Publications by authors named "James Gerlach"
Unlabelled: We compared the performance of fully automated quantification of attenuation-corrected (AC) and noncorrected (NC) myocardial perfusion SPECT (MPS) with the corresponding performance of experienced readers for detection of coronary artery disease (CAD).
Methods: Rest-stress (99m)Tc-sestamibi MPS studies (n = 995; 650 consecutive cases with coronary angiography and 345 with likelihood of CAD < 5%) were obtained by MPS with AC. The total perfusion deficit (TPD) for AC and NC data was compared with the visual summed stress and rest scores of 2 experienced readers.
Background: Attenuation corrected myocardial perfusion SPECT (AC-MPS) has been demonstrated to improve the specificity of detecting coronary artery disease (CAD) by visual analysis which utilizes both non-corrected (NC) and AC data. However, the combined automated quantification of NC and AC-MPS has not been previously described. We aimed to develop a combined quantitative analysis from AC and NC data to improve the accuracy of automated detection of CAD from AC-MPS.
View Article and Find Full Text PDFUnlabelled: We aimed to improve the quantification of myocardial perfusion stress-rest changes in myocardial perfusion SPECT (MPS) studies for the optimal automatic detection of ischemia and coronary artery disease (CAD).
Methods: Rest-stress (99m)Tc MPS studies (997 cases; 651 consecutive cases with correlating angiography and 346 cases with less than 5% likelihood (low likelihood [LLK]) of CAD) were analyzed. Normal limits for stress-rest changes were derived from additional LLK patients (40 women, 40 men).
Purpose: To develop 3D quantitative measures of regional myocardial wall motion and thickening using cardiac magnetic resonance imaging (MRI) and to validate them by comparison to standard visual scoring assessment.
Materials And Methods: In all, 53 consecutive subjects with short-axis slices and mid-ventricular 2-chamber/4-chamber views were analyzed. After correction for breath-hold-related misregistration, 3D myocardial boundaries were fitted to images and edited by an imaging cardiologist.
Unlabelled: Left ventricular (LV) segmentation, including accurate assignment of LV contours, is essential for the quantitative assessment of myocardial perfusion SPECT (MPS). Two major types of segmentation failures are observed in clinical practices: incorrect LV shape determination and incorrect valve-plane (VP) positioning. We have developed a technique to automatically detect these failures for both nongated and gated studies.
View Article and Find Full Text PDFBackground: Current guidelines of Food and Drug Administration for the evaluation of SPECT myocardial perfusion imaging (MPI) in clinical trials recommend independent visual interpretation by multiple experts. Few studies have addressed whether quantitative SPECT MPI assessment would be more reproducible for this application.
Methods And Results: We studied 31 patients (age 68 +/- 13, 25 male) with abnormal stress MPI who underwent repeat exercise (n = 11) or adenosine (n = 20) MPI within 9-22 months (mean 14.
Background: There have been limited data regarding the value of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the detection of left main coronary artery disease (CAD).
Methods And Results: We studied 101 patients with angiographic left main CAD (> or = 50% stenosis) and no prior myocardial infarction or coronary revascularization who underwent gated exercise or adenosine stress technetium 99m sestamibi SPECT MPI. By perfusion assessment alone, high-risk disease with moderate to severe defects (> 10% myocardium at stress) was identified in only 56% of patients visually and 59% quantitatively.
Background: Ventricular remodeling is predictive of congestive heart failure (CHF). We aimed to automatically quantify a new myocardial shape variable on gated myocardial perfusion single photon emission computed tomography (SPECT) (MPS) and to evaluate the association of this new SPECT parameter with the risk of hospitalization for CHF.
Methods And Results: A computer algorithm was used to measure the 3-dimensional (3D) left ventricular (LV) shape index (LVSI), derived as the ratio of maximum 3D short- and long-axis LV dimensions, for end systole and end diastole.
Background: We aimed to compare normal limits and the detection of coronary artery disease (CAD) with attenuation-corrected (AC) and non-attenuation-corrected (NC) myocardial perfusion single photon emission computed tomography (MPS) by use of a recently improved automated quantification technique.
Methods And Results: We acquired 415 rest/stress technetium 99m MPS studies on a Vertex dual-detector camera with a gadolinium 153 line source (Vantage Pro). Gender-specific NC, AC, and gender-combined AC normal limits were created from rest/stress images of 50 women and 50 men with a low likelihood of CAD (< 5%) and a median body mass index (BMI) of 30 kg/m2 in each gender group.
Background: The diagnostic value of gated myocardial perfusion single-photon emission computed tomography (MPS) with combined supine and prone acquisitions to detect coronary artery disease (CAD) in obese and nonobese patients has not been defined.
Methods And Results: We studied 1511 patients without prior myocardial infarction or coronary revascularization who either had coronary angiography within 3 months of MPS (n = 785) or had a low pretest likelihood of CAD (n = 726). All patients underwent rest thallium 201/gated exercise or adenosine stress technetium 99m sestamibi MPS in both the supine and prone positions.
Unlabelled: The aim of our study was to derive and to validate the normal threshold for an automatically measured left ventricular transient ischemic dilation (TID) ratio in patients referred for adenosine stress myocardial perfusion SPECT (MPS) and to assess the value of integrating TID in detecting severe and extensive coronary artery disease (CAD).
Methods: Normal limits for the TID ratio were derived using dual-isotope MPS data from 38 patients with a low (<5%) likelihood of CAD. Criteria for abnormality were calculated on the basis of data from 179 consecutive patients who had undergone coronary angiography less than 3 mo after index adenosine MPS: 41 patients (23%) had severe and extensive CAD (> or =90% stenosis) in the proximal left anterior descending artery or in 2 or more coronary arteries, 64 (36%) had no significant CAD (<70% stenosis), and 74 (41%) had mild or moderate CAD.
Objectives: The aim of this research was to determine whether presence of atrial fibrillation (AF) provides incremental prognostic information relative to myocardial perfusion single-photon emission computed tomography (MPS) with respect to risk of cardiac death (CD).
Background: The prognostic significance of AF in patients undergoing MPS is not known.
Methods: A total of 16,048 consecutive patients undergoing MPS were followed-up for a mean of 2.
Background: Recently, a 17-segment model of the left ventricle has been recommended as an optimally weighted approach for interpreting myocardial perfusion single photon emission computed tomography (SPECT). Methods to convert databases from previous 20- to new 17-segment data and criteria for abnormality for the 17-segment scores are needed.
Methods And Results: Initially, for derivation of the conversion algorithm, 65 patients were studied (algorithm population) (pilot group, n = 28; validation group, n = 37).
Objectives: This study evaluated the prognostic value of transient ischemic dilation (TID) of the left ventricle (LV) in patients with normal stress myocardial perfusion single photon emission computed tomography (MPS).
Background: The prognostic value of TID in patients with an otherwise normal MPS has not been defined.
Methods: We identified 1,560 patients who had normal stress MPS (436 vasodilator and 1,124 exercise stress), and no rest LV enlargement (Population 1) and followed up for 2.