Therefore we prefer to employ them in risk patients only, as ionic cm in current use are safe and cheap.

Brain↗
PubMed1985

Criteria for choice and use of contrast media in intra-arterial D.S.A.

The authors investigated the optimal characteristics of contrast media for use in intra-arterial DSA. 209 injections in 108 patients were evaluated, most of them in the abdominal and peripheral regions. In order to decrease contrast media osmolarity and obtain an adequate mixing with blood, contrast media with low iodine concentration were injected using the same volumes and flow rates of conventional arteriography. Good results were obtained with ionic contrast media, 100 and 150 mgI/ml. depending on the area investigated. The low concentrations allowed the use of ionic agents with an osmolarity very close to that of the non ionic contrast media: the pain has been eliminated and the heat sensation reduced. Furthermore the comparison with the cost of nonionic agents shows a great saving.

Angiography↗
PubMed1985

Routine evaluation of arteriopathies of the lower extremities by digital subtraction angiography.

Intravenous digital subtraction angiography (DSA) was performed in 119 patients with lower extremity ischemia using a 14" amplifier. Four injections of contrast medium were usually necessary for a complete evaluation of this vascular region. Images of good quality were obtained in most cases; movement artifacts and a faint opacification accounted for any poor results, which occurred mainly under the knee. The technique of pixel shifting turned out to be very useful to remove movement artifacts. The "measuring field" allowed us to minimize the problem of the inhomo geneous saturation of the amplifier. In 8% of the cases an intra-arterial DSA has been performed after an unsatisfactory intravenous examination. Conventional angiography appears to be no longer necessary.

Aged↗
PubMed1984

Digital subtraction angiography in postoperative evaluation of peripheral vascular disease.

The authors present the results of intravenous Digital Subtraction Angiography (DSA) in 41 patients examined after vascular surgery for peripheral disease. The digital technique has always been able to show the patency of the graft or the existence of complications (obstruction, stenosis, pseudoaneurysm), even in asymptomatic patients. The images were of good or excellent quality in 90% of the cases. The equipment with C-arm proved to be very useful for the oblique projections which were required in about 20% of the examinations.

Angiography↗
PubMed1983

Intra-arterial digital angiography of the liver. Preliminary results.

The authors report the preliminary results of the intraarterial digital angiography of the liver. A series of 30 patients were examined comparing conventional and digital technique following the injection of the coeliac, splenic, hepatic and mesenteric arteries. The results obtained with the digital technique have been of good quality and sometimes even better in spite of significant dilution of the contrast medium. It is concluded that intraarterial digital angiography of the liver gives some advantages compared with the conventional technique, that is the use of a much lower concentrated contrast medium, the better visualization of the portal branches and its collaterals and the very low cost of the film material.

Adult↗