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Biomedical subjects

Lawrence R Goodman

Publications and source records attributed to Lawrence R Goodman.

15 recordsLinked to original sources
PubMed2006

Multidetector computed tomography for acute pulmonary embolism.

BACKGROUND: The accuracy of multidetector computed tomographic angiography (CTA) for the diagnosis of acute pulmonary embolism has not been determined conclusively. METHODS: The Prospective Investigation of Pulmonary Embolism Diagnosis II trial was a prospective, multicenter investigation of the accuracy of multidetector CTA alone and combined with venous-phase imaging (CTA-CTV) for the diagnosis of acute pulmonary embolism. We used a composite reference test to confirm or rule out the diagnosis of pulmonary embolism. RESULTS: Among 824 patients with a reference diagnosis and a completed CT study, CTA was inconclusive in 51 because of poor image quality. Excluding such inconclusive studies, the sensitivity of CTA was 83 percent and the specificity was 96 percent. Positive predictive values were 96 percent with a concordantly high or low probability on clinical assessment, 92 percent with an intermediate probability on clinical assessment, and nondiagnostic if clinical probability was discordant. CTA-CTV was inconclusive in 87 of 824 patients because the image quality of either CTA or CTV was poor. The sensitivity of CTA-CTV for pulmonary embolism was 90 percent, and specificity was 95 percent. CTA-CTV was also nondiagnostic with a discordant clinical probability. CONCLUSIONS: In patients with suspected pulmonary embolism, multidetector CTA-CTV has a higher diagnostic sensitivity than does CTA alone, with similar specificity. The predictive value of either CTA or CTA-CTV is high with a concordant clinical assessment, but additional testing is necessary when the clinical probability is inconsistent with the imaging results.

Acute Disease↗
PubMed2006

Diagnostic pathways in acute pulmonary embolism: recommendations of the PIOPED II investigators.

PURPOSE: To formulate comprehensive recommendations for the diagnostic approach to patients with suspected pulmonary embolism, based on randomized trials. METHODS: Diagnostic management recommendations were formulated based on results of the Prospective Investigation of Pulmonary Embolism Diagnosis II (PIOPED II) and outcome studies. RESULTS: The PIOPED II investigators recommend stratification of all patients with suspected pulmonary embolism according to an objective clinical probability assessment. D-dimer should be measured by the quantitative rapid enzyme-linked immunosorbent assay (ELISA), and the combination of a negative D-dimer with a low or moderate clinical probability can safely exclude pulmonary embolism in many patients. If pulmonary embolism is not excluded, contrast-enhanced computed tomographic pulmonary angiography (CT angiography) in combination with venous phase imaging (CT venography), is recommended by most PIOPED II investigators, although CT angiography plus clinical assessment is an option. In pregnant women, ventilation/perfusion scans are recommended by many as the first imaging test following D-dimer and perhaps venous ultrasound. In patients with discordant findings of clinical assessment and CT angiograms or CT angiogram/CT venogram, further evaluation may be necessary. CONCLUSION: The sequence for diagnostic test in patients with suspected pulmonary embolism depends on the clinical circumstances.

Acute Disease↗
PubMed2006

Inherent variability of CT lung nodule measurements in vivo using semiautomated volumetric measurements.

OBJECTIVE: The objective of our study was to evaluate repeatability and reproducibility of lung nodule volume measurements using volumetric nodule-sizing software. MATERIALS AND METHODS: Fifty nodules, less than 20 mm in diameter, in 29 patients were scanned with 1.25-mm collimation using MDCT (time 1 = T1). During the same session, two additional scans, using identical technique, were obtained through each nodule (T2, T3). Three observers working independently then obtained volumetric measurements using a semiautomated volumetric nodule-sizing software package. Qualitative nodule characterization was also performed. The Bland-Altman method for assessing measurement agreement was used to calculate the 95% limits for agreement for nodule volumes at T1, T2, and T3. RESULTS: Automated nodule segmentation was successful in 438 (97%) of 450 measurements. Forty-three nodules were available for final evaluation. Twenty-six nodules had well-defined edges, and 17 had irregular or spiculated margins. Seventeen were freestanding, 16 were juxtapleural, and 10 were juxtavascular in location. Average nodule volume was 345.5 mm(3) (range, 49.3-1,434 mm(3)). The mean interobserver variability (repeatability) was 0.018% (SD = 0.73%), and the SD of the mean for the three contemporaneous scans (reproducibility) was 13.1% (confidence limits, +/- 25.6%). SD and confidence limits narrowed as volumes increased. CONCLUSION: Volumetric measurements show minimal interobserver variability (0.018%) but an interscan SEM of 13.1% (confidence limits, +/- 25.6%). Repeatability and reproducibility of volumetric measurements are better than those of linear measurements reported in the literature.

Adult↗
PubMed2005

CT of deep venous thrombosis and pulmonary embolus: does iso-osmolar contrast agent improve vascular opacification?

PURPOSE: To prospectively compare the vascular attenuation achieved with the iso-osmolar dimeric contrast agent iodixanol with that achieved with the nonionic monomeric contrast agent iohexol for computed tomographic (CT) venography after CT pulmonary angiography. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained, and 51 consecutive patients undergoing CT pulmonary angiography and CT venography were recruited. A 130-mL dose of iodixanol 320 was injected intravenously at a rate of 4 mL/sec and followed by injection of 50 mL of saline. CT venography was performed after 3.5 minutes. From prior studies, 51 patients of similar weight were picked as control subjects. They received a similar iodine load with iohexol 300 and were studied with a similar technique. Section thickness was 1.25 mm for pulmonary emboli and 5 mm for deep venous thrombosis. Test and control group characteristics (ie, sex, age, and weight) were not significantly different (P >.05). Additionally, in test patients who had undergone CT pulmonary angiography and CT venography during the two preceding years, current and previously obtained CT scans were compared (ie, paired studies). Regions of interest were measured in four pulmonary artery and four lower extremity vein locations by two independent observers. RESULTS: Iodixanol increased average attenuation by 7 HU (P <.05) in the lower extremities and decreased average attenuation by 42 HU (P <.05) in the pulmonary arteries. In the 11 paired studies, similar results were obtained. CONCLUSION: Iodixanol caused a modest but statistically significant improvement in venous attenuation and a decrease in arterial attenuation. The diagnostic importance of this small increase in venous attenuation is not clear.

Adult↗
PubMed2005

Clinicians' response to radiologists' reports of isolated subsegmental pulmonary embolism or inconclusive interpretation of pulmonary embolism using MDCT.

OBJECTIVE: The purpose of our study was to investigate clinician response and patient outcome associated with the radiologist's report of isolated subsegmental pulmonary emboli (ISSPE) or indeterminate or inconclusive results on MDCT for venous thromboembolism. MATERIALS AND METHODS: All patients were examined using 8- or 16-MDCT. Reported findings on combined CT pulmonary angiography and CT venography of 1,435 consecutive patients were analyzed retrospectively. The charts of patients of interest with ISSPE or with indeterminate or inconclusive pulmonary embolism results were analyzed for clinician response and recurrent symptoms of venous thromboembolism in both treated and untreated patients during the following 3 months. RESULTS: We studied 207 patients of interest, and follow-up was available on 192 (92.8%) (67 ISSPEs, 125 inconclusive). Of the 192 patients, 25 (37%) of 67 patients with ISSPE and 108 (86%) of 125 patients with inconclusive results did not receive anticoagulation. Two patients with ISSPE and two patients with inconclusive results returned with new symptoms suggesting recurrent venous thromboembolism, but no venous thromboembolism was found. Thirteen (10%) of 133 untreated patients died without clinical evidence of recurrent venous thromboembolism. In 61 patients who received anticoagulation (42/67 [63%] ISSPE and 17/125 [14%] inconclusive), five patients returned with venous thromboembolism symptoms. None had recurrent emboli. Two (3%) of 61 patients who received anticoagulation died of other diseases. CONCLUSION: Patients with ISSPE more commonly received anticoagulation than not. In the patients who did not receive anticoagulation, no recurrent pulmonary embolism was identified on follow-up. In most patients with inconclusive findings on CT pulmonary angiography, clinicians chose to withhold anticoagulation without additional imaging workup. No adverse effects of this clinical decision were uncovered.

Angiography↗
PubMed2004

Incidence of asymptomatic pulmonary embolism in moderately to severely injured trauma patients.

BACKGROUND: Chest computed tomographic (CT) scanning is used frequently to evaluate symptomatic patients for pulmonary embolus (PE). The incidence of PE diagnosed by helical CT scanning in asymptomatic patients is unknown. METHODS: Asymptomatic trauma patients with an Injury Severity Score > or = 9 were studied with contrast-enhanced helical CT images of the chest, pelvis, and lower extremities. Clot burden was assessed using an anatomic scoring system. Patients not receiving anticoagulation were followed. RESULTS: Twenty-two of 90 patients had a PE. Four had major clot burden, including one patient with a saddle embolus. Risk factors for asymptomatic PE include age (odds ratio [OR], 1.04), head injury (OR, 6.78), chest injury (OR, 4.51), lower extremity injury (OR, 5.03), and transfusion (OR, 3.42). Thirty percent of patients receiving pharmacologic prophylaxis had a PE. CONCLUSION: Asymptomatic PE occur in 24% of moderately to severely injured patients. Age, head, chest, and lower extremity injury are associated with an increased risk. Standard thromboembolic prophylaxis is not reliably protective.

Adult↗
PubMed2003

Venous thromboembolic disease: where does multidetector computed tomography fit?

Introduction of helical CT started a new era in the diagnosis of PE. It is noninvasive and readily available. Developments in helical CT technology (particularly introduction of multidetector scanners) improved image quality by decreasing the scanning time and slice thickness. With the addition of indirect CT venography to CT pulmonary angiography, CT also took the role of venous ultrasound, thus creating a single examination for diagnosis of VTD. On the other hand, CT is not perfect at all circumstances, especially in the evaluation of subsegmental arteries. Careful selection of patients for imaging studies will save time, cost, and radiation.

Fibrin Fibrinogen Degradation Products↗
PubMed2003

CT for the diagnosis of venous thromboembolic disease.

Spiral CT, venous ultrasound, ventilation-perfusion scanning, and D-dimer tests are routinely used in the diagnosis of venous thromboembolic disease. Advances in multidetector spiral CT and the combination of CT pulmonary angiography and venography as a one-step evaluation of venous thromboembolic disease have markedly improved detection of subsegmental emboli and deep pelvic venous thrombi and decreased the role of conventional pulmonary angiography. As CT has improved, many have questioned what "gold standard" CT should be compared with. Recent clinical outcome studies suggest that CT results are as good as pulmonary angiography and conventional imaging algorithms. Because the sensitivity of CT pulmonary angiography now exceeds 85%, it also appears that it is also more cost effective than other diagnostic approaches.

Algorithms↗
PubMed2002

CT for thromboembolic disease.

CTPA has dramatically changed the diagnostic approach to PE in the last decade. The addition of CTV has created a single diagnostic test that can evaluate for both important components of venous thromboembolic disease. Newer, multislice scanners will provide thinner images and more complete anatomic coverage. Shorter scan times will minimize motion artifacts. These improvements may continue to improve the diagnostic yield of CTPA. The availability of an accurate noninvasive diagnostic tool to evaluate for PE and DVT should lead to a better understanding of the wide range of presentations of thromboembolic disease. The next decade may produce improvements in understanding of the epidemiology of PE and perhaps to a more tailored approach to treatment for thromboembolic disease.

Acute Disease↗
PubMed2002

Overview of Prospective Investigation of Pulmonary Embolism Diagnosis II.

The Prospective Investigation of Pulmonary Embolism Diagnosis II (PIOPED II) is a prospective multicenter study funded by the National Heart, Lung, and Blood Institute which began recruiting patients in the fall of 2001. It was designed to assess the efficacy of the spiral computed tomographic pulmonary angiogram in patients suspected of having acute pulmonary embolism (PE). In contrast to the original PIOPED study, which used contrast pulmonary angiography as the primary reference test for PE, PIOPED II will use a composite reference test for venous thromboembolism that is based on the ventilation/perfusion lung scan, venous compression ultrasound of the lower extremities, digital subtraction pulmonary angiography, and contrast venography in various combinations to establish the PE status of the patient. New criteria for ventilation/perfusion lung scan diagnosis have been developed for PIOPED II. This article describes the various techniques that will be used, the combination of the composite reference tests that will be used to determine the PE status of the patient, and the PIOPED II diagnostic criteria that will be used for the ventilation/perfusion scan diagnosis of PE in the study.

Angiography, Digital Subtraction↗
PubMed2002

Indirect CT venography following CT pulmonary angiography: spectrum of CT findings.

SUMMARY: Pulmonary embolism (PE) and deep venous thrombosis (DVT) represent two manifestations of the same syndrome, venous thromboembolism. Contrast-enhanced computed tomography (CT) angiography is a practical, efficient alternative to conventional imaging for PE. Following the pulmonary examination, the inferior vena cava (IVC) and the iliac, femoral, and popliteal veins can be studied with CT without additional intravenous contrast administration. Indirect CT venography (CTV) after CT pulmonary angiography (CTPA) simplifies and shortens venous thromboembolism work-up. Initial studies indicate that CTV is comparable to ultrasound in the evaluation of femoral/popliteal DVT. CTV has the advantage of evaluating the iliac veins and inferior vena cava, vessels poorly seen on sonography and venography. Combining CTV with CTPA increases confidence in withholding treatment when results for both the pulmonary arteries and leg veins are negative and increases the diagnosis of venous thromboembolism by 25% over CTPA alone. This pictorial essay will review the normal venous anatomy, CTV technique, and the findings of acute and chronic DVT. Interpretive pitfalls and alternative diagnoses are also reviewed.

Angiography↗