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Biomedical subjects

P Pignoli

Publications and source records attributed to P Pignoli.

At least 19 recordsLinked to original sources
PubMed1993

Transverse Doppler spectral analysis for a correct interpretation of flow sonograms.

The classic Doppler equation predicts that scatterers moving transversely to the ultrasound beam yield a zero frequency shift in the received echoes. An original theoretical approach, which has been developed in the last few years, has demonstrated that any focused beam leads to the generation of a Doppler spectrum with a nonzero bandwidth even for a transverse flow orientation. Based on this new theory, it is shown here that "transverse" Doppler spectral analysis can also be usefully applied in vivo. Experimental results obtained by observing normal and diseased carotid arteries at 90 degrees show that the information obtained with this approach is complementary to that provided by the mean frequency alone, which is given by the classic Doppler equation.

Blood Flow Velocity↗
PubMed1989

Clinical evaluation of a new anti-aliasing technique for ultrasound pulsed Doppler analysis.

Clinical evaluation of a new method of Doppler spectral analysis is discussed in this paper. According to this method, which basically involves a proper reformatting of the data provided by a conventional spectrum analyser, the frequency range usually considered in pulsed systems is considerably extended. This has been demonstrated even in extreme clinical conditions, corresponding to tight stenosis in major arteries. Details of materials and methods employed in this evaluation are included. Examples of experimental results are reported, along with a discussion about some possible applications of the new technique.

Arterial Occlusive Diseases↗
PubMed1988

Ultrasonographic measurement of the common carotid artery wall thickness in hypercholesterolemic patients. A new model for the quantitation and follow-up of preclinical atherosclerosis in living human subjects.

Ultrasound high resolution B-mode imaging of human arteries allows in vivo an accurate and non-invasive determination of the thickness of the intimal-medial complex. A computer assisted procedure to measure this parameter at the level of common carotid arteries was developed. The average difference between duplicate thickness determinations was 4.6%. The thickness of the intimal medial complex of common carotid arteries was then measured in a group of hypercholesterolemic patients. This parameter was significantly greater in these patients as compared to controls (P less than 0.001). The prevalence of small plaques in the carotid arterial tree was also significantly increased in patients. Analysis of data showed that in controls, but not in patients, the thickness of the intimal medial complex increases with age (r = 0.46, P less than 0.05). Within the hypercholesterolemic group, intimal-medial complex values were greater in male patients and in smokers. It is concluded that the common carotid arteries of hypercholesterolemic patients show thickening of the intimal-medial complex. Cigarette smoking, male sex and age increase the extent of this modification. The determination of this parameter using a non-invasive technique may represent an important tool to monitor in vivo the progression and/or the regression of early atherosclerosis in man.

Adult↗
PubMed1986

Ultrasound evaluation of atherosclerosis. Methodological problems and technological developments.

The evaluation of atherosclerosis requires the definition of the object to be measured and of the questions the investigation is required to answer. In the first part of this paper some of the problems that arise when planning and defining evaluation of atherosclerosis are discussed. The second part is a review of the principal methods based on ultrasound technology. The working principles and clinical applications of each method are discussed. The rationale of each type of instrument with respect to others is highlighted.

Arteriosclerosis↗
PubMed1986

Intimal plus medial thickness of the arterial wall: a direct measurement with ultrasound imaging.

A study in vitro of specimens of human aortic and common carotid arteries was carried out to determine the feasibility of direct measurement (i.e., not from residual lumen) of arterial wall thickness with B mode real-time imaging. Measurements in vivo by the same technique were also obtained from common carotid arteries of 10 young normal male subjects. Aortic samples were classified as class A (relatively normal) or class B (with one or more atherosclerotic plaques). In all class A and 85% of class B arterial samples a characteristic B mode image composed of two parallel echogenic lines separated by a hypoechoic space was found. The distance between the two lines (B mode image of intimal + medial thickness) was measured and correlated with the thickness of different combinations of tunicae evaluated by gross and microscopic examination. On the basis of these findings and the results of dissection experiments on the intima and adventitia we concluded that results of B mode imaging of intimal + medial thickness did not differ significantly from the intimal + medial thickness measured on pathologic examination. With respect to the accuracy of measurements obtained by B mode imaging as compared with pathologic findings, we found an error of less than 20% for measurements in 77% of normal and pathologic aortic walls. In addition, no significant difference was found between B mode-determined intimal + medial thickness in the common carotid arteries evaluated in vitro and that determined by this method in vivo in young subjects, indicating that B mode imaging represents a useful approach for the measurement of intimal + medial thickness of human arteries in vivo.

Adult↗
PubMed1985

Hemodynamic factors changing blood flow velocity waveform and profile in normal human brachial artery.

We have investigated the influence of changes of perfusion pressure and local peripheral resistance on blood flow velocity waveform and profile in normal human peripheral arteries. Blood flow velocity and profile were recorded from the distal end of the left brachial artery in ten normal subjects by means of an ultrasonic device. The records were obtained in basal conditions and after blood pressure in the brachial artery and local peripheral vascular resistance were changed, separately or together, by progressive inflation of two arm cuffs, one encircling the proximal half of the left arm and the other the middle part of the left forearm. Both blood flow velocity waveform and profile were shown to be markedly modified by changes in perfusion pressure and local peripheral vascular resistance. Reduction of perfusion pressure decreased both forward and reverse peak velocities, but had the largest effect upon reverse velocity. The upslope and the downslope of the forward velocity wave were left unchanged. Increase in local peripheral vascular resistance markedly augmented reverse peak velocity, whether perfusion pressure was normal or reduced. Increased resistance only slightly influenced peak forward velocity.

Arm↗
PubMed1984

[Diagnostic algorithms. Analysis of the factors conditioning their definition. An illustrative case (bilio-pancreatic pathology)].

A case of biliopancreatic pathology studied with traditional (the old algorithm) and the latest (new algorithm) diagnostic techniques is examined. A comparative analysis reveals the second to be simpler, less expensive and less dangerous to the patient. The hope is expressed that doctors will become better informed of the diagnostic criteria to employ for the purpose of cost reduction.

Biliary Tract Diseases↗
PubMed1982

In vivo recording of blood velocity profiles and studies in vitro of profile alterations induced by known stenoses.

Recordings of blood velocity profiles and their behavior in the time domain in some peripheral human vessels (carotid arteries and limb vessels) are reported. Measurements have been obtained with a pulsed ultrasonic instrument based on the analysis of the cross-correlation function of blood-diffused echoes. The alterations of blood velocity profiles and of the velocity in the time domain, induced by known stenosis, have been studied in vitro as a function of the distance between stenosis and measuring point, and the position of the sample volume along the diameter. These studies may be useful for a better comprehension of blood velocity measurements made with ultrasound equipment for clinical noninvasive diagnostic purposes.

Journal Article↗
PubMed1981

[The role of penile Doppler sonography in impotent diabetics].

Penile systolic pressure has been evaluated by the Doppler-sonographic method in 15 diabetic patients suffering from erectile impotence. Urodynamic tests have also been carried out in some patients for a diagnosis of neurological impotence. The results obtained show the possibility of a double or sole origin (neurogenic or vascular, or both) in the pathogenesis of this symptom in diabetic subjects.

Adult↗
PubMed1981

[The role of penile Doppler sonography in the diagnosis of vascular impotence. Preliminary studies].

Normal, potent arteriopathic and impotent arteriopathic subjects have been studied by means of the Doppler method for the determination of penile systolic pressure. A penile systolic pressure value less than 75 mmHg and a penisarm pressure index of than 0.55 were always associated with impotence. If present in the arteriopathic, impotence is not always caused by vascular factors.

Auscultation↗
PubMed1981

The behavior of the Nicoladoni-Branham sign at rest and under effort.

The Nicoladoni-Branham sign may change because of exercise. Both dogs with femoral AVF and patients with lower-extremity AVF showed an increase in the Nicoladoni-Branham reaction after exercise as compared with its magnitude at rest. In both groups the AVFs were located near active muscles. We did not find this behavior in 3 patients with AVFs at points distant from the muscles used in exercise.

Animals↗
PubMed1980

[25 years of experience in the treatment of Raynaud's disease and Raynaud-like syndromes].

Reference is made to a series of 620 cases of Raynaud's phenomenon observed at the University of Milan between 1951 and 1977. The following parameters are analysed: sex, age, aetiology (where known), incidence of involvement of the four limbs, presence or otherwise of a complete sign, percentage of trophic lesions, arteriographic picture, lab examinations performed. 534 thoracic sympathectomies were performed in 464 patients with Raynaud or Raynaud-like forms. The results are described.

Adult↗
PubMedDate not supplied

[An unusual case of atherosclerotic aneurysm of the trunk of the superior mesenteric artery, successfully treated with surgery].

A case of atherosclerotic aneurysm of the superior mesenteric artery is reported. This was located about 15 cm from its origin and immediately distal to the middle colic artery in a patient who had been operated on 4 years previously with aorto-iliac substitution for aneurysm of the same nature with ligature and section of the inferior mesenteric artery at the origin. Interruption of the latter created further technical problems solved with a serie of anastomoses that permitted the introduction of a good direct flow from the superior mesenteric respectively to the right colic and into an ileal branch which became a bridge or, rather, a "new mesenteric" assuring excellent pulsed flow into the underlying ileal branches, one of which anastomized at the ileocolic. This enabled direct, valid, pulsed flow to be resumed.

Aged↗