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Biomedical subjects

D F Yankelevitz

Publications and source records attributed to D F Yankelevitz.

At least 37 records · Page 2Linked to original sources
PubMed1999

Small pulmonary nodules: evaluation with repeat CT--preliminary experience.

PURPOSE: To assess the use of early repeat computed tomography (CT) of solitary pulmonary nodules to determine nodule growth. MATERIALS AND METHODS: The authors performed repeat CT of nodule phantoms to assess the accuracy of their measurement technique. They then used this technique to assess nodule growth (nine malignant, six benign) in 15 patients (nine men, six women; age range, 60-79 years; average age, 66 years) who underwent repeat CT as part of their routine clinical protocol. The final diagnosis was established with surgical resection or follow-up for more than 2 years after an indeterminate biopsy. RESULTS: Results of phantom experiments revealed that the method used to determine area change is sensitive enough to help detect nodule growth if one pixel is added around the entire circumference of a nodule. With use of standard exponential growth curves and known tumor growth rates, malignant growth could be detected in vivo within 30 days. All 15 in vivo nodules were correctly classified with early repeat CT. CONCLUSION: Preliminary experience with early repeat CT suggests that a single repeat CT scan obtained 30 days after the first scan can depict growth in most malignant tumors as small as 5 mm.

Adenocarcinoma↗
PubMed1999

Assessment of deep venous thrombosis using routine pelvic CT.

OBJECTIVE: The purpose of this study was to assess routine pelvic CT both for accuracy in diagnosis of deep venous thrombosis and for frequency of detection of clinically unsuspected pelvic thrombi. MATERIALS AND METHODS: We reviewed the CT records of patients who had undergone pelvic CT during a 6-month period and cross-referenced these records to reports on lower extremity venous sonography to identify patients who had undergone this test within 1 week of pelvic CT. We compared the frequency and location of venous thrombosis revealed through these two tests. To identify unsuspected deep venous thrombosis detected on pelvic CT, we reviewed the charts of patients for whom a clot was reported to determine if it had been clinically suspected before CT. RESULTS: Among the 52 patients who underwent both CT and lower extremity venous sonography, the findings were in agreement for 49 (94%). The techniques disagreed for three patients; two patients had deep venous thrombosis detected on sonography but not on CT and the other had a clot detected on CT but not on sonography. The prevalence of unsuspected deep venous thrombosis detected by CT was 1.1%, and 73% of these patients underwent anticoagulation therapy without further confirmatory tests. CONCLUSION: Unsuspected deep venous thrombosis is commonly seen on routine pelvic CT and should be carefully sought during such examinations. CT appears to be relatively accurate in the detection of deep venous thrombosis. Thus, CT venography combined with pulmonary CT angiography may significantly increase the percentage of patients who are appropriately treated for thromboembolic disease because both deep venous thrombosis and pulmonary emboli can be identified by this combined test.

Contrast Media↗
PubMed1998

Evaluation of diagnostic imaging tests: diagnostic probability estimation.

In the evaluation of a diagnostic imaging test for the diagnosis of a particular illness in a particular category of patients, the test should be construed as leading to a test result in the sense of a set of descriptive readings from the image(s), not interpretation of these; and in the evaluation of the test, therefore, the first challenge is the translation of each test result (set of readings) into the corresponding probability that the illness is present. This interpretive translation should not be subjective, nor should it be based on an objective algorithm founded on clinical judgments. Instead, a suitable diagnostic probability function (of the elements in the test result) should be derived empirically by logistic regression analysis of suitable data. We illustrate this alternative outlook by reanalysis of the data from the Prospective Investigation of Pulmonary Embolism Diagnosis.

Adult↗
PubMed1997

Evaluation of algorithms for the diagnosis of pulmonary embolism.

The development of new diagnostic tests for diagnosing pulmonary embolism (PE) has not yet resulted in any single algorithm being universally accepted. It is at least partially due to the perception by the clinicians ordering the tests that insufficient weight is given to the actual mortality and morbidity costs of pulmonary angiography in comparison to those associated with PE and its treatment. It also becomes more difficult to intuitively integrate all of the competing factors (e.g., sensitivity, specificity, costs, morbidity, mortality) for the different algorithms to choose the most cost-effective sequence. We evaluated the algorithm recommended by the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) investigators, designated by V, and compared it to pulmonary arteriography (A), MR angiography (M), and CT angiography (C) which directly visualize the pulmonary arteries. Using standard economic approaches to loss of life and morbidity to determine the possible costs, we compared the different algorithms for all possible prevalence values. The sensitivity and specificity rates used in making these comparisons were the average values reported in the literature. We found that the recommended algorithm, V, had the lowest cost, provided that economically reasonable morbidity and mortality costs were used. It seems that this algorithm provides sufficient sensitivity and specificity to compensate for the risks of angiography as compared with the other algorithms that avoid these risks. Neither M nor C can compete with this standard algorithm despite their lower mortality and morbidity costs, and the costs of A alone are too high. In the future, however, the inclusion of venous studies with M and/or C may improve the results sufficiently to become more cost-effective than V.

Algorithms↗
PubMed1996

Needle-tip repositioning during computed-tomography-guided transthoracic needle aspiration biopsy of small deep pulmonary lesions: minor adjustments make a big difference.

The aim of the study was to determine whether a thin-gauge transthoracic biopsy needle would be deflected from a straight path as it passed through lung tissue, and whether partially withdrawing the needle and reinserting it while applying pressure could significantly change the degree of deflection. Using a cadaver lung, we showed that the needle tip was deflected, on average, 2.5 mm from a straight path in a direction opposite to the bevel. The reinsertion technique using pressure caused the average deflection to increase to 6.3 mm, a significant difference from the previous value. We have found this technique to be useful in the performance of transthoracic needle aspiration biopsy of small deep pulmonary nodules where differences in positioning of the needle tip by only a few millimeters can achieve the correct, rather than an indeterminate, diagnosis.

Biopsy, Needle↗
PubMed1996

Pitfalls in CT-guided transthoracic needle biopsy of pulmonary nodules.

Successful performance of transthoracic needle biopsy of pulmonary nodules under computed tomographic (CT) guidance requires both accurate placement of the needle tip within the nodule and withdrawal of an adequate sample from the lesion. Failure to complete the biopsy procedure or to establish a definitive tissue diagnosis may be due to a number of factors. Potential pitfalls in transthoracic needle biopsy include technical factors related to the patient, CT scanning, or the biopsy needle; factors related to the size, location, or internal characteristics of the nodule or to an abnormality within adjacent parenchyma; and complications that may occur during transthoracic needle biopsy, such as pneumothorax or parenchymal hemorrhage. Awareness of how these pitfalls may be avoided or minimized should help expedite the performance of transthoracic needle biopsy and increase the likelihood of a diagnostic result.

Biopsy, Needle↗
PubMed1996

Juxtaphrenic peak in upper and middle lobe volume loss: assessment with CT.

PURPOSE: To investigate the anatomic basis for the juxtaphrenic peak (JP) in upper and/or middle lobe volume loss through radiographic and computed tomographic (CT) correlation. MATERIALS AND METHODS: Chest radiographs and CT scans were reviewed in 32 patients with upper or middle lobe volume loss. The study included 33 cases of volume loss: 12 affected the left upper lobe; 12, the right upper lobe; five, the right upper and middle lobes; and four, the middle lobe. JPs and linear opacities identified on chest radiographs were correlated with juxtadiaphragmatic structures on CT scans. RESULTS: A JP was identified in 22 of 33 (67%) cases, including nine of 12 (75%) with left upper lobe volume loss and eight of 12 (67%) with right upper lobe, four of five (80%) with combined upper and middle lobe, and one of four (25%) with middle lobe volume loss. The JP was due to an inferior accessory fissure in 14 of 22 (64%) cases. Other causes included a medial septum and an accessory fissure other than the inferior accessory fissure. CONCLUSION: The JP sign is seen in the majority of cases with upper lobe or combined upper and middle lobe volume loss. The sign is most commonly related to an inferior accessory fissure.

Adolescent↗
PubMed1996

Aspiration of a large pneumothorax resulting from transthoracic needle biopsy.

PURPOSE: To determine whether simple aspiration of air from the pleural space could obviate chest tube placement in patients with a large pneumothorax after transthoracic needle biopsy. MATERIALS AND METHODS: Seventeen patients, who developed a large pneumothorax (> 30%) during computed tomographic (CT)-guided transthoracic needle biopsy and otherwise would have required chest tube placement, underwent percutaneous aspiration of the pneumothorax while on the CT scanner table. Air was aspirated from the pleural space by using an 18-gauge intravenous catheter attached to a three-way stopcock and a 50-mL syringe. The patients were positioned with the puncture site down after aspiration of the pneumothoraces and oxygen was administered both during and after the procedure. RESULTS: The pneumothorax was almost completely aspirated in all 17 patients. Twelve (70%) patients did not require chest tube placement. Follow-up chest radiographs obtained 2 and 4 hours after the procedure revealed complete or almost complete resolution of the pneumothorax in eight (47%) patients and partial recurrence of a small, stable pneumothorax in four (24%) patients. The remaining five (29%) patients had recurrence of their pneumothorax, which ultimately required chest tube placement. CONCLUSION: Percutaneous catheter aspiration of a large biopsy-induced pneumothorax is safe and easy to perform and may obviate chest tube placement.

Adult↗
PubMed1996

Accuracy and efficacy of chest radiography in the intensive care unit.

In summary, the chest radiograph has only moderate accuracy in visualizing opacification caused by cardiopulmonary abnormalities and may be quite nonspecific as to etiology, whereas it has high diagnostic accuracy for detecting malpositioning of tubes and lines. While focal parenchymal abnormalities are usually visualized on chest radiographs, identification of concomitant abnormalities when ARDS or PE already exist is more difficult. Atelectasis, aspiration, pneumonia, pulmonary hemorrhage, pulmonary thromboembolism, atypical cardiogenic edema, asymmetric ARDS, and neoplasms may be indistinguishable. Repeat chest radiographs and different views may be helpful, as the progression and time course of various etiologies can be quite different. On the other hand, Winer-Muram et al found that review of prior radiographs and clinical data did not improve the diagnostic accuracy for either ARDS or pneumonia. Pleural effusions may even be difficult to distinguish from parenchymal processes, particularly when the patient is in the supine position. Additional views with the patient in a different position--semi-erect, decubitus, or cross-table lateral--may be of assistance. In most cases, pneumothorax is readily detected. Additional studies such as the decubitus view occasionally may be necessary for further evaluation when there is uncertainty about the findings. Subcutaneous air is readily visualized radiographically. Pneumomediastinum and interstitial pulmonary emphysema may be more difficult to see. It is well known that CT allows visualization of much smaller abnormal air collections than radiography. Despite this lack of sensitivity and specificity of chest films, studies have shown that up to 65% of daily films in the ICU reveal significant and/or unsuspected abnormalities that may change the patient's diagnosis or management. Based on these results, the consensus opinion of the ACR Expert Panel found that daily chest radiographs are indicated on patients with acute cardiopulmonary problems and those receiving mechanical ventilation. Patients who require cardiac monitoring but are otherwise stable require only an initial admission film. Additional radiographs are indicated only when a new device is placed or when there is a specific question regarding cardiopulmonary status. It is also noteworthy that despite the chest film being the most commonly ordered radiologic examination for inpatients, there are no comprehensive studies evaluating its cost-effectiveness. Although several studies have done a very limited cost accounting of the potential savings by eliminating routine films in the evaluation of specific subsets of patients, overall impact on patient outcome has not been investigated. Thus, a true assessment of cost-effectiveness has yet to be determined.

Catheterization, Swan-Ganz↗
PubMed1995

The solitary pulmonary nodule: update 1995.

PURPOSE: This study analyzed the clinical characteristics, diagnostic evaluation, prevalence of malignancy, and outcome of patients with a solitary pulmonary nodule (SPN) encountered in the outpatient practice of a pulmonologist in an urban university hospital from 1990 to 1993. PATIENTS AND METHODS: SPN was defined as a round or ovoid density < or = 3 cm in diameter within the lung parenchyma. Patients with and without lung cancer in SPNs were compared. RESULTS: Forty patients had a mean age of 65 years, an almost equal sex distribution, high prevalences of cardiovascular disease (53%) and chronic obstructive pulmonary disease (COPD) (33%), but a low incidence of tuberculosis. The mean size of SPNs was 1.8 cm. The prevalence of malignancy was 53%. In SPNs < or = 2 cm in diameter, the prevalence of malignancy was 43%. Nonsurgical biopsy techniques made a diagnosis in 78% of patients. In 94% of patients with lung cancer in SPNs, the tumor was resectable (stage 1, 2, or 3A), emphasizing the need for early detection. Despite the small size of the SPNs, the prevalence of malignancy was high. CONCLUSION: Despite the advanced age and high prevalence of cardiovascular disease and COPD in patients with SPNs, lung cancer that occurs in these lesions appears to have a favorable prognosis if detected promptly.

Aged↗
PubMed1995

Variability in lesion depth on prone and supine CT scans of the chest: implications for the accuracy of transthoracic needle aspiration biopsy.

Transthoracic needle biopsy of the lung is often performed fluoroscopically in the prone position; nodule depth measurements are made from accompanying computed tomographic (CT) scans performed supine. We evaluated the effect of prone and supine positioning on the effect of nodule depth as measured from the skin surface. Twenty consecutive patients having CT-guided biopsy performed in the prone position were assessed. Nodule depth from posterior skin surface to nodule was compared with prebiopsy supine CT scan. Nodules above the carina showed minimal change in depth. Those below the carina showed considerable variability, with depth changes < or = 4.0 cm. Awareness of the magnitude of the potential effect of patient position on lesion depth should be helpful in reducing the likelihood of false negative results in fluoroscopically guided biopsy.

Biopsy, Needle↗
PubMed1995

Changing practice patterns in the workup of pulmonary embolism.

STUDY OBJECTIVE: While the "gold standard" for diagnosis of pulmonary embolism remains selective pulmonary angiography and its sensitivity and specificity are very high, it is not frequently used. The Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) clinical trial results confirmed the low mortality and morbidity of pulmonary angiogram and the need for further evaluation of patients with "low" and "intermediate" probability ventilation/perfusion scans. We wanted to determine whether physician behavior changed from 1988 to 1991. DESIGN: Retrospective review of inpatients having a ventilation/perfusion scan for suspected pulmonary embolism. The official reading of the ventilation/perfusion scans, venous leg sonograms with Doppler, contrast leg venograms, and pulmonary angiograms were recorded as well as the final diagnosis and treatment. SETTING: A large city hospital--The New York Hospital-Cornell Medical Center, New York. PATIENTS: All inpatients who had a ventilation perfusion scan in 1988 and all inpatients who had the procedure in 1991. INTERVENTION: None. RESULTS: The percentages of patients in each ventilation/perfusion scan category were similar in 1988 and 1991 as was the percentage of those who underwent anticoagulation therapy. Significantly more sonograms, however, were performed in 1991 along with fewer angiograms and venograms without any significant change in the overall cost. CONCLUSIONS: In 1991, additional diagnostic tests were performed after a low or intermediate ventilation/perfusion scan, but the percentage of patients who underwent anticoagulation did not change from 1988. This suggests that better diagnostic screening approaches with more explicit guidelines need to be developed that take into account the local disease prevalence and hospital diagnostic and practice patterns.

Clinical Competence↗
PubMed1994

Appropriate window and level settings in CT-guided biopsies.

The purpose of this study was to investigate the factors that help determine the needle tip location during computed tomographic (CT)-guided thin needle aspirations. We devised a model using a bottle filled with air, mineral oil, and water into which we could insert a needle. We then obtained CT images using both 5- and 10-mm slice thicknesses and determined the Hounsfield units (HUs) in regions of interest surrounding the needle shaft and some distance away from the needle shaft. We demonstrated that the presence of the needle increases the average HUs of the background both in the same region of interest and in the region of interest some distance from the needle. This effect is seen in air, fat, and water and thus occurs regardless of the attenuation of the background medium. A decrease in slice thickness causes this effect to be even more marked. These experimental results coincided with the theoretical results obtained from an equation that approximates the HUs of the pixels.

Artifacts↗