Search PubMed⌕ Search

Biomedical subjects

L E Derchi

Publications and source records attributed to L E Derchi.

At least 37 records · Page 2Linked to original sources
PubMed2000

US of nerve entrapments in osteofibrous tunnels of the upper and lower limbs.

The diagnosis of nerve entrapment at osteofibrous tunnels relies primarily on clinical and electrodiagnostic findings. Recently, the refinement of high-frequency broadband transducers with a range of 5-15 MHz, sophisticated focusing in the near field, and sensitive color and power Doppler technology have improved the ability to evaluate peripheral nerve entrapment in osteofibrous tunnels with ultrasonography (US). In the upper limb, osteofibrous tunnels amenable to US examination include the carpal tunnel for the median nerve and the cubital and Guyon tunnels for the ulnar nerve. In the lower limb, these tunnels include the fibular neck for the common peroneal nerve, the tarsal tunnel for the posterior tibial nerve, and the intermetatarsal spaces for the interdigital nerves. High-resolution US allows direct imaging of the involved nerves, as well as documentation of changes in nerve shape and echotexture that occur in compressive syndromes. A spectrum of extrinsic causes of entrapment, such as tenosynovitis, ganglia, soft-tissue tumors, bone and joint abnormalities, and anomalous muscles, can also be diagnosed with US. With continued experience, it is likely that this technique will be increasingly used to evaluate nerve entrapment syndromes.

Arm↗
PubMed2000

Identification of feeding arteries to establish the intra- or extraparotid location of jugulodigastric nodules: value of color Doppler sonography.

OBJECTIVE: The objective of our study was to determine the value of color Doppler imaging as an adjunct to gray-scale sonography to reveal the intra- or extraparotid origin of jugulodigastric nodules of uncertain location. SUBJECTS AND METHODS: Forty nodules in the jugulodigastric area from 38 patients were imaged with gray-scale, color, and power Doppler sonography. Nodules receiving vessels from salivary glands were assumed to be intraglandular; those accepting vessels from paraparotid spaces were considered to arise from outside the gland. Imaging results were correlated with biopsy and surgical findings. RESULTS: In 38 of 40 cases, color and power Doppler sonography displayed discrete feeding arteries leading to the nodules: 25 nodules had one supplying artery, nine received two arteries, and four had three or more arteries. Intraparotid nodules received vessels from the gland in 20 cases. In two cases, the source of vessels was indeterminate. In two malignant tumors, multiple arteries derived from both the parotid and the neck spaces. All 14 extraparotid nodules received the arterial supply from paraparotid spaces. Color Doppler sonography enabled prediction of the intraglandular location of the nodules in 91% of cases and the extraglandular location in 87.5% of cases. The correct diagnosis was achieved in 34 of 40 nodules, with a global accuracy of 85%. CONCLUSION: Color Doppler sonography can help to assess the intra- or extraparotid location of jugulodigastric nodules. In practice, this technique can support the diagnosis when gray-scale sonography raises doubts about the origin of a jugulodigastric nodule.

Adenolymphoma↗
PubMed1999

Sonographic features of incidentally detected, small, nonpalpable ovarian dermoids.

PURPOSE: We describe the transvaginal sonographic features of incidentally detected, small, nonpalpable ovarian dermoid cysts. METHODS: A total of 38 small (less than 3 cm in diameter), nonpalpable, incidentally discovered ovarian dermoids in 35 women were retrospectively reviewed; 3 patients had small bilateral lesions, and 7 had a small ovarian dermoid detected during preoperative evaluation of a symptomatic, large, contralateral lesion. RESULTS: Transvaginal sonography permitted identification of all 38 dermoids, whereas abdominal sonography detected only 22 of the lesions. Three main structural patterns were observed with transvaginal sonography: (1) 20 of 38 lesions had a solid, hyperechoic appearance, either homogeneous (11) or heterogeneous (9); (2) a fluid-filled area with a hyperechoic focus in its wall was seen in 10 cases; and (3) a mixed pattern, with solid and liquid areas, was seen in 8 cases. Calcifications were appreciated in 7 lesions. Acoustic shadowing was noted in 30 cases, either as a shadow posterior to the hyperechoic portion of the mass or as an edge shadow lateral to the lesion. Doppler studies were obtained for 20 lesions but proved inconclusive: 4 mixed-pattern dermoids had a few internal signals with a low resistance pattern; in the remaining cases, there were signals at the periphery of the cysts, but it could not be determined whether these were from vessels within the lesions or from vessels in the surrounding ovarian parenchyma. Surgery confirmed benign cystic dermoids in all 38 cases. CONCLUSIONS: Sonographically, small ovarian dermoids have a variety of textural patterns quite similar to those encountered in large, symptomatic lesions. The increased resolution capabilities provided by transvaginal sonography allow incidental detection of previously unsuspected dermoids and permit identification of their nature.

Adolescent↗
PubMed1999

Testicular microlithiasis: US findings in six pediatric cases and literature review.

The aim of this article is to report on six pediatric cases of testicular microlithiasis (TM) and to review literature reports, in order to schedule US and/or other control examinations, particularly when concomitant focal or diffuse alterations of the testicular parenchymal structure are present, considering the possible association of TM with testicular tumors. Six patients (age range 4-12 years) underwent US examination for scrotal trauma (two cases) unilateral cryptorchidism (one case) follow-up after orchidopexy for bilateral cryptorchidism (one case), and varicocele (two cases). Five examinations were performed with high-frequency probes (10/13 MHz) and seven with 5/7.5-MHz frequency transducers. Follow-up US examinations were performed at different times depending on initial clinical indications, presence of underlying disease, and initial US findings. Two of the six patients underwent three US examinations, two patients underwent two US examinations, and the remaining two patients underwent only one US examination. The patients underwent a total of 12 US examinations. Microliths were bilateral in four patients and unilateral in two patients. In these two latter cases, the contralateral testis was, in one case, cryptorchid and could not be evaluated by US; in the other case it was small and hyperechogenic with orchidopexy sequelae. In three cases microliths were distributed throughout the testis. In the remaining three cases they were present in limited areas of parenchyma. As to the importance of microliths, it was defined as mild in three cases and moderate/severe in three cases. Intratubular testicular microlithiasis is a well-proved histological finding (biopsy or autopsy). More recent is the US demonstration of TM with consequent definition of its pattern: usually bilateral hyperechogenic multiple small foci without acoustic shadows with complete or partial extension to the parenchyma. Testicular microlithiasis is a rare finding. Moreover, the pediatric cases reported in the literature are very few. However, the use of high-frequency US transducers (10-13 MHz) has recently allowed an easier demonstration of this disease also in children. Of particular interest is the study of the still-debated association of microliths with other diseases such as neoplasms. Some aspects need further investigation, namely the real incidence of microliths in the healthy population, the incidence of tumors in patients with microliths, the differences between adults and children, and the different types of follow-up at different ages. In pediatric age, if TM represents an isolated sign, patients need non-invasive US follow-up until adult age. Only if TM is in association with focal lesions of testis parenchyma is it mandatory to perform biopsy or surgical treatment.

Child↗
PubMed1999

Tendon and nerve sonography.

The refinement of high frequency transducers has improved the ability of ultrasound (US) to detect fine textural abnormalities of tendons and nerves and to identify a variety of pathologic conditions. Characteristic echotextural patterns, closely resembling the histologic ones, are typically depicted in these structures using high US frequencies. In tendon imaging, US can identify tendon dislocations, degenerative changes, differentiate partial from complete tears and determine whether the patient has to be treated surgically or conservatively. A spectrum of findings in inflammatory conditions, including paratendonitis and tenosynovitis, and tendon tumors also can be detected. In nerve imaging, US can support clinical and electrophysiologic testing for detection of compressing lesions caused by nerve entrapment in a variety of osteofibrous tunnels of the limbs and extremities. Nerve tears and tumors also can be diagnosed. Overall, US is an effective technique for imaging tendons and nerves.

Humans↗
PubMed1999

Increased renal resistive index in patients with essential hypertension: a marker of target organ damage.

BACKGROUND: Increased renal resistance detected by ultrasound (US) Doppler has been reported in severe essential hypertension (EH) and recently was shown to correlate with the degree of renal impairment in hypertensive patients with chronic renal failure. However, the pathophysiological significance of this finding is still controversial. METHODS: In a group of 211 untreated patients with EH, we evaluated renal resistive index (RI) by US Doppler of interlobar arteries and early signs of target organ damage (TOD). Albuminuria was measured as the albumin to creatinine ratio (ACR) in three non-consecutive first morning urine samples. Left ventricular mass was evaluated by M-B mode echocardiography, and carotid wall thickness (IMT) by high resolution US scan. RESULTS: RI was positively correlated with age (r=0.25, P=0.003) and systolic blood pressure (SBP) (r=0.2, P=0.02) and with signs of early TOD, namely ACR (r=0.22, P=0.01) and IMT (r=0.17, P<0.05), and inversely correlated with renal volume (r=-0.22, P=0.01) and diastolic blood pressure (r=-0.23, P=0.006). Multiple linear regression analysis demonstrated that age, gender, ACR and SBP independently influence RI and together account for approximately 20% of its variations (F=8.153, P<0.0001). When clinical data were analysed according to the degree of RI, the patients in the top quartile were found to be older (P<0.05) and with higher SBP (P<0.05) as well as early signs of TOD, namely increased ACR (P<0.002) and IMT (P<0.005 by ANOVA), despite similar body mass index, uric acid, fasting blood glucose, lipid profile and duration of hypertension. Furthermore, patients with higher RI showed a significantly higher prevalence of microalbuminuria (13 vs 12 vs 3 vs 33% chi2=11.72, P=0.008) and left ventricular hypertrophy (40 vs 43 vs 32 vs 60%, chi2=9.25, P<0.05). CONCLUSIONS: Increased RI is associated with early signs of TOD in EH and could be a marker of intrarenal atherosclerosis.

Adult↗
PubMed1999

[Defecography by spiral computed tomography].

PURPOSE: We investigated the possible role of helical CT defecography in pelvic floor disorders by comparing our results with those of conventional defecography. MATERIAL AND METHODS: Our series consisted of 90 patients, namely 62 women and 28 men, ranging in age 24-82 years. They were all submitted to conventional defecography, and 18 questionable cases were also studied with helical CT defecography. The conventional examination was performed during the 4 standard phases of resting, squeezing, Valsalva and straining; we used a remote-control unit. The parameters for helical CT defecography were: 5 mm beam collimation, pitch 2, 120 KV, 250 mAs and 18-20 degrees gantry inclination to acquire coronal images of the pelvic floor. The rectal ampulla was distended with a bolus of 300 mL nonionic iodinated contrast agent (dilution: 3 g/cc). The patient wore a napkin and was seated on the table, except for those who could not hold the position and were thus examined supine. Twenty-second helical scans were performed at rest and during evacuation; multiplanar reconstructions were obtained especially on the sagittal plane for comparison with conventional defecographic images. RESULTS: An unquestionable diagnosis could be made in all the 18 patients submitted to helical CT defecography. The diagnosis was in agreement with proctology results and added new information in all cases. Sixteen patients had constipation and 2 fecal incontinence--one from rectal prolapse and the other from a rectovaginal fistula. In this latter case helical CT defecography permitted to confirm the fistula and suggest its course. One patient had a previously undetected ovarian cancer metastatic to the anterior rectal wall. DISCUSSION AND CONCLUSIONS: Coronal helical CT defecography images permitted to map the perineal floor muscles, while sagittal reconstructions provided information on the ampulla and the levator ani. To conclude, helical CT defecography performed well in the study of pelvic floor disorders and can follow conventional defecography especially in questionable cases.

Adult↗
PubMed1998

Intrarenal arteriosclerosis and impairment of kidney function in NIDDM subjects.

It is currently under debate whether the pathogenesis of end-stage renal failure in non-insulin-dependent diabetes mellitus (NIDDM) is a consequence of microangiopathy alone. The aim of this study was to investigate intrarenal arteriosclerosis and its correlation with kidney function in NIDDM. In 36 diabetic subjects, and in 10 age- and sex-matched healthy control subjects we measured kidney volume and resistive index of the interlobar arteries by duplex Doppler ultrasonography. Clinical and metabolic parameters, renal function and vascular sequelae of the disease were also evaluated. In diabetic subjects resistive index (median 0.72, range 0.54-0.79) was higher than in control subjects (median 0.62, range 0.57-0.66) (2p < 0.002). Kidney volume and resistive index correlated with age (p < 0.004), body mass index (p < 0.001), mean blood pressure (p < 0.001), total and LDL cholesterol (p < 0.01) and creatinine clearance (p < 0.001 and < 0.01, respectively). Kidney volume also correlated with HbA1 (p < 0.01) and resistive index with uric acid (p < 0.01). Lower body macroangiopathy was associated with increased resistive index and reduced kidney volume (2p < 0.05), while upper body macroangiopathy and microangiopathy were not. Our data suggest that macroangiopathy rather than microangiopathy is mainly responsible for impairment of kidney function in NIDDM. The resistive index of interlobar arteries seems to be a reliable marker of intrarenal arteriosclerosis and can be used as a non-invasive, easily available parameter of its evolution.

Arteriosclerosis↗
PubMed1998

High-resolution US of non-traumatic recurrent dislocation of the peroneal tendons: a case report.

We report the case of a young girl with recurrent sharp pain in the outer aspect of the ankle. She had no previous trauma. High-resolution US (HRUS) showed a complete intermittent dislocation of the peroneal tendons. Post-traumatic chronic peroneal instability is quite common, whereas complete dislocation is rare. HRUS is an important adjunct to clinical examination and radiographic evaluation of patients with musculoskeletal disorders of the foot and ankle [1]. This paper reports its value in non-traumatic recurrent dislocation of the peroneal tendons.

Ankle Joint↗
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

Power Doppler sonography: general principles, clinical applications, and future prospects.

Power Doppler sonography (PD) is a technique that displays the strength of the Doppler signal, rather than the flow velocity and directional information. Its increased flow sensitivity and better vascular delineation have been used to document the presence and characteristics of flow in vessels that are poorly imaged with conventional color Doppler (CD), to identify areas of ischemia, to demonstrate inflammatory hyperemia or increased and irregular flow in tumors, as well as to assess serial vascular changes related to interval therapy. The present review reports the general principles of PD, portrays the results of clinical studies available in the literature, and suggests future trends of development.

Blood Vessels↗
PubMed1998

The anterior tilt of the acromion: radiographic evaluation and correlation with shoulder diseases.

The aim of this study was to test whether the anterior tilt of the acromion can be objectively evaluated on lateral radiographs, and whether there is a relation between this anatomical feature and the most common shoulder diseases. Lateral radiographs of 15 dried scapulas were performed in neutral position and with 5 degrees of caudal, cranial, anterior and posterior angulations. Two hundred and forty-three shoulders, both asymptomatic and affected by chronic and post-traumatic impingement, calcific tendinitis and instability, were examined by conventional radiography. The presence of rotator-cuff tears was investigated by sonography. A method was elaborated to obtain reproducible lateral radiographs and to determine the acromial tilt angle. Inter- and intraobserver and inter- and intraoperator variations in measurements were evaluated. Variations in tube angulation produced changes in tilt-angle values on dried scapulas. The average tilt angle for the chronic impingement and the instability groups were significantly different from the post-traumatic, calcific tendinitis and control groups. Rotator-cuff tears were significantly more frequent in the chronic impingement group and related to a more acute tilt angle. The inter- and intraobserver variability coefficients were 0.95 and 0.98, whereas the inter- and intraoperator variability coefficients were 0.94 and 0.96, respectively. Conventional radiography using fluoroscopy for positioning is a well-reproducible method for the evaluation of acromial tilt. There is a significant difference in tilt-angle values between some groups of subjects examined, but the lack of specificity limits the clinical importance of such measurement.

Acromion↗
PubMed1998

Power Doppler sonography: clinical applications.

OBJECTIVE: Color Doppler imaging (CD) has had a great impact on ultrasonography (US). This technique depicts local flow by encoding an estimate of the mean Doppler frequency shift at a particular position in color. However, the choice of the mean frequency shift as the parameter for representing flow in color Doppler is somewhat arbitrary. Power Doppler ultrasound is a technique that encodes the power in the Doppler signal in color. This parameter is fundamentally different from the mean frequency shift. The frequency is determined by the velocity of the red blood cells, while the power depends on the amount of blood present. Providing an image of a different property of blood flow, power Doppler has shown several key advantages over colour Doppler, including higher sensitivity to flow, better edge definition and depiction of continuity of flow. In this paper we review the results of power Doppler clinical studies. MATERIALS AND METHODS: All relevant information available in the literature on the potential clinical applications of this technique was revised to give a detailed survey. RESULTS: The increased flow sensitivity and better vascular detailing of power Doppler have been used to detect flow presence and characteristics in vessels that are poorly imaged with conventional color Doppler. The improved depiction of tissue vasculature has shown potential advantages, especially in some areas, such as the cortex of native kidneys and renal allografts, the prepuberal testis, the infant hip and the bowel wall, in which color Doppler is not sensitive enough to detect clinically important, slow and poor flow in small vessels. In inflammatory conditions, power Doppler was valuable in depicting increased flow in vessels that are dilated because of inflammatory response. In this field, advantages have been reported in acute cholecystitis and in inflammatory states of musculoskeletal tissues. The higher sensitivity to slow flow and the improved detailing of the course of tortuous and irregular vessels made power Doppler a promising technique to image intratumoral vessels and, thereby, to ameliorate the accuracy of color Doppler in predicting the likelihood of benign versus malignant nature of nodules. Specific flow patterns, missed at color Doppler studies, have been indicated with power Doppler in some tumors of the liver and breast. In different settings, power Doppler also permitted to monitor serial blood flow changes after therapy and to display them as color intensity, allowing the observer to distinguish flow changes. CONCLUSION: Although the actual role of power Doppler in changing patient management has not been assessed yet, this technique can depict flow which was previously undetectable, and thus permits an easier and more confident diagnosis in body regions where the ultrasound signal is weak because blood vessels are small.

Blood Vessels↗