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D H Stephens

Publications and source records attributed to D H Stephens.

89 records · Page 5Linked to original sources
PubMed1976

Initial clinical experience with computerized tomography of the body.

Computerized tomography of the body, now possible with an instrument that can complete a scan rapidly enough to permit patients to suspend respiration, adds an important new dimension to radiologic diagnosis. Cross-sectional antomy is uniquely reconstructed to provide accurate diagnostic information for various disorders throughout the body.

Ascites↗
PubMed1975

Computed tomography of liver specimens.

Fourteen liver specimens were studied by computed tomography with pathological correlation to evaluate the possible application of this technique to the diagnosis of hepatic lesions. Lesions were clearly demonstrated in 9 of 10 abnormal specimens, but differentiation among hepatomas, metastases, and cysts was not possible in vitro.

Autopsy↗
PubMed1975

Retrograde pancreatography in autopsy specimens.

Sixty-two pancreases were dissected at autopsy. In 55 of them, the pancreatic ducts were filled with 50 per cent Hypaqje and roentgenograms were made prior to dissection. Clinical information (available in every case) was correlated with the gross and microscopic findings and findings on the pancreatograms. The anatomically and functionally predominant duct was considered the "main pancreatic duct" regardless of its embryologic development. The common bile and main pancreatic duct opened independently into the duodenum in 8 of the 62 cases (13 per cent). The accessory pancreatic duct had a patent orifice into the duodenum in 12 of 57 cases (21 per cent). The ampulla of Vater was well developed in only 4 of the 62 cases (6 per cent), but an ampullary dilatation was present twice as often at the end of the acessory pancreatic duct, in both those that ended blindly and those that opened into the duodenum. The orifices for the accessory duct were often tiny pinhole openings. There were 2 primary carcinomas of the pancreas, one in the head and one in the tail. The pancreatic duct was almost completely obstructed in each case. Both tumors were undifferentiated adenocarcinomas, and extravasation occurred into each one of them. Extravasation also occurred into a necrotic lymphoma involving the tail of the pancreas, and into two areas of abscess formation in another case. Diffuse, dense, fluffy opacification of pancreatic parenchyma, due to alteration in cell membrane permeability, was demonstrated in acute pancreatitis, infarction, autolysis, and overfilling of the ducts by vigorous injection. Three pancreases showed microscopic changes of chronic pancreatitis. The pancreatogram on one was normal, but the microscopic changes were minimal, and pancreatitis was not suspected clinically. The other 2 cases were symptomatic, and their pancreatograms showed strictures and irregularities of the main pancreatic duct as well as saccular ectasia was present in three additional pancreases, two of which showed squamous metaplasia of ductal epithelium without other microscopic stigmata of chronic pancreatitis and no clinical features to suggest pancreatitis. The possibilities exist that ectasia of secondary ducts and squamous metaplasia of ductal epithelium are manifestations of low-grade injury and that "subclinical pancreatitis" may be common in the general population.

Adult↗
PubMed1975

Intraluminal duodenal diverticulum. Report of two cases and review of the literature.

Diverticula rarely occur within the lumen of the duodenum. They arise near the papilla of Vater and extend distally. The diverticulum is lined on both sides with duodenal mucosa, and its eccentric opening is usually proximal in the sac. The diverticulum results from incomplete recanalization of the intestinal lumen after the proliferative epithelial stage in the 7-week embryo and represents either a remnant of one of two channels formed during recanalization or a distal ballooning of a congenital duodenal diaphragm. Although the patient with a diverticulum may be asymptomatic, most patients present with abdominal pain and obstructive symptoms; pancreatitis and gastrointestinal bleeding may be associated with the diverticulum. Barium study shows a characteristic radiolucent halo that represents the wall of the diverticulum. Surgery should be approached with caution because injury to the papilla is a hazard, and in children, coexisting congenital anomalies may be present.

Adult↗
PubMedDate not supplied

CT of pancreatic neoplasms. Part II: The unusual tumors.

The pancreas gives rise to a remarkable variety of neoplasms other than ductal adenocarcinoma. Although no individual type of tumor in this category is prevalent enough to qualify as common, most types are currently encountered with a frequency far greater than that in decades of the recent past. This change is largely the result of the expanded use of contemporary abdominal imaging. The unusual tumors of the pancreas vary greatly in their biologic behavior and, accordingly, in their clinical consequences and therapeutic requirements. Accurate diagnosis, therefore, can be of considerable clinical relevance. Not only is it worthwhile to distinguish one type of unusual pancreatic tumors from another, it is perhaps of even greater consequence to distinguish the unusual tumors from ordinary pancreatic adenocarcinomas. The goals of this discussion are to expand radiologic awareness of these uncommon but interesting pancreatic neoplasms and to increase familiarity with their diagnostically salient features.

Adenoma, Islet Cell↗
PubMedDate not supplied

MRI of pancreatic islet cell carcinoma.

OBJECTIVE: The purpose of this study is to report the spectrum of MR findings of pancreatic islet cell carcinoma. MATERIALS AND METHODS: The MR scans of 33 patients with islet cell carcinoma were retrospectively reviewed. Magnetic resonance detected the primary tumor in 21 of 27 patients (78%) who had not had prior resection of their primary tumor. Mean tumor diameter was 7.1 cm (range 3.5-13.0 cm). RESULTS: In all patients, the primary tumor on T1-weighted images (TR/TE = 250/15) was of signal intensity equal to or lower than that of the adjacent normal pancreas. The primary tumor on T2-weighted images (TR/TE = 2,000/> or = 100) was of signal intensity the same as or higher than fat in 18 of 21 patients (86%) and had mixed signal intensity in the other 3 (14%). Hepatic metastases were found in 28 of 33 patients (85%). Liver metastases were categorized as "usual" (variably circumscribed, homogeneous lesions of medium signal intensity on T2-weighted images) in 19 of 28 patients (68%), necrotic in 8 of 28 (29%), hemorrhagic in 3 of 28 (11%), and calcified in 1 of 28 (4%). Extrahepatic metastases were found in 18 of 33 patients (55%). CONCLUSION: We conclude that MRI is an excellent modality for the diagnosis and routine follow-up of patients with islet cell carcinoma.

Adenoma, Islet Cell↗
PubMedDate not supplied

Mosaic pattern of hepatocellular carcinoma: histologic basis for a characteristic CT appearance.

PURPOSE: The mosaic pattern is a characteristic CT appearance for hepatocellular carcinoma (HCC). This study was designed to assess the tissue composition responsible for the CT mosaic pattern. METHOD: Gross and whole-mount histologic sections of 10 HCC tumors from eight patients were prepared at identical levels as preoperative CT sections. CT features of the mosaic tumor pattern were spatially registered with the corresponding pathologic sections. RESULTS: CT of mosaic HCC demonstrated enhancing nodules (9/10), low attenuation areas (9/10), and internal septa (3/10). Spatial registration of CT and microscopic sections showed that enhancing tissue was viable tumor in nine of nine. Low attenuation areas were either necrotic (4/9) or of mixed tissue (5/9), including areas of necrosis, fibrosis, and hemorrhage. CONCLUSION: The variable tissue composition of HCC accounts for the mosaic CT pattern. In most patients, enhancing nodules indicate viable tumor cells, and low attenuation areas represent necrosis, fibrosis, or hemorrhage.

Aged↗
PubMedDate not supplied

CT characteristics of metastatic disease of the pancreas.

Contrast material-enhanced computed tomographic (CT) scans obtained over a 10-year period in 66 patients with metastases to the pancreas were retrospectively reviewed. The primary tumors most commonly responsible for these metastases were renal cell carcinoma (30.3%) and bronchogenic carcinoma (22.7%). Metastases showed no predilection for any particular part of the pancreas. The majority (75.8%) of metastases appeared as tumors with discrete margins, and most of these tumors were round or ovoid with smooth borders. Over three-fourths of the lesions demonstrated enhancement (usually heterogeneous). Vascular involvement was uncommon. In those patients in whom pancreatic metastases were discovered some time after the primary tumor was identified, the interval ranged from 2 to 295 months, with the longest mean interval (120.2 months) being associated with metastatic tumors from renal cell carcinoma. The appearance of these tumors at CT--predominantly hyperattenuating masses, often with nonenhancing internal components--was similar to that of primary renal cell carcinoma. In most pancreatic metastases, however, clinical information in conjunction with CT characteristics such as multiplicity of tumors or hypervascularity permit differentiation of metastases from primary neoplasm. When diagnosis of a pancreatic neoplasm is uncertain, percutaneous biopsy often permits histologic confirmation of the tumor type.

Adolescent↗
PubMedDate not supplied

Celiac plexus block. Retrocrural computed tomographic anatomy in patients with and without pancreatic cancer.

BACKGROUND AND OBJECTIVES: Neurolytic celiac plexus block is often performed for analgesia from pancreatic cancer, but it is not known if the cancer alters the anatomy relevant to the successful performance of retrocrural celiac plexus block. METHODS: Abdominal computed tomographic scans were used to simulate retrocrural celiac plexus block in patients with and without pancreatic cancer. RESULTS: Simulated right-sided needle placement in the retrocrural space was more likely to fail in patients with pancreatic cancer than in patients without cancer. Such predicted failure often occurred when the cross-sectional area of the right retrocrural space was less than 1.0 cm2. CONCLUSIONS: The predicted success of stimulated retrocrural celiac plexus block differed between patients with and without pancreatic cancer. These findings have implications for the performance of celiac plexus block.

Adult↗
PubMedDate not supplied

CT of pancreatic neoplasms. Part I: Adenocarcinoma.

Adenocarcinoma of the pancreas has been one of the most formidable, diseases of the past half century, consistently ranking among the leading causes of death from cancer in the industrialized world. The profound diagnostic difficulties that characterized this neoplasm during the early decades of that era have largely given way to radiologic advances of recent decades. Daunting therapeutic challenges persist, however, as few individuals in whom this common form of pancreatic cancer develops are aware of their illness before the disease has advanced beyond the stage of curability. The benefits of recent diagnostic break-throughs in pancreatic adenocarcinoma are nonetheless immense. Although their proportion remains disappointingly small, an increasing number of persons owe their lives to the detection of pancreatic carcinoma at a stage amenable to complete surgical resection. Far more patients benefit from timely detection, accurate staging, and nonsurgical biopsy of an unresectable neoplasm. Still more, perhaps, benefit from the confident exclusion of pancreatic cancer as a source of worrisome symptoms. The goal of this discussion is to help the radiologist achieve full diagnostic potential in examining patients who have, or who are suspected to have, adenocarcinoma of the pancreas. As the leading method in the diagnostic advance on pancreatic cancer, computed tomography (CT) is given predominant attention. The principles of diagnostic interpretation, however, are based on an understanding of the neoplasm itself. In that respect, the manifestations of pancreatic adenocarcinoma as displayed by CT are in large measure just as pertinent to any other worthwhile method of pancreatic imaging.

Adenocarcinoma↗