PubMed Health⌕ Search

Biomedical subjects

V Nicolet

Publications and source records attributed to V Nicolet.

At least 19 recordsLinked to original sources
PubMed2001

Detection of renal artery stenosis: prospective comparison of captopril-enhanced Doppler sonography, captopril-enhanced scintigraphy, and MR angiography.

OBJECTIVE: The objective of our study was to compare the value of captopril-enhanced Doppler sonography, captopril-enhanced renal scintigraphy, and gadolinium-enhanced MR angiography for detecting renal artery stenosis. SUBJECTS AND METHODS: Forty-one patients with suspected renovascular hypertension were prospectively examined with captopril-enhanced Doppler sonography, captopril-enhanced renal scintigraphy, gadolinium-enhanced MR angiography, and catheter angiography. The sensitivity and specificity of each technique for detecting renal artery stenosis measuring 50% or greater and 70% or greater were compared using the McNemar test. Positive and negative predictive values were estimated for populations with 5% and 30% prevalence of renal artery stenosis. Kappa values for interobserver agreement were assessed for both gadolinium-enhanced MR angiography and catheter angiography. RESULTS: For detecting renal artery stenosis measuring 50% or greater, the sensitivity of gadolinium-enhanced MR angiography (96.6%) was greater than that of captopril-enhanced Doppler sonography (69%, p = 0.005) and captopril-enhanced renal scintigraphy (41.4%, p = 0.001). No significant difference in specificity was observed among modalities. For renal artery stenosis measuring 50% or greater, positive and negative predictive values were respectively 62% and 86% for captopril-enhanced Doppler sonography, 49% and 76% for captopril-enhanced renal scintigraphy, and 53% and 98% for gadolinium-enhanced MR angiography. Interobserver agreement was high for both gadolinium-enhanced MR angiography (kappa = 0.829) and catheter angiography (kappa = 0.729). CONCLUSION: Gadolinium-enhanced MR angiography is the most accurate noninvasive modality for detecting renal artery stenosis greater than or equal to 50%. The use of captopril-enhanced Doppler sonography in combination with gadolinium-enhanced MR angiography for identifying renal artery stenosis needs to be evaluated with a cost-effectiveness analysis.

Adult↗
PubMed2000

Percutaneous revascularization of the renal arteries: predictors of outcome.

PURPOSE: To identify predictors of clinical outcome after percutaneous revascularization of the renal arteries. MATERIALS AND METHODS: In 63 patients, the therapeutic response was retrospectively assessed after percutaneous revascularization of the renal arteries indicated for hypertension (41.3%), renal failure (4.8%), or both (53.9%). All patients underwent percutaneous transluminal renal angioplasty, complemented by stent insertion in 30 patients. The authors analyzed the role of clinical and imaging factors, including scintigraphy, Doppler sonography, and angiography for predicting clinical success. RESULTS: In the hypertensive population, there were three cures (5.6%), 26 improvements (48.1%), and 25 failures (46.3%). Among patients with renal insufficiency, 12 were improved (37.5%), 11 were stabilized (34.4%), and nine deteriorated (28.1%). Predictors of favorable outcome for hypertension were shorter duration of hypertension, higher diastolic blood pressure, fibromuscular dysplasia, abnormal Doppler study, higher percentage of angiographic stenosis, and lower grade of aortic atheromatous disease. Predictors of favorable outcome for renal failure were nondiabetic status, abnormal Doppler study, and higher percentage of angiographic stenosis. Abnormal Doppler and scintigraphic examinations predicted successful treatment of hypertension in 60% and 53.8% of cases, respectively, and renal insufficiency in 85% and 60% of cases, respectively. CONCLUSION: Clinical and angiographic variables were the best predictors of therapeutic success for hypertension. Doppler sonography was useful in patients with renal failure.

Angiography↗
PubMed1998

Detection of renal artery stenosis with Doppler sonography before and after administration of captopril: value of early systolic rise.

OBJECTIVE: The goal of this study was to assess the value of quantitative and qualitative analysis of the early systolic rise on Doppler waveforms obtained before and after administration of captopril in patients suspected of having renal artery stenosis. SUBJECTS AND METHODS: Seventy-one hypertensive patients (135 kidneys) were studied with transrenal Doppler sonography. Ninety-six kidneys were studied again after administration of captopril. All patients also underwent renal angiography. All Doppler studies were independently reviewed by two observers. Specific criteria for Doppler waveform patterns that were applied in the detection of renal artery stenosis included acceleration, acceleration time of early systolic rise, differential velocity of systolic rise, and resistive index. These criteria were then correlated with angiography, and receiver operating characteristic curves were generated. RESULTS: On the basis of waveform pattern recognition. Doppler sonograms obtained before administration of captopril had a sensitivity of 81% and a specificity of 98% for the detection of renal artery stenosis greater than or equal to 50%. Sensitivity of Doppler sonography obtained after administration of captopril was 100%, and specificity was 100%. For renal artery stenosis greater than or equal to 70%, sensitivity was 94% and specificity was 89% before administration of captopril. The area under the receiver operating characteristic curve for the acceleration criterion was significantly larger after administration of captopril (p = .009) for the detection of renal artery stenosis greater than or equal to 50%. After captopril administration, an acceleration threshold value of 440 cm/sec2 for early systolic rise was associated with a sensitivity of 100% and a specificity of 94% for the detection of renal artery stenosis greater than or equal to 50%. CONCLUSION: Doppler sonography of the renal arteries performed before administration of captopril appears to be an excellent screening tool in the detection of severe stenosis (> or = 70%). Administration of captopril improves the detection of renal artery stenosis greater than or equal to 50% with Doppler sonography when observers use both morphologic and quantitative criteria.

Antihypertensive Agents↗
PubMed1996

Autosplenectomy in systemic lupus erythematosus.

Autosplenectomy in systemic lupus erythematosus (SLE) is associated with a high mortality rate due to Streptococcus pneumoniae sepsis. We describe 2 patients who developed autosplenectomy in the setting of an acute SLE exacerbation. Followup of both patients 12 and 5.5 years after the initial diagnosis of autosplenectomy revealed persistent absence of the spleen. Pneumococcal vaccine was given to both patients. In contrast with reports describing life threatening infections in 46.7% of asplenic patients with SLE, none developed during prolonged followup of our patients. Our data and review of 13 other patients with SLE with autosplenectomy suggest that the 23-valent pneumococcal vaccine should be given promptly to patients with SLE when a diagnosis of autosplenectomy is established.

Adult↗
PubMed1995

Renal artery stenosis: evaluation of Doppler US after inhibition of angiotensin-converting enzyme with captopril.

PURPOSE: To evaluate the modifications of Doppler ultrasound waveform morphology after inhibition of angiotensin-converting enzyme with captopril to increase the sensitivity of Doppler sonography in detecting renal artery stenosis. MATERIALS AND METHODS: Sixty-two renal arteries were studied in 31 hypertensive patients who underwent Doppler scanning before and 1 hour after administration of captopril prior to undergoing angiography. Pattern recognition criteria were applied to classify the Doppler waveforms as having a normal or pulsus tardus configuration. Doppler scanning results were compared with those of arteriography. RESULTS: On the basis of recognition of the pulsus tardus, precaptopril Doppler scanning showed 13 (68%) of 19 significant renal artery stenoses found at angiography (95% confidence interval, 0.43, 0.85), whereas 19 (100%) of 19 stenoses were detected with postcaptopril Doppler scanning (95% confidence interval, 0.85, 1.0). CONCLUSION: Captopril significantly (95% confidence intervals) increases Doppler scanning sensitivity in detecting renal artery stenoses by inducing or enhancing the pulsus tardus distal to a significant renal artery stenosis.

Adult↗
PubMed1994

Correction of deteriorating renal function by superselective embolization of an arcuate renal artery pseudoaneurysm.

We performed superselective embolization of an iatrogenic pseudoaneurysm of the right kidney that was causing hematuria and deterioration of renal function in a patient with chronic renal failure. An arcuate artery was embolized with absorbable gelatin sponge and a straight embolization wire without significant loss of renal vascularization, thus restoring baseline renal function. To our knowledge the clinical and technical aspects of our case are unique. The technique is described.

Aged↗
PubMed1993

Imaging of the salivary glands.

The most common conditions affecting the salivary glands are calculi, inflammation and tumours. Plain radiography may be useful, especially in showing calculi. Sialography is the examination of choice for inflammatory diseases, whereas ultrasonography, computed tomography and magnetic resonance imaging are particularly useful in evaluating masses in the salivary glands. Radionuclide studies are sometimes helpful in evaluating inflammatory or tumoral diseases. Each technique has its place, and the methods are often complementary. In this review article the authors present the techniques that they use in evaluating diseases of the salivary glands.

Humans↗
PubMed1991

Diffuse metastatic involvement of the breast.

Metastases to the breast are not very common and, according to the recent literature, usually present as nodules, most often single but sometimes multiple, generally without retraction or thickening of the skin. The authors reviewed 21 such cases from the last 15 years. In six patients the metastatic infiltration presented as diffuse thickening of the skin and increased density of the breast, as can be seen in inflammatory diseases or after radiotherapy. In five of these six women lymphangitic spread of the carcinoma was demonstrated by microscopy.

Adult↗
PubMed1988

Thickening of the renal collecting system: a nonspecific finding at US.

The records of 22 patients in whom wall thickening of the renal collecting system was seen at ultrasound (US) were retrospectively reviewed. Wall thickening was found in 15 patients with renal transplants and seven with native kidneys. Severe thickening occurred with transplant rejection, but thickening also occurred with urinary tract infection, reflux, or chronic obstruction in both transplanted and native kidneys. As such, thickening of the renal collecting system seen at US is a nonspecific finding that must be correlated with the clinical and laboratory findings.

Adult↗
PubMed1986

Percutaneous fine-needle aspiration biopsy of the pancreas.

Percutaneous fine needle aspiration biopsy of the pancreas allows to obtain without surgery a tissue proven diagnosis of focal lesions of the pancreas. Ultrasound (US), computed tomography (CT), or fluoroscopy are used to guide the positioning of the needle in the lesion. Various benign and malignant lesions can be diagnosed and the cytologic features of them are presented. The average sensitivity of the technique in the diagnosis of pancreatic carcinoma is 80.5% in the literature. The use of percutaneous fine needle biopsy of the pancreas decreases the number of investigations to be done in a patient with pancreatic disease.

Adenocarcinoma↗
PubMed1986

Unsuspected pheochromocytoma: risk of blood-pressure alterations during percutaneous adrenal biopsy.

Four unsuspected pheochromocytomas were discovered during percutaneous fine-needle biopsy of the adrenal gland under ultrasound (n = 1) and computed tomographic (n = 3) guidance. One patient suffered an acute episode of alternating hypertension and hypotension during the procedure. A second patient had no alterations in vital signs during the procedure but had a severe hypertensive crisis during induction of anesthesia at surgery. Neither biopsy nor surgery affected the vital signs in the other two patients. During biopsy study of adrenal lesions, the possibility of unsuspected pheochromocytoma should be considered, and the interventional radiologist must be familiar with the emergency treatment of hypotensive or hypertensive crises that may occur.

Adrenal Gland Neoplasms↗
PubMed1986

Detection of an asymptomatic gastroduodenal artery aneurysm by real-time and pulsed Doppler sonography.

We describe an asymptomatic gastroduodenal artery aneurysm detected by real-time sonography. This lesion had the ultrasonographic characteristics of an aneurysm except for its unusual location and the absence of turbulent echogenic flow and pulsation. Pulsed-Doppler sonography confirmed the diagnosis by demonstrating bidirectional flow with systolic acceleration in the anechoic portion of the lesion.

Aneurysm↗
PubMed1984

Urinary tract infection in children. A reappraisal of its radiologic investigation.

In a prospective study, 100 children with either an acute or a previous history of urinary tract infection were investigated by intravenous urography, micturition cystourethrography, and ultrasonography. The results from the three diagnostic modalities were compared: The urinary tracts in 59 patients were normal, and revealed some abnormality in 41. Ultrasonography proved to be superior to intravenous urography in outlining renal contours and in detecting subtle cortical changes secondary to urinary tract infection (such as slight increases in cortical thickness and edema or cortical scarring). The mucosa of the renal pelvis and bladder was more easily assessed by ultrasound than by intravenous urography. Both modalities were "equally" accurate in detecting important congenital malformations of the urinary tract. Ultrasound failed to detect 24 of 28 ureters demonstrating reflux on voiding cystourethrography. We propose that carefully performed abdominal ultrasonography can replace intravenous urography in the initial investigation of urinary tract infection in children. It should be done in association with a radiographic or radionuclide voiding cystogram. Intravenous urography would then become a complementary examination for abnormal or problematic patients.

Adolescent↗
PubMed1984

Sonographic appearances of the wall of ovarian dermoid cysts.

A review of the sonograms of 25 patients with proven ovarian benign cystic teratomas was undertaken to study the appearance of the tumor wall. It was partially or completely identified in 12 (48%), being most often thin and hypoechoic, relative to the more echogenic contents of the tumor and of the surrounding tissues. In one patient the dermoid cyst demonstrated a circumferential hyperechoic wall due to a thick layer of adipose tissue. This latter appearance is most specific but is rarely seen in dermoid tumors.

Dermoid Cyst↗
PubMedDate not supplied

Imaging of renovascular hypertension: respective values of renal scintigraphy, renal Doppler US, and MR angiography.

Renovascular hypertension affects 15%-30% of patients who have clinical criteria suggestive of renovascular disease. Noninvasive screening is crucial for patient selection prior to conventional angiography and renal revascularization. Renal scintigraphy has been reported to be sensitive for detection of renovascular hypertension, but some of its limitations (eg, in the setting of bilateral renal artery stenosis and renal failure) should be considered. Doppler ultrasonography (US) allows direct evaluation of the renal arteries as well as transrenal Doppler waveform analysis, but it remains operator dependent. Gadolinium-enhanced magnetic resonance (MR) angiography is becoming an excellent alternative to conventional angiography. The main limiting factors of this technique are inadequate visualization of segmental and accessory renal arteries as well as a tendency toward overestimation of stenoses. Given the high cost and low availability of MR angiography, scintigraphy and Doppler US should be considered the primary studies in screening for renovascular hypertension. MR angiography could be reserved for patients with inconclusive scintigraphic and Doppler US results, patients with high clinical suspicion of renovascular hypertension, and patients with a contraindication to conventional angiography.

Evaluation Studies as Topic↗