Search PubMed⌕ Search

Biomedical subjects

L E Derchi

Publications and source records attributed to L E Derchi.

At least 73 records · Page 4Linked to original sources
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

High resolution sonography of the flexor tendons in trigger fingers.

A sonographic study was conducted to analyze changes of the flexor tendons in patients with trigger fingers. We evaluated thickness and echotexture of the flexor tendons of the fingers in 54 patients with 66 symptomatic digits using 10 and 13 MHz "small parts" transducers; the results were compared with those observed in 20 normal controls. Images were obtained on the volar surface of the hand, at the head of metacarpals, and at the base of first phalanx, where the first annular pulley of the digital canal is located and where the changes occurring during passive assisted extension of the fingers were evaluated. Normal tendons were 2.9 to 4.4 mm thick (mean, 3.71 +/- 0.46) and had fibrillar echotexture. Patients had tendons ranging from 3.8 to 6.7 mm (mean, 5.41 +/- 0.94); the difference from controls was highly significant (P < 0.001). A cyst was attached on the volar surface of the involved tendons in 15 cases. Diffuse thickening of the synovial sheath was present in 20 tendons, whereas 17 tendons had irregular internal echotexture. Extension movements caused changes in shape of both cysts and peritendinous envelopes. In conclusion, sonography seems able to identify a variety of pathologic changes affecting tendons in these patients and may help both to explain the pathophysiology of their clinical situation and guide therapeutic decisions.

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

[Diagnostic reliability of radiography in shoulder trauma. Considerations on the use and choice of more radiographic projections].

The radiographic examination of the shoulder, one of the most common studies performed in the emergency department of examine trauma patients, very often yields poor and incorrect results. A radiographic study of the shoulder requires at least two radiographs, and different projections-namely, a frontal anteroposterior view and some additional projections, at right angles to one another. The shoulder radiographs of 126 patients examined for acute trauma were retrospectively reviewed to investigate the adequacy of lateral and oblique apical views in detecting shoulder injuries missed on anteroposterior view. The antero-posterior view was the most effective one, showing 88% of the injuries. Even though the oblique apical and the lateral views were less sensitive than the antero-posterior view, detecting 82% and 60% of the injuries, respectively, they were more sensitive for some specific injuries missed by the other views. Thus, glenohumeral dislocations with or without fracture and some clavicular fractures were best depicted by the oblique apical view, while the fractures of the body and coracoid process of the scapula were best detected by the lateral view. However, the two views had a complementary role and, in our series of patients, both of them showed four injuries missed by the anteroposterior view. Therefore, we conclude that the radiologist should collaborate with the orthopedist to choose which projections to use in each patient on the basis of physical and clinical examinations.

Female↗
PubMed1995

Normal prostate gland: examination with color Doppler US.

PURPOSE: To evaluate the vascular anatomy of the prostate gland with transrectal color Doppler ultrasound (US). MATERIALS AND METHODS: Thirty-five normal prostate glands were studied. Imaging findings were interpreted on the basis of findings from previous anatomic studies. RESULTS: Distribution of flow signals within the gland was differentiated into two parenchymal groups of arteries, urethral and capsular. The urethral group entered the prostate at the bladder neck and sent forth branches to supply the periurethral zone and the inner portion of the gland. The capsular group coursed along the anterolateral surface of the prostate and sent forth perforating branches to the outer portion of the gland. Intraprostatic venous signals were seen mainly within the periurethral zone. CONCLUSION: Transrectal color Doppler US can depict the vascular anatomy of the prostate gland. Knowledge of the normal vascular appearance of the gland should aid in the differentiation of normal from abnormal findings.

Adult↗
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↗
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

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

Ultrasonographic imaging and Doppler analysis of renal changes in non-insulin-dependent diabetes mellitus.

RATIONALE AND OBJECTIVES: We used ultrasonographic imaging and Doppler analysis to assess renal changes in patients with non-insulin-dependent diabetes mellitus (NIDDM) and normal renal function, as established by normal serum creatinine levels and the absence of macroalbuminuria. METHODS: Renal parenchymal echogenicity, renal volume, and resistive index (RI) were blindly evaluated for 85 NIDDM patients and 42 age-matched control subjects (C). Results were analyzed and correlated with the following clinical parameters: patient age, duration of diabetes, blood pressure, blood glucose and cholesterol levels, and the presence of microalbuminuria. RESULTS: Normal renal parenchymal echogenicity was seen in all but one NIDDM patient; however, in comparison with C, diabetic patients had significantly higher renal volume (mean +/- standard deviation, 314.01 +/- 72.74 vs 227.64 +/- 58.76) and RI (mean +/- standard deviation, 0.71 +/- 0.05 vs 0.64 +/- 0.02). An RI higher than 0.70 was found in 55 of 85 (65%) NIDDM patients; an increased RI was directly correlated with patient age, whereas an inverse correlation existed between an increased RI and renal volume. No statistically significant differences were observed for the duration of diabetes, arterial hypertension, blood levels of glucose and cholesterol, and the presence of microalbuminuria. CONCLUSIONS: NIDDM patients with normal renal function show a significant increase in renal volume and RI in comparison with C. Demonstration of these findings may aid in the detection of early renal involvement in NIDDM patients. However, further investigations are needed to understand fully the correlation of such changes with the pathology of diabetic nephropathy and to provide an interpretation of the pathophysiologic mechanisms underlying changes in intrarenal vascular impedance in NIDDM patients.

Aged↗
PubMed1994

Color Doppler sonography of salivary glands.

OBJECTIVE: We used color Doppler sonography to evaluate the vascular anatomy of the salivary glands and to analyze physiologic changes that occur during salivary stimulation in normal subjects and the flow alterations that occur in diseased glands. SUBJECTS AND METHODS: The vascular appearance of the three major salivary glands was examined in healthy volunteers (n = 24); in patients with chronic autoimmune diseases, including Sjögren's syndrome (n = 23) and salivary sarcoidosis (n = 2); and in a variety of benign (n = 49) and malignant (n = 13) nodules. Physiologic changes were assessed in healthy volunteers by means of a stimulation test with lemon and were quantified with color images and spectral analysis. Tumor vascularity was graded on a four-step analog scale of 0 to (+3) and classified as either peripheral or hilar, depending on the distribution of vessels. RESULTS: In the control subjects, color Doppler imaging accurately reflected the complex vascular anatomy of the salivary glands and showed dramatic changes occurring in parenchymal vessels during lemon stimulation as a result of the intense hyperemia associated with the secretion of saliva. Sjögren's syndrome and sarcoidosis showed a diffuse hypervascular pattern when morphologic changes of salivary parenchyma were seen on gray-scale sonograms. Benign tumors showed a lower grade of vascularity than did malignant tumors. All but one of the hypovascular nodules graded as 0 (n = 8) and + (n = 23) were benign. Conversely, eight of 11 nodules labeled with the highest grade of tumor vascularity (+3) were malignant. When the pattern of tumor flow signals was peripheral, it could be considered specific enough to aid in diagnosing pleomorphic adenoma. Peak systolic velocities greater than 60 cm/sec were never detected in benign tumors and were seen in only 44% of malignant tumors. CONCLUSION: Color Doppler sonography is a promising technique for analyzing the vascularity of the salivary glands and for characterizing some pathologic conditions. Our experience suggests that color Doppler sonography can provide additional diagnostic information in patients with chronic inflammatory diseases or suspected malignant tumors and can help in differentiating pleomorphic adenomas from other salivary gland tumors.

Adult↗
PubMed1994

Color Doppler ultrasonography in pediatric intussusception.

CDU was used in 11 children with intussusception. Demonstration of vascular images within the "pseudokidney" mass was possible in none of 11 cases. Of them, eight could be treated by hydrostatic reduction. In the remaining case, marked edema of the bowel wall did not allow reduction, and surgery had to be performed: no necrosis was observed in the surgical specimen. Both patients in whom CDU failed to demonstrate vascular signals had necrosis at surgery, and bowel resection was performed. Because of the limited number of patients examined at this time, no firm conclusions can be drawn from our experience. However, CDU seems a promising technique in detecting vascular changes occurring in intussusception, with a possible role as a predictive tool of bowel necrosis.

Child, Preschool↗
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↗
PubMed1994

[Evaluation of rheumatoid arthritis of the knee with Doppler color].

Color-Doppler US was used to study the vascularization of the synovial membrane and of the periarticular tissues of the knee in 14 normal subjects and 15 patients with active rheumatoid arthritis. The normal subjects exhibited few spot signals within the connectival spaces surrounding the knee and adjacent to the femoral condyles and to the tibial plates. The signals were mostly arterial and impedance was high because of the absence of inversion of diastole. A hypervascular pattern was detected in 13/15 patients with rheumatoid arthritis as a result of hyperemia associated with inflammation and synovial neoangiogenesis. In these patients, the signals came mostly from the synovial pannus and the soft tissues surrounding the joint. Spectral analysis detected both venous and arterial waveforms with lower resistance than normal (resistive index ranging 0.65 to 0.76). After local treatment, both venous and low-impedance arterial signals were no longer detectable in 4/9 patients with clinical remission. In conclusion, color-Doppler US can support gray-scale US in the assessment of joint inflammation in rheumatoid arthritis patients. Vascular findings seem to correlate well with local symptoms. Color-Doppler US could make a useful tool for monitoring the clinical activity of the disease in selected joints.

Adult↗
PubMed1993

Analysis of echotexture of tendons with US.

To evaluate changes in echotexture of normal tendons at different frequencies and establish an anatomic correlation for fibrillar echoes, normal calcaneal tendons were examined in vitro at 7.5, 10, 13, and 15 MHz in calves (n = 8) and sheep (n = 6) and in vivo in humans (n = 8). Histologic correlation was obtained in vitro with 22-gauge needles that marked the position of echogenic fibrils under ultrasound (US) guidance. The human study group consisted of 25 patients with a clinical diagnosis of calcaneal tendon disease and 15 patients who underwent surgery for rupture of the Achilles tendon. At all four frequencies, normal tendons showed an internal network of fine parallel and linear fibrillar echoes that became more numerous and thinner as US frequency increased. These echoes were caused by specular reflections at the interface between collagen bundles and endotendineum septa. In patients, tendons showed a variety of basic changes in fibrillar pattern: increased fibrillar thickness (33 patients), interruption (17 patients), fragmentation (12 patients), and disappearance of echotexture (15 patients). It is concluded that US holds promise in detection of minimal changes in tendinous structure.

Achilles Tendon↗