Edward Buonocore

Differentiating benign from malignant lung lesions using quantitative parameters of FDG PET images

UNLABELLED Fluorine-18 labeled deoxyglucose positron-emission tomography (FDG-PET) applications in oncology include the differential diagnosis of chest masses and single pulmonary nodules. However, FDG is not tumor-specific; rather, it also accumulates in inflammatory processes. This study was performed to identify image parameters that would improve the specificity of PET. METHODS Twenty-six patients who had benign and malignant lung lesions were examined retrospectively. Positron-emission tomography data were acquired in dynamic scanning mode after intravenous bolus of 250-402 MBq of FDG. Standardized uptake values (SUVs) were calculated and Patlak analyses were performed in selected regions of interest in the PET images. Positron-emission tomography results were related to histological diagnosis (N = 49) or clinical follow-up (N = 3). RESULTS The specificity and sensitivity of the original PET scan reports, which was based on visual image interpretation and loosely applied SUVs, was 100% and 73%, respectively. Using the SUVs with a cut-off value of 3.8 and Kpat value with a cut-off at 0.025 min-1 improved the specificity to 81% and 85%. CONCLUSION FDG-PET image interpretation can be facilitated by using SUV information or the accumulation rate of the radiotracer (Patlak). With additional validation, this method could have a significant cost-effective impact on the medical/surgical management of chest masses.

Evaluation of Renal Homotransplantation by Selective Angiography

Management of the patient after renal homotransplantation is often complicated and frequently requires answers to problems not previously encountered. Oliguria is the most common diagnostic question in the early postoperative period. In cadaver renal transplants oliguria may be the result of acute renal failure secondary to ischemia (1), vascular thrombosis, ureteral perforation and slough, or the rejection phenomenon. The ideal management of each of these entities requires early and accurate diagnosis. In an effort to distinguish between these complications, angiography was performed on 20 patients who received renal homotransplantations from living or from cadaver donors at the Cleveland Clinic Hospital, Cleveland, Ohio, since August 1963. Angiograms were obtained primarily to evaluate persistent anuria or oliguria in cadaver transplants, or oliguria after initial diuresis in live donor transplants. Materials and Methods Angiograms were obtained of 20 renal homografts, 15 of which were kidneys from cada...

Selective Arteriography as a Localizing and Provocative Test in the Diagnosis of Pheochromocytoma

The diagnosis of pheochromocytoma is suspected in patients with paroxysmal or sustained hypertension associated with symptoms of headache, excessive perspiration, and palpitation (1). Many patients have nonspecific symptoms, however, and additional diagnostic evidence is sought from chemical, pharmacologic, or radiologic studies. Standard roentgen examinations, e.g., urography or laminagraphy, have not been sufficiently accurate for the diagnosis and localization of pheochromocytoma (2–4). The specialized radiographic technics such as retroperitoneal gas insufflation and arteriography may provide direct visualization of the tumor, but they carry a risk and have been associated with fatalities. Air embolism may be a complication of retroperitoneal gas insufflation. Death after aortography undertaken in patients with pheochromocytoma was reported by Saltz and his associates (6), and by Koonce, Pollock, and Glassy (7). In the two cases, the blood pressure was elevated after aortography, and vasomotor collaps...

Positron-emission computed tomography of the pancreas: a preliminary study.

Twenty-seven patients with suspected pancreatic disease were examined with emission computed tomography (ECT) with 11C-labeled amino acids. Of 24 patients with known clinical outcome, there were 1 false positive and 2 false negative results. One finding of interest was the increased concentration of radiopharmaceutical that accurately delineated the presence and extent of 4 pancreatic carcinomas and 1 lymphoma. In the normal subjects ECT reliably identified the pancreas. Disadvantages of ECT include the need for a cyclotron and high-quality hot chemistry laboratory, and the relatively long scanning time. The advantage of ECT is that it offers a unique opportunity to image biologic activity of the pancreas.

Contractions of the Renal Arteries During Arteriography

Interest in renal artery disease as a cause of hypertension has resulted in the frequent use of renal arteriography in the evaluation of the hypertensive patient. Although various pathologic lesions of the renal artery have been described, the occurrence of its functional narrowing has not been generally recognized. In many instances, these contractions closely resemble fixed renal artery disease. The occurrence of contractions in various arteries has been described previously. Theander (16) reported four instances of long segments of undulating contractions observed during arteriography of the lower extremities. These he termed “stationary arterial waves.” In three of the patients arterial obstruction was distal to the waves, and in one there was an obscure vascular disease. Amplatz (2) presented a similar example of a long segment of contractions in the internal carotid artery of a patient who had occlusion of the homolateral and middle cerebral artery. Other authors (5, 6, 11, 19) have also demonstrate...

Pulmonary embolism: how V/Q scanning helps in diagnosis

Ventilation-perfusion (V/Q) scanning is a useful predictor of pulmonary embolism. However, chest films and arterial blood gas studies are essential for proper interpretation of V/Q studies. The combination of clear, rapid reporting and good clinical judgment leads to improved management of patients in whom pulmonary embolism is suspected and avoids severe, life-threatening consequences.

Double and triple contrast technics in examination of the upper gastrointestinal tract in problem cases

SummaryFifty-two patients with suggestive but inconclusive abnormalities on standard roentgenographic examinations and/or clinical suspicion of gastrointestinal disease were examined using barium spray. Pneumoperitoneum was induced in 19 of these patients. Double- and triple-contrast views of the gastrointestinal mucosa and gastric wall were produced. The evaluation of distensibility and the measurement of gastric-wall thickness improved the diagnostic accuracy in these patients. Thirty-two patients were considered normal despite suspicious clinical or roentgenographic findings. In 1 patient, a gastric ulcer escaped detection. In 19 patients, the barium spray and pneumoperitoneum confirmed that a lesion was present. Triple-contrast views of the gastric wall revealed infiltrating malignancies from primary and metastatic tumors that were not appreciated by standard roentgenographic studies.