Biomedical subjects

D F Yankelevitz

Publications and source records attributed to D F Yankelevitz.

63 records · Page 4Linked to original sources

PubMedDate not supplied

Pneumothorax during fluoroscopic biopsy: effect on nodule depth.

Transthoracic needle aspiration biopsy of lung nodules is often performed under fluoroscopic guidance after measurement of lesion depth on preliminary computed tomography (CT) scans is obtained. We evaluated the change in depth of nodules in 10 patients in whom pneumothorax developed during CT-guided biopsy. We observed that nodule depth changed by an amount equal to the size of the pneumothorax. Awareness of the potential effect of pneumothorax on lesion depth should be helpful in reducing the likelihood of false-negative results with CT-assisted fluoroscopic biopsy when only single-plane fluoroscopy is available.

Biopsy, Needle↗

PubMedDate not supplied

Radiographic screening for cancer. Proposed paradigm for requisite research.

Computed tomography (CT) imaging as an excellent approach to the detection and characterization of small solitary pulmonary nodules (SSPN) raises three questions: (1) How often does CT imaging lead to detection of SSPN? (2) How often is such an SSPN malignant? (3) If malignant, how curable is it? The first question pertains to decisions about screening use of CT (clinical or mass screening), the second to decisions about screening for SSPN and diagnosis of malignancy given SSPN, and the third--in the context of known curability at ordinary clinical diagnosis--to decisions about screening for SSPN, diagnosis given SSPN and intervention given malignant SSPN. We present a three component study design that addresses these questions. The first is directed primarily to the first question. Some 1000 persons at high risk for lung cancer will be screened for SSPN using screening-type CT. The primary aim is to determine the prevalence of CT-detectable SSPN as a joint function of risk-relevant aspects of the person. The second component addresses the prevalence of malignancy among the detected cases of SSPN. To develop the prevalence function, a larger series of CT-detected SSPN will be obtained by developing a multi-center SSPN "registry." A subsequent, third component will focus on the registered cases of malignant SSPN screening incidentally detected and address their curability on the basis of long-term follow-up. This design, in lieu of a randomized trial, may represent a new paradigm for applied research on radiologic technologies in cancer screening, given its advantages in terms of research efficiency and implications to decisions about diagnostic workup and therapeutic intervention.

Decision Making↗

PubMedDate not supplied

Chest radiography in the ICU.

Proper positioning and assessment of abnormalities and complications of the above-mentioned devices have a significant impact on the management of critically ill patients in the intensive care unit (ICU). The timely assessment of new or rapidly evolving findings is critical. Optimal radiographic technique, availability of images to the clinicians, and rapid reporting by the radiologist all serve to maximize the efficacy of bedside chest radiography in the ICU. Sometimes, changes in cardiopulmonary status may only be appreciated on chest radiographs (CXRs). Complications from ventilatory assistance, such as barotrauma, occur frequently and must be detected promptly. The position of monitoring devices, an important component of critical care management, is best checked radiographically. Indications for CXRs and the recommended frequency for repeat follow-up CXRs are based on the existing literature and the consensus of an expert panel formed by the American College of Radiology.

Foreign Bodies↗

PubMedDate not supplied

CT-guided transthoracic needle biopsy of small solitary pulmonary nodules.

The use of CT guidance in performing transthoracic needle biopsy is well established. We evaluated its accuracy in the diagnosis of small solitary nodules and found it to be highly accurate regardless of size or location. While specific benign diagnoses were uncommon, additional confidence in a benign diagnosis can be gained by careful analysis of needle tip location using strict CT criteria.

Biopsy, Needle↗

PubMedDate not supplied

Derivation for relating calcification and size in small pulmonary nodules.

Pulmonary nodules less than 10 mm in length are often detected on computed tomography (CT) scans after the examination is completed. No further imaging may be possible and it would be useful to determine whether the nodule is sufficiently calcified to be considered benign. We wanted to use the relationship between the true and apparent nodule density on 10-mm CT sections to determine the true density of the nodule. An understanding of the partial volume effect on 10-mm CT images of small pulmonary nodules allowed us to identify accurately those which were diffusely calcified without having to resort to obtaining additional 1-mm CT sections.

Calcinosis↗

PubMedDate not supplied

CT-guided transthoracic needle biopsy following indeterminate fiberoptic bronchoscopy in solitary pulmonary nodules.

We evaluated the role of computed tomography (CT)-guided transthoracic needle biopsy (TNB) in patients with solitary pulmonary nodule and indeterminate flexible fiberoptic bronchoscopy (FOB). A review of 112 patients with solitary nodules under 3 cm in size who underwent TNB was carried out. A total of 48 patients had prior FOB with negative or indeterminate results. We reviewed the results of CT-guided TNB of these 48 patients with respect to the cytology results, nodule size and location, and complications of the procedure. Among the 48 patients who had FOB with indeterminate cytology, 32 were found to have malignant cytology on subsequent TNB. Among the remaining 16 patients, eight had diagnostic thoracotomy, which showed that six of the nodules were benign and two were malignant. The remaining eight patients who did not undergo surgery have been followed for more than 2 years, without evidence of growth. Results were not influenced by size or location. TNB offers a high yield for diagnosis in this patient population.

Biopsy, Needle↗

PubMedDate not supplied

Neural networks for the analysis of small pulmonary nodules.

PURPOSE: Small pulmonary nodules can be readily detected by computed tomography (CT). The goal of this detection is to diagnose early lung cancer as the five year survival at this early stage is over 70% in contradistinction to the overall 5-year survival of around 10%. Critical to the efficacy of CT for early lung cancer detection is the ability to distinguish between benign and malignant nodules. We explored the usefulness of neural networks (NNs) to help in this differentiation. METHODS: CT images of 28 pulmonary nodules, 14 benign and 14 malignant, each having a diameter less than 3 cm were selected. All were sufficiently malignant in appearance to require needle biopsy and surgery. The statistical-multiple object detection and location system (S-MODALS) NN technique developed for automatic target recognition (ATR) was used to differentiate between these benign and malignant nodules. RESULTS: S-MODALS was able to correctly identify all but three benign nodules. S-MODALS classified a nodule as malignant because it looked similar to other malignant nodules. It identified the most similar nodules to display them to the radiologist. The specific features of the nodule that determined its classification were also shown, so that S-MODALS is not simply a "black box" technique but gives insight into the NN diagnostics. CONCLUSION: This initial evaluation of S-MODALS NNs using pulmonary nodules whose CT features were very suspicious for lung cancer demonstrated the potential to reduce the number of biopsies without missing malignant nodules. S-MODALS performed well, but additional optimization of the techniques specifically for CT images would further enhance its performance.

Biopsy↗

PubMedDate not supplied

Optimization of contrast delivery for pulmonary CT angiography.

Pulmonary CT angiography is becoming an increasingly important tool for diagnosing Pulmonary Emboli. An important aspect in optimizing the quality of these studies is achieving maximum levels of enhancement of the pulmonary arteries. In this study we reviewed the current literature to see if there was any standardization of protocols to achieve this purpose, and found that there was no consensus. Using well described techniques for determining blood flow we were able to demonstrate the proper time delays to achieve the highest levels of enhancement. As contrast flows into the pulmonary arteries, the degree of enhancement rapidly reaches a plateau phase. This is then followed by a recirculation phase where enhancement starts to increase again. The proper time delays between scan time and start of contrast infusion should allow for enhancement to be within this recirculation phase. An experimental model was developed to demonstrate the principles.

Angiography↗

PubMedDate not supplied

MR imaging of pleural effusions.

To investigate the in vivo magnetic resonance (MR) characteristics of pleural effusions, MR imaging was performed on 22 patients who also underwent thoracentesis. Correlation of the MR scans with results of thoracentesis revealed significant differences among three types of effusions: transudates (T) (n = 4), simple exudates (SE) (n = 9), which did not have malignant cells or infection, and complex exudates (CE) (n = 9), which did have malignant cells or infection. Using normalized MR intensities, CE were more intense than SE, which were brighter than T. The second and third echoes (TE 66 and 99 ms) provided the best differentiation for these three classes of effusions, with p less than 0.06 and p less than 0.006, respectively. Qualitative visual assessment of the increase in signal intensity was also useful in differentiating among the three types of effusions (p less than 0.02). Effective T2 values (normalized to fat) were significantly shorter for exudates than for T (p less than 0.02). Heterogeneity, loculation, and size of effusions were well evaluated on MR. Magnetic resonance is not specific for the etiology of effusions. Nevertheless, with analysis of both quantitative and qualitative parameters, MR may provide an effective noninvasive means for the initial characterization and serial follow-up of pleural effusions.

Adult↗