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Biomedical subjects

L Barozzi

Publications and source records attributed to L Barozzi.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Abdominal Doppler ultrasonography in the diagnosis of renovascular diseases. Double-blind prospective study].

Our work was aimed at evaluating the sensitivity and specificity and the positive and negative predictive values of abdominal Doppler US in the diagnosis of renovascular disease. Fifty hypertensive patients (23 men and 27 women) with 100 bilaterally single renal arteries (66 of them normal and 34 stenosed) were studied by means of color (26 cases) and duplex (24 cases) Doppler US. The following US variables were considered in the diagnosis of renal artery stenosis: increased peak systolic velocity in the renal artery, increased ratio between peak systolic velocity in the renal artery and in the aorta, increased parenchymal acceleration time and increased resistive index. Feasibility was 100% for all variables. The general multivariate statistic model of discriminate analysis was used to define three calculation levels, according to: a) duplex vs. color Doppler equipment, b) hemodynamic variables and c) optimal cutoff values. US examinations were performed by a single observer in a double-blind study, before angiography, so as to eliminate interobserver variability. On the whole abdominal Doppler US exhibited optimal specificity and fairly good sensitivity. Specificity increased (94% to 97%) with the use of color Doppler according to the different combinations of variables, but sensitivity remained the same. The calculation including all the Doppler variables increased sensitivity from 73% (with true values) to 93% (with threshold values). The positive predictive value demonstrated that 90% of the renal arteries with increased peak systolic velocity and 100% of those with increased parenchymal acceleration time were stenosed. However, the negative predictive value demonstrated that 15% of the renal arteries with no increase in peak systolic velocity is misdiagnosed as normal. In conclusion, abdominal Doppler US can be used to study renovascular disease patients, but the examination must always be based on different hemodynamic variables and true values.

Double-Blind Method↗
PubMed1993

[Color-Doppler and angioplasty in renovascular hypertension].

Renovascular hypertension is defined as a kind of hypertension secondary to altered renal perfusion with the activation of the renin-angiotensin system. Since a large number of these patients benefits from treatment--be it medical, surgical or angioplastic--a non-invasive low-cost method allowing accurate screening was looked for. Color-Doppler was employed by many authors to evaluate renovascular hypertension, for both the early diagnosis of the condition and the evaluation of treatment results in renal artery stenoses. However, the authors agree that color-Doppler cannot play a major role in the screening of renovascular hypertension due to the various qualitative and quantitative variables not being adequately codified, to the lack of a single color-Doppler method and to the difficult comparison of the results from the different units. Nevertheless, improved results are promised by technological evolution, together with the possibility to codify color-Doppler variables more easily repeatable. B-mode units with 3.5 and 5 MHz probes were employed in the thinnest subjects. In 5-25% of cases accessory renal arteries were observed. After identifying the vessel to be studied with several spatial scans, the smallest possible sample volume (usually 3-5 mm) was positioned. The normal flowmetric range was 0.07-0.1 s: it must not exceed 0.16 s, with persistence of high diastolic flow. Some authors' criteria were followed to define either stenosis or renal artery obstruction; moreover, pulsatile flow index was considered, together with the resistive index, pulsatility index and stenosis index.

Angioplasty↗
PubMed1992

Detection of renal artery stenosis by means of captopril renal scintigraphy in patients with multiple renal arteries.

Both captopril renal scintigraphy (CRS) and conventional arteriography were retrospectively evaluated in 64 patients to study CRS efficacy in hypertensive patients with multiple renal arteries (MRA). The presence of MRA was angiographically demonstrated in 9 patients, 7 unilaterally and 2 bilaterally, with a total of 11 kidneys supplied by 2 or more arteries. Overall, 25 MRA were identified and 7 were affected by stenosis of > 50%, causing a reduction of arterial supply in 5 of 11 kidneys. CRS correctly diagnosed all five ischemic kidneys (true positives) and five of six nonischemic kidneys (true negatives); in one case in which perfusion was not reduced, the CRS diagnosis was falsely positive. In the presence of MRA, CRS proved effective in identifying renal artery stenosis of > 50%, involving either one or all the MRA. This study shows that the presence of MRA is not a drawback in the evaluation of renal artery stenosis by means of CRS.

Adult↗
PubMed1992

[Renal artery stenosis. Doppler color study before and after angioplasty].

Doppler flowmetry can be successfully employed to assess arterial patency after percutaneous transluminal angioplasty (PTA). The aim of this study was to assess color Doppler sensitivity in detecting renal artery stenosis prior to percutaneous angioplasty (PTRA) and vessel patency after it. Eleven patients (7 males and 4 females) affected with renal artery stenosis, unilateral in 9 cases and bilaterally in 2, underwent color-Doppler evaluation 1 day before and 7 days after PTRA. The operator was unaware of dilatation results. A total of 13 stenoses were treated. The qualitative and quantitative parameters we employed were: a) broadening of the spectrum, b) peak systolic frequency > 4000 Hz, c) stenosis index > 50%. Before PTRA, mean systolic peak at the stenosis was 7978 (range 4050-12500 Hz), while stenosis index was 71.9% (range 48-89%). After PTRA complete recovery was observed in 5 cases, no improvement in 1 and incomplete recovery in 7. Doppler results were in agreement with those of angiography in 6/13 while partial agreement only was seen in 7/13. Our results, although obtained in a small and highly selected group of patients, would seem to support the value of color-Doppler for the follow-up of patients after PTRA.

Adult↗
PubMed1991

Duplex-sonography and color-Doppler evaluation of renal artery stenosis--angiographic correlation.

Echo Doppler has been used in 22 patients with suspected renovascular hypertension (RVH) to detect stenosis or occlusion of the renal artery. In 12 cases duplex Doppler technique was used and in 10 color Doppler. The Doppler examination was always performed before angiography which was considered the reference gold-standard. Using duplex Doppler the diagnosis of RVH was based on qualitative (spectral analysis of the waveform) and semi quantitative parameters (resistive index). With color Doppler two other quantitative parameters were used, peak systolic frequency shift at the level of the stenosis and stenosis index. The color Doppler has shown a better specificity and a better PPV. The sensitivity of the color Doppler was comparable to that of the duplex scanner (89% and 90%, respectively). Further studies are necessary in order to define the diagnostic parameters, the reproducibility and the intra- and interobserver reproducibility. The technological progress may in the future reduce the difficulty and the time of examination.

Adolescent↗
PubMed1991

[Duplex and Doppler color echocardiography for the study of renovascular hypertension. Comparison with arteriography].

Doppler US was employed to examine 46 patients with suspected renovascular hypertension (RVI) to detect stenosis/occlusion of the renal artery. In 25 cases duplex-Doppler technique was used, in 19 color-Doppler US, and 2 patients were examined with both methods. Doppler US was always performed before angiography which was considered as the reference gold standard. Using duplex-Doppler US, the diagnosis of renal artery stenosis was based on qualitative (spectral analysis of the waveform and absence of flow signal in cases of renal artery occlusion), and semiquantitative parameters (resistive index). Diagnostic accuracy of duplex US--which was compared with that of angiography--was 83%, its sensitivity was 91.6%, and specificity was 85%. With color-Doppler, two additional quantitative parameters were used (peak systolic frequency shift at the stenosis and stenosis index). In this group of patients sensitivity was 70%, specificity was 100%, and accuracy 85%. The good diagnostic yield of the method is counter-balanced by some limitations--e.g., operator dependence and long examination time (30-40 minutes, especially with duplex US). In the authors' opinion, Doppler technique can be used in the diagnosis of RVI, even though further study is necessary to exactly define diagnostic parameters, and to verify reproducibility and both inter- and intra-observer repeatibility. Technological progress may in the future reduce both difficulty and time of the examination.

Adult↗
PubMed1989

[Tumors of the testis. Correlations between echographic, macroscopic and histological features in 48 cases].

The authors retrospectively reviewed the ultrasonographic findings of 48 histologically confirmed testicular neoplasms in order to analyse the echomorphologic findings and identify any typical patterns. A wide spectrum of US features was observed for testicular tumors, corresponding to the different macromorphologic parenchymal textures of the various neoplasms. US was extremely useful for differentiating testicular tumors from non-neoplastic scrotal pathologies. US could neither distinguish the only benign lesion nor classify histologically malignant neoplasms. US was 100% accurate in the evaluation of testicular tumors, and allowed the identification of frequent typical patterns in some types of neoplasms.

Adolescent↗
PubMed1989

[Ultrasonography in syringocele of the male urethra (ultrasound-urethrography)].

The authors have studied 5 patients with syringocele--or cystic dilatation of the excretory ducts in Cowper's glands--using a 7.5 MHz linear high-definition US probe. The urethra was distended with a saline solution introduced through a small Foley's balloon catheter placed in the navicular fossa. Longitudinal and transverse scans were employed at both the penis and the perineal region. The syringocele appears on US scans as a tubular image at the bulbous urethra, parallel to the urethral canal, with a "double tube" appearance. It is easily differentiated from urethral stenosis, while it may be confused with congenital urethral duplication, which is extremely uncommon. US with a small-part probe can be considered an useful imaging technique and a valid alternative to conventional radiology, especially in young patients, to avoid high dose exposure.

Adult↗
PubMed1989

[Surgical ultrasonography of the seminal vesicles in andrologic pathology. Research in progress].

The authors describe their experience with percutaneous transperineal puncture (PTP) of the seminal vesicles in andrologic pathologic conditions, using transrectal US guidance. Three cases are reported: 2 anomalies of the genital ducts and one prostatic-vesicular abscess. In the first two cases PTP allowed a diagnosis to be reached on the basis of the analysis of vesicular fluid. Moreover, the examination allowed the selection of the patients to be submitted to surgery for seminal duct anomaly (endoscopic resection of the colliculus seminalis). In cases 1 and 3 PTP allowed the aspiration of the fluid from a cyst in the left ejaculatory duct and from a prostatic-vesicular abscess, respectively. These procedures were facilitated using US guidance. The clinical possibilities and utility of PTP have not yet been completely defined. The authors suggest a diagnostic protocol to be used in the presence of azoocytospermia, where US must be performed only in patients with excretory infertility. The present paper must be considered a work in progress. Further study is required to identify the clinical indications of interventional US of the seminal vesicles in patients with andrologic pathologic conditions.

Abscess↗
PubMed1989

[Obstructive bladder neck syndrome in women].

Primary bladder neck obstruction in women is quite rare and its symptoms--dysuria, frequency, and urgency--are equivocal. Routine radiological investigations alone do not allow a diagnosis to be made, due to the lack of simultaneous measurements of detrusor pressure and urine flow. A precise diagnosis is thus to be obtained by synchronous video urodynamic studies which allow the depiction of nonfunneling or tight bladder neck during the entire phase of detrusor contraction, of bladder trabeculae and diverticula, vesico-ureteral reflux, long micturition time and incomplete voiding. When these radiological signs are associated with a rise in detrusor voiding pressure over 60 cm of water and with peak urine flow lower than 15 ml/s, the diagnosis of bladder neck obstruction is unquestionable, and the appropriate pharmacologic/endoscopic treatment can be administered.

Adult↗
PubMed1988

[Ureteral obstruction secondary to aortofemoral bypass].

Hydroureteronephrosis is reported as a frequent late complication of aorto-femoral bypass grafts in patients with aorto-iliac obstruction. To define the actual incidence of this potentially critical complication, renal ultrasonography (US) was performed on 79 asymptomatic patients who had previously undergone aortic reconstruction, after a mean interval of 71.6 months. Unilateral hydronephrosis was found in 6 cases (7.6%). Dilatation was mild or moderate (grade I or II) in 4 cases, and severe (grade III) in 2. Ivp was performed in this selected group: hydronephrosis was mild in 3 patients with ureteral stenosis where the iliac limb of the graft crossed the ureter. In 2 cases nonfunctioning kidneys were demonstrated corresponding to severe sonographic hydronephrosis. These 2 patients underwent anterograde and retrograde pyelography, that showed the site and extent of the obstruction. One patient was a false positive because of obstruction of pyelo-ureteral junction. Even though X-rays showed high sensitivity and specificity in detecting this complication of aorto-femoral reconstruction, US is noninvasive and less expensive and does not require contrast medium. A routine pre- and post-operative ultrasound study is suggested in patients undergoing by-pass surgery to early recognise ureteral obstruction and to avoid irreversible renal damage.

Aged↗
PubMed1988

[Diagnosis by imaging of secondary neoplastic lesions of the digestive tract].

Secondary neoplasms involving the alimentary tract are not common. This work is aimed at evaluating their characteristic roentgenological features, providing, when possible, the criteria for discriminating secondary from primary lesions. Forty-five patients with secondary neoplasms of the alimentary tract were examined by conventional radiology, ultrasonography and CT. Both CT and US are highly accurate in such cases, since these lesions are displayed directly. However, double-contrast gastrointestinal examination must be performed, because it indirectly demonstrates both intrinsic and extrinsic lesions, thus providing all elements for a correct local staging.

Adult↗
PubMed1986

[Diagnostic images of renal angiomyolipoma].

The authors report 26 cases of renal angiomyolipomas (AML) detected in a three-years period (1983-85). In all cases echography, in 6 renal arteriography and in 13 CT were performed. The review of the pathway and of literature stress some new aspects in diagnostic problems of AML. The extensive use of diagnostic ultrasound shows an higher rate of tumors than in the pre-echographic period. Most of these lesions are asymptomatic and incidentally detected as small nodules. Ultrasound, combined with CT, can resolve the diagnostic dilemma of benign lesion. An echographic follow-up is sufficient to confirm this evaluation in typical cases. In large or bleeding tumors and when there is a prevalence of connective and/or muscular tissue, a diagnostic and ablative surgery is mandatory.

Adult↗