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Biomedical subjects

L E Derchi

Publications and source records attributed to L E Derchi.

At least 55 records · Page 3Linked to original sources
PubMed1998

Color Doppler ultrasonography of soft-tissue masses.

PURPOSE: To evaluate the capability of color Doppler ultrasonography to differentiate between benign and malignant soft-tissue tumors. MATERIAL AND METHODS: We reviewed the ultrasonographic (US) and color Doppler (CD) findings in 46 consecutive patients with a palpable periskeletal mass. The presence of 3 or more vascular hila and of tortuous and irregular internal vessels within the lesions was considered an indication of malignancy. The CD diagnosis was compared with that obtained at US alone. RESULTS: The sensitivity and specificity of CD were respectively 85% and 92%; these values were higher than those obtained at US alone, respectively 75% and 50%. Arteriovenous malformations presented as lesions with large internal vessels that had low vascular impedance and were easily diagnosed. The wave form patterns within solid tumors were not specific. CONCLUSION: At present, US is commonly employed to confirm the presence of a suspected soft-tissue mass, to locate it accurately, and to indicate its nature. CD finding enhance the role of the US technique in such lesions. The combined use of US and CD can allow the differentiation of benign from malignant lesions, and thus provide a better basis for treatment.

Adolescent↗
PubMed1998

Radiology of adjustable silicone gastric banding for morbid obesity.

We reviewed the radiological findings in 45 morbidly obese patients (weight range 80-129 kg; mean 95.7 kg) after gastric restriction surgery with adjustable silicone gastric banding (ASBG) according to the Kuzmak technique. Radiographic studies of the stomach were performed before, and at 4 and 12 months after surgery; symptomatic patients underwent additional studies when needed. Patients were evaluated using both liquid barium and a solid opaque meal to assess post-operative gastric morphology as well as emptying time of the proximal gastric pouch. 27 patients had a normal clinical course. Variation of the calibre of the silicone band under radiographic guidance was required in 12 of these patients, based on dilatation of the proximal pouch, variation of the stomal calibre from operative values, or an emptying time longer than 30 min. All these problems disappeared after the adjustment manoeuvres. 18 patients had complications, of which five had stomal stenosis which could not be managed through simple deflation of the band; two had posterior bending and dilatation of the proximal pouch; four had gastritis and oesophagitis; six had infection of the inflatable reservoir; one had cranial displacement of the band, and two had migration of the band into the stomach. Removal of the gastric band was necessary in 11 cases, and removal of the reservoir alone had to be performed in three additional patients. Radiology plays an important role in evaluating complications after gastric restriction surgery. Knowing the variety of findings enables accurate treatment planning and follow-up of these patients.

Adolescent↗
PubMed1998

Sonographic evaluation of tears of the gastrocnemius medial head ("tennis leg")

Rupture of the medial head of the gastrocnemius muscle, or tennis leg, is a common lesion affecting middle-aged persons. An imaging examination may be needed to rule out other diseases and assess the severity of the tear. We reviewed the sonographic images of 65 patients with clinically suspected tennis leg. Fifty-one partial and 14 complete tears were diagnosed. Twenty-five patients had follow-up examinations (15 days to 24 months; mean, 45 days). The torn muscle fibers, hematoma, and the reparative process were appreciated by ultrasonography. Ultrasonography may be a useful noninvasive, low-cost modality for diagnosis and follow-up of tennis leg.

Adult↗
PubMed1998

[Study with thoracic and abdominal spiral CT in intensive care unit patients].

INTRODUCTION: The severe clinical conditions of intensive care unit patients need frequent imaging studies to detect the pathologic changes in the patients' situation and to plan the correct therapeutic management. The yield of bedside plain radiography is often not diagnostic but moving the patients to the radiology department could affect their clinical conditions. Conventional CT is difficult to perform in these patients because they need continuous assistance and cannot cooperate during the diagnostic examination. MATERIAL AND METHODS: The authors examined with Spiral CT 46 unconscious patients in poor clinical conditions who presented a variety of pulmonary and abdominal diseases. Thirty coma patients were submitted to bedside chest radiography and then to Spiral CT because there was disagreement between the radiographic and the clinical findings. Sixteen patients with abdominal conditions underwent Spiral Ct, 11 of them after bedside US. The chest and abdomen were examined with Spiral CT in 2/16 patients and the abdomen only in 5 cases; twenty-two of 46 patients were under assisted ventilation. During all the Spiral CT studies, the patients had their arms along the body. Spiral CT results were compared with those of bedside chest radiography in 30 cases and with those of bedside abdominal US in 11 patients. DISCUSSION AND CONCLUSIONS: Spiral CT is a fast examination technique with no major artifacts which can be used safely also in unconscious patients. It confirmed a variety of pathologic conditions which may be misdiagnosed by conventional chest radiography, which improves the care of these patients. Bedside plain radiography is limited by several factors depending on the patient (no cooperation, variable respiration, still decubitus), the examination technique (X-ray projection, exposure, poor diagnostic yield), and the anatomical region of interest (mediastinal vessels). Even though our technical standard for conventional radiography was high, Spiral CT was better in detecting parenchymal consolidation and pleural effusion, a missed pneumothorax or thromboembolic disease. We always performed Spiral CT when the clinical findings did not match the results of bedside plain radiography. Moving the patients was very easy because the intensive care unit in our hospital is in the same building as the radiology department and there were dedicated devices supporting the coma patients.

Aged↗
PubMed1997

US imaging and color Doppler in patients undergoing inhibitory therapy with calcitriol for secondary hyperparathyroidism.

The aim of this study was to evaluate the changes in volume, structure, and flow pattern of parathyroid glands in uremic patients with secondary hyperparathyroidism treated with long-term intravenous calcitriol (CTL) therapy. Ultrasonography was used to follow-up volume changes occurring in 18 enlarged glands in 11 patients during an 18-month period; in 6 of these cases, 11 glands were followed-up also with color-Doppler to monitor variations in flow pattern. Vascularization was classified using three grades: grade 0 = no color signal; grade I = vessels covering less than 50 % of glandular cross-sectional area; grade II = vascular signals covering more than 50 % of glandular cross-sectional area. No significant changes in volume were demonstrated during the 18 months of follow-up. On the contrary, significant decrease in flow was observed with almost complete disappearance of color-Doppler signals. This finding related well with the observed decrease in parathormone blood levels. Lack of volume changes during medical therapy demonstrates the inability of US alone to monitor the effect of this treatment on the parathyroid glands. Conversely, the observed intraglandular flow reduction indicates the possibility to use color Doppler to monitor the effects of CLT in uremic hemodialyzed patients with secondary hyperparathyroidism. This imaging procedure can be proposed for follow-up of the response of the parathyroid glands to therapy.

Blood Flow Velocity↗
PubMed1997

Leiomyomas of the gallbladder and splenic calcifications in an HIV-infected child.

Smooth muscle neoplasms seem to be particularly frequent in children with AIDS, and several cases of such lesions, both benign and malignant (leiomyomas and leiomyosarcomas), have recently been reported in the literature. We describe here the imaging findings in a boy with AIDS who developed two leiomyomas of the gallbladder wall as well as calcification of the intraparenchymal splenic arteries.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Transudative vs exudative pleural effusions: differentiation using Gd-DTPA-enhanced MRI.

The aim of this study was to investigate the capability of Gd-DTPA-enhanced MRI to differentiate between exudative and transudative pleural effusions. An MRI examination was performed on 22 patients with different types of pleural effusion (10 transudative and 12 exudative effusions). T1-weighted SE images were obtained before and 20 min after administration of Gd-DTPA (0.1 mmol/kg). The degree of enhancement of pleural effusions was evaluated both by visual assessment and by quantitative analysis of images. None of 10 transudative effusions showed significative enhancement, whereas 10 of 12 exudative effusions showed enhancement (sensitivity 83 %, specificity 100 %, positive predictive value 100 %). The postcontrast signal intensity ratios (SIRs) of exudates were significantly higher than corresponding precontrast ratios (P = 0. 0109) and the postcontrast SIRs of exudates were significantly higher than those of transudates (P = 0.0300). Exudative pleural effusions show a significant enhancement following administration of Gd-DTPA. We presume that this may be caused by increased pleural permeability and more rapid passage of a large amount of Gd-DTPA from the blood into the pleural fluid in case of exudative effusions. In our limited group of patients, signal enhancement proved the presence of an exudative effusion. Absence of signal enhancement suggests a transudate, but does not exclude an exudate.

Contrast Media↗
PubMed1997

Superior vena cava stents: Doppler US of the internal mammary veins to detect collateral flow--preliminary observations.

In 12 patients with superior vena cava syndrome secondary to malignant disease, duplex Doppler ultrasound (US) was performed in the internal mammary veins. In all patients, flow was retrograde. After stent placement, flow direction was again antegrade on one side (17%) or both sides (83%). During follow-up in the internal mammary veins, blood flow remained unchanged in 10 patients and retrograde flow recurred in two patients at 2 and 5 months, respectively. In these two patients, helical computed tomography showed stent failure. Successful treatment in one patient normalized the direction of flow in the internal mammary vein. Doppler US in the internal mammary veins allowed accurate evaluation of function of superior vena cava stents.

Collateral Circulation↗
PubMed1997

Elastofibroma dorsi: sonographic findings.

OBJECTIVE: Elastofibroma dorsi is a rare, slow-growing reactive pseudotumor of connective tissue typically located in the subscapular region. We report the sonographic characteristics of three cases of elastofibroma dorsi. CONCLUSION: The sonographic appearance of elastofibroma dorsi consists of arrays of interspersed linear or curvilinear hypoechoic stands against an echogenic background. These findings reflect the alternating pattern of fibroelastic streaks and fat that is also detected with other imaging techniques and found on pathologic specimens. In the proper clinical setting, a prospective sonographic diagnosis can obviate the need for further imaging assessment and biopsy.

Adult↗
PubMed1996

CT-guided needle localization of lung nodules for thoracoscopic resection.

We used CT to guide positioning of hookwires within 19 lung nodules in order to localize them prior to thoracoscopic surgery. Both Hawkins III and Kopans-type needles with internal hookwires were employed. Nodule diameter ranged between 0.7 and 4 cm (mean 1.7 cm), and depth from the site of entry of the needle into the pleural surface ranged from 0.5 to 8 cm. Needles were advanced using a technique identical to that for CT-guided biopsy, and localization proved successful in 18 of 19 cases. During surgery, dislodgement of the guidewire occurred in 5 cases, probably due to traction manoeuvers on it. In all these cases the hook of the wire had been opened within the nodule. No dislodgement occurred in patients in whom the needle had been advanced beyond the nodule and the hook allowed to open in the pulmonary parenchyma deep to it. Severe complications did not occur: there was moderate pleuritic pain in 16 cases and asymptomatic pneumothorax in 13 patients. Computer-tomography-guided needle localization of lung nodules is a safe and relatively easy procedure that allows thoracoscopic surgery of lesions which otherwise might be impossible to locate and resect.

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

"Aggressive" renal angiomyolipoma.

PURPOSE: We describe the US and CT examinations of 4 patients with renal angiomyolipoma with an "aggressive" appearance, and review the literature. MATERIAL AND METHODS: The imaging findings in 4 patients with benign renal angiomyolipomas associated with thrombosis of the renal vein and/or inferior vena cava are presented. In one case, enlarged lymph nodes at the renal hilum were found. RESULTS: CT demonstrated fat densities within both tumor and thrombus. In one patient, small lymph nodes with low density internal areas were detected in the para-aortic region. When considering our patients together with those reported in the literature, we found that most angiomyolipomas with venous invasion were large and centrally located within the kidney. Venous thrombosis was observed in 9 lesions of the right kidney, and in only 4 of the left one; detection of the site of origin was impossible in one case. One patient only had symptoms due to the thrombus; 10 had problems due to the tumor; and 3 were asymptomatic. Only 4 patients with pararenal enlarged lymph nodes have been reported on in the imaging literature. Fat-containing nodes were detected by CT in one case only; the others had enlarged nodes of soft-tissue density. In one patient the diagnosis of hamartomatous lymph node invasion was established by angiography. CONCLUSION: In patients with renal angiomyolipoma, demonstration of both fatty thrombus and the fatty infiltration of lymph nodes of the renal hilum cannot be regarded as an indication of malignancy, but only of local aggressive behavior. Although surgery is commonly contemplated to prevent symptoms from venous thrombosis, conservative treatment seems possible. Detection of enlarged lymph nodes of soft tissue density may cause difficult diagnostic problems, with the diagnosis addressed only by the presence of associated lesions. Increased awareness that renal angiomyolipoma can sometimes appear "aggressive" could help to prevent such lesions from being considered malignant, and thus avoid surgical confirmation of their nature.

Adult↗