Biomedical subjects
Publications and source records attributed to E B Black.
Ultrasonography of the pelvis at mid-menstrual cycle in normal women has demonstrated small quantities of free fluid in 40% of cycles. Two thirds of the cycles associated with pain had ultrasonically demonstrated fluid at ovulation. These sonographic findings at Mittelschmerz confirm the physiological trauma of ovulation.
CT of the pancrease permitted correct positive diagnosis in 28/50 or 56% of patients with chronic pancreatitis proved by laparotomy or retrograde ductography. Diagnoses were based on CT identification of one or more specific hallmarks of chronic pancreatitis including calcifications (18/50 or 36%), parenchymal atrophy (7/50 or 14%) and pancreatic duct dilatation (2/50 or 4%), as well as the principal surgical complications, pseudocyst and abscess (15/50 or 30%). In 9 patients, CT disclosed pancreatic calcifications not visible on conventional radiographs. In 32 patients, ultrasound was less informative than CT giving a correct diagnosis in 8 pseudocycts (25%). In the patient with unexplained upper abdominal complaints, a positive CT diagnosis of chronic pancreatitis permits more confident patient management than a negative, or "no tumor" diagnosis rendered by other noninvasive examinations.
Sequential gray-scale sonograms were obtained during 20 menstrual cycles in 16 normal female volunteers. Hormonal and physical parameters of an ovulatory cycle were correlated with morphological changes in the ovaries, uterus, and cul-de-sac as seen on the sonogram. Ovarian cysts of two sizes were observed, corresponding chronologically and morphologically to Graafian follicles and corpora lutea. Small amounts of free pelvic fluid were demonstrated in many women at ovulation. A characteristic uterine appearance is seen prior to menstruation and is related to hormonal influences on the uterus. These findings emphasize the importance of recognizing normal physiological changes when interpreting gynecologic sonograms.
Because of the broad spectrum of echogenicity inherent in the heterogeneous composition of the abdominal viscera, system gain variations may be useful in gray scale ultrasound imaging to improve lesion definition. In general, Anechoic or hypoechoic processes may be accentuated by scanning in the higher gain ranges, while hyperechoic lesions may be better delineated at lower gain levels. Thus adjustments in "acoustic contrast" may supplement and reinforce information derived from an initial standard medium gain scan. Although the liver serves as a model in this report, careful selection of a variety of system gain levels can be helpful in evaluating focal lesions in any organ.
A previously undescribed sign of common bile duct obstruction during intravenous cholangiography - initial visualization of proximal intrahepatic ducts - was observed in 26 patients with surgically proven obstructive disease of the distal common duct. In all cases, opacification of intrahepatic biliary radicles occurred on standard interval films prior to visualization of the extrahepatic common bile duct, the reverse of the normal sequence. The abnormal opacification pattern reflects stasis of bile flow in the presence of distal obstruction and seems analogous to the urographic finding of opacified intra-renal calyces as the initial manifestation of distal ureteral obstruction. Recognition of the alteration in the initial cholangiographic opacification sequence signals the need for delayed films to confirm the diagnosis of a distal choledochal obstruction.
Clinical examinations with the whole body CT scanner require considerable individualization of examination technique in relation to specific organs, anatomic areas, and clinical problems. Careful selection of radiographic factors, patient position, contrast agents, and pharmacologic adjuncts will optimize diagnostic results and patient throughput.
A method for assessing the effect of computed body tomography on diagnostic understanding and therapeutic decision making is described and the results in the first 184 patients are presented. The patients' referring physicians provided the primary data used for the evaluation. CT improved diagnostic understanding in 41% of patients, reassured the physician about previously planned therapy in 43%, contributed to a change in therapy in 17%, and improved precision of previously planned treatment in an additional 10%. CT contributed to a decision not to perform surgery in 21% of patients in whom an operation had been provisionally planned While CT can play an important role in patient management, its measured value depends on the clinical problems investigated and the level of efficacy on which it is judged.