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F Pretolesi

Publications and source records attributed to F Pretolesi.

29 records · Page 2Linked to original sources
PubMed1996

Interlobular vasculature in renal transplants: a power Doppler US study with MR correlation.

PURPOSE: To evaluate, with power Doppler (PD) ultrasound (US), the normal interlobular vasculature in patients who underwent renal transplantation and to assess if defects of the PD signal at the interlobular level correspond to cortical areas that lack blood perfusion at magnetic resonance (MR) imaging. MATERIALS AND METHODS: Thirty-two normal and 33 malfunctioning transplanted kidneys were studied with PD US (6.5 MHz). PD images of interlobular vessels were graded on a scale of normal (pattern I) and decreasing visualization. In kidneys with focal (pattern II) and diffuse (pattern III) absence of interlobular signal, correlative dynamic MR imaging was performed. RESULTS: Interlobular vessels were consistently depicted with PD US in the proximal cortex of normally functioning transplanted kidneys. Of kidneys with a pattern II appearance, five had no contrast material enhancement in the cortical sites in which the interlobular PD signal was detected and three were contrast enhanced but it was less intense than that in adjacent cortical sites with normal interlobular vasculature. All transplanted kidneys with a pattern III appearance had delayed contrast enhancement. CONCLUSIONS: Although PD US appears to depict the interlobular vasculature up to the renal capsule, care should be taken in the diagnosis of perfusion defects, since absence of detectable flow at the interlobular level does not always correspond to cortical areas that lack perfusion on MR images.

Adult↗
PubMed1995

Benign lymphoepithelial parotid lesions in HIV-positive patients: spectrum of findings at gray-scale and Doppler sonography.

OBJECTIVE: Benign lymphoepithelial lesions are intraparotid nodules that develop as an early manifestation of HIV infection. The purpose of this study was to describe the spectrum of sonographic and Doppler findings of benign lymphoepithelial lesions in HIV-positive patients and to assess whether these findings are specific for the diagnosis of such lesions. SUBJECTS AND METHODS: Nine HIV-positive patients with swelling of the parotid gland caused by single or multiple parotid nodules were evaluated. Fourteen nodules were identified sonographically and proved to be benign lymphoepithelial lesions at cytologic examination. They were assessed with gray-scale, duplex, color Doppler, and power Doppler sonography. For each nodule, the echogenicity, grade and pattern of vascularity, and spectral tracings were evaluated. RESULTS: Benign lymphoepithelial lesions manifested as parotid nodules with a wide spectrum of sonographic appearances, ranging from simple cysts to mixed masses with predominantly solid components. Cystic lesions (10/14) were not purely anechoic; they had an internal network of thin septa supplied by vessel pedicles and, in four of 10 cases, a solid mural nodule. On the other hand, mixed nodules (4/14) had a higher conspicuity of solid tissue and thicker stromal septa, thus resembling a parotid neoplasm more than a cyst. The overall grade of vascularity of benign lymphoepithelial lesions varied from avascular to intensely hypervascular. Generally, mixed nodules were more hypervascular than were the cystlike ones. Spectral analysis showed slow velocity (peak systolic velocity range, 8-28 cm/sec; mean, 20 20 cm/sec) and low impedance (resistive index range, 0.36-0.70; mean, 0.57) arterial flows. CONCLUSION: The spectrum of sonographic and Doppler features of benign lymphoepithelial lesions in HIV-positive patients is broad. Sonographic findings are non-specific for the diagnosis of such lesions, especially in cases of mixed solid-cystic isolated nodules.

Adult↗
PubMed1994

[CT-guided celiac ganglion block. The authors' own experience].

Celiac plexus neurolysis is considered an effective technique for relieving abdominal cancer pain. CT yields accurate anatomical detailing, thus allowing the indirect location of the celiac plexus and the planning of needle trajectory and positioning. September 1992 to December 1993, twenty-eight celiac plexus neurolyses for pain relief were performed in 26 patients (13 men and 13 women), 17 through the anterior and 11 through the posterior access. These patients had been referred to our department for pain management. Forty-eight hours after alcoholization, 20 patients (71%) had complete pain regression and their analgesic treatment was thus discontinued. 36% of the patients did not need any analgesics for 30 to 169 days. No neurologic complications were observed. Only transient orthostatic hypotension requiring no treatment developed in all our patients during the first 24 hours after the block. To conclude, we believe celiac plexus alcoholization under CT guidance to be a safe and effective technique for relieving abdominal pain due to cancer or benign conditions. We prefer the anterior approach because it is better accepted by the patients and more easily performed by the operators.

Abdominal Neoplasms↗
PubMed1992

[Artifacts in echo-Doppler and color-Doppler].

It is well known that artifacts can be observed during US examinations; the same is true also for Doppler and color-Doppler images of blood flow. Recognizing these artifacts is important to avoid image misinterpretations and, when possible, to overcome them by modifying either techniques or unit settings, or both. This work was aimed at presenting the several artifacts which can be observed during Doppler investigations, at classifying them, and trying to understand the physical and/or technical principles underlying their origin. Doppler and color-Doppler artifacts can be divided into four large groups: 1) artifacts regarding evaluation of the presence of flow; 2) artifacts regarding evaluation of the direction of flow; 3) artifacts regarding determination of the velocity of flow; 4) artifacts affecting spatial location, on the screen, of the examined vessel. Each of the above can cause severe diagnostic misinterpretations, if not correctly recognized and interpreted. It must be kept in mind that an accurate analysis of unit settings during scanning, and the meticulous evaluation of the obtained color images are of the utmost importance for the proper use of this valuable but difficult diagnostic technique.

Artifacts↗
PubMed1991

[Captopril-induced changes in renal flow: evaluation using Doppler echography].

It is well known that angiotensin antagonists cause increase of renal blood flow. We have examined, using duplex Doppler sonography, the changes of renal blood flow velocity induced by oral administration of 50 mg. of Captopril. We examined 19 kidneys in 17 subjects without hypertension. Both peak systolic and diastolic velocities were measured at renal hilum and at arcuate arteries, and the resistive index (RI) was calculated. In conclusion duplex Doppler sonography shows significant increase of blood flow velocities both at the hilum and at the arcuate arteries, without variation of the RI, thus showing that changes affect the whole Doppler wave, both in systole and diastole.

Blood Flow Velocity↗
PubMedDate not supplied

Metastatic nodules of the abdominal wall: US and CT evaluation..

PURPOSE: Metastatic recurrence in the abdominal wall surgical scar is not uncommon. Our aim was to evaluate the role of ultrasonography (US), computed tomography (CT) and percutaneous fine needle aspiration biopsy in the diagnosis of metastatic recurrence along the surgical scar. MATERIALS AND METHODS: We evaluated 17 nodules in the surgical scar, either single (n=9 patients) or multiple (n=2 patients), in 11 patients operated on for known abdominal neoplasm confirmed by histology. The most common primary tumour was colonic carcinoma. All patients had undergone open surgery, and the lesions were detected at routine follow-up or at diagnostic examinations performed for clinical suspicion of recurrence. Ultrasonography (7.5-10/10-13 MHz) and fine needle biopsy were performed in all cases; contrast-enhanced CT was carried out in 10 patients. All lesions underwent histopathological examination. RESULTS: The histological findings showed 16/17 metastatic nodules and one suture granuloma. Lesions had variable size (15-55 mm), roundish shape, ill-defined margins (60% cases) and hypoechoic solid echotexture. All were characterised by marked contrast medium uptake on CT examination. US-guided aspiration biopsy precisely defined the metastatic nature of the nodules in 16/17 cases. In the patient with suture granuloma, both CT and US findings suggested malignancy; however, cytology showed only scant fibrous material. The anterior abdominal wall was the most common site of metastatic disease (14 lesions). CONCLUSIONS: US enables an accurate detection and diagnosis of metastatic nodules along the surgical scar. Fine needle aspiration biopsy represents, in our opinion, the most suitable procedure for providing an accurate diagnosis of this condition.

Abdominal Neoplasms↗