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Biomedical subjects

E K Fishman

Publications and source records attributed to E K Fishman.

At least 217 records · Page 12Linked to original sources

Spiral CT arterial portography of the liver.

The enhancement characteristics of the liver, aorta, and hepatic vein were evaluated during computed tomography with arterial portography (CTAP) performed with spiral technique in 10 patients. The attenuation of the liver was nearly constant over the scanning interval (average attenuation, 168 HU +/- 16). The attenuation of the aorta increased by an average of 54 HU +/- 31, and the average attenuation of the hepatic vein was 250 HU +/- 34. These data indicate that high levels of liver parenchymal and vascular enhancement can be reliably obtained with CTAP performed with spiral technique.

Adult↗

Detection of focal hepatic lesions with spiral CT: comparison of 4- and 8-mm interscan spacing.

OBJECTIVE: The objective of this study was to determine if spiral CT with 4-mm interscan spacing results in increased confidence in or rate of detection of focal hepatic lesions when compared with spiral CT with 8-mm interscan spacing. MATERIALS AND METHODS: Spiral CT scans of the liver of 42 consecutive patients with suspected hepatic disease were independently reviewed by three senior radiologists in two sets: one set was reconstructed with 8-mm interscan spacing and one set was reconstructed with 4-mm interscan spacing. The slice thickness was 8 mm for both data sets. The number and sizes of focal hepatic lesions were documented. RESULTS: Thirty-three of the 42 patients had least one focal lesion. The lesion size varied from 2 mm to 21 cm. When 8-mm interscan spacing was used, 297 lesions were detected (212 were considered definite). When 4-mm interscan spacing was used, 318 lesions were detected (258 were considered definite). Therefore, 7% more lesions were detected with 4-mm interscan spacing than with 8-mm interscan spacing (p = .05), and 22% more were diagnosed definitively (p < .01). If lesions larger than 4 cm are excluded, 10% more lesions were detected with 4-mm interscan spacing, and 33% more were diagnosed definitively. Of the lesions detected exclusively with 4-mm interscan spacing, 69% were less than 1.0 cm in diameter. CONCLUSION: Spiral CT with smaller interscan spacing (4 instead of 8 mm) results in increased confidence in and rate of detection of focal liver lesions. The additional benefit is most significant with smaller lesions.

Adult↗

Spiral CT of the liver.

The usefulness of CT in the detection and characterization of hepatic disease is well established. Requirements for high-quality examinations include rapid bolus infusion of iodinated contrast materials, rapid acquisition of axial images, and minimal respiratory motion in the patient. These requirements are satisfied in spiral or helical CT. Spiral CT is the latest advance in rapid scanning techniques. In the spiral scan mode, image acquisition is continuous, as patients are advanced at a constant rate through the CT gantry. This eliminates the interscan delay and the gap between scan slices. Because the scan can be completed within a single breath-hold, respiratory misregistration of adjacent scan slices is eliminated. These factors also contribute to high-quality multidimensional displays (e.g., coronal and sagittal views). In this pictorial essay, we illustrate the advantages and applications of spiral CT scanning for imaging the liver.

Humans↗

Preoperative determination of the resectability of hepatic tumors: efficacy of CT during arterial portography.

OBJECTIVE: A multiinstitutional study was performed to evaluate the efficacy of CT during arterial portography for determining the resectability of hepatic tumors. The impact of findings from CT during arterial portography on patients' treatment (i.e., surgical vs nonsurgical) was assessed. In patients considered to have resectable tumors, the accuracy of CT during arterial portography for predicting surgical findings was also evaluated. MATERIALS AND METHODS: A retrospective study was done of 404 patients from three institutions who had CT during arterial portography during the period 1985-1991 as part of preoperative staging to determine the resectability of hepatic tumors. The tumors included metastases from colorectal carcinoma in 197 patients (49%); other hepatic metastases, mostly from adenocarcinoma of the stomach, pancreas, and biliary tree in 123 (30%); and primary hepatocellular carcinoma in 84 (21%). Imaging results were correlated with results of percutaneous biopsy of at least one hepatic lesion in patients whose tumors were considered unresectable. In patients whose tumors were considered resectable, results were correlated with preoperative percutaneous biopsy (obtained in almost all cases) and pathologic examination of a surgical specimen (all cases). Although each case was considered individually, four criteria were used for resectability: (1) accessibility of all lesions to lobar or wedge resection that would yield clear margins, (2) anticipation that residual liver tissue after resection would provide sufficient function, (3) the absence of invasion of central hepatic vascular or biliary structures, and (4) the absence of extrahepatic disease. No specific restriction was made with respect to the number of hepatic lesions present. The accuracy of findings by CT during arterial portography for predicting resectability was assessed in the 146 patients who had tumors that were considered resectable on the basis of imaging findings and had surgery. RESULTS: Of 404 patients, only 146 (36%) were thought to be candidates for resection on the basis of findings from CT during arterial portography. Of these, 122 (84%) actually had resection. The 24 patients who did not have resection included 22 patients with disease understaged or overstaged by CT during arterial portography, one with true-negative findings by CT during arterial portography, and one who died during surgery. The accuracy of findings by CT during arterial portography for predicting results at surgery was 85% for all patients and 91% for the subset of patients who had primary colorectal tumors with hepatic metastases. CONCLUSION: Our experience shows that CT during arterial portography is a useful procedure for assessing the resectability of hepatic tumors. In our study, 64% of patients were spared unnecessary surgery.(ABSTRACT TRUNCATED AT 400 WORDS)

Carcinoma↗

Spiral CT of the abdomen: clinical applications.

Spiral CT is a technique for rapid scan acquisition. It involves continuous scanning as the patient is advanced at a constant rate through the CT gantry. This eliminates interscan delay and the gap between scan slices. The acquired scan is a volume dataset, resulting in improved multidimensional displays. The entire abdomen is scanned within approximately 30 s, so that optimal contrast dynamics for evaluation of the vasculature are easily obtained. High levels of parenchymal enhancement are readily achieved throughout the duration of the scan. These factors also contribute to the improved quality of the multidimensional displays. In this article, applications and clinical experience with spiral CT in the abdomen are reviewed.

Female↗

CT evaluation of breast cancer: spectrum of disease.

Breast cancer is the second most common cancer in women. Although computed tomography is not typically used as a primary diagnostic modality for detection of a breast mass, it is playing an increasing role in the accurate staging of breast cancer as well as in determining patterns or recurrence. This article reviews the role of CT in the evaluation of breast cancer with specific emphasis on the varying patterns of disease recurrence. Specific emphasis is placed on complications and recurrences in the chest, axilla, the abdomen (including involvement of the major abdominal organs), as well as the musculoskeletal system. Specific case examples illustrating the various pathologic processes involving patients with breast cancer are presented.

Breast Neoplasms↗

Computed tomography appearance of bone metastases of leiomyosarcoma.

Bone lesions in leiomyosarcoma are uncommon. When encountered, they are usually a late manifestation of disease seen in the setting of widespread systemic metastases. We present five cases of metastatic leiomyosarcoma, including one in which a bone lesion predated detection of a primary gastric leiomyosarcoma and one in which bone metastases signaled disease recurrence. Computed tomography in 14 of 16 osseous leiomyosarcomas demonstrated a lytic, non-expansile pattern.

Adult↗

Eosinophilic granuloma simulating an aggressive rib neoplasm: CT evaluation.

Eosinophilic granuloma of bone can pose difficulties in diagnosis. We report a case of eosinophilic granuloma of rib origin in a child presenting with an enlarging chest mass whose appearance on computed tomography suggested Ewing sarcoma. Eosinophilic granuloma should be included in the differential diagnosis of an aggressive rib mass on CT in the pediatric patient.

Bone Neoplasms↗

Three-dimensional display of hepatic venous anatomy generated from spiral computed tomography data: preliminary results.

A new method is presented for generating three-dimensional images of the hepatic venous anatomy from helical computed tomography (CT) scans using volumetric rendering. The helical CT scans were obtained using peripheral injection of intravenous contrast via a power injector. Five patients with suspected liver tumors were studied from which one sample case was selected for illustration. Surgical planning of hepatic resection from three-dimensional images will soon become a practical part of patient care.

Adult↗

Sequential chemotherapy and immunotherapy for the treatment of metastatic melanoma.

Interferon (IFN) has numerous biological properties, and more recently a new role for interferon has emerged, as a modulator of cytotoxic chemotherapeutic agents. This is based upon preclinical data that demonstrate additive and/or synergistic effects of IFN with a number of anticancer drugs including cisplatin against human cancer cell lines. Therefore, we evaluated the outpatient use of recombinant alpha 2a-interferon, 3-15 MU/m2 given on 3 consecutive days, subcutaneously, followed by intravenously administered cisplatin, 25-60 mg/m2, every 21 days. In this phase I clinical study, 23 patients with advanced malignant melanoma were treated. Dose-limiting toxicities included decline in performance status, fatigue, and anorexia. No synergistic or unpredictable toxicities were seen. Of the 20 patients who completed two cycles of therapy, there were three partial responses, for an overall response rate of 15%. Interestingly, responses occurred at the intermediate dose levels.

Adult↗

Examination of the pathologic anatomy of ankle fractures.

A prospective study of the translational and rotational displacement of the lateral malleolus in ankle fractures was carried out utilizing roentgenographic techniques. Twenty-six ankle fractures in 25 patients were studied using both routine plain films and CT scanning with two- and three-dimensional multiplanar reconstruction. Eighty-one percent were Lauge-Hansen supination-external rotation type injuries. Overall, 21 fractures did not involve the medial malleolus. Initial talar shift was less than or equal to 2 mm in 15 fractures. Although all patients exhibited external rotation deformities of the lateral malleolus on plain films, only one fracture was found to possess any degree of external rotation relative to the talus. The proximal fibula was seen on CT scans to have increased internal rotation with respect to the tibia in 19 cases. One patient had a slightly externally rotated proximal fibula; the remainder appeared normally aligned. The displacements measured by the CT scans at the talofibular articulation were compared with the standard plain film measurements. The displacements at the distal lateral malleolus were consistently overestimated by the plain roentgenograms, presumably because the capsular and ligamentous attachments to the distal fibula limit malleolar displacement. The talocrural angle, determined on both plain films and CT scans, was also not found to be a sensitive measure of fibular shortening nor of the severity of the fracture. The results of this study suggest that, in an isolated lateral malleolar ankle fracture, the apparent external rotation of the fracture fragment is relative only to the proximal fibula and is not associated with derangement of the talofibular articulation. Based on these mechanical considerations, surgical intervention for such fractures may not be necessary. This hypothesis is consistent with previous long-term clinical studies.

Adolescent↗

Nephrotoxicity of high-osmolality versus low-osmolality contrast media: randomized clinical trial.

The comparative frequency of and risk factors for nephrotoxicity with low-osmolality contrast medium (LOM) versus high-osmolality contrast medium (HOM) were investigated. A randomized, double-blind clinical trial was conducted in patients undergoing diagnostic angiocardiography (n = 430) or contrast material-enhanced body computed tomography (CT) (n = 499). Nephrotoxicity was defined as an increase in serum creatinine level that was greater than both 33% and 0.4 mg/dL (40 mumols/L) above the baseline level within 48 hours after the radiologic procedure. The frequency of nephrotoxicity was similar in patients who received LOM versus those who received HOM: 13 of 479 (2.7%) versus 13 of 450 (2.9%), respectively (P = .87), overall; 4.4% versus 4.0% in angiocardiography patients (P = .84); and 1.2% versus 2.0% in body CT patients (P = .35). Factors associated (P less than .05) with increased risk of nephrotoxicity were insulin-dependent diabetes, baseline serum creatinine level greater than 1.5 mg/dL (130 mumols/L), concurrent use of furosemide, and angiocardiographic examination. Patients who have preexisting renal insufficiency may be at higher risk for nephrotoxicity with HOM than with LOM.

Angiocardiography↗

Comparison of helical and serial CT with regard to three-dimensional imaging of musculoskeletal anatomy.

To test the hypothesis that helical computed tomographic (CT) scans provide three-dimensional images as good as or better than those provided by serial CT, two objects were used to study the effects of helical CT: an angled cylindrical bone phantom and a human cadaveric femur specimen with a simulated fracture 1 mm wide. Both objects were immersed in a water bath, and a series of helical and serial CT scans were obtained with various parameters. Volumetric rendering was applied to the resultant data sets to create three-dimensional images, which three radiologists reviewed in a blinded manner to rate their fidelity, accuracy, and diagnostic usefulness. As expected, the images obtained with thin collimation and small intersection spacing or slow table movement were considered superior. Helical and serial CT data acquired with similar parameters were similar in quality, but helical CT is approximately five times faster than serial CT; hence, it is possible to use thinner collimation and obtain more sectional data with helical CT.

Femur↗

Hepatic masses in infants and children: CT evaluation.

Hepatic masses are uncommon in children. Although some lesions may have overlapping appearances on CT, a careful analysis of the CT characteristics of the lesion, in combination with the age of the patient and the clinical and laboratory data, can lead to a specific diagnosis in many cases [1-5]. In this pictorial essay, the spectrum of hepatic masses in children is reviewed, with emphasis on the key CT findings that help in differentiating the various lesions.

Adolescent↗