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Biomedical subjects

M Bertolotto

Publications and source records attributed to M Bertolotto.

At least 37 records · Page 2Linked to original sources
PubMed1998

Duplex Doppler analysis of interlobular arteries in transplanted kidneys.

The aim of our study was to analyze changes in spectral Doppler waveforms between interlobar and interlobular arteries in renal transplants and to determine whether sampling location at interlobular level can be suitable for intrarenal resistive index (RI) measurements. Paired series of spectral tracings from interlobar arteries and respective interlobular branches were obtained in 62 consecutive renal transplants at 6.5-MHz Doppler frequency. The values of peak systolic velocity (PSV), end diastolic velocity (EDV) and RI were significantly (P < 0.01) reduced when calculated at interlobular level. In 38 % of cases, an interlobar RI higher than 0.70 corresponded to a normal interlobular RI. The values of PSV, EDV, and RI did not differ significantly at interlobular level between allograft subsets with normal and elevated serum creatinine level. Both intra- and interobserver variation were higher at interlobular than at interlobar level when performing the RI. During a conventional study of renal vasculature, an underestimation of abnormal RI findings can be expected from the incidental evaluation of interlobular tracings. We recommend sonologists to pay attention in accurately locating the sample volume at interlobar-arcuate level when evaluating intrarenal RI.

Adult↗
PubMed1998

Ultrasound and Doppler features of accessory spleens and splenic grafts.

16 splenic grafts and 24 accessory spleens were evaluated with ultrasound, colour Doppler and power Doppler imaging, in order to compare the features of splenic grafts and accessory spleens. 12 splenic grafts (11 surgically implanted, 1 islet of splenosis) were detected in eight patients following splenectomy 6-12 months previously. Four of the surgically implanted splenic grafts were found in three patients following splenectomy 16-18 days previously. 21 accessory spleens were incidentally detected in 20 subjects who had not been operated upon, whereas three enlarged accessory spleens were found in 10 patients who underwent splenectomy 6-12 months previously. The size, shape, rim features, echogenicity, acoustic enhancement and vascularization of the splenic grafts and accessory spleens were evaluated. The splenic grafts were oval with lobulated margins, an inhomogeneous pattern in 36% and acoustic enhancement in 64%. Multiple feeding vessels arising from the surrounding tissue entered the periphery of 10 splenic grafts in the eight patients operated on 6-12 months previously, whereas no vascular signals were detected in the four splenic grafts of the three patients operated on 16-18 days ago. Accessory spleens were round with smooth echogenic margins and a vascular hilum arising from the splenic vessels. In conclusion colour Doppler and power Doppler allow differentiation between accessory spleens and splenic grafts basing on their shape and vascular supply.

Humans↗
PubMed1997

[Role of Doppler color ultrasonography and of flowmetric analysis in the diagnosis and follow-up of Grave's disease].

Hyperthyroidism in Graves' disease is caused by the presence of circulating autoantibodies to the THS receptors on the thyroid cells. Thyroid-suppression therapy prevents hormone production directly, without affecting the pathogenetic process. We performed color Doppler US of the thyroid gland and pulsed Doppler analysis of thyroid artery flow in 21 patients with Graves' disease before and during medical treatment. US results were compared with those of a control group of 40 healthy subjects and correlated with the values of thyroid hormones, TSH, and thyroid microsomal and thyroglobulin antibodies. The thyroid gland was hypovascularized in the control group. Pulsed Doppler examination of the thyroid arteries exhibited peak systolic velocity of PSV 20 +/- 4 cm/s, diastolic velocity of 8 +/- 1 cm/s, and resistive index of 0.60 +/- 0.04. The thyroid gland of Graves' disease patients was hypervascularized. Pulsed Doppler examination of the thyroid arteries exhibited peak systolic velocity (PSV = 51 +/- 12 cm/s), end diastolic velocity (VD = 15 +/- 4 cm/s), and resistive index (RI = 0.71 +/- 0.04) significantly higher than in normal subjects (p < 0.001). Circulating thyroid hormones and flow parameters normalized after 6-8 months of medical therapy (PSV = 20 +/- 6 cm/s, VD = 9 +/- 3 cm/s, RI = 0.58 +/- 0.07). Conversely, the color Doppler patterns normalized only in a patient with normal TSH and antibodies. Sampling of the thyroid arteries proved more repeatable than sampling of parenchymal vessels.

Blood Flow Velocity↗
PubMed1996

Hemangiopericytoma of the greater omentum: US and CT appearance.

The US, Doppler and CT appearances in a patient with hemangiopericytoma of the greater omentum are presented. Ultrasound revealed a solid mass with heterogeneous echo pattern, well-defined margins and marked vascularity with low impedance flow (mean resistive index 0.42). The tumour was mobile. It was detected below the left kidney at the first US examination and had migrated into the pelvis 14 days later. At CT the tumour demonstrated strong but brief peripheral enhancement and a central hypodense scar.

Adult↗
PubMed1996

Primary lymphoma of the mandible with diffuse widening of the mandibular canal: report of a case.

A case of primary non-Hodgkin's lymphoma (NHL) of the mandible with unusual radiographic presentation is reported. The panoramic radiography revealed diffuse widening of the right mandibular canal with ill-defined margins and absence of edge sclerosis. Computed tomography showed infiltration of the superior portion of the canal with involvement of the vestibular cortex of the bone and of the alveolar ridge.

Adult↗
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↗
PubMed1996

Imaging of patients with pancreaticobiliary diversion for obesity: post-operative anatomy and findings in small bowel obstruction.

Pancreaticobiliary diversion is a surgical procedure undertaken for obesity. It consists of a distal gastrectomy with a long Roux-en-Y reconstruction, the enteroenterostomy being placed 200 cm distal to the gastroenterostomy and 50 cm proximal to the ileocaecal valve. Three intestinal limbs are recognized: (a) the alimentary loop from the gastroenterostomy to the enteroenterostomy; (b) common loop from the enteroenterostomy to the ileocaecal valve and (c) pancreaticobiliary loop from the duodenum to the enteroenterostomy. The radiological findings in 15 pancreaticobiliary diversion patients with small bowel obstruction were reviewed (15 plain abdominal radiographs, 13 ultrasound (US), 8 CT) and compared with 20 plain abdominal radiographs, 10 US, and 10 CT studies performed for other causes in patients with pancreaticobiliary diversion and 15 CT scans from non-operated patients. After pancreaticobiliary diversion the pancreaticobiliary loop was completely air-free. In the patients operated on more than 1 year previously, alimentary and common loops were significantly larger than the pancreaticobiliary loop and small bowel loops of non-operated subjects. Obstruction of the pancreaticobiliary loop arrests only the flow of pancreaticobiliary secretions with non-specific clinical findings. Plain abdominal radiographs were not diagnostic in all but two cases with radiographically detectable dilated fluid filled loops. Air-fluid levels were never apparent. US and CT showed markedly dilatated intestinal loops and duodenum. Obstruction of the alimentary and common loops presented with symptoms, clinical signs, and radiological findings more typical for bowel obstruction in intact subjects.

Adolescent↗
PubMed1996

Ultrasonography of peripheral nerves.

During sonographic examination of the extremities using high frequency "small-parts" equipment, peripheral nerves may be identified in virtually all patients. Peripheral nerves have a typical ultrasonographic pattern that correlates well with histologic structure and facilitates differentiation between nerves and tendons. The ability of this technique to depict peripheral nerves makes it possible, in many instances, to study nerve abnormalities in trauma, entrapment syndromes and tumors. Ultrasound can enable differentiation of an endoneural from an extraneural space-occupying lesion and evaluation of the extent and consistency of the lesion, as well as the integrity and dynamic behavior of the nerve involved at follow-up study. The purpose of this review article is to describe the normal ultrasonographic appearance of peripheral nerves and to discuss the potential role of this technique to image nerve lesions noninvasively. A series of paradigmatic ultrasound images of diverse pathologic processes involving peripheral nerves is presented. Although the ultrasound study of peripheral nerves remains in its infancy, with further refinement of ultrasound technology and a more precise knowledge of the ultrasound appearance of the extremities we may be optimistic to the future impact of this technique on diagnosis, treatment and prognosis in patients clinically suspected to have a nerve lesion.

Humans↗
PubMed1996

[Calcifying giant-cell Sertoli tumor: description of a case with atypical echographic presentation].

Large cell calcifying Sertoli cell tumor of the testis is an extremely rare type of sex cord tumor with low malignant potential that occurs in the first and second ecades of life. Twenty-eight cases have been reported in the literature and, to our knowledge, only 2 had an aggressive behaviour. Patient age, tumor size, histological malignant patterns such as pleomorphism and high mitotic rate seem to heavy influence the future neoplasm malignancy. Ultrasonography imaging of the large cell calcifying has described in only 6 cases. We report an experience with a large cell calcifying Seroli cell tumor of the testis and point out the unusual sonographic findings. Moreover, if histologic examination suggests no malignant features, we suggest local excision as ideal therapy for the preservation of testicular parenchyma.

Adolescent↗
PubMed1995

Echotexture of peripheral nerves: correlation between US and histologic findings and criteria to differentiate tendons.

PURPOSE: To correlate the histologic structure and echotexture of peripheral nerves and verify if ultrasound (US) findings can be used to differentiate nerve from tendon. MATERIALS AND METHODS: In an in vitro study, the echotexture of normal peripheral nerves was correlated with the histologic findings. In an in vivo study, US was used to differentiate median nerve from flexor pollicis longus tendon in healthy volunteers (12 male and eight female subjects 7-68 years of age; mean age, 35 years). RESULTS: US examination of the peripheral nerve specimens showed hypoechoic areas separated by hyperechoic bands. The hypoechoic areas corresponded to neuronal fascicles at histologic examination. This fascicular pattern was clear in all median and ulnar nerves, 15 of 20 vagus nerves, and 19 of 20 sciatic nerves in the volunteers but not in recurrent laryngeal nerves. CONCLUSION: Peripheral nerves have a typical US pattern that correlates with histologic structure and facilitates differentiation between nerves and tendons.

Adolescent↗
PubMed1995

High resolution ultrasound anatomy of normal Achilles tendon.

To evaluate the ultrasound (US) appearance of the normal Achilles tendon at increasing frequency and establish an anatomical correlation for US findings, 30 normal tendons were examined in vivo and three in vitro with 10 MHz and 15 MHz mechanical sector probes. Side-by-side comparison was performed in vitro between the sonograms and the corresponding anatomical sections. Two tendinous portions were detected by presence of an internal acoustic interface which had different appearances: one (type I) or two (type II) continuous lines of increased thickness and greater reflectivity than adjacent fibrils; or displacement (type III) of the distal portion of the well insonated sector of the tendon body. When, on coronal scans of the tendon, no intratendinous linear echoes of increased reflectivity were visible, the two portions of the tendon were identified through the converging course of their bundles (type 0 pattern). Different echogenicity allowed the detection of two tendinous portions, also on axial images. Scanning of isolated tendons allowed precise location of these interfaces at the boundary between anatomically distinct tendinous portions arising from the soleus and gastrocnemius muscles. Although the normal Achilles tendon is commonly regarded as a uniform structure by US, the use of high resolution probes allows identification of its constituent portions. Their identification may be useful to avoid misdiagnoses of pathological findings.

Achilles Tendon↗
PubMed1994

Case report: US detection of tendinous metastasis from malignant melanoma.

The introduction of high frequency transducers has considerably improved the application of US in the study of musculo-tendinous diseases. We report a rare case of tendinous metastasis from malignant melanoma. The tumour (high karyokinetic index, Clark level IV) arose 4 years earlier in the dorsal region. The patient was admitted for pain in the left knee. A nodular hypoechoic lesion, 0.8 cm in diameter, poorly marginated, located in the subcutaneous tissue and involving the patellar tendon was identified with ultrasound. Histological examination confirmed the diagnosis.

Adult↗
PubMed1994

[Dopamine-induced variations in intrarenal resistance. Evaluation with Doppler ultrasound].

Low-dose dopamine is commonly used for the management of acute renal failure because of its exclusively renal vasodilator effect which is mediated through two specific receptors. However, the experimental background of this role is controversial in man. Indeed, the available data come mainly from animal trials and uncontrolled studies in patients with left ventricular dysfunction who need other drugs to improve cardiac output. This work was aimed at investigating Doppler value in assessing the effects of low-dose dopamine infusion in healthy subjects. Heart rate, arterial blood pressure and RI were measured before, during (at 10, 20 and 30 minutes) and after low-dose dopamine infusion in 4 healthy volunteers. In all subjects the RI reduced significantly, returning to the initial values after drug infusion. Indeed, the average RI (0.648 +/- 0.015 before drug administration) decreased to 0.595 +/- 0.026 within 10 min of infusion and remained almost the same during the infusion (0.596 +/- 0.024 within 20 min of infusion, 0.585 +/- 0.032 within 30 min). Within 10 min of the end of infusion, the average RI returned to similar values to those measured before drug administration (0.643 +/- 0.02). Changes in heart rate and arterial blood pressure were not significant. Our results confirm the vasodilator role of low-dose dopamine to be free of systemic effects in healthy volunteers with no therapeutic support which would cause extrarenal decrease in peripheral vascular resistance.

Adult↗