Biomedical subjects

Dava Smith

Publications and source records attributed to Dava Smith.

3 recordsLinked to original sources

PubMed2003

General utilities of multislice tomography in the cardiac field.

OBJECTS: To show all cardiac evaluations multislice computed tomography (MSCT) can perform. METHODS: MSCTs were performed on an MSCT scanner (Mx8000; Philips Medical Systems) with enhanced contrast acquisition. The reconstructed images were sent to a workstation for multiplanar reconstruction, volume rendering, and 3-D reconstruction. A total of 140 patients were studied with MSCT and conventional angiography (CA) to assess coronary artery stenosis. 30 of these patients were also evaluated by intravascular ultrasound (IVUS) for plaque characterization. A group of 20 patients were studied with MSCT, gated single-photon emission computed tomography (SPECT), and echocardiography for myocardial perfusion test and volumetric analysis. RESULTS: The results of MSCT versus CA showed a sensitivity of 79.2% and a specificity of 93.7%, whereas for MSCT versus IVUS the sensitivity was 84.4% and the specificity 91.6%. A total of 156 plaques were detected by both methods. 105 (67%) were soft, 14 (24%) were fibrous and 37 (9%) were calcified. In the evaluation of myocardial perfusion, the cardiac software showed a sensitivity of 55% and a specificity of 80%. However, general evaluation disclosed a sensitivity of 88.5% and a specificity of 96.4%. The volumetric analysis showed a good correlation between MSCT and echocardiography for end-systolic volume (ESV), rS = 0.874, and end-diastolic volume (EDV), rS = 0.828. There was also a good correlation for the evaluation of the left ventricular anatomy: septal wall rS = 0.96, posterior wall rS = 0.81, and diameter of left ventricle rS = 0.69. CONCLUSION: Nowadays, MSCT allows different cardiologic evaluations with the same acquisition as that for the coronary arteries. These data show a general view of the patient providing information that is obtained by the hand of multiple cardiologic methods such as DA, IVUS, gated SPECT, and echocardiography.

Angina Pectoris↗

PubMed2003

[Virtual Colonoscopy. Experience in 500 patients].

OBJECTIVE: To show our experience and results in Virtual Colonoscopy (VC). MATERIAL AND METHOD: Five hundred patients with personal or familial history of colorectal carcinoma and/or adenomas, or any kind of coloproctologic symptoms were studied. VCs were practiced using a helical CT scanner (300 patients) and a multislice CT scanner (200 patients) a few hours after Conventional Colonoscopy (CC), considered the gold standard. The patients were evaluated in a prospective blind study, to determine sensitivity and specificity of VC. Findings were classified as: 1) normal studies; 2) studies with pathological findings. This one was subdivided into: 2a) Lesions below 5 mm., 2b) Lesions between 5-9 mm., 2c) Lesions above 9 mm. RESULTS: VC detected 253 normal studies whereas CC only detected 233. The sensitivity and specificity for each subgroup were: 2a) 87.8% and 86.9%; 2b) 95.6% and 91.4%; 2c) 100.0% and 100.0% respectively. CONCLUSION: VC is a feasible and useful method for evaluating the entire colon. It is well tolerated, it has no complications and a high sensitivity and specificity for elevated lesions, especially the ones above or equal to 5 mm.

Adult↗

PubMedDate not supplied

Assessment of automatic vessel tracking techniques in preoperative planning of transluminal aortic stent graft implantation.

OBJECTIVE: To evaluate automatic vessel tracking techniques in the course of preoperative planning prior to transluminal aortic endograft implantation by comparing accuracy, reproducibility, and postprocessing time with source image and volume-rendered analysis methods. METHODS: Multislice computed tomography datasets of 5 patients with abdominal aortic aneurysms were preoperatively examined, performing volumetric analysis of diameter and position of renal artery orifices, aneurysmal neck, maximal aneurysmal extension, aortic bifurcation, and iliac arteries and bifurcation. Analysis was realized by utilizing transverse datasets, volume rendering, and automated vessel tracking strategies (MxView, Philips, Best, The Netherlands). Measurement techniques were evaluated by 2 independent readers 3 times for each patient and measurement modality. Statistical analysis evaluated accuracy of the measurements and intra- and interobserver reliability. Postprocessing time was documented. RESULTS: Using transverse source datasets, intraobserver reliability ranged from 0.49 to 0.58. Intraobserver reliability improved to 0.7 to 0.98 when volume-rendered datasets were evaluated. Interobserver variability for transverse and volume-rendered datasets ranged from 0.49 to 0.76 and 0.70 to 0.96, respectively. Automated vessel tracking datasets did not demonstrate any intra- or interobserver variability. Based on transverse datasets, the length and diameter of iliac arteries and location and diameter of the aneurysmal neck were measured as statistically different in all cases in contrast to volume rendering and automated segmentation techniques. Postprocessing time consumption for measurements based on transverse, volume-rendered, and automated tracking segmentation datasets averaged 3.32 minutes, 25.43 minutes, and 2.24 minutes, respectively. CONCLUSIONS: Preoperative measurements improve significantly if datasets are evaluated based on volume-rendering techniques. This time-consuming procedure can be shortened, while further reducing observer variability, with automatic segmentation techniques.

Aged↗