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Biomedical subjects

L Bacarini

Publications and source records attributed to L Bacarini.

At least 19 recordsLinked to original sources
PubMed1992

[Extrarenal ultrasound and color Doppler: renal artery stenosis].

There is a long term interest in noninvasive Doppler (Duplex Doppler, Color Doppler) methods to screen patients with reno-vascular hypertension resistant to medical therapy. Doppler criteria for the diagnosis of renal artery stenosis in native kidneys vary (peak systolic velocity exceeding 100 cm/sec; RAR (Renal Aortic Ratio) exceeding 3.5; Doppler shift frequency exceeding 6-8 KHz; dampened peripheral waveform; lack of signal in complete occlusion). When the vessels are adequately visualized (about 40% of cases) sensitivity and specificity are quite good (80-90%). In the transplanted kidney Doppler diagnosis of renal artery is easier (diagnostic accuracy about 90%). The diagnostic criteria have been well codified (Doppler shift of 7.5 KHz at an insonating frequency of 3 MHz).

Diagnosis, Differential↗
PubMed1992

[Bone mineral content measurement: reflections on the equipment].

Metabolic bone disorders are extremely interesting from an epidemiological, clinical and social point of view. In particular, some of them are important for they are typical of elderly people--i.e., the portion of population which is on the increase due to the lengthening of the average life. On the other hand, thanks to the current intervention techniques, the number of chronic nephropathics (in whom metabolic bone conditions may develop) has markedly increased. Therefore, sufficiently reliable methods are needed to allow the thorough evaluation of bone mineral components. Unfortunately, these methods are only of quantitative value because they are unable to discriminate the statuses of the two essential bone components--i.e., cortex and spongiosa--; we all know that bone mineral loss can currently be quantified only when amounting to < 20% of the total value, due to the addition of the mineral contents of the two components. In this paper the authors briefly report on the noninvasive techniques currently in use for the measurement of bone mineral components, especially relative to their physical bases, the knowledge of which is essential for a correct evaluation. The authors accurately reviewed the literature data relative to the various techniques and compared the results obtained by the different authors. Thus, no personal experience is reported, since this paper is aimed at being considered as a reference mark for the reader to be helped in the choice of the equipment suiting him most. However, as to preventing metabolic osteopathies, quantitative methods cannot yield absolute data, which addresses the current research to densitometry by means of the Compton method. The latter may finally lead to the development of operative equipment allowing not only the separate measurement of cortical and spongiose values, but also the qualitative evaluation of bone status--i.e., not limited to mineral loss but including also the determination of the protein, fat and water components.

Absorptiometry, Photon↗
PubMed1991

[The echo-guided fine-needle biopsy of thoracic and abdominal masses].

Five hundred and seventy-two US-guided fine-needle biopsies were performed on 561 patients (1.2 puncture/patient); in two cases only minor complications were observed. The patients were 12 to 86 years old--most of them ranging 40 to 75. In 5.42% of cases FNAB proved inadequate; 1.75% of the diagnoses was questionable, 28.89% was negative, and 63.98% positive. A comparison with histology was possible in 218 cases: 2 false positives and 5 false negatives were observed. The low rate of false-positive findings demonstrates US-guided FNAB to have high positive predictive value. The method had 95% sensitivity, 98.4% specificity and 84.3% accuracy. The high reliability of FNAB depends on the possibility of centering the lesion through the direct US visualization of the needle tip. This characteristic, together with the presence of the cytologist, who immediately evaluates the aspirated material, helps reduce the number of unnecessary biopsies and, consequently, complications.

Abdomen↗
PubMed1991

[The intraoperative echography of malignant hepatic lesions].

IOU (intraoperative ultrasound) is nowadays an indispensable technique for the surgeon to confirm the information collected from preoperative tests or to gain further information that may modify surgical strategy. A series of 350 patients were studied with IOU: in 67 cases the liver was involved, with 23 malignant lesions. In the latter group, 10 lesions were found which had been missed even at palpation; the size of 9 of them could be correctly assessed, which had been overestimated in 8 cases and underestimated in 1 before surgery. Moreover, in 39.1% of the cases, the information yielded by IOU determined a change in surgical strategy, favoring a more accurate dissection of the lesion. Surgery was modified depending on the recognition of: nonpalpable lesions (5 cases); portal thrombosis (1 case); lesions bigger (2 cases)--smaller (2 cases) than preoperatively diagnosed. Moreover, IOU was a useful tool to guide the surgeon during intervention, by yielding accurate anatomical information on the segment/segments hosting the lesion.

Diagnosis, Differential↗
PubMed1991

[The hypothesis of a diagnostic-prognostic assessment of intestinal invagination with the aim of treatment by echo-guided pneumatic reduction].

The authors investigated the role of US in the diagnostic-prognostic evaluation of enteric intussusception, for the use of US-guided pneumatic reduction (RPEG). In the last 5 years, 59 young patients were examined; 44 of them had clinically suspected enteric intussusception which was confirmed by US. US allowed site and nature of the condition to be demonstrated (sensitivity and specificity: 100%), while supplying helpful predictive prognostic elements as to the extent of intussuscepted loop involvement (predictive prognostic value: 100%). On the contrary, its etiological screening capabilities were poor (11%) in the identification of secondary forms (5 ileal diverticula). A grading score was introduced to select the patients undergoing RPEG. Six clinical and US parameters were considered, with values increasing according to severity of the condition. The higher the score, the lower the chances of therapeutical success with RPEG. In 3 cases (2 loop necroses and 1 severe intestinal obstruction) with US score greater than 6 [9] and clinical score greater than 11 [15], RPEG, was replaced by surgery. Fourteen patients underwent RPEG: positive results were obtained in 12 cases (85%). In one case, a short-term relapse (within 6 hours) was observed.

Acute Disease↗
PubMed1991

[Utility of the Doppler technique in the uro-nephrologic field].

Doppler techniques (echo Doppler, Color Doppler) may be useful in many urologic and nephrologic applications. Renal vein thrombosis can be determined by discovering a combination of a distended, thrombus-filled renal vein and the absence of detectable flow. The use of Doppler as screening technique for suspected renal artery hypertension remains controversial. Although patency of the renal artery can be assessed by Doppler, it is difficult to evaluate always the entire course of the vessel and it is impossible to detect multiple renal arteries. In the renal masses Doppler can investigate the vascularity: most malignant lesions gives rise to abnormal, high frequency, Doppler shifted signals that can aid the differential diagnosis of benign and malignant conditions. Doppler has recently been shown to help distinguish between the dilated renal pelvis and renal obstruction. A Resistive Index (RI) of 0.70 or greater is suspicious for obstruction, while a value of less than this virtually rules out the diagnosis in most cases. The use of Doppler techniques in renal transplants has become routine. Doppler assesses the presence of blood flow in the main renal arteries and veins, the presence of post-surgical abnormalities such as pseudo-aneurysms, stenoses, A-V fistulas and has proven useful in the evaluation of flow waveforms associated with variety of different abnormalities which can produce a decrease in renal function. Acute vascular rejection produces an increased resistance to flow with decreased, absent or reversed diastolic flow within the transplant kidney. Severe rejection produces abnormalities of the RI which are non-specific; severe acute tubular necrosis, infections, obstructions, peri-renal collections can also produce elevated RI.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗
PubMed1991

[Ultrasonography of the borderline between normal and pathological state of the hip in newborn infants (borderline hip)].

Infant hips are classified, according to Graf, in 4 US types on the basis of the morphologic changes in both the cartilaginous and the bony roofs (type I, II, III, IV). Out of 6,000 examined hips, 170 (2.8%) were considered, which could be classified neither as type I (mature) nor as type II (delayed/immature ossification). These hips were called borderline hips. They exhibited some characteristic US features: good bone modeling, rounded cotyle, and alpha angle 60 degrees +/- 2. They were always observed during the first month of the patients' life. Anamnestic data were not specific (27.5% breech delivery, and 13% oligohydramnios); clinics sometimes overestimated the actual anatomic development (64/170 cases with positivity of Ortolani's sign and/or restricted abduction; 25% of patients presented with no suspicious signs). Dynamic hip examination showed only physiological cranial deflection of the cartilaginous roof. Finally, borderline hips developed into type I hips in 99% of cases, within the third month of the patients' life.

Follow-Up Studies↗
PubMed1991

[Diagnostic errors in the echography of the hip in newborns].

Neonatal hip sonography according to Graf employs a standardized image in a frontal section plane ("3-point system") and a good scanner adjustment (the femoral head must be anechoic, like the hyaline cartilage roof triangle). Pathologic conditions can change some of these parameters. The authors examined 6,000 neonatal hips in order to point out the commonest causes of diagnostic error. Two types of error were considered: method errors and interpretation errors. Method errors: they are due to the choice of transducer and frequency, to scanner adjustment and definition of the standard section plane. Their incidence was 2.25% and supported by an uncorrect definition of the standard section plane. Interpretation errors: they come from the wrong localization of some reference points--i.e., lower iliac margin, labrum--, uncorrect evaluation of increased echogenicity of the cartilaginous roof, infant age, application of radiographic criteria and uncorrect measurements of alpha and beta angles. Interpretation errors had 5.5% incidence; they were all due to the uncorrect measurement of alpha (3.18%) and beta (2.33%) angles, especially in pathological hips (68%). To reduce the number of errors, the authors suggest to strictly apply Graf's method, to make a diagnosis based on the morphological changes of the cartilaginous and osseous acetabular roof and, only later on, to measure alpha and beta angles to confirm the diagnosis or in the follow-up.

Diagnostic Errors↗
PubMed1987

[Prostaglandin E2 liberation in the synovial fluid induced by organo-iodinated contrast media. Interrelations with the genesis of post-arthrographic pain].

RCM have been observed to cause--during arthrography--the appearance of a slow onset painful symptomatology with the clinical characteristics of a slight and transient acute arthritis. These substances are supposed to set in a production of humoral mediators of inflammation with algogenic action--PGE2 in particular. During arthrography of the knee the release of synovial fluid PGE2 after RCM introduction was studied. Two RCM were compared: meglumine iothalamate and iopamidol. Twenty patients underwent arthrography of the knee: synovial fluid PGE2 concentration was measured both before and 15' after RCM introduction with 125I-RIA method. Results show a significant increase in PGE2 concentration after both iothalamate (p less than 0.0001) and iopamidol (p less than 0.01) --especially in iothalamate--treated patients (p less than 0.01). A physiopathologic mechanism about post-arthrographic pain and, more generally, about RCM toxicity is thus hypothesized.

Arthrography↗
PubMed1985

[Accessory spleen: echographic images].

In a three-year period, 25 cases of accessory spleen were diagnosed by means of ultrasound. Accessory spleens were demonstrated to be eterotopic nodes of normal splenic tissue, situated usually near the main spleen, to which they may be bound by a pedicle. Their dimensions are usually less than 2 cm. Accessory spleen is usually present in a 10% of normal subjects and represents a TC or US occasional finding. When large, the accessory spleen causes problems about a differential diagnosis with neoplasms of the left upper quadrant. It must not be confused with polysplenia or with splenosis; TC, angiography and scintigraphy may be useful in these cases.

Diagnosis, Differential↗
PubMed1980

[Epidural venography in the diagnosis of lumbar disease (author's transl)].

80 patients with back pain and sciatalgia were studied by plain-film of lumbosacral spine, radiculography and epidural phlebography; 30 of them were surgically controlled. Radiculographic and phlebographic specimens were compared and phlebography showed more sensibility and specificity in the study of extradural pathology. The analysis of the phlebographic alterations suggested a semeiologic criterion we think that could be usefully used in the study of osteoligamentous lesions in lumbosacral spine.

Back Pain↗
PubMed1978

[Criteria for choosing the screen-film system in x-ray diagnosis (author's transl)].

The physical dimensions to be kept in mind in choosing the screen-film system in radiography are defined and discussed. As an example of applying the method, the results of measuring these dimensions on 5 types of film and 6 types of screen are reported and their optimal combinations indicated as a function of examination conditions.

Radiographic Image Enhancement↗
PubMed1977

The use of abdominal contrast tomography in liver disease.

The value of a high dose infusion technique using urographic contrast medium followed by tomography was studied in 44 patients with liver disease. The method was found to be of value in showing cysts, abscesses and cystic disease of the liver. Large tumours, primary and secondary, can also be demonstrated. Normal bile ducts are not visible, but become apparent when they are dilated.

Contrast Media↗