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R Taillefer

Publications and source records attributed to R Taillefer.

At least 37 records · Page 2Linked to original sources
PubMed1995

Technetium-99m-sestamibi prone scintimammography to detect primary breast cancer and axillary lymph node involvement.

UNLABELLED: The purpose of this study was to evaluate prospectively the sensitivity and specificity of scintimammography in the detection of both primary breast cancer and axillary lymph node involvement. METHODS: Sixty-five consecutive women referred for a suspicious breast lesion on clinical examination and/or with abnormal mammographies suggestive of malignancies were studied with scintimammography using planar prone imaging (with a chest positioning device with semicircular lateral aperture on the imaging table) performed 15 min postinjection of 25-30 mCi 99mTc-sestamibi. Three planar views, right and left lateral prone and anterior supine thoracic views, were obtained (8-10 min/view). The entire breast and ipsilateral axillary region were included in the field of view. Excisional breast biopsy and/or fine needle aspiration cytology were performed in all patients within 4 wk after scintimammography. Axillary node dissection was also performed. RESULTS: The largest primary tumor measured 2 x 3 cm. There were 47 primary breast cancers (8 different histologic types) and 18 benign breast lesions (5 histologic types). The sensitivity of scintimammography for detecting primary breast cancer was 91.5% (43 true-positive, 4 false-negative) and the specificity was 94.4% (17 true-negative, 1 false-positive). Metastatic axillary lymph node involvement was seen in 19 of 41 patients. The sensitivity of scintimammography to detect metastatic lymph nodes was 84.2% (16 true-positive, 3 false-negative) and the specificity was 90.9% (20 true-positive, 2 false-positive). CONCLUSION: This preliminary study confirms the results of some previous reports, which showed the high diagnostic accuracy of scintimammography in detecting breast cancer. This study also shows the potential value of this procedure to detect axillary lymph node involvement as concomitant information.

Axilla↗
PubMed1994

Antireflux operations in patients with scleroderma.

Fourteen patients with scleroderma underwent antireflux operations (10 short Nissen, 2 Collis-Nissen, 1 Collis-Belsey, and 1 vagotomy and antrectomy with Roux-en-Y). Esophageal function was assessed preoperatively and postoperatively with a follow-up range of 8 to 181 months (mean, 65 months). Reflux symptoms were relieved in 10 of the 14 patients (p < 0.01), as shown by a decrease in their 24-hour acid exposure of from 15% to 7.5% (p < 0.05). However, the lower esophageal sphincter pressure gradient created by the operations did not increase significantly (3.7 +/- 3.4 mm Hg to 5.5 +/- 3.5 mm Hg). The esophageal acid exposure decreased sufficiently to promote some alleviation of the esophagitis. Radiologic signs of stenosis regressed in 6 of 7 patients. Postoperative endoscopic assessment revealed complete or partial healing of erosions seen preoperatively in 6 of the 7 patients so studied, and healing of all ulcers in 3 patients. Twelve patients continued to have columnar metaplasia. Manometric studies disclosed no significant changes in propulsion and contractility. Distal esophageal resting pressures rose significantly from 6.2 to 9.4 mm Hg (p < 0.05 mm Hg), suggestive of stasis. Radionuclide transit studies, however, showed no significant decrease in the esophageal emptying capacity after operation. It is concluded that conventional antireflux operations in patients with scleroderma can palliate reflux damage without jeopardizing esophageal function.

Adult↗
PubMed1994

Detection of myocardial necrosis and inflammation by nuclear cardiac imaging.

For almost two decades, Tc-99m pyrophosphate has been the preferred infarct-avid imaging agent in nuclear cardiology. More recently, Indium-III- and Tc-99m-labeled antimyosin monoclonal antibody imaging have been extensively investigated. Although In-III antimyosin is not yet available in North America, this radioimmunoscintigraphic procedure is very promising for detection of both Q-wave and non-Q-wave myocardial infarction, especially when other standard diagnostic modalities fail to be contributive. When appropriately applied, radionuclide imaging with infarct-avid agents may provide very helpful clinical information.

Animals↗
PubMed1994

Thallium-201-dipyridamole imaging: comparison between a standard dose and a high dose of dipyridamole in the detection of coronary artery disease.

UNLABELLED: The purpose of this study was to compare two different doses of dipyridamole as a pharmacologic stress test for 201Tl imaging. METHODS: Twenty-four patients with significant coronary artery disease (15 had undergone a coronary angiogram and 9 had undergone a previous 201Tl study with a significant lesion) were prospectively studied. Within 1 wk, all patients underwent two 201T-dipyridamole myocardial planar studies, one using a standard dose (STD) and the other, a high dose (HIGH) of dipyridamole. The protocol order was randomly assigned. The STD protocol used a dose of 0.14 mg/kg/min for a duration of 4 min (0.56 mg/kg), and the HIGH protocol used a dose of 0.14 mg/kg min for a duration of 6 min (0.84 mg/kg). The 201Tl was injected 3 min after the end of the dipyridamole infusion. Images, obtained 5 min and 4 hr later, were interpreted (divided into five segments each) by three blinded observers. RESULTS: The STD protocol showed normal, ischemia and scar in 252, 91 and 17 segments, respectively. The HIGH protocol detected 232, 118 and 10 segments, respectively. A side-by-side evaluation was done to evaluate the defect extent subjectively, which was greater with HIGH in 14, equal in six and smaller in four patients. One or more side effects were seen in 14 patients with STD and in 19 with HIGH. Increased heart rate (8 bpm for STD and 19 bpm for HIGH, p < 0.001) was the only significant change seen in the hemodynamic parameters. CONCLUSION: This preliminary study indicates that a high dose of dipyridamole seems to be safe and can be helpful to increase the sensitivity of 201Tl imaging.

Coronary Disease↗
PubMed1992

Gastric inhibitory polypeptide-dependent cortisol hypersecretion--a new cause of Cushing's syndrome.

BACKGROUND: Corticotropin-independent nodular adrenal hyperplasia is a rare cause of Cushing's syndrome, and the factors responsible for the adrenal hyperplasia are not known. METHODS: We studied a 48-year-old woman with Cushing's syndrome, nodular adrenal hyperplasia, and undetectable plasma corticotropin concentrations in whom food stimulated cortisol secretion. RESULTS: Cortisol secretion had an inverse diurnal rhythm in this patient, with low-to-normal fasting plasma cortisol concentrations and elevated postprandial cortisol concentrations that could not be suppressed with dexamethasone. The cortisol concentrations increased in response to oral glucose (4-fold increase) and a lipid-rich meal (4.8-fold increase) or a protein-rich meal (2.6-fold increase), but not intravenous glucose. The infusion of somatostatin blunted the plasma cortisol response to oral glucose. Intravenous infusion of gastric inhibitory polypeptide (GIP) for one hour increased the plasma cortisol concentration in the patient but not in four normal subjects. Fasting plasma GIP concentrations in the patient were similar to those in the normal subjects; feeding the patient test meals induced increases in plasma GIP concentrations that paralleled those in plasma cortisol concentrations. Cell suspensions of adrenal tissue from the patient produced more cortisol when stimulated by GIP than when stimulated by corticotropin. In contrast, adrenal cells from normal adults and fetuses or patients with cortisol-producting or aldosterone-producing adenomas responded to corticotropin but not to GIP. CONCLUSIONS: Nodular adrenal hyperplasia and Cushing's syndrome may be food-dependent as a result of abnormal responsiveness of adrenal cells to physiologic secretion of GIP. "Illicit" (ectopic) expression of GIP receptors on adrenal cells presumably underlies this disorder.

Adrenal Glands↗
PubMed1992

Comparison between technetium-99m-teboroxime and thallium-201 dipyridamole planar myocardial perfusion imaging in detection of coronary artery disease.

Technetium-99m (TC-99m)-teboroxime is a new myocardial perfusion imaging agent. The purpose of this prospective study was to compare Tc-99m-teboroxime with thallium-201 imaging after the administration of dipyridamole. Thirty patients referred for the evaluation of chest pain were studied with both thallium-201 and Tc-99m-teboroxime dipyridamole scans (mean interval 2 days). Dipyridamole was administered at 0.142 mg/kg/min for 4 minutes. Planar imaging (3 standard views) was obtained at 5 and 240 minutes after the injection of 2.2 mCi of thallium-201. Tc-99m-teboroxime (18 to 25 mCi) was injected after dipyridamole infusion. A second injection, at rest, was repeated 4 hours later. Planar imaging (3 standard views of 1 minute/view for the first 2 views, and 90 seconds for the last view) was obtained 2 minutes after Tc-99m-teboroxime injection. Blinded reading was performed by 3 observers. Thallium-201 showed perfusion defects in 182 myocardial segments corresponding to 33 of 45 (73%) significantly stenosed coronary arteries (greater than or equal to 70% reduction in endoluminal diameter), and Tc-99m-teboroxime detected 160 abnormal segments corresponding to 29 of 45 (64%) stenosed arteries. Thallium-201 and Tc-99m-teboroxime studies were normal in 3 patients. In conclusion, this study shows that there is a good correlation in the imaging results found with thallium-201 and Tc-99m-teboroxime using dipyridamole infusion on both a segmental and a diagnostic comparison.

Adult↗
PubMed1992

Long-term effect of total fundoplication on the myotomized esophagus.

From 1978 to 1983, 17 patients had an esophagocardiomyotomy with an added short total fundoplication as an antireflux procedure. Thirteen had achalasia and 4, diffuse esophageal spasm. All patients initially had the usual symptoms of these motor disorders. Early after the operation all became asymptomatic, but over the years of follow-up, symptoms reappeared in 14 of 17 patients, and 5 required reoperation. The distal esophageal transverse diameter showed progressive dilatation from 3.9 cm preoperatively to more than 6 cm after 10 years of evolution. Over the same period, deterioration in the esophageal emptying capacity caused esophageal stasis to increase from 32% to 75%. Manometric changes were significant after the operation: resting pressures in the esophageal body decreased from 10.5 to 4.4 mm Hg (p < 0.001) proximally and from 12.2 to 4.6 mm Hg distally (p < 0.001). Peak contraction pressures became significantly weaker: 38 to 30 mm Hg in the proximal esophagus (p < 0.001) and from 49.2 to 28.1 in the distal esophagus (p < 0.001). Tertiary contractions were unchanged distally, but peristalsis reappeared in more than 30% of all swallows in the proximal half of the esophageal body. The resting pressure gradient in the lower esophageal sphincter area was reduced from 25.5 to 7.4 mm Hg by the operation. This gradient remained stable over 10 years of follow-up. No significant acid exposure was documented in 8 patients undergoing 24-hour pH recordings after their operation. Endoscopy revealed dilatation and retention without evidence of reflux esophagitis damage. Total fundoplication when associated with esophageal myotomy results in improved symptoms in the early postoperative phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Scleroderma and esophageal reflux, surgical monitoring].

Ten patients with documented scleroderma were assessed before and after antireflux operations over a twelve year period. The approach was through the left chest in 9 of 10 patients (7 short Nissen, 1 Collis Nissen, 1 Collis Belsey) and through the abdomen for 1 (vagotomy, antrectomy and Roux en Y). Clinically, 5 of 10 patients still mention episodes of heartburn. Dysphagia, which was present in 8 patients before the operation, has been replaced by a slow emptying impression in five. Endoscopically five patients had a columnar lined esophageal mucosa. Four more were considered to have ulcerative esophagitis and stricture which proved to be also Barrett's esophagus in the postoperative assessment. Three patients had preoperative 24 h pH assessment when the technique became available. Their postoperative control studies revealed persistent acid exposure but to a lesser degree. All ten patients had 24 h pH studies in their postoperative assessment and 5 out of 10 still show abnormal exposure to acid. Esophageal motility studies did not reveal significant changes to the hypomotility of the distal esophageal body and to the decreased tone of the Lower Esophageal Sphincter area. Both radiologically and using esophageal transit scintigrams the esophagus shows atony and poor emptying before the operation. Retention is increased following the creation of an antireflux technique at the esophagogastric junction. The success rate of antireflux operations in scleroderma patients is limited. The ideal procedure to use in this condition remains unclear.

Adult↗
PubMed1992

Detection and localization of parathyroid adenomas in patients with hyperparathyroidism using a single radionuclide imaging procedure with technetium-99m-sestamibi (double-phase study)

Dual radionuclide imaging using a combination of 201Tl with either 99mTcO4- or 123I is recognized as a useful procedure in the preoperative localization of parathyroid adenomas. Recently, 99mTc-sestamibi (MIBI) has been introduced for myocardial perfusion imaging as an alternative to 201Tl. The purpose of this prospective study was to evaluate parathyroid scan using early and late imaging following MIBI injection. Twenty-three patients (21 F, 2 M, mean age: 57 yr) with a clinical and biologic diagnosis of hyperparathyroidism were submitted to a MIBI study prior to surgical exploration of the neck. Cervico-thoracic planar imaging (anterior view, 10 min/view) was performed at 15 min and at 2-3 hr after an intravenous injection of 20-25 mCi of MIBI. A positive MIBI scan for parathyroid adenoma was defined as an area of increased focal uptake which persisted on late imaging, contrary to the uptake in the normal thyroid tissue which progressively decreases over time (differential washout). Surgical exploration of the neck, performed between 1 day and 72 days (average: 16 days) after the MIBI study, showed a parathyroid adenoma in 21 patients and hyperplasia in two patients. MIBI scan correctly detected and localized 19/21 adenomas (90%). In conclusion, parathyroid imaging using a single radionuclide with MIBI (early and late study with differential washout analysis) is a promising procedure in the preoperative detection and localization of parathyroid adenomas in patients with primary hyperparathyroidism.

Adenoma↗
PubMed1992

New agents labelled with technetium 99m for myocardial perfusion imaging.

New agents labelled with technetium 99m (99mTc) are now available for myocardial perfusion imaging. In this article the author reviews the biologic characteristics, the imaging protocols and the clinical usefulness of thallous chloride Tl 201, 99mTc-sestamibi and 99mTc-teboroxime (not yet available in Canada), as well as their complementary roles in the detection of coronary artery disease.

Clinical Protocols↗
PubMed1992

Blinded evaluation of planar technetium-99m-sestamibi myocardial perfusion studies.

Sestamibi planar myocardial perfusion studies were performed at Hotel-Dieu de Montreal on 28 patients with documented coronary artery disease and 16 normal subjects. Stress and rest studies were performed on separate days. These studies were sent to Virginia for interpretation while blinded as to age, sex, and other clinical information. Studies were quantitated independently by two operators (using a computer program modified for Sestamibi), and interpreted independently by two experienced interpreters. Computer quantitation of 2816 segments gave an average interoperator deviation of 2.2%. Pure quantitative criteria were applied for computer interpretation. By varying the detection threshold, we produced the entire ROC curve relating sensitivity and specificity as a function of detection threshold. Using only computer criteria for normal or abnormal, interoperator agreement by patient was 98% and 93% by view. The computer could achieve equal positive and negative predictive accuracy of 87%. Interpreters, allowed both quantitative and subjective judgment, agreed on 91% of 44 patients, 90% of 132 views, and 92% of 660 segments. Interpreters averaged 94% positive and 86% negative predictive accuracy.

Adult↗
PubMed1992

Comparison between thallium-201, technetium-99m-sestamibi and technetium-99m-teboroxime planar myocardial perfusion imaging in detection of coronary artery disease.

Technetium-99m-sestamibi (MIBI) and 99mTc-teboroxime (TEBO) are two new myocardial perfusion imaging agents. The purpose of this prospective study was to compare MIBI and TEBO to 201TI planar imaging. Eighteen patients with significant coronary artery disease on coronary angiogram were submitted to three treadmill stress tests performed within 3 mo and were imaged with the three radiopharmaceuticals as follows. 1. TI: 2.2 mCi, immediate and delayed views (4 hr later, 8 min/view). 2. TEBO: 15-20 mCi at stress (1 min/view) and a second injection was repeated 4 hr later at rest (20-25 mCi). 3. MIBI: 15-18 mCi at stress (8 min/view) and 1-4 days later, 15-18 mCi at rest. Patients achieved similar levels of exercise. A blinded reading was performed by three observers. The left ventricle was divided into three segments/view and ischemic/normal wall ratios were also determined. Segmental comparison showed an agreement in 85% (138/162) of the segments between TI and TEBO, in 92% (149/162) between TI and MIBI and in 84% (136/162) between MIBI and TEBO. Abnormal TI, MIBI and TEBO studies were seen in 16 (89%), 16 (89%) and 15 (83%) patients, respectively, detecting 77, 75 and 65 abnormal segments. Ischemic-to-normal wall ratios were 0.75 +/- 0.06, 0.73 +/- 0.08 and 0.78 +/- 0.08 for TI, MIBI and TEBO, respectively. In conclusion, although the biologic characteristics of these agents are different, this study showed a good correlation between them in detection of significant coronary artery disease (high pretest likelihood population).

Aged↗
PubMed1991

Technetium 99m SESTAMIBI myocardial perfusion imaging: comparison between treadmill, dipyridamole and trans-oesophageal atrial pacing "stress" tests in normal subjects.

The purpose of this study was to determine the blood clearance, myocardial uptake and heart/lung and heart/liver ratios of technetium 99m methoxyisobutylisonitrile (99mTc-SESTAMIBI) following 3 different types of cardiac stimulation in normal subjects: treadmill stress (STRESS), intravenous administration of dipyridamole (DIP) and trans-oesophageal atrial pacing (TAP). Ten normal volunteers were submitted to 3 injections of 99mTc-SESTAMIBI (10 mCi/70 kg, separated by an interval of 7 days) following STRESS (standard Bruce protocol), DIP (0.142 mg/kg.min during 4 min) and TAP procedures. Blood samples were collected from 1 to 60 min after each 99mTc-SESTAMIBI injection. Planar imaging was performed at 5, 30 and 60 min. Blood retention (percentage of injected dose at 1 min) was 56% +/- 4%, 24% +/- 4% and 38% +/- 6% for STRESS, DIP and TAP, respectively (P less than 0.001). Myocardial uptake was similar for the 3 procedures while the heart lung ratio at 60 min was 3.1 +/- 0.5, 3.8 +/- 0.6 and 3.2 +/- 0.5 for STRESS, DIP and TAP, respectively. Heart/liver ratio at 60 min was 1.9 +/- 0.5, 1.3 +/- 0.3 and 1.1 +/- 0.2 for STRESS, DIP and TAP, respectively (P less than 0.001). These results demonstrated that the 3 types of cardiac stimulation show good imaging parameters with 99mTc-SESTA-MIBI.

Adult↗
PubMed1991

Technetium-99m-sestamibi myocardial perfusion imaging in detection of coronary artery disease: comparison between initial (1-hour) and delayed (3-hour) postexercise images.

Technetium-99m-sestamibi, a new myocardial perfusion imaging agent, does not show significant or rapid myocardial redistribution following its intravenous injection at stress. The purpose of this study was to evaluate the myocardial clearance of 99mTc-sestamibi and ischemic/normal wall ratios at 1 hr and at 3 hr after injection at stress in patients with significant coronary artery disease. Twenty-five patients with ischemic defects on 201Tl scans (n = 15) and/or significant disease on coronary angiogram (n = 18) were prospectively studied. Planar images were obtained at 65 and at 190 min after an injection at stress of 20-25 mCi of 99mTc-sestamibi. A rest study was performed 1-6 days later. Ischemic/normal wall ratios were 0.73 +/- 0.10 and 0.83 +/- 0.12 (p less than 0.05) at 1 and 3 hr, respectively (0.98 +/- 0.15 at rest). Myocardial washout was 26% +/- 12% for normal walls and 15% +/- 8% for ischemic walls (p less than 0.001). Segmental analysis showed 48 and 46 ischemic segments at 1 and 3 hr, respectively. In conclusion, although only a few ischemic segments were missed at 3 hr, significantly lower ischemic/normal wall ratios were found at 1 hr. Faster myocardial washout from normal walls is responsible for the partial reduction of this ratio.

Coronary Disease↗
PubMed1990

Technetium-99m sestamibi myocardial imaging: same-day rest-stress studies and dipyridamole.

Unlike thallium-201, technetium-99m (Tc-99m) sestamibi does not redistribute in the myocardium after injection. Thus, 2 separate injections, 1 at rest and the other at stress (or after dipyridamole), are required to differentiate ischemia from scar. From a physical viewpoint, a 24-hour interval between the 2 injections is preferable for detection of coronary artery disease (CAD) with Tc-99m sestamibi imaging. However, same-day studies are more convenient in clinical practice. Results of studies using different Tc-99m sestamibi injection protocols are presented with emphasis on the advantages of a rest-stress injection sequence with a low dose at rest (7 mCi) followed 2 hours later by a higher dose at stress (25 mCi). A prospective study was conducted in a patient population with proven CAD using same-day studies to compare a rest-stress (7 and 25 mCi, respectively) to a stress-rest (7 and 25 mCi) Tc-99m sestamibi injection sequence. There was an agreement in 87.3% of the analyzed segments between the 2 protocols. However, the largest discordance for type of defect applied to 7.4% of the segments judged ischemic in the rest-stress protocol, which were called scars on stress-rest. This study showed that a rest-stress sequence is preferable when using a same-day protocol with a short time interval (less than 2 hours) between the 2 Tc-99m sestamibi injections because the rest image performed initially represents a "true" rest study, which is not necessarily the case with the stress-rest sequence. Preliminary studies were performed to evaluate dipyridamole with Tc-99m sestamibi imaging in normal subjects and in patients with CAD. These studies showed that treadmill and dipyridamole Tc-99m sestamibi imaging are comparable and the results are similar to those obtained with thallium-201.

Coronary Disease↗