Biomedical subjects
Publications and source records attributed to E M James.
Insertion of a screw biopsy stylet into a thin-walled biopsy needle greatly enhances detection of the needle during ultrasound-guided percutaneous biopsy. This technique is helpful when precise needle-tip localization is needed for biopsies of small lesions.
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Computed tomography (CT) scans and sonograms of 37 patients with hepatocellular carcinoma (hepatoma) were reviewed to determine the characteristics of the tumour and to compare the modalities in terms of accuracy in defining tumour morphology and ability to predict vascular invasion and extrahepatic spread. By CT, slightly over 50% of the tumours were multicentric, about 40% were solitary, and the rest were diffuse. About half of the hepatomas were heterogeneous in density before injection of contrast agent and most became enhanced in a non-uniform manner. In addition, about a quarter of the tumours either became visible or were better seen after injection of contrast agent. At sonography, approximately two-thirds of the neoplasms were thought to be solitary and one-third multicentric. The majority also had a mixed echo texture. Although the lesion was identified in all 13 patients who had both studies, sonography underestimated the extent of hepatic involvement in 38% of the cases. Sonography also failed to demonstrate lymphadenopathy that was detected by CT in two patients. In general, both techniques were effective in identifying vascular invasion. CT was very accurate in showing the extent of hepatic involvement but was unable to identify direct invasion of neighbouring structures. Because each technique has limitations in the evaluation of hepatoma, we believe that both should be performed if curative resection is being considered.
1. CT and sonography are helpful in distinguishing between an obstructing lesion and hepatocellular disease as the cause of jaundice. 2. CT and sonography can demonstrate the level and extent of an obstructing lesion, and can define its nature if a mass more than 1-2 cm is present; sonography is usually the preferred screening study because of its availability, relatively low cost and lack of radiation hazard. 3. PTC or ERCP is useful in the evaluation of jaundice when sonography and CT are equivocal, fail to provide information necessary to establish proper therapy, or are at variance with the clinical impression of obstructive jaundice; in addition to defining obstructions these techniques can detect atrophy, sequestra, stones, abscesses, fistulas, primary sclerosing cholangitis, etc. 4. PBD offers an expedient alternative to surgical decompression in patients with obstructive jaundice, since most cancers that cause biliary obstruction are not resectable for cure at the time of diagnosis.
The authors reviewed the features on high-frequency (10 MHz), realtime sonograms of parathyroid carcinoma in eight patients to identify characteristics that could preoperatively distinguish malignant from benign lesions. The mean diameter of the eight carcinomas was 2.4 cm. They were typically ovoid or round and had a lobulated contour. The carcinomas were predominantly hypoechoic relative to the adjacent thyroid, but two of the eight contained both hypoechoic and hyperechoic regions, and three contained cystic spaces. Two carcinomas were grossly invasive on ultrasonographic (US) examination, although seven were proved histologically to be invasive. High-resolution US provides a noninvasive means to localize primary and locally recurrent parathyroid carcinomas preoperatively but fails to distinguish carcinomas from large adenomas reliably, except in cases with extensive invasion of adjacent structures.
Twenty-nine patients with surgically proved benign pancreatic insulinoma were studied by preoperative or intraoperative sonography. Twenty-five patients had solitary pancreatic tumors; four had multiple tumors. Six of the patients with solitary insulinomas and one of the patients with multiple insulinomas had undergone previous unsuccessful exploration. Preoperative sonography was performed in 24 patients with solitary insulinomas, and 15 (63%) were localized. Intraoperative sonography was performed in 22 patients with solitary insulinomas, and 19 (86%) were visualized without having been previously located by palpation. Four of these visible solitary tumors (18%) were not detected by palpation at surgery. All the solitary insulinomas were detected with the combination of palpation and intraoperative sonography. In each of the six patients with solitary insulinoma who had undergone previous surgery, the tumor was visible with intraoperative sonography, which also demonstrated nonpalpable insulinomas in two of the four patients with multiple tumors. Preoperative real-time sonography is a sensitive, noninvasive, inexpensive method for localization of insulinoma. Intraoperative high-frequency sonography is a highly sensitive method for the detection of insulinoma. Intraoperative sonography is also valuable to determine the relationship of the insulinoma to pancreatic and bile ducts and thereby facilitate safe enucleation.
High-resolution (10-MHz) ultrasonography produces extremely detailed anatomic images of the testis. The sonographic features most helpful in detecting tumors are mass, bright echogenic foci, and diffuse parenchymal texture change. Of 29 patients with testicular neoplasms, 21 (72%) had one or more masses, 19 (66%) had one or more echogenic foci, and nine (31%) had a diffuse parenchymal texture change. Bright echogenic foci were present in six (86%) of seven testes that had a regressed germ-cell tumor. In an attempt to define the histologic features of bright echogenic foci, we performed needle localization under real-time guidance on four operative specimens. We observed immature bone and cartilage, calcification, tubular atrophy and fibrosis, and focal noncalcific scarring. Discovery of occult testicular neoplasms was common (9/29); four patients were thought to have had "extragonadal" germ-cell tumors before abnormalities were found on the sonograms.
Sixty consecutive postoperative patients with recurrent or persistent hyperparathyroidism were scanned before reoperation using high-frequency (10 MHz) real-time sonography. The sonograms were interpreted prospectively, and the results correlated with subsequent surgical findings to determine the diagnostic accuracy of this technique in the localization of enlarged parathyroid glands. A total of 59 abnormal glands were found in 51 patients at operation: 45 in the neck and 14 in the mediastinum. Sonography identified 37 of the 45 cervical glands for a sensitivity of 82% in the neck. The mediastinum cannot be evaluated by sonography due to the bony thoracic cage, although if the mediastinal glands are included, the overall sensitivity was 63%. In the 14 patients with negative neck explorations but positive mediastinal explorations, sonography was negative in 12 patients, but false-positives were suspected in two patients, yielding a specificity of 86% in the neck. High-frequency sonography is a sensitive, rapid, and noninvasive technique for localizing enlarged cervical parathyroid glands in patients with recurrent or persistent hyperparathyroidism.
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Familial benign hypercalcemia, or familial hypocalciuric hypercalcemia (FHH), is frequently confused with primary hyperparathyroidism, but the consistent failure of subtotal parathyroidectomy to normalize serum calcium levels in FHH makes accurate distinction from familial hyperparathyroidism imperative. Because ultrasonography frequently demonstrates enlargement of the parathyroid glands in hyperparathyroidism, we examined 14 hypercalcemic adults (who had not undergone operation) from seven kindreds with FHH by using a high-resolution real-time scanner. We compared our results with those from 156 patients (who had undergone scanning preoperatively) with surgically confirmed hyperparathyroidism. Enlargement of the parathyroid glands was detected ultrasonographically in 137 of 156 (88%) of the total group of patients with hyperparathyroidism and in 17 of 24 patients (71%) with hyperparathyroidism who had hypercalcemia (serum calcium, 10.6 to 11.0 mg/dl) comparable to that of the FHH group (mean value, 10.7 mg/dl). In contrast, the single possible parathyroid lesion seen in the FHH group was substantially smaller (4 mm) than the smallest (7 mm, 75 mg) abnormal gland reliably detected by ultrasonography in the group with hyperparathyroidism and was conceivably normal in size. Patients with FHH have a dramatic absence of ultrasonographic parathyroid enlargement. High-resolution parathyroid ultrasonography may be of ancillary diagnostic benefit in patients with familial hypercalcemia.
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The sonographic findings of 125 renal masses that did not meet the sonographic criteria of benign simple cyst were retrospectively reviewed and correlated with the pathologic diagnosis. Of the 125 masses, 102 were renal cell carcinoma. These carcinomas, two of nine angiomyolipomas, and the 14 other renal masses of various histologic types exhibited a broad spectrum of sonographic findings. Seven of nine angiomyolipomas and the one multiloculated cystic nephroma had a rather characteristic sonographic appearance. With the knowledge of this spectrum of sonographic findings and strict attention to scanning techniques and sonographic criteria, the radiologist should be able to define the characteristics of a variety of renal masses and suggest the correct diagnosis. It should be possible to make the diagnosis of angiomyolipoma confidently if the characteristic sonographic and computed tomographic appearance of these tumors can be demonstrated. In some cases, the correct histologic diagnosis of a renal mass can be made only with biopsy or surgery.
Intraoperative localization of pancreatic insulinomas in four patients using a commercially available real-time scanner is described. Four tumors that were suspected preoperatively were confirmed and another that had not been suspected was identified.
We present a case of persistent hyperparathyroidism in which high-resolution real-time ultrasonography was used to perform a percutaneous needle biopsy of a parathyroid tumor. Additionally, intraoperative ultrasonography was valuable in the precise localization of the tumor and thereby reduced the need for extensive surgical reexploration.
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Small-part, real-time ultrasonography using a high-resolution real-time ultrasound scanner was evaluated in 100 consecutive patients undergoing cervical exploration for primary hyperparathyroidism. The radiologic accuracy was 76%. This accuracy was related directly to the weight of the resected gland(s). The surgical success rate with ultrasonography was 96%, whereas the rate without ultrasonography was 97%. Operating time was not appreciably decreased. The exact role of this new modality in the management of primary hyperparathyroidism is as yet unclear.
One hundren patients underwent high-resolution dynamic ultrasound imaging of the carotid bifurcation immediately before cerebral angiography. The examinations were interpreted independently. A positive ultrasound interpretation indicated the presence of moderate to extensive atheromatous plaque, while a negative interpretation indicated normal vessels or minimal atheromatous disease. Ten percent of the ultrasound examinations were technically unsatisfactory. Of the remaining studies, there was satisfactory correlation between ultrasound and angiography in approximately 85% and disagreement in 15%. The majority of ultrasound errors were "false positive" (although these probably represent false-negative angiograms). Although atheromatous disease was accurately detected by ultrasound, stenosis, ulceration, intraluminal thrombus, and vessel occlusion were not reliably identified.