Biomedical subjects
M L Skolnick
Publications and source records attributed to M L Skolnick.
Detection of malignant tumors in end-stage cirrhotic livers: efficacy of sonography as a screening technique.
OBJECTIVE: Patients with hepatic cirrhosis are at an increased risk of developing primary malignant tumors of the liver. If these tumors are discovered early, current therapies may be curative. We conducted a prospective study to assess the accuracy of sonographic screening for the detection of malignant tumors in cirrhotic livers as determined by correlation with resected whole livers. SUBJECTS AND METHODS: A total of 200 prospectively interpreted preoperative sonograms from 200 patients with cirrhosis who underwent hepatic transplantation were correlated with specimens of freshly resected whole livers. The results were analyzed to determine the sensitivity and specificity of sonography in identifying patients with malignant tumors and detecting individual tumors in each patient. RESULTS: Pathologic examination showed 80 malignant lesions in 34 patients (28 with hepatocellular carcinoma, three with cholangiocarcinoma, two with metastases, and one with non-Hodgkin's lymphoma) and three hemangiomas in two patients. Sonography correctly showed malignant tumors in 17 of the 34 patients, for a sensitivity of 50%. Sonograms were false-positive for malignant tumors in three patients, two of whom had a total of three hemangiomas. Sonography correctly showed 36 of the 80 malignant lesions, for a lesion sensitivity of 45% and specificity of 98%. Of the 44 missed lesions, 24 were 1 cm or less, 12 were between 1 and 3 cm, and eight were more than 3 cm in diameter. CONCLUSION: Our results show that sonography is highly insensitive in the detection of malignant lesions in end-stage cirrhotic livers and thus is not a reliable screening technique. However, because of sonography's very high specificity, any sonographically identified lesion in a cirrhotic liver should be considered malignant until proved otherwise.
Pneumocystis carinii infection presenting as necrotizing thyroiditis and hypothyroidism.
Extrapulmonary Pneumocystis infection has been increasingly reported in patients with acquired immune deficiency syndrome (AIDS), in particular, recently in association with the increasing use of aerosolized pentamidine. This report describes the unusual presentation of extrapulmonary Pneumocystis infection as a thyroid neck mass and clinical hypothyroidism in a 37-year-old man with hemophilia and AIDS. This case differs from the previously reported single case of isolated thyroid pneumocystosis in the presence of a rapidly enlarging neck mass, lack of previous Pneumocystis, and prior prophylaxis with aerosolized pentamidine. The pathologic and electron microscopic description of the peculiar flocculent necrotic thyroid material is contrasted with typical pulmonary alveolar findings in Pneumocystis pneumonia (PCP), the differential diagnoses of a rapidly expanding neck mass, and diagnostic difficulties of hypothyroidism in patients with AIDS are discussed. Finally, it is emphasized that use of aerosolized pentamidine, although successful for prevention of pulmonary PCP, may be insufficient to prevent extrapulmonary infection.
Primary CT diagnosis of abdominal masses in a PACS environment.
Whether the display medium--film versus cathode ray tube (CRT)--affects observer performance during interpretation of computed tomographic (CT) images is an important research issue in these times of implementation and growth of picture archiving and communications systems in radiology. The authors performed a multiobserver receiver operating characteristic (ROC) study to determine the performance of radiologists who read abdominal CT studies displayed on film, as well as on a high-resolution workstation (video monitor) that made use of three different display modes. A total of 166 examinations were evaluated by eight radiologists, who recorded their ordinal confidence ratings of the demonstration of presence or absence of abdominal masses. ROC analysis showed small differences in the confidence ratings assigned by individual readers for the detection and interpretation tasks. Results for the group as a whole showed no significant reduction or improvement in observer performance when ratings for any one of the workstation display modes were analyzed. The results of this study demonstrate that current CRT display technology is adequate for enabling the primary detection of abdominal masses with CT examinations.
Estimation of ultrasound beam width in the elevation (section thickness) plane.
Ultrasound image resolution depends on beam width in the scan and elevation (section thickness) planes. The effect of the beam width in the elevation plane is usually not measured because calculation of the elevation dimension is tedious. The author describes a phantom technique that easily displays the ultrasound beam profile in the elevation plane and compares it with the beam profile in the scan plane.
The role of ultrasound-guided needle aspiration of breast masses.
Ultrasonically guided aspiration cytology is an accurate and cost-effective method for managing sonographically indeterminate breast masses (masses that do not have all the ultrasonic criteria of simple cysts). Forty-five breast masses were aspirated. Of these, fifteen (33%) were atypical cysts, twenty-one (47%) were benign solid masses, three (7%) were malignant and six (13%) were solid lesions with nondiagnostic aspirate material. Since the tip of the needle is ultrasonically identified within the mass prior to aspiration, the accuracy of tissue sampling is potentially greater than with palpation alone. Lesions over five millimeters in diameter can be reliably sampled for cytology. This method can reduce the number of surgical biopsies performed by distinguishing atypical cysts from benign solid lesions and detecting malignant lesions when small. The simplicity of the technique encourages its use whenever an ultrasound study detects a noncystic mass.
Pseudoaneurysms complicating organ transplantation: roles of CT, duplex sonography, and angiography.
In a retrospective study of proved pseudoaneurysms (PAs) in 15 patients with transplanted organs (11 liver, three kidney, one pancreas), the results of computed tomography (CT), duplex sonography, and angiography were reviewed. Of the 15 cases of PA, eight occurred at the arterial anastomosis and seven were nonanastomotic. Three of the eight anastomotic PAs were caused by infection. Of the seven nonanastomotic PAs, four were caused by percutaneous biopsy, two were caused by infection, and one was of undetermined cause. In nine (60%) of the 15 patients the PAs were incidentally detected at imaging studies performed for other reasons. Diagnosis requires a high degree of suspicion. CT was performed in nine cases and duplex sonography in ten. The diagnosis of PA was made with CT in six (67%) patients and with duplex sonography in five (50%). CT and duplex sonography could not enable diagnosis when the PA was small, when the arterial anastomosis was not included in the field of study, or when enhancement with intravenously administered contract material was suboptimal. Angiography depicted the PAs in all 15 patients. In three liver transplant recipients with gastrointestinal tract bleeding, the causative PAs were detected only with angiography.
Acute allograft rejection in liver transplant recipients: lack of correlation with loss of hepatic artery diastolic flow.
Eighty hepatic artery Doppler ultrasound (US) examinations performed in 49 patients after liver transplantation were retrospectively analyzed to determine if loss of diastolic flow correlated with pathologic evidence of acute allograft rejection. All 80 Doppler examinations were performed within 7 days of hepatic needle biopsy. Forty-three Doppler waveforms from 27 patients showed normal diastolic flow. Seventeen Doppler studies in 17 patients showed complete absence of diastolic flow. Review of biopsy results for each group showed no significant difference in the proportion of acute allograft rejection present (42% for the normal group and 46% for the group lacking diastolic flow). The data from 53 US and biopsy examinations performed 2 days apart in 37 patients confirmed the lack of correlation between absent hepatic artery diastolic blood flow and rejection. The authors conclude that the loss of hepatic artery diastolic flow has no apparent clinical application for the diagnosis of acute hepatic allograft rejection.
Duplex Doppler sonography in the evaluation of adult patients before and after liver transplantation.
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The role of sonography and transhepatic cholangiography in the diagnosis of biliary complications after liver transplantation.
We retrospectively reviewed the results of real-time sonography in 41 patients in whom biliary complications after liver transplantation were documented by percutaneous transhepatic cholangiography. Abnormalities included bile duct stricture (26 cases), occluded internal biliary stent (six cases), common duct redundancy with resultant functional biliary obstruction (three cases), bile leak (three cases), choledocholithiasis (two cases), and an abscess in a cystic duct remnant (one case). Sonography was abnormal in 22 of the 41 cases (sensitivity, 54%). Bile duct dilatation was the positive sonographic finding in 19 (86%) of the 22 abnormal examinations. In the remaining 19 patients, sonography was normal. Sonography is not a reliable test for the early detection of biliary abnormalities after liver transplantation. Percutaneous transhepatic cholangiography should be performed in patients with suspected biliary complications after liver transplantation.
Percutaneous transhepatic cholangiography rather than ultrasound as a screening test for postoperative biliary complications in liver transplant patients.
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Doppler ultrasound as a screen for hepatic artery thrombosis after liver transplantation.
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Hepatic artery thrombosis after liver transplantation: radiologic evaluation.
Hepatic artery thrombosis after liver transplantation is a devastating event requiring emergency retransplantation in most patients. Early clinical signs are often nonspecific. Before duplex sonography (combined real-time and pulsed Doppler) capability was acquired in October 1984, 76% of all transplants in this institution referred for angiography with a clinical suspicion of hepatic artery thrombosis had patent arteries. In an effort to reduce the number of negative angiograms, CT, real-time sonography, and pulsed Doppler have been evaluated as screening examinations to determine which patients need angiography. Of 14 patients with focal inhomogeneity of the liver architecture detected by CT and/or real-time sonography, 12 (86%) had hepatic artery thrombosis, one had slow arterial flow with hepatic necrosis, and one had a biloma with a patent hepatic artery. In 29 patients undergoing duplex sonography of the hepatic artery, six (21%) had absence of a Doppler arterial pulse. All six had abnormal angiograms: Four had thrombosis, one had a significant stenosis, and one had slow flow with biopsy-proven ischemia. Of 23 patients with a Doppler pulse, two had hepatic artery thrombosis at surgery. However, real-time sonography demonstrated focal inhomogeneity in the liver in both cases. Our data demonstrate that pulsed Doppler of the hepatic artery combined with real-time sonography of the liver parenchyma currently is the optimal screening test for selecting patients who require hepatic angiography after liver transplantation. A diagnostic algorithm is provided.
In vivo hepatic volume determination using sonography and computed tomography. Validation and a comparison of the two techniques.
Ultrasonography and computed tomography were used to determine hepatic volume in vivo. The data obtained were compared with the weight and volume of the same livers after surgical removal at the time of orthotopic hepatic transplantation. The relationship between hepatic weight and volume was found to be linear over a 16-fold range of weights and a 19-fold range of volumes. The sonographic results more closely paralleled the results obtained directly. These data demonstrate that both methods can determine, within acceptable limits, hepatic volume or weight. The sonographic technique, however, is more accurate than the computed tomography scan method as it allows the use of sagittal scanning of the liver, which is superior to the transverse scanning technique required by the computed tomography scanner. In addition, these results demonstrate that these methods might be applied in the future for better matching of donors and recipients of orthotopic liver transplants.
Sonography of cholesterol in the biliary system.
The sonographic features of cholesterol within the biliary system are reviewed and a new sign is described. That cholesterol causes high reflecting echoes and may cause shadowing has been known; however, its ability to cause reverberatory artifactual echoes has not been previously appreciated. These sonographic features, while not specific, should favor the diagnosis of cholesterol stones and cholesterol polyps in the appropriate clinical situation.
[Newer abdominal applications of diagnostic ultrasound].
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Ultrasonography of hemorrhagic splenic cysts.
Cysts arising from the spleen are much less common than those arising from other organs such as kidney, liver, and ovary (1). Hemorrhagic cysts of the spleen are rare (1), but we have encountered two patients with this entitiy. The ultrasonograms in each patient demonstrated gravity-dependent layering of two fluids of distinctly different echogenicity. The fluids were contained within a spherical mass. Acoustic enhancement was exhibited behind the mass in each case. This suggested the diagnosis of hemorrhagic cyst.
Atypical pseudocysts of the pancreas: an ultrasonographic evaluation.
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