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N M Hudson

Publications and source records attributed to N M Hudson.

9 recordsLinked to original sources
PubMed2000

Coronary artery disease: combined stress MR imaging protocol-one-stop evaluation of myocardial perfusion and function.

The authors developed and tested a dual stress magnetic resonance (MR) imaging protocol to evaluate myocardial perfusion, function, and hibernation. The technique was well tolerated, and high-quality images were achieved. The comprehensive information obtained can be used to guide clinical management decisions regarding coronary artery revascularization procedures. This protocol offers a one-stop assessment of patients with coronary artery disease with use of a clinical MR imager.

Adenosine↗
PubMed1994

Use of expandable wire stents for malignant airway obstruction.

The symptoms of progressive dyspnea and stridor in the setting of malignant airway obstruction are severe and distressing. Conservative nebulizer and oxygen therapy offer little relief, and conventional stenting with T tubes requires a tracheostomy. In this article, we describe our experience with stenting in the treatment of malignant mediastinal disease using the Gianturco expanding metal-wire stents. The technique of placement is simple and the procedure was successful in all 21 cases. Relief of stridor was immediate and the dyspnea usually abated. These benefits continued through the mean survival period after stenting of 134 days (range, 2 to 799 days). The patients required only brief hospitalization (2.83 days) before returning home or to the referring institution. It appears that expandable wire stents may offer a simple yet effective intervention in the palliative treatment of mediastinal malignancy.

Adult↗
PubMed1993

Assessment of myocardial perfusion and function using gated methoxy-isobutyl-isonitrile scintigraphy to detect restenosis after coronary angioplasty.

BACKGROUND: Technetium-99m-methoxy-isobutyl-isonitrile (MIBI) has been shown to be a useful perfusion agent, and its improved imaging characteristics also allow evaluation of myocardial function. We evaluated the use of gated MIBI scintigraphy in patients undergoing percutaneous transluminal coronary angioplasty to show improvements in myocardial perfusion and function and to detect restenosis. METHODS: Gated MIBI scintigraphy was performed in a preliminary study in 25 patients before angioplasty. Twenty-one patients who had undergone a successful procedure were re-examined 3 months later. Myocardial perfusion was evaluated and function measured using myocardial profiles along four axes. RESULTS: Before angioplasty, 18 out of 21 patients had a reversible perfusion defect, and computer analysis of fractional shortening showed 19 out of 21 had abnormalities of left ventricular function during exercise. Only 11 out of 21 had a positive stress test. Mean global fractional shortening before angioplasty was 27.3% at rest and 26.6% during exercise (not significant). After angioplasty, left ventricular function was improved during exercise, with global fractional shortening increasing from 26.6% to 32.7% (P < 0.001). Repeat angiography was performed in 16 patients. Lesions in four patients had restenosed, in 11 they had not, and in one a different artery was occluded. Three of the four patients with restenosed lesions were identified using repeat perfusion imaging, and all four from abnormalities in left ventricular function. An abnormality in a new region was detected using both methods in the patient with the new occlusion. Normal perfusion and function were found in nine of the 11 patients without restenosed lesions. Two patients continued to have a positive stress test: one with a restenosed lesion and one with new disease. CONCLUSION: Dual assessment with gated MIBI scintigraphy provides useful data in patients undergoing angioplasty and may help in the selection of patients for repeat angiography.

Adult↗
PubMed1992

Gated technetium-99m methoxy-isobutylisonitrile perfusion imaging.

Technetium-99m methoxy-isobutylisonitrile, has been shown to be a useful perfusion agent for detecting coronary artery disease. Gated acquisition of perfusion images may remove motion artefact and improve detection. We compared the results of sensitivity and specificity for detecting coronary artery disease using perfusion images from the whole cardiac cycle (ungated) or from end-diastolic (gated) frames in 46 subjects, 31 with significant coronary disease and 15 with normal coronary arteries. There was no significant difference in detection of patients with coronary disease between the ungated and end-diastolic images: 25/31 with the ungated image and 28/31 with the end-diastolic. An improvement was made in detecting defects in the left anterior descending artery territory: 17/20 with the end-diastolic vs 11/20 with the ungated image (P less than 0.05) and in the right coronary artery region: 16/21 vs 10/21 (P less than 0.05), with an overall improvement in detecting regions supplied by stenosed coronary arteries: 45/55 end-diastolic vs 31/55 ungated (P less than 0.01). These results suggest use of the end-diastolic frame can significantly enhance the diagnostic capacity of methoxy-isobutylisonitrile perfusion imaging.

Adult↗
PubMed1992

Evaluation of changes in myocardial function on exercise in patients with coronary artery disease using gated MIBI scintigraphy.

Technetium-99m-methoxy-isobutyl-isonitrile (MIBI) is a myocardial perfusion agent which allows simultaneous assessment of left ventricular function. We evaluated left ventricular (LV) function with exercise using a new method of myocardial profiling in 43 patients with chest pain. Twenty-eight had significant coronary artery disease and 15 were normal on coronary angiography. Results were compared to equilibrium radionuclide ventriculography. MIBI fractional shortening (FS) correlated well with ejection fraction (EF) on exercise (r = 0.79, P = less than 0.001). There was also a good correlation between changes in global function from rest to exercise (r = 0.82, P = less than 0.001) with a sensitivity of diagnosing CAD of 71% and specificity of 80%. New regional wall abnormalities were detected in 25/28 with CAD with a sensitivity of 89% and specificity of 60%. There was also a close correlation between mean diameters measured with gated MIBI scans and volumes measured with RNV, end-diastolic diameter (EDD) versus end-diastolic volume (EDV) r = 0.78 (P = less than 0.001) at rest and r = 0.74 (P = less than 0.001) on exercise and end-systolic diameter (ESD) versus end-systolic volume (ESV) r = 0.72 (P = less than 0.001) at rest and r = 0.72 (P = less than 0.001) on exercise. This produced a sensitivity for detecting CAD of 79% and a specificity of 73%. These results show that gated MIBI scanning on exercise provides information comparable to RNV so enhancing the diagnostic usefulness of MIBI.

Adult↗
PubMed1991

Gated 99Tcm-MIBI myocardial function imaging.

The introduction of the 99Tcm isonitrile perfusion agents has provided improved myocardial image quality with conventional imaging equipment allowing improved edge definition on gating. We evaluated left ventricular wall motion in 46 patients using gated 99Tcm-2-methoxy-2-methyl-isopropyl-1-isonitrile (MIBI) scintigraphy. Using a method of myocardial profiles in four axes, global and regional fractional shortening (FS) were assessed. A good correlation was found between FS in the left anterior oblique (LAO) 40 degrees projection and ejection fraction (EF) on gated radionuclide ventriculography (r = 0.81, P less than 0.001). This was improved by using FS in two planes, LAO 40 degrees and anterior (r = 0.88, P less than 0.001). There was also a good correlation between FS in two planes and EF on cine-angiography (r = 0.72, P less than 0.001). There was good intra- and interobserver agreement with the studies. Assessment of myocardial function using gated MIBI imaging and myocardial profiles provides useful additional information to the perfusion scan, thus enhancing the diagnostic usefulness of the agent.

Adult↗
PubMed1976

The prognostic significance of coronary artery calcification seen on fluoroscopy.

Fluoroscopic detection of coronary artery calcification (C.A.C.) has no prognostic significance. Of 440 patients screened 78 were found to have C.A.C. The five year survival of this group was the same as that of a control group. Age, sex, distribution, and extent were also without significance. Improved equipment available today allows recognition of smaller areas of calcification which may have clinical significance.

Adult↗