50 results on '"Pozniak MA"'
Search Results
2. Compatibility of adaptive responses with combining strength and endurance training.
- Author
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McCarthy JP, Agre JC, Graf BK, Pozniak MA, and Vailas AC
- Published
- 1995
- Full Text
- View/download PDF
3. How Do Cancer-Specific Computed Tomography Protocols Compare With the American College of Radiology Dose Index Registry? An Analysis of Computed Tomography Dose at 2 Cancer Centers.
- Author
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Szczykutowicz TP, Ahmad M, Liu X, Pozniak MA, Lubner MG, and Jensen CT
- Subjects
- Male, Humans, Radiation Dosage, Tomography, X-Ray Computed methods, Registries, Testicular Neoplasms, Radiology
- Abstract
Background: Little guidance exists on how to stratify radiation dose according to diagnostic task. Changing dose for different cancer types is currently not informed by the American College of Radiology Dose Index Registry dose survey., Methods: A total of 9602 patient examinations were pulled from 2 National Cancer Institute designated cancer centers. Computed tomography dose (CTDI vol ) was extracted, and patient water equivalent diameter was calculated. N-way analysis of variance was used to compare the dose levels between 2 protocols used at site 1, and three protocols used at site 2., Results: Sites 1 and 2 both independently stratified their doses according to cancer indications in similar ways. For example, both sites used lower doses ( P < 0.001) for follow-up of testicular cancer, leukemia, and lymphoma. Median dose at median patient size from lowest to highest dose level for site 1 were 17.9 (17.7-18.0) mGy (mean [95% confidence interval]) and 26.8 (26.2-27.4) mGy. For site 2, they were 12.1 (10.6-13.7) mGy, 25.5 (25.2-25.7) mGy, and 34.2 (33.8-34.5) mGy. Both sites had higher doses ( P < 0.001) between their routine and high-image-quality protocols, with an increase of 48% between these doses for site 1 and 25% for site 2. High-image-quality protocols were largely applied for detection of low-contrast liver lesions or subtle pelvic pathology., Conclusions: We demonstrated that 2 cancer centers independently choose to stratify their cancer doses in similar ways. Sites 1 and 2 dose data were higher than the American College of Radiology Dose Index Registry dose survey data. We thus propose including a cancer-specific subset for the dose registry., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
4. Clinical implications of non-contrast-enhanced computed tomography for follow-up after endovascular abdominal aortic aneurysm repair.
- Author
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Bobadilla JL, Suwanabol PA, Reeder SB, Pozniak MA, Bley TA, and Tefera G
- Subjects
- Aged, Aged, 80 and over, Aortic Rupture therapy, Endoleak therapy, Female, Humans, Male, Predictive Value of Tests, Radiation Dosage, Retrospective Studies, Risk Factors, Time Factors, Treatment Outcome, Aortic Aneurysm, Abdominal diagnostic imaging, Aortic Aneurysm, Abdominal surgery, Aortic Rupture diagnostic imaging, Aortography methods, Blood Vessel Prosthesis Implantation adverse effects, Endoleak diagnostic imaging, Endovascular Procedures adverse effects, Tomography, X-Ray Computed
- Abstract
Background: There is growing concern over the long-term radiation exposure from serial computed tomographic (CT) scan follow-up after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs). Screening for endoleaks with non-contrast-enhanced volumetric CT has been shown to significantly reduce radiation doses. We evaluated the use of NCT as the primary method of follow-up after EVAR of AAAs., Methods: Our institutional post-EVAR CT protocol consisted of contrast-enhanced CT angiography (CTA) 1 month after repair, followed by NCT at 3 or 6 and 12 months, and annually thereafter. At each follow-up scan, immediate 3-dimensional volume analysis was performed. If the volume change was <2%, NCT follow-up was continued. If the volume increased by ≥2% on nonenhanced images, contrast-enhanced CT was performed immediately to identify potential endoleaks. All images were reviewed by an experienced cardiovascular radiologist. End points included identification of endoleak, reintervention, and rupture., Results: Over a 7-year period, 126 patients were followed. Serial CTA was performed in 59 patients, while 67 patients were followed with the NCT protocol. The mean follow-up was 2.07 years. There were no differences in age, sex, or initial aneurysm volume or size. There were 35 total endoleaks identified. Twenty of these were early endoleaks (<30 days post-EVAR). The remaining 15 leaks were late in nature (10 in the contrast group and 5 in the noncontrast group; P=0.17). NCT aneurysm sac volume changes prompted contrasted studies in all 5 late leaks. The mean volume change was 11.2 cm3, an average change of 5.88%. These findings were not significantly different than the late leaks found by routine contrast studies (8.9 cm3; 4.98% [P=0.58]). There were no delayed ruptures or emergent reinterventions in the NCT group., Conclusions: Serial NCT appears to be safe and effective as the sole means of follow-up after EVAR for AAAs. AAA volume increases of ≥2% should prompt further contrast-enhanced CT imaging. Changes of <2% can be safely followed with serial NCT. This protocol requires dedicated cardiovascular radiologist involvement, and patients should be retained in the radiology suite until real-time image evaluation can be completed., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
- Full Text
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5. Automated renal stone volume measurement by noncontrast computerized tomography is more reproducible than manual linear size measurement.
- Author
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Patel SR, Stanton P, Zelinski N, Borman EJ, Pozniak MA, Nakada SY, and Pickhardt PJ
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- Humans, Middle Aged, Observer Variation, Prone Position, Reproducibility of Results, Retrospective Studies, Supine Position, Kidney Calculi diagnostic imaging, Kidney Calculi pathology, Tomography, X-Ray Computed methods, Tomography, X-Ray Computed statistics & numerical data
- Abstract
Purpose: We compared the reproducibility of automated volume and manual linear measurements using same study supine and prone, low dose, noncontrast computerized tomography series., Materials and Methods: The patient cohort comprised 50 consecutive adults with a mean age of 56.4 years in whom renal calculi were identified during computerized tomography colonography screening. The largest stone per patient was assessed with the supine and prone computerized tomography series serving as mutual controls. Automated stone volume was derived using a commercially available coronary artery calcium scoring tool. Supine-prone reproducibility for automated volume was compared with intra-observer supine-prone manual linear measurement. Interobserver variability was also assessed for manual linear measurements of the same supine or prone series., Results: Mean ± SD linear size and volume of the 50 index calculi was 4.5 ± 2.7 mm (range 1.8 to 16) and 141.7 ± 456.1 mm(3), respectively. The mean supine-prone error for automated stone volume was 16.3% compared with an average 11.7% 1-dimensional intra-observer error for manual axial measurement. Only 2 of 15 cases with a volume error of greater than 20% were 5 mm or greater in linear size. The average interobserver linear error for the same computerized tomography series was 26.3% but automated volume measurement of the same series did not vary., Conclusions: Automated noncontrast computerized tomography renal stone volume is more reproducible than manual linear size measurement and it avoids the often large interobserver variability seen with manual assessment. Since small linear differences correspond to much larger volume changes, greater absolute volume errors are acceptable. Automated volume measurement may be an improved clinical parameter to use for following the renal stone burden., (Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.)
- Published
- 2011
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6. Background fluctuation of kidney function versus contrast-induced nephrotoxicity.
- Author
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Bruce RJ, Djamali A, Shinki K, Michel SJ, Fine JP, and Pozniak MA
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- Analysis of Variance, Creatinine urine, Female, Glomerular Filtration Rate drug effects, Humans, Incidence, Kidney Diseases epidemiology, Male, Middle Aged, Retrospective Studies, Tomography, X-Ray Computed, Wisconsin epidemiology, Contrast Media adverse effects, Iohexol adverse effects, Kidney Diseases chemically induced, Triiodobenzoic Acids adverse effects
- Abstract
Objective: The reported incidence of contrast-induced acute kidney injury varies widely. Almost no studies have been conducted to quantify the background fluctuation of kidney function of patients receiving iodinated contrast medium. The purpose of this study was a retrospective comparison of the incidence of acute kidney injury among patients undergoing CT with low-osmolar (iohexol) or isoosmolar (iodixanol) contrast medium with the incidence among patients undergoing CT without contrast administration., Materials and Methods: Creatinine concentration and estimated glomerular filtration rate were evaluated for 11,588 patients. Rates of acute kidney injury (defined as a 0.5 mg/dL increase in serum creatinine concentration or a 25% or greater decrease in estimated glomerular filtration rate within 3 days after CT) were compared among groups and stratified according to creatinine concentration and estimated glomerular filtration rate before the imaging examination., Results: In all groups, the incidence of acute kidney injury increased with increasing baseline creatinine concentration. No significant difference in incidence of presumed contrast-induced kidney injury was identified between the isoosmolar contrast medium and the control groups. The incidence of acute kidney injury in the low-osmolar contrast medium cohort paralleled that of the control cohort up to a creatinine level of 1.8 mg/dL, but increases above this level were associated with a higher incidence of acute kidney injury., Conclusion: We identified a high incidence of acute kidney injury among control subjects undergoing unenhanced CT. The incidence of creatinine elevation in this group was statistically similar to that in the isoosmolar contrast medium group for all baseline creatinine values and all stages of chronic kidney disease. These findings suggest that the additional risk of acute kidney injury accompanying administration of contrast medium (contrast-induced nephrotoxicity) may be overstated and that much of the creatinine elevation in these patients is attributable to background fluctuation, underlying disease, or treatment.
- Published
- 2009
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7. Aortic aneurysm volume calculation: effect of operator experience.
- Author
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Caldwell DP, Pulfer KA, Jaggi GR, Knuteson HL, Fine JP, and Pozniak MA
- Subjects
- Humans, Observer Variation, Task Performance and Analysis, Vascular Patency, Aortic Aneurysm, Abdominal pathology
- Abstract
Background: We have successfully applied sequential volumetric analysis of abdominal aortic aneurysms to exclude endoleak in patients who have an aortic endostent. This study compared the effect of variable operator experience on volumetric calculation accuracy., Methods: Four operators with different experience levels calculated abdominal aneurysm volumes in 10 patients at two different times (>/= 1 week apart). The four reviewers were ranked as having a high level of experience (one full-time laboratory worker specializing in three dimensions with 3 years of experience), a moderate level of experience (one part-time laboratory worker specializing in three dimensions/computed tomographic technician with 1 year of part-time experience), and a low level of experience (two individuals taught volumetric measurements for the purposes of this study: a fellow in abdominal imaging and a computed tomographic technician). All volumes were calculated with a GE Advantage 4.0 workstation (General Electric, Waukesha, WI, USA)., Results: Mean aneurysm volume and volume difference between two measurements were calculated for four operators. The average (standard deviation) percent volume differences were 1.2% (0.2%) for the experienced reader, 3.2% (0.3%) for the moderately experienced reader, and 6.0% (1.0%) and 5.8% (1.1%) for the two readers with light experience. Differences between averages were statistically significant (p < 0.005)., Conclusion: We have defined a percent margin of error for aortic aneurysm volume measurement and have shown a direct correlate to level of experience. Diagnosis of endoleak based on aneurysm volume enlargement on serial scans needs to account for the level of operator experience.
- Published
- 2005
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8. Radial artery pseudoaneurysm: a maneuver to decrease the risk of thrombin therapy.
- Author
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Pozniak MA, Mitchell C, and Ledwidge M
- Subjects
- Aged, Aneurysm, False diagnostic imaging, Humans, Male, Aneurysm, False drug therapy, Coagulants administration & dosage, Radial Artery diagnostic imaging, Thrombin administration & dosage, Ultrasonography, Doppler, Ultrasonography, Interventional
- Published
- 2005
- Full Text
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9. Intraoperative sonography of intracranial arteriovenous malformations: how we do it.
- Author
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Griffith S, Pozniak MA, Mitchell CC, Ledwidge ME, Dempsey R, Peters A, and Taylor E
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- Humans, Intracranial Arteriovenous Malformations diagnostic imaging, Monitoring, Intraoperative methods, Ultrasonography, Doppler, Color methods, Ultrasonography, Doppler, Transcranial methods
- Abstract
Objective: We have advanced the application of intraoperative neurosonography by combining gray scale sonographic imaging with pulsed wave Doppler and color flow Doppler imaging to guide and confirm resection of arteriovenous malformations of the brain. We want to share our technique with the imaging community., Methods: We present a review of our scan technique as it has evolved over the 3 years during which we have been assisting our neurosurgical team., Results and Conclusions: Our experience has indicated that a combination of sonographic imaging and color and spectral Doppler imaging improves surgical resection of such lesions.
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- 2004
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10. Twinkling artifact related to intravesicular suture.
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Mitchell C, Pozniak MA, Zagzebski J, and Ledwidge M
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- Female, Humans, Middle Aged, Ultrasonography, Foreign Bodies diagnostic imaging, Sutures, Urinary Bladder diagnostic imaging
- Published
- 2003
- Full Text
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11. Using a saline chaser to decrease contrast media in abdominal CT.
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Dorio PJ, Lee FT Jr, Henseler KP, Pilot M, Pozniak MA, Winter TC 3rd, and Shock SA
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- Adult, Aged, Aged, 80 and over, Contrast Media adverse effects, Contrast Media economics, Cost Savings, Female, Humans, Kidney Diseases chemically induced, Kidney Diseases prevention & control, Male, Middle Aged, Prospective Studies, Radiographic Image Enhancement economics, Radiographic Image Enhancement methods, Sensitivity and Specificity, Tomography, Spiral Computed economics, Contrast Media administration & dosage, Iohexol adverse effects, Iohexol economics, Liver Neoplasms diagnostic imaging, Liver Neoplasms secondary, Sodium Chloride administration & dosage, Tomography, Spiral Computed methods
- Abstract
Objective: The purpose of this study was to compare hepatic tumor conspicuity on CT after injection of either 150 mL of contrast material or 100 mL of contrast material plus a 50-mL saline chaser., Subjects and Methods: We evaluated 86 hypoattenuating liver metastases in 26 patients. Patients underwent CT in two sessions separated by a mean of 85 days: one time with 150 mL of contrast material and the other time with 100 mL of contrast material followed by a 50-mL saline chaser. The order of the sessions was randomized. Contrast material was administered via power injector and matched for injection rate and delay time. Attenuation values were obtained from normal liver tissue and metastases and from the spleen, kidney, aorta, and inferior vena cava., Results: The 150 mL dose of contrast material caused slightly greater liver and tumor attenuation than 100 mL of contrast material with a chaser (mean hepatic attenuation, 95.6 vs 89.8 H, respectively; p < 0.03, paired t test; mean tumor attenuation, 53.2 vs 49.1 H, respectively; r = 0.71, p = 0.09). The difference in conspicuity of liver lesions was slightly greater with 150 mL than with 100 mL with a chaser (46.8 H vs 44.2 H; r = 0.46, p = 0.08, paired t test), but was of doubtful clinical significance (2.6 H). Kidney, spleen, and vascular structures enhanced more with 150 mL than with 100 mL and a chaser., Conclusion: Using 100 mL of contrast material and a saline chaser did not result in a meaningful difference in liver parenchyma attenuation or lesion conspicuity compared with using 150 mL of contrast medium alone. Routine use of a chaser for abdominal CT may yield cost savings and a decreased risk of contrast nephropathy.
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- 2003
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12. Donor-derived malignancy: transmission of small-cell lung cancer via renal transplantation.
- Author
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Winter TC, Keller PR, Lee FT Jr, and Pozniak MA
- Subjects
- Adult, Carcinoma, Small Cell immunology, Carcinoma, Small Cell surgery, Disease Transmission, Infectious, Female, Humans, Kidney Neoplasms immunology, Kidney Neoplasms surgery, Neoplasm Transplantation, Tomography, X-Ray Computed, Ultrasonography, Carcinoma, Small Cell diagnostic imaging, Carcinoma, Small Cell etiology, Kidney Neoplasms diagnostic imaging, Kidney Neoplasms etiology, Kidney Transplantation adverse effects
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- 2001
- Full Text
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13. Three-dimensional CT angiography of spontaneous portosystemic shunts.
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Henseler KP, Pozniak MA, Lee FT Jr, and Winter TC 3rd
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- Esophageal and Gastric Varices etiology, Humans, Hypertension, Portal complications, Imaging, Three-Dimensional, Liver Circulation, Liver Diseases complications, Angiography methods, Esophageal and Gastric Varices diagnostic imaging, Tomography, X-Ray Computed
- Abstract
Spontaneous portosystemic shunts (varices) are a well-known complication of severe liver disease and portal hypertension. Computed tomographic (CT) angiography was used to image the hepatic vasculature of 198 patients with end-stage liver disease in anticipation of liver transplantation. Performance of a delayed acquisition during the portal phase of enhancement enables evaluation of portal and variceal anatomy without the need for an additional injection of contrast material. Three-dimensional (3D) reconstruction of portal-phase CT angiograms enhances the perception of the courses and anatomic relationships of varices. This information is valuable for surgical planning. Common varices include the left gastric vein, short gastric veins, paraumbilical veins, and splenic vein; in cases of more unusual, complex shunts, 3D rendering is indispensable. By precisely demonstrating the courses of varices, CT angiography allows the surgeon to plan the operative approach and determine the need for surgical varix ligation or preoperative interventional embolization.
- Published
- 2001
- Full Text
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14. Intraoperative sonographic assessment of graft patency during extracranial-intracranial bypass.
- Author
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Badie B, Lee FT Jr, Pozniak MA, and Strother CM
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- Adult, Brain pathology, Humans, Intraoperative Period, Magnetic Resonance Angiography, Magnetic Resonance Imaging, Male, Blood Vessel Prosthesis, Cerebral Revascularization, Ultrasonography, Doppler, Duplex, Vascular Patency
- Abstract
Extracranial-intracranial (EC-IC) bypass may be necessary to facilitate treatment of unclippable posterior circulation fusiform aneurysms. Although intraoperative digital subtraction angiography (DSA) allows assessment of graft patency, this technique, because of difficulties inherent in performing selective catheterization and angiography in the operating room, has limitations. Duplex sonography, in contrast, is easily performed, and provides information regarding graft patency and blood flow direction during EC-IC bypass procedures. This latter information proved useful in determining the time of parent artery occlusion after two EC-IC bypass procedures performed for treatment of a fusiform midbasilar artery aneurysm.
- Published
- 2000
15. Phlegmasia cerulea dolens with compartment syndrome: a complication of femoral vein catheterization.
- Author
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Wood KE, Reedy JS, Pozniak MA, and Coursin DB
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- Adult, Ceftriaxone administration & dosage, Critical Care, Erythromycin administration & dosage, Femoral Vein diagnostic imaging, Humans, Male, Ultrasonography, Catheterization, Central Venous, Compartment Syndromes diagnostic imaging, Drug Therapy, Combination therapeutic use, Pneumonia, Bacterial drug therapy, Respiratory Insufficiency drug therapy, Thrombophlebitis diagnostic imaging
- Abstract
Objective: Central venous catheterization is commonly performed in the critically ill. The femoral vein is widely accepted as an insertion site with complications thought to be comparable to other central access sites. We used serial ultrasound examinations with Doppler to examine the evolution of a heretofore undescribed complication of femoral vein catheterization, phlegmasia cerulea dolens with compartment syndrome., Design: Serial ultrasounds were performed in patients before the insertion of femoral venous catheters and sequentially every 48 hrs while the catheters were in place. The noncatheterized leg served as a control., Setting: A trauma and life support center of a tertiary multidisciplinary critical care unit., Patient: A 32-yr-old man with respiratory failure as a consequence of a severe community-acquired pneumonia that required central venous access for antibiotics because no peripheral sites could be obtained., Interventions: None., Measurements and Main Results: The initial ultrasound examination of both legs before femoral catheter insertion revealed no sign of venous thrombosis. Ultrasound of the catheterized leg at 48 hrs revealed a small nonocclusive thrombosis, whereas the opposite leg remained normal. At 72 hrs, the catheterized leg had clinical and ultrasonographic evidence of a massive thrombosis. A compartment syndrome defined by pressure measurements soon ensued and required emergent surgical release., Conclusions: This case report and a review of the available literature suggest that thrombosis associated with femoral vein catheterization should be considered when clinicians decide where to obtain central venous access when multiple sites are available. This report also suggests the utility of serial ultrasound examinations to define clinically nonapparent thrombosis as an early indicator of a potentially catastrophic complication.
- Published
- 2000
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16. Non-contrast-enhanced helical computed tomography for the evaluation of patients with acute flank pain.
- Author
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Dorio PJ, Pozniak MA, Lee FT Jr, and Kuhlman JE
- Subjects
- Acute Disease, Adolescent, Adult, Aged, Aged, 80 and over, Child, Female, Humans, Hydronephrosis diagnostic imaging, Male, Middle Aged, Retrospective Studies, Sensitivity and Specificity, Ureteral Calculi complications, Pain etiology, Tomography, X-Ray Computed methods, Ureteral Calculi diagnostic imaging
- Abstract
The purpose of this study was to determine the sensitivity, specificity, and positive predictive value of non-contrast-enhanced helical CT as the primary imaging modality for the evaluation of patients with acute flank pain at the University of Wisconsin. A retrospective review of 163 computed tomography (CT) examinations, dating from 3/4/97 to 3/25/98, was performed. Statistical calculations were performed using only clinically-confirmed data. Sixty-five true positives, 3 false positives, 64 true negatives, and 1 false negative yield a sensitivity of 98.5%, a specificity of 95.5%, and a positive predictive value of 95.6%. A timely diagnosis of non-genitourinary system pathology occurred in 7% of cases, improving the overall efficacy of this modality for the evaluation of flank pain. The University of Wisconsin experience confirms the accuracy and efficacy of using non-contrast-enhanced helical CT in the diagnosis of a suspected obstructing ureteral calculus. The highly accurate and timely diagnosis of an obstructing ureteral calculus, or of extraurinary tract pathology, establishes non-contrast-enhanced helical CT as the diagnostic study of choice for the evaluation of the patient with acute flank pain.
- Published
- 1999
17. Computed tomographic angiography in the preoperative evaluation of potential renal transplant donors.
- Author
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Pozniak MA and Lee FT Jr
- Subjects
- Angiography, Animals, Humans, Preoperative Care, Kidney blood supply, Kidney Transplantation, Living Donors, Renal Artery diagnostic imaging, Renal Veins diagnostic imaging, Tomography, X-Ray Computed methods
- Abstract
The preoperative screening of potential renal transplant donors has undergone a major evolution with the introduction of computed tomographic angiography. With computed tomographic angiography, the radiologist is able to provide the surgeon with precise and valuable preoperative details of renal arterial and venous anatomy. In addition, computed tomographic angiography provides valuable information regarding the renal parenchyma and adjacent organs. This helps reduce the risks and complications associated with transplant surgery and improves the chances of a successful outcome. Helical computed tomographic angiography is rapidly replacing intravenous urography and conventional angiography as the imaging modality of choice for evaluating renal donors.
- Published
- 1999
- Full Text
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18. Radiographic and CT findings of blunt chest trauma: aortic injuries and looking beyond them.
- Author
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Kuhlman JE, Pozniak MA, Collins J, and Knisely BL
- Subjects
- Aorta, Thoracic injuries, Female, Humans, Male, Aortic Rupture diagnostic imaging, Thoracic Injuries diagnostic imaging, Tomography, X-Ray Computed methods, Wounds, Nonpenetrating diagnostic imaging
- Abstract
Increasingly, helical CT is being used to screen trauma patients for aortic injury. Most aortic injuries visible at CT occur at or near the level of the ligamentum arteriosus; these injuries manifest as mediastinal hematoma, aortic contour deformity, intimal flaps, intraluminal debris, pseudoaneurysm, and pseudocoarctation. In the process of searching for aortic injury, however, the radiologist should not overlook other serious and more common thoracic injuries. Tracheobronchial tears appear at CT and radiography with persistent pneumothorax, subcutaneous emphysema, "fallen lung" sign, and malposition of endotracheal tube. The ruptured diaphragm, which tears more often on the left, appears asymmetric, irregular, or discontinuous, with herniation of bowel or viscera into the chest. In esophageal rupture, CT and radiography demonstrate left pneumothorax, pneumomediastinum, subcutaneous emphysema, and pleural effusion and atelectasis on the left. CT is better than trauma radiography for depicting fractures of the thoracic vertebral bodies and ribs, as well as for revealing pulmonary contusions and lacerations. CT is also useful for demonstrating unsuspected injuries caused by seat belts. Observation of these injuries should prompt a search for other serious internal organ injuries.
- Published
- 1998
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19. CT angiography of potential renal transplant donors.
- Author
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Pozniak MA, Balison DJ, Lee FT Jr, Tambeaux RH, Uehling DT, and Moon TD
- Subjects
- Female, Humans, Image Processing, Computer-Assisted, Kidney Diseases diagnostic imaging, Male, Radiographic Image Interpretation, Computer-Assisted, Renal Artery anatomy & histology, Renal Artery diagnostic imaging, Renal Veins anatomy & histology, Renal Veins diagnostic imaging, Sensitivity and Specificity, Angiography methods, Kidney blood supply, Kidney diagnostic imaging, Kidney Transplantation, Living Donors, Tomography, X-Ray Computed methods
- Abstract
Renal transplantation has grown rapidly over the past 30 years, resulting in an inadequate supply of organs to meet the ever-increasing demand. This has led to an increase in the number of living-related donors. Advances in imaging technology now allow safe, rapid, and relatively noninvasive evaluation of potential donors. Helical computed tomographic (CT) angiography is a fast, minimally invasive procedure that is quickly becoming the imaging modality of choice for preoperative evaluation of potential renal transplant donors. Helical CT, combined with low-osmolar intravenous contrast materials, has enabled CT angiography to depict arterial and venous anatomy accurately. Between July 1995 and March 1997, CT angiography was performed in 205 potential renal donors. Correlation with surgical findings in 136 donor nephrectomies helped confirm a high level of accuracy for CT angiography in the assessment of the renal vasculature: Sensitivity and specificity for identifying specific vessels was 99.6% and 99.6% for main renal arteries, 76.9% and 89.9% for polar arteries, and 98.7% and 95.5% for main renal veins, respectively. CT angiography allows the radiologist to provide the transplant surgeon with precise preoperative anatomy of the renal vasculature, thus reducing the risks and complications associated with the harvesting procedure and improving the chances for a successful outcome. However, accurate radiologic interpretation depends on the radiologist's experience level, attention to detail, and commitment to careful image evaluation.
- Published
- 1998
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20. Sonography of testicular tumors and tumor-like conditions: a radiologic-pathologic correlation.
- Author
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Geraghty MJ, Lee FT Jr, Bernsten SA, Gilchrist K, Pozniak MA, and Yandow DJ
- Subjects
- Adult, Diagnostic Imaging, Humans, Male, Scrotum pathology, Testicular Diseases diagnosis, Testicular Diseases diagnostic imaging, Testicular Neoplasms diagnosis, Testis pathology, Ultrasonography, Testicular Neoplasms diagnostic imaging
- Abstract
Malignant testicular tumors are an important clinical problem, and ultrasound is the most frequently ordered imaging modality once a palpable scrotal mass is discovered. Numerous articles discussing the role of ultrasound in the evaluation of testicular pathology have confirmed the value of preoperative imaging. This article presents a review of imaging literature regarding testicular neoplasms, with an emphasis on correlation of gross and microscopic tumor pathology and imaging findings. Also included are sections on anatomy, epidemiology, histogenesis, and tumor markers.
- Published
- 1998
21. Three-dimensional computed tomographic angiography of a horseshoe kidney with ureteropelvic junction obstruction.
- Author
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Pozniak MA and Nakada SY
- Subjects
- Humans, Kidney Pelvis, Tomography, X-Ray Computed, Ureteral Obstruction diagnostic imaging, Kidney abnormalities, Kidney diagnostic imaging, Ureteral Obstruction complications
- Published
- 1997
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22. Conventional color Doppler velocity sonography versus color Doppler energy sonography for the diagnosis of acute experimental torsion of the spermatic cord.
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Lee FT Jr, Winter DB, Madsen FA, Zagzebski JA, Pozniak MA, Chosy SG, and Scanlan KA
- Subjects
- Animals, Blood Flow Velocity, Dogs, Male, Observer Variation, Sensitivity and Specificity, Spermatic Cord Torsion epidemiology, Testis blood supply, Testis diagnostic imaging, Spermatic Cord Torsion diagnostic imaging, Ultrasonography, Doppler, Color methods
- Abstract
Objective: We compared color Doppler velocity sonography and color Doppler energy sonography for the diagnosis of spermatic cord torsion in a canine model and determined the degree of torsion necessary to acutely halt testicular blood flow., Materials and Methods: Spermatic cord torsion was created in five dogs by exposing and rotating the ipsilateral testis 0 degree, 180 degrees, 270 degrees, 360 degrees, 450 degrees, and 540 degrees. Detorsion followed. The testicles were scanned at each torsion stop using both color Doppler velocity sonography and color Doppler energy sonography. Doppler parameters were optimized (by phantom and test scans) and maintained at a tolerable noise level throughout the experiment. Readers who were unaware of the degree of torsion compared flow in the rotated and contralateral control testes., Results: Flow became undetectable by color Doppler velocity sonography and color Doppler energy sonography at 450 degrees in four of five cases and at 540 degrees in one of five cases. We found no significant difference between the velocity and the energy techniques for detecting this absence of flow (p > .05, Wilcoxon test). We found a significant difference in degree of flow for both techniques when comparing controls and all degrees of torsion combined (p < .006, Mann-Whitney test), but significance was achieved at lesser degrees of torsion with the velocity technique than with the energy technique (180 degrees and 360 degrees, respectively, Wilcoxon test)., Conclusion: Color Doppler energy sonography was not significantly more sensitive than color Doppler velocity sonography for the diagnosis of spermatic cord torsion in this model. Complete occlusion of arterial inflow occurred at 450-540 degrees of torsion.
- Published
- 1996
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23. A randomized comparison of iodixanol and iohexol in adult body computed tomography scanning.
- Author
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Lee FT Jr, Caroline DF, Thornbury JR, Gembala RB, Kelcz F, Pozniak MA, Rima JB, and Sargent BE
- Subjects
- Double-Blind Method, Female, Humans, Male, Middle Aged, Contrast Media adverse effects, Iohexol adverse effects, Tomography, X-Ray Computed, Triiodobenzoic Acids adverse effects
- Abstract
Rationale and Objectives: We compared the safety and imaging efficacy of iodixanol-270 (270 mg I/ml), iodixanol-320 (320 mg I/ml), both of which are isosmolal to blood, and iohexol-300 (300 mg I/ml) for body computed tomography (CT) scanning., Methods: One hundred twenty-six patients from the University of Wisconsin Hospital and Temple University Hospital scheduled to undergo body CT examinations were randomly assigned to receive either iodixanol-270, iodixanol-320, or iohexol-300. Patients were monitored with questioning and vital signs before injection, immediately after injection, and at 24 and 48 hr. Extensive laboratory evaluation also was performed., Results: No serious reactions or deaths occurred in any group. The occurrence of overall minor adverse events (usually warmth, headache, taste distortion, rash) was similar for the different groups. Laboratory results showed no significant difference across groups. There was no significant difference in image quality detected among groups., Conclusion: There was no detectable difference in safety and imaging efficacy among the three contrast groups in this study. However, patients from the University of Wisconsin experienced significantly less injection discomfort with iodixanol-270 than with iohexol-300. Large clinical studies may more definitively determine the presence and nature of the relative advantages of iodixanol compared with currently available ionic and nonionic contrast agents.
- Published
- 1996
- Full Text
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24. Interleukin-2-induced splenic enlargement.
- Author
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Pozniak MA, Christy PS, Albertini MR, Duffek SM, and Schiller JH
- Subjects
- Adult, Aged, Female, Granulocyte-Macrophage Colony-Stimulating Factor therapeutic use, Humans, Immunotherapy adverse effects, Male, Middle Aged, Splenomegaly pathology, Interleukin-2 adverse effects, Splenomegaly etiology
- Abstract
Background: Splenomegaly in patients with cancer raises the suspicion of tumor involvement. Splenic enlargement in the absence of splenic metastases, however, has been reported in patients treated with interleukin-2 (IL-2) immunotherapy. This study characterizes the change in spleen size that occurred in 42 patients treated with IL-2 between 1989 and 1993 for nonhematologic malignancies., Methods: Computed tomography (CT) scans before and during immunotherapy were available for review on all 42 patients and after immunotherapy on 16 of these patients. The splenic index was measured for each CT by a single reader blinded to the time course of IL-2 therapy., Results: Mean splenic index increased 64.1% from 646 cm3 (standard deviation [SD], 387) pre-IL-2 to 1059 cm3 (SD, 534) during therapy with IL-2 (P < 0.0001). The splenic index remained elevated at 1112 cm3 (SD, 633) after completion of IL-2 therapy., Conclusions: Splenomegaly, temporally associated with IL-2 therapy for nonhematologic malignancies, is likely to represent a sequela of therapy and not tumor progression.
- Published
- 1995
- Full Text
- View/download PDF
25. Imaging of pancreas transplants.
- Author
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Pozniak MA, Propeck PA, Kelcz F, and Sollinger H
- Subjects
- Humans, Pancreas diagnostic imaging, Pancreas pathology, Postoperative Complications diagnostic imaging, Radiography, Radionuclide Imaging, Ultrasonography, Pancreas Transplantation, Postoperative Complications diagnosis
- Abstract
The pancreas transplant is difficult to monitor both clinically and by imaging. Complications such as thrombosis, infection, pancreatitis, bleeding, anastomotic leak, or rejection may quickly progress to transplant failure. Ultrasound, CT, MR imaging, fluoroscopy, nuclear scintigraphy, and angiography may be used to help define the etiology of transplant compromise; however, all have marked limitations, and none has proved to be the study of choice. The surgeon and radiologist must carefully coordinate clinical suspicion with the strengths of the various modalities to optimize a timely diagnosis.
- Published
- 1995
26. Minor vascular anatomy of the abdomen and pelvis: a CT atlas.
- Author
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Stallard DJ, Tu RK, Gould MJ, Pozniak MA, and Pettersen JC
- Subjects
- Blood Vessels anatomy & histology, Humans, Intestine, Small blood supply, Mesentery anatomy & histology, Pelvis diagnostic imaging, Radiography, Abdominal, Abdomen blood supply, Pelvis blood supply, Tomography, X-Ray Computed
- Abstract
With the early generations of computed tomographic (CT) scanners, interpretation of abdominal and pelvic scans focused on the solid organs, hollow viscera, and retroperitoneum. Attention to blood vessels generally was given only to the aorta and inferior vena cava and their larger branches. The newer generations of scanners allow rapid acquisition of high-resolution images during the vascular phase of mechanical bolus injection of intravenous contrast material. Visualization of second-order vascular branches has thus become routine. Recent improvements in software allow real-time reconstruction of data in multiple planes, which enables demonstration of long segments of vessels within a single image. Approximately 7,000 abdominal and pelvic CT scans were reviewed with attention to vascular detail. Cases are presented that illustrate peripancreatic, perigastric, parietal, and hypogastric vessels; fetal remnants and structures that may be mistaken for vessels; and collateral pathways of both arterial and venous flow. With increasing use of helical CT scanning, smaller vessels can be identified with greater confidence. Knowledge of normal CT vascular anatomy facilitates understanding of collateral pathways when vessel engorgement is perceived.
- Published
- 1994
- Full Text
- View/download PDF
27. US case of the day. Median arcuate ligament syndrome (celiac artery compression syndrome).
- Author
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Sproat IA, Pozniak MA, and Kennell TW
- Subjects
- Adult, Constriction, Pathologic diagnostic imaging, Female, Humans, Syndrome, Ultrasonography, Celiac Artery diagnostic imaging, Peripheral Vascular Diseases diagnostic imaging
- Published
- 1993
- Full Text
- View/download PDF
28. US case of the day. Polysplenia syndrome.
- Author
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Lee FT Jr, Pozniak MA, and Helgerson RB
- Subjects
- Adult, Diagnosis, Differential, Humans, Male, Syndrome, Ultrasonography, Abnormalities, Multiple diagnostic imaging, Spleen abnormalities
- Published
- 1993
- Full Text
- View/download PDF
29. Ultrasound case of the day. Combined iatrogenic CFA pseudoaneurysm and CFA-CFV arteriovenous fistula.
- Author
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Digman KE and Pozniak MA
- Subjects
- Aneurysm etiology, Arteriovenous Fistula etiology, Cardiac Catheterization adverse effects, Humans, Male, Middle Aged, Ultrasonography, Aneurysm diagnostic imaging, Arteriovenous Fistula diagnostic imaging, Femoral Artery diagnostic imaging, Femoral Vein diagnostic imaging
- Published
- 1993
- Full Text
- View/download PDF
30. Upper inferior vena caval anastomotic stenosis in liver transplant recipients: Doppler US diagnosis.
- Author
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Rossi AR, Pozniak MA, and Zarvan NP
- Subjects
- Adolescent, Adult, Anastomosis, Surgical, Child, Child, Preschool, Constriction, Pathologic diagnostic imaging, Female, Hepatic Veins diagnostic imaging, Humans, Infant, Male, Middle Aged, Ultrasonography, Liver Transplantation, Postoperative Complications diagnostic imaging, Vena Cava, Inferior diagnostic imaging
- Abstract
Ultrasound (US) is routinely used as a screening tool for liver transplant dysfunction. Its use in the detection of significant vascular complications of liver transplantation such as thrombosis or stenosis of the hepatic artery and portal vein is well recognized. Its role in the detection of anastomotic stenosis of the inferior vena cava (IVC) has not been defined. The authors present US findings in five patients with such stenosis. The gray-scale and Doppler findings in all cases consisted of loss of normal hepatic vein and IVC periodicity. Some studies also showed distention of the hepatic veins and IVC and a high-velocity jet at the anastomosis, and in one case the stenosis was visualized with color Doppler US. While there are other causes of absent periodicity in the hepatic veins, this finding in the appropriate clinical setting may be a sensitive indicator of upper IVC anastomotic stenosis.
- Published
- 1993
- Full Text
- View/download PDF
31. Ultrasound case of the day. Bilateral testicular microlithiasis with a left testicular seminoma.
- Author
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Propeck PA, Desouky SS, Warner TF, and Pozniak MA
- Subjects
- Humans, Male, Middle Aged, Ultrasonography, Calculi diagnostic imaging, Calculi pathology, Dysgerminoma diagnostic imaging, Dysgerminoma pathology, Testicular Diseases diagnostic imaging, Testicular Diseases pathology, Testicular Neoplasms diagnostic imaging, Testicular Neoplasms pathology
- Published
- 1993
- Full Text
- View/download PDF
32. Ultrasound case of the day. Herniating paraumbilical vein varix.
- Author
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Stallard DJ, Pozniak MA, and Paulson BA
- Subjects
- Adult, Hernia diagnostic imaging, Humans, Ultrasonography, Vascular Diseases diagnostic imaging, Umbilical Veins diagnostic imaging, Varicose Veins diagnostic imaging
- Published
- 1993
- Full Text
- View/download PDF
33. Ultrasound case of the day. Gallbladder varices.
- Author
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Paulson BA and Pozniak MA
- Subjects
- Cholecystography, Gallbladder diagnostic imaging, Humans, Male, Middle Aged, Tomography, X-Ray Computed, Ultrasonography, Gallbladder blood supply, Varicose Veins diagnostic imaging
- Published
- 1993
- Full Text
- View/download PDF
34. Ultrasonographic evaluation of renal transplantation.
- Author
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Pozniak MA, Dodd GD 3rd, and Kelcz F
- Subjects
- Humans, Hydronephrosis diagnostic imaging, Kidney diagnostic imaging, Postoperative Complications diagnostic imaging, Renal Artery Obstruction diagnostic imaging, Ultrasonography, Kidney Transplantation diagnostic imaging
- Abstract
Ultrasonography of the renal transplant is still a key screening examination for transplant dysfunction. The addition of Doppler technology has permitted screening for hemodynamic alterations. Ambitious researchers predicted that these hemodynamic profiles would permit the differentiation of rejection from other complicating factors; however, recent research and clinical experience has shown this to be ineffective. Imaging identification of a dilated collecting system identifies the patient population that should undergo a Whitaker procedure. Identification of large or increasing fluid collections helps focus attention to possible hemorrhage or urine leak. Similarly, the ultrasonographic identification of a lymphocele as the cause of leg edema or hydronephrosis rapidly focuses surgical treatment. Doppler evaluation of hemodynamics must be performed on all renal transplant recipients. Although the role of the resistive index in predicting rejection has been minimized lately, numerous vascular complications, if untreated, would result in loss of the kidney. Doppler sonography identifies those patients who would benefit most from renal arteriography. The evaluation of renal morphology on the basis of ultrasonography alone has little role in predicting the cause of transplant dysfunction. We continue to evaluate renal size and to correlate it with the clinical presentation as well as resistive index to defer patients from biopsy if a more obvious cause of dysfunction is identified.
- Published
- 1992
35. Sonography of renal transplants in dogs: the effect of acute tubular necrosis, cyclosporine nephrotoxicity, and acute rejection on resistive index and renal length.
- Author
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Pozniak MA, Kelcz F, D'Alessandro A, Oberley T, and Stratta R
- Subjects
- Animals, Dogs, Kidney drug effects, Postoperative Complications diagnostic imaging, Renal Circulation, Ultrasonography, Vascular Resistance, Cyclosporine adverse effects, Graft Rejection, Kidney diagnostic imaging, Kidney Transplantation, Kidney Tubular Necrosis, Acute diagnostic imaging
- Abstract
Results of studies on the accuracy of the resistive index as a predictor of acute renal transplant rejection have varied widely. Clinical evaluations are limited by the inability to control the numerous coincidental factors that affect vascular resistance. We performed a controlled study in dogs to isolate the effects of acute tubular necrosis, cyclosporine toxicity, and acute rejection on the resistive index, and to compare them with a population of normal control subjects. By doing so, we hoped to identify the patterns of change in the resistive index over time and possibly explain the wide spectrum of resistive index data reported in the literature. Resistive index, a parameter calculated from relative systolic and diastolic velocity, indicates parenchymal resistance to perfusion. Since an increase in renal length also has been reported useful in predicting rejection, we studied changes in length in each of the isolated conditions. The normal control group (four dogs) had heterotopic autotransplantation with minimal cold ischemic time. The acute tubular necrosis group (six dogs) had heterotopic autotransplantation with 1 hr of warm ischemic time. The cyclosporine toxicity group (four dogs) was allowed approximately 3 months to heal from heterotopic autotransplantation. Very high (toxic) doses of cyclosporine were then administered. The acute rejection group (five dogs) had heterotopic allografting with minimal cold ischemic time. No medications were administered. In all groups, the abnormalities induced were confirmed by biopsy. Creatinine levels were also used to monitor cyclosporine toxicity. In the normal control and acute tubular necrosis groups, resistive index increased immediately after surgery, returning to baseline within 10 days. Renal length increased slightly in both groups, but the duration of increase was longer in the acute tubular necrosis group. No significant change in resistive index or renal length was seen in the cyclosporine toxicity group. In the acute rejection group, an initial decrease in resistive index during the mild to moderate phase was followed by a rapidly progressive increase with worsening rejection. Renal length increased progressively beginning immediately after surgery. Our study determined the patterns of change in resistance and renal length over time as caused by the isolated pathologic states. Our finding that vascular resistance decreased in mild to moderate acute rejection was unexpected, since almost all the literature reports resistive index elevation. This may explain some of the conflicting results obtained in Doppler investigations of rejection. Our results on renal length reinforce the positive clinical reports of its predictive value in rejection.
- Published
- 1992
- Full Text
- View/download PDF
36. Spectral and color Doppler artifacts.
- Author
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Pozniak MA, Zagzebski JA, and Scanlan KA
- Subjects
- Color, Doppler Effect, Humans, Artifacts, Ultrasonography methods
- Abstract
Artifacts in spectral and color Doppler imaging can be confusing and lead to misinterpretation of flow information. The authors review these artifacts by considering three main causes: inappropriate equipment settings, anatomic factors, and physical and technical limitations of the modality. Incorrect gain, wall-filter, or velocity scale settings can cause loss of clinically important information or distortion of the tracing. Reflection of the Doppler signal from highly reflective surfaces can create a color Doppler mirror image. Vascular motion can introduce artifactual variation in velocity as the sample volume passes through different velocities in a laminar flow state. Unintentional motion can cause a generalized Doppler shift. Increasing the angle of Doppler interrogation degrades the quality of the tracing and gives the impression of spectral broadening. As angulation approaches 90 degrees, directional ambiguity can occur, suggesting bidirectional flow. Grating and side lobes can interrogate areas unrelated to the sample volume and introduce extraneous Doppler information to the apparent area of interrogation. Recognition of these artifacts is essential to proper interpretation of Doppler information and rendering a correct diagnosis.
- Published
- 1992
- Full Text
- View/download PDF
37. Hepatofugal arterial signal in the main portal vein: an indicator of intravascular tumor spread.
- Author
-
Pozniak MA and Baus KM
- Subjects
- Adolescent, Carcinoma, Hepatocellular pathology, Humans, Liver Neoplasms pathology, Male, Middle Aged, Neoplastic Cells, Circulating, Portal Vein diagnostic imaging, Ultrasonography, Carcinoma, Hepatocellular diagnostic imaging, Liver Neoplasms diagnostic imaging, Portal Vein pathology
- Abstract
Five patients with thrombosis of the main portal vein underwent Doppler ultrasound (US). Three of these patients had confirmed hepatocellular carcinoma. Doppler US allowed differentiation between bland thrombus and tumor thrombus in two of the three patients. Tumor thrombus of the main portal vein was characterized at US by an intraportal arterial waveform in a hepatofugal direction.
- Published
- 1991
- Full Text
- View/download PDF
38. Renal transplant ultrasound: imaging and Doppler.
- Author
-
Pozniak MA, Kelcz F, and Dodd GD 3rd
- Subjects
- Humans, Kidney Transplantation adverse effects, Postoperative Complications diagnostic imaging, Ultrasonography, Kidney diagnostic imaging, Kidney Transplantation pathology
- Published
- 1991
39. Complications of hepatic arterial infusion chemotherapy.
- Author
-
Pozniak MA, Babel SG, and Trump DL
- Subjects
- Aged, Chemical and Drug Induced Liver Injury diagnostic imaging, Chemical and Drug Induced Liver Injury etiology, Cholangitis, Sclerosing chemically induced, Cholangitis, Sclerosing diagnostic imaging, Female, Floxuridine adverse effects, Floxuridine therapeutic use, Gastrointestinal Diseases chemically induced, Gastrointestinal Diseases diagnostic imaging, Gastrointestinal Diseases etiology, Gastrointestinal Neoplasms pathology, Humans, Liver Abscess diagnostic imaging, Liver Abscess etiology, Liver Neoplasms drug therapy, Liver Neoplasms secondary, Male, Middle Aged, Retrospective Studies, Tomography, X-Ray Computed, Floxuridine administration & dosage, Hepatic Artery, Infusion Pumps, Implantable, Infusions, Intra-Arterial adverse effects
- Abstract
Chemotherapy by direct hepatic arterial infusion (HAI) results in reduction in tumor mass in a large percentage of patients. The authors reviewed records for 45 patients with metastatic cancer of the gastrointestinal tract who underwent HAI chemotherapy with floxuridine, administrated via an implanted pump. Twenty-seven of the 45 patients suffered complications, including gastrointestinal ulceration (18%), hepatitis (24%), sclerosing cholangitis (7%), and abscess (2%). The complication rates in this series were similar to those previously reported. The toxicity of HAI chemotherapy continues to limit its efficacy.
- Published
- 1991
- Full Text
- View/download PDF
40. Pyramidal appearance and resistive index: insensitive and nonspecific sonographic indicators of renal transplant rejection.
- Author
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Kelcz F, Pozniak MA, Pirsch JD, and Oberly TD
- Subjects
- Adult, Creatinine blood, Female, Humans, Male, Predictive Value of Tests, ROC Curve, Graft Rejection, Kidney Medulla pathology, Kidney Transplantation pathology, Ultrasonography methods
- Abstract
Renal transplantation patients undergoing biopsy were examined with duplex Doppler sonography to establish the sensitivity and specificity of this technique in the detection of rejection. The study population consisted of 89 consecutive patients, who received renal transplants 1 week to 17 years before our examination and underwent 96 core needle biopsies within 24 hr of sonography. The resistive index (RI), defined as the difference between the peak systolic and end diastolic flow velocities divided by the peak systolic velocity (expressed as a percentage), was measured in the main, segmental, interlobar, and arcuate renal arteries. Furthermore, the prominence of the renal pyramids, as determined by their size and echogenicity, was prospectively evaluated. Biopsy was used to establish diagnosis, but in cases of equivocal results, hospital course was the final arbiter. The most frequent diagnoses in the patients were acute rejection (41 patients) and chronic rejection (19 patients). Receiver-operating-characteristic curve analysis established that, regardless of the vessel in which it was measured, the use of RI to assign a diagnosis of acute rejection was no better than establishing this in a random manner. We did note, however, that patients with chronic rejection or cyclosporine toxicity were unlikely to have RIs greater than 80%. We further found that prominent pyramids were neither sensitive nor specific in the detection of acute rejection and that prominent pyramids were not correlated with elevated RI.
- Published
- 1990
- Full Text
- View/download PDF
41. Current status of small-bowel ultrasound.
- Author
-
Pozniak MA, Scanlan KA, Yandow D, and Mulligan G
- Subjects
- Humans, Intestinal Neoplasms diagnosis, Intestine, Small pathology, Intestinal Diseases diagnosis, Intestine, Small anatomy & histology, Ultrasonography
- Abstract
Ultrasonography offers direct imaging of the bowel wall and allows dynamic evaluation of peristalsis. It helps to differentiate eosinophilic gastroenteritis from regional enteritis and lymphoma, displays a typical appearance in intussusception and is quite specific in the afferent loop syndrome, closed-loop obstruction and lymphedema. It may be helpful in ischemia of the bowel and in the evaluation of acute appendicitis.
- Published
- 1990
42. Value of transperineal sonography in the assessment of vaginal atresia.
- Author
-
Scanlan KA, Pozniak MA, Fagerholm M, and Shapiro S
- Subjects
- Adolescent, Adult, Child, Female, Humans, Perineum, Ultrasonography methods, Vagina abnormalities
- Abstract
We studied the value of transperineal sonography in the preoperative assessment of seven patients with clinically suspected vaginal atresia. Although transabdominal scanning is useful to determine if hydrocolpos or hydrometrocolpos is present, this method does not allow measurement of the thickness of a caudally placed obstructive septum. This information is useful in planning reconstructive surgery. All seven patients had transabdominal sonography, with five showing a low-lying obstruction. In those five patients, the distance between the perineal surface and the caudal aspect of the distended vagina, measured with electronic calipers on the transperineal sonograms, ranged from 1.0 to 4.0 cm. We conclude that when vaginal atresia is clinically suspected, transabdominal sonography should be performed to confirm the diagnosis. When a low-lying obstruction is identified, transperineal sonography should be performed to determine the length of the obstructive segment.
- Published
- 1990
- Full Text
- View/download PDF
43. Cardiac involvement in metastatic breast cancer.
- Author
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Volk MJ, Carbone PP, Pozniak MA, and Rahko PS
- Subjects
- Adult, Female, Heart Neoplasms drug therapy, Heart Neoplasms epidemiology, Humans, Mitral Valve Stenosis etiology, Neoplasm Invasiveness, Tomography, X-Ray Computed, Breast Neoplasms, Heart Neoplasms secondary, Lung Neoplasms secondary
- Abstract
Metastatic disease is the most common cause of death in breast cancer. Although cardiac involvement has been reported in 12% to 30% of cases, intra-atrial involvement is rare. In this report we describe a 41-year-old woman with metastatic breast cancer whose left atrium was invaded by a metastatic tumor that resulted in intermittent left ventricular in-flow obstruction. Such a presentation has not been described previously in metastatic breast cancer. The pertinent literature is reviewed.
- Published
- 1990
44. Computed tomography with stress maneuver to demonstrate sternoclavicular joint dislocation.
- Author
-
Burnstein MI and Pozniak MA
- Subjects
- Adult, Humans, Joint Instability diagnostic imaging, Male, Movement, Joint Dislocations diagnostic imaging, Sternoclavicular Joint injuries, Tomography, X-Ray Computed methods
- Abstract
Axial CT is the method of choice for radiographic evaluation of sternoclavicular joint dislocation. A technique for demonstrating the degree of mobility at the sternoclavicular joint during CT examination is described. This method allows for the determination of the true magnitude of hypermobility at the dislocated sternoclavicular joint.
- Published
- 1990
- Full Text
- View/download PDF
45. Venous lake bleeding: a complication of chorionic villus sampling.
- Author
-
Pozniak MA, Cullenward MJ, Zickuhr D, and Curet LB
- Subjects
- Adult, Chromosome Disorders, Female, Humans, Maternal Age, Pregnancy, Pregnancy, High-Risk, Chorionic Villi ultrastructure, Chromosome Aberrations diagnosis, Hematoma etiology, Placenta, Prenatal Diagnosis
- Published
- 1988
- Full Text
- View/download PDF
46. Splenic abscess in a previously infarcted spleen.
- Author
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Mehta RC, Wilson MA, and Pozniak MA
- Subjects
- Abscess diagnosis, Humans, Male, Middle Aged, Splenic Diseases diagnosis, Abscess etiology, Splenic Infarction complications
- Published
- 1989
- Full Text
- View/download PDF
47. Clinical efficacy of Kitecko ultrasonic conductor.
- Author
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Pozniak MA, Crass JR, Zagzebski J, Madsen E, and Labinski C
- Subjects
- Humans, Polymers, Ultrasonography instrumentation
- Abstract
A homogeneous synthetic polymer block (Kitecko) was evaluated for ultrasound imaging of small parts, superficial structures, and the pediatric patient. The block is intended to be used as an offset and replaces the traditional way of scanning with water paths, fluid-filled surgical gloves or IV bags. A randomized paired comparison of the Kitecko pad conductor and a water path system (IV bag) was performed. One hundred pediatric and adult patients were scanned using both conductors. The images were encoded and subsequently evaluated for image quality, including artifact, attenuation, resolution, and distortion. A statistical analysis showed significantly higher scores (P less than .01) with the Kitecko substance when compared to water path scanning when evaluating for reverberation artifact, scatter artifact, and spatial resolution.
- Published
- 1989
- Full Text
- View/download PDF
48. A device to aid in ultrasound imaging.
- Author
-
Crass JR, Pozniak MA, Baumann JL, and Feinberg SB
- Subjects
- Humans, Ultrasonography instrumentation
- Published
- 1987
- Full Text
- View/download PDF
49. Extraneous factors affecting resistive index.
- Author
-
Pozniak MA, Kelcz F, Stratta RJ, and Oberley TD
- Subjects
- Animals, Dogs, False Positive Reactions, Humans, Ultrasonics, Vascular Resistance, Graft Rejection, Kidney Transplantation, Renal Artery pathology, Renal Veins pathology, Ultrasonography
- Abstract
Recently, numerous studies have referred to the resistive index as an accurate indicator of acute renal transplant rejection. We encountered several factors other than rejection that resulted in an elevation of the resistive index in both clinical and experimental situations. Any compressive effect on the kidney will elevate the resistive index. This compression may arise from an adjacent mass such as a fluid collection, most commonly hematoma, or even from excessive pressure transmitted via the transducer by a heavy-handed technician. Resistive index elevation also has been demonstrated in experimentally induced hypotension. Technically inaccurate scanning can yield a falsely low resistive index, but these previously mentioned entities can falsely elevate it, leading to an incorrect diagnosis of acute rejection.
- Published
- 1988
- Full Text
- View/download PDF
50. Inflammatory aortic aneurysm (periaortic fibrosis): radiologic imaging.
- Author
-
Cullenward MJ, Scanlan KA, Pozniak MA, and Acher CA
- Subjects
- Aged, Aorta, Abdominal diagnostic imaging, Aortic Aneurysm therapy, Diagnosis, Differential, Female, Humans, Inflammation diagnostic imaging, Male, Middle Aged, Radiography, Ultrasonography, Aortic Aneurysm diagnostic imaging
- Abstract
Inflammatory aneurysms represent a distinct surgical entity with a reported incidence varying from 5% to 23% of all abdominal aortic aneurysms. Surgical repair of inflammatory aneurysms is associated with a higher morbidity and mortality than is repair of simple aortic aneurysms. Complicated cases require suprarenal aortic control, and the surgeon must be forewarned to maximize the chance for successful aneurysm repair. Preoperative diagnosis of this entity by cross-sectional imaging facilitates improved planning of the operative approach and permits the institution of preoperative steroid treatment to reduce the volume of the periaortic fibrotic mass. Ultrasound demonstrates the inflammatory process as a hypoechoic mass surrounding the intensely echogenic, thickened aortic wall. Computed tomography reveals a thickened, often calcified aortic wall and a mass of periaortic inflammatory tissue. Dynamic scanning reveals rapid intraluminal enhancement, slightly delayed enhancement of the inflammatory mass, and nonenhancement of the thick fibrous adventitia.
- Published
- 1986
- Full Text
- View/download PDF
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