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Biomedical subjects

R B Jeffrey

Publications and source records attributed to R B Jeffrey.

At least 73 records · Page 4Linked to original sources
PubMed1995

Dual-phase helical CT of the liver: value of arterial phase scans in the detection of small (< or = 1.5 cm) malignant hepatic neoplasms.

OBJECTIVE: Helical CT scanners now allow sequential arterial phase and portal venous phase scans of the entire liver to be obtained during a single bolus injection of contrast material. The purpose of this study was to determine if arterial phase scans improve detection of small (< or = 1.5 cm) malignant hepatic neoplasms when compared with portal venous scans alone. MATERIALS AND METHODS: Dual-phase helical CT of the liver was done in 96 patients referred for known or suspected malignant hepatic lesions. Malignant hepatic neoplasms were detected in 38 patients (27 with at least one small neoplasm), one patient had undetected metastases, one patient had a benign hepatic neoplasm, and 56 patients had no hepatic neoplasm. Proof of individual neoplasms was based on biopsy results, surgical findings, or findings on other imaging studies (primarily follow-up CT). The absence of disease was established by surgical or autopsy findings, findings on subsequent imaging studies, or a combination of clinical and laboratory data. A total of 150 ml of 60% nonionic contrast material was infused at 5 ml/sec followed by sequential arterial phase and portal venous phase helical scans of the liver. Three radiologists retrospectively reviewed the scans. Individual lesions were measured and the conspicuity of each lesion on arterial phase and portal venous phase scans was compared. The percentage of patients in whom some malignant neoplasms were detected better on the arterial phase scan was calculated using categories based on lesion size and typical tumor vascularity. RESULTS: In 10 (37%) of 27 patients who had at least one small malignant neoplasm, lesions 1.5 cm or less in diameter were only visible or were more conspicuous on the arterial phase scan. No malignant neoplasms more than 1.5 cm in diameter were visible only on the arterial phase scan. In four (11%) of 38 cases, malignant neoplasms more than 1.5 cm in diameter were more conspicuous on the arterial phase scan. The arterial phase scans improved lesion conspicuity in nine (39%) of 23 patients who had typically hypervascular neoplasms, whereas lesion conspicuity was improved in three (20%) of 15 patients who had typically hypovascular neoplasms (p = .02). The arterial phase scan resulted in the false-positive detection of lesions in two (2%) of 96 cases. CONCLUSION: Arterial phase helical CT of the liver improves detection of some small, malignant hepatic neoplasms when performed in addition to portal venous scanning. The value is greatest in those patients who have hypervascular neoplasms.

Adolescent↗
PubMed1995

Detection of ureteral calculi in patients with suspected renal colic: value of reformatted noncontrast helical CT.

OBJECTIVE: The purpose of this study was to determine the value of reformatted noncontrast helical CT in patients with suspected renal colic. We hoped to determine whether this technique might create images acceptable to both radiologists and clinicians and replace our current protocol of sonography and abdominal plain film. SUBJECTS AND METHODS: Thirty-four consecutive patients with signs and symptoms of renal colic were imaged with both noncontrast helical CT and a combination of plain film of the abdomen and renal sonography. Reformatting of the helical CT data was performed on a workstation to create a variety of reformatted displays. The correlative studies were interpreted by separate blinded observers. Clinical data, including the presence of hematuria and the documentation of stone passage or removal, were recorded. RESULTS: Findings on 18 CT examinations were interpreted as positive for the presence of ureteral calculi; 16 of these cases were determined to be true positives on the basis of later-documented passage of a calculus. Thirteen of the 16 cases proved to be positive were interpreted as positive for renal calculi using the combination of abdominal plain film and renal sonography. The most useful CT reformatting technique was curved planar reformatting of the ureters to determine whether a ureteral calculus was present. CONCLUSION: In this study, noncontrast helical CT was a rapid and accurate method for determining the presence of ureteral calculi causing renal colic. The reformatted views produced images similar in appearance to excretory urograms, aiding greatly in communicating with clinicians. Limitations on the technique include the time and equipment necessary for reformatting and the suboptimal quality of reformatted images when little retroperitoneal fat is present.

Adult↗
PubMed1995

Color Doppler sonography of the cystic artery: comparison of normal controls and patients with acute cholecystitis.

Color Doppler sonography was used to evaluate the length and distribution of the cystic artery in the gallbladder wall in 115 normal adults and in 54 patients with surgically proved cholecystitis. All patients were scanned with a 5 MHz curved array transducer optimized for low volume color sensitivity. A specific attempt was made to visualize the cystic artery throughout its course. Spectral Doppler waveforms were obtained to document arterial flow. The length of the cystic artery visualized was analyzed as a quartile percentage length of the anterior gallbladder wall. The distribution of the cystic artery flow also was analyzed in specific quartiles. Of 54 patients with acute cholecystitis, 26% had cystic artery length greater than half of the anterior gallbladder wall, compared with 2% of 115 normal controls (P < 0.001); 19% of patients with cholecystitis had flow in the distal (fundal) quartile, compared to 0% of normal controls (P < 0.0001). Although the presence or absence of flow in the gallbladder is not a reliable finding to establish the diagnosis of acute cholecystitis, length of cystic artery visualized is a potentially useful criterion to suggest the diagnosis of acute cholecystitis, especially in cases in which flow in the distal fundal quartile of the gallbladder. The usefulness of color Doppler sonography in acute cholecystitis is limited owing to the fact that it is insensitive, and many patients with cholecystitis have no detectable flow or have normal flow patterns.

Acute Disease↗
PubMed1994

Adnexal torsion: color Doppler diagnosis and laparoscopic treatment.

The present case documents normalization of ovarian perfusion after conservative laparoscopic treatment of adnexal torsion. At our institution, Doppler flow assessment in cases of suspected torsion represents an important element of diagnosis and, in this case, allowed for early diagnosis with conservative laparoscopic treatment with documented normalization of ovarian flow postoperatively.

Adnexal Diseases↗
PubMed1994

Chronic mesenteric ischemia: evaluation with phase-contrast cine MR imaging.

PURPOSE: To compare superior mesenteric artery (SMA) blood flow in healthy volunteers and patients with stenoses in the fasting state and after food intake by using phase-contrast (PC) cine magnetic resonance (MR) imaging. MATERIALS AND METHODS: Ten healthy subjects, four asymptomatic patients (three with 50% stenosis, one with 70% stenosis), and one symptomatic patient (with 80% stenosis) were studied. All subjects were studied after fasting at least 8 hours and 15, 30, and 45 minutes after ingesting a standard meal. RESULTS: In healthy volunteers, SMA blood flow at all postprandial intervals increased significantly compared with that obtained after fasting (P < or = .0005). The percentage change in SMA blood flow 30 minutes after food intake provided the best distinction between the healthy subjects, the asymptomatic patients, and the symptomatic patient. CONCLUSION: Cine PC MR imaging is an effective, noninvasive technique for measuring SMA blood flow.

Adult↗
PubMed1994

Spiral CT of renal artery stenosis: comparison of three-dimensional rendering techniques.

PURPOSE: To evaluate the accuracy of computed tomographic (CT) angiography in the detection of renal artery stenosis (RAS). MATERIALS AND METHODS: CT angiography was performed in 31 patients undergoing conventional renal arteriography. CT angiographic data were reconstructed with shaded surface display (SSD) and maximum-intensity projection (MIP). Stenosis was graded with a four-point scale (grades 0-3). The presence of mural calcification, poststenotic dilatation, and nephrographic abnormalities was also noted. RESULTS: CT angiography depicted all main (n = 62) and accessory (n = 11) renal arteries that were seen at conventional arteriography. MIP CT angiography was 92% sensitive and 83% specific for the detection of grade 2-3 stenoses (> or = 70% stenosis). SSD CT angiography was 59% sensitive and 82% specific for the detection of grade 2-3 stenoses. The accuracy of stenosis grading was 80% with MIP and 55% with SSD CT angiography. Poststenotic dilatation and the presence of an abnormal nephrogram were 85% and 98% specific, respectively. CONCLUSION: CT angiography shows promise in the diagnosis of RAS. The accuracy of CT angiography varies with the three-dimensional rendering technique employed.

Adult↗
PubMed1994

Inflamed pericholecystic fat: color Doppler flow imaging and clinical features.

PURPOSE: To analyze the color Doppler flow imaging features and clinical importance of inflamed pericholecystic fat. MATERIALS AND METHODS: Forty patients with surgically proved right upper quadrant inflammatory lesions in the gallbladder or the pericholecystic space underwent color Doppler sonography (CDS). Findings in the pericholecystic space were correlated with those at computed tomography (CT) in four patients and with surgical findings in 40 patients. RESULTS: CDS performed in 12 (30%) of the 40 patients demonstrated echogenic pericholecystic masses greater than 1 cm in diameter that contained internal vascularity. CT in four patients and surgical findings in all 12 patients demonstrated inflamed fat adherent to the gallbladder. CONCLUSION: Identification with CDS of inflamed pericholecystic fat may provide preoperative information that could be pertinent in the decision to perform open or laparoscopic cholecystectomy in patients with acute cholecystitis.

Acute Disease↗
PubMed1994

Sonographic diagnosis of acute appendicitis: interpretive pitfalls.

Graded compression sonography has proven to be of significant clinical value in the assessment of patients with right lower quadrant pain and possible appendicitis [1-3]. Despite its proven utility, a number of imaging pitfalls must be kept in mind when sonograms of the right lower quadrant are interpreted. The purpose of this pictorial essay is to illustrate a number of important limitations and areas of interpretive difficulty in sonography for appendicitis.

Acute Disease↗
PubMed1994

Differentiating sigmoid diverticulitis from carcinoma on CT scans: mesenteric inflammation suggests diverticulitis.

OBJECTIVE: The purpose of this study was to analyze the usefulness of two specific CT signs of sigmoid mesenteric inflammation (fluid at the root of the mesentery and vascular engorgement) for identifying and differentiating sigmoid diverticulitis from carcinoma. MATERIALS AND METHODS: CT scans of 69 patients with surgically proved sigmoid diverticulitis were retrospectively reviewed and compared with CT findings in 29 patients with surgically proved sigmoid carcinoma. Two specific patterns of inflammation of the sigmoid mesentery were analyzed: fluid at the root of the sigmoid mesentery and engorgement of the sigmoid mesenteric vessels. RESULTS: The CT findings were present more often in patients with sigmoid diverticulitis than in those with carcinoma (p < .001). Fluid at the base of the mesentery had a sensitivity, specificity, and positive predictive value for diverticulitis of 36%, 90%, and 89% respectively. Vascular engorgement alone had a sensitivity, specificity, and positive predictive value of 29%, 100%, and 100%, respectively. CONCLUSION: Our results suggest that CT findings of fluid at the root of the mesentery and vascular engorgement are useful in distinguishing sigmoid diverticulitis from carcinoma of the sigmoid.

Adult↗
PubMed1994

CT diagnosis of blunt pancreatic trauma: importance of detecting fluid between the pancreas and the splenic vein.

OBJECTIVE: The purpose of this study was to determine the value of detecting fluid between the splenic vein and the pancreas on CT scans in the diagnosis of pancreatic injury after blunt abdominal trauma. MATERIALS AND METHODS: We retrospectively reviewed the abdominal CT scans of 10 patients with surgical- or autopsy-proved pancreatic injury after blunt abdominal trauma. The finding of fluid interdigitating between the pancreas and the splenic vein was then studied along with the reported CT features of pancreatic injury. These included intraperitoneal fluid, fluid in the lesser sac, extraperitoneal fluid, pancreatic edema or hematoma, and thickening of the anterior renal fascia. RESULTS: The CT scans of all 10 patients reviewed showed abnormalities suggesting pancreatic injury. Only 40% of patients showed all of the findings reported in the literature. Fluid interdigitating between the splenic vein and the pancreatic parenchyma was seen on CT scans in 90%. CONCLUSION: Our experience suggests that fluid between the splenic vein and the pancreas is a helpful CT finding for the diagnosis of pancreatic injury after blunt abdominal trauma. This finding was easy to recognize and in the proper clinical setting directs attention to additional subtle findings of pancreatic injury.

Adult↗
PubMed1994

Evaluation of pelvic masses with magnetic resonance imaging and ultrasonography.

Magnetic resonance imaging is becoming increasingly useful in characterizing adnexal masses, whereas endovaginal ultrasound is an invaluable technique for examining the uterus and adnexa. This pictorial essay depicts the internal architectural details necessary for characterization of various adnexal masses imaged with both EVU and MR imaging. Forty consecutive examinations that revealed 51 adnexal masses were reviewed. All patients had MR imaging and EVU examinations within 1 week of each other. T1- and T2-weighted images in coronal, axial, and sagittal planes were included. Fat suppression technique also was used in selected cases. EVU, because of its high spatial resolution, was able to depict better internal architectural details, allowing specific diagnosis of most adnexal masses, whereas MR imaging was superior in differentiating hemorrhagic masses from dermoids when specific fat suppression techniques were used.

Adnexal Diseases↗
PubMed1994

Color Doppler sonography of focal gastrointestinal lesions: initial clinical experience.

Graded compression color Doppler sonography was used to evaluate gastrointestinal blood flow in 20 normal fasting subjects and 32 patients with focal gastrointestinal lesions. Imaging was optimized for color sensitivity using a 5 MHz linear array transducer. Criteria were established for normal mural blood flow based on findings in normal controls. Two reviewers blinded to the final diagnosis compared patterns of mural vascularity in normal and abnormal patients. Increased mural blood flow was demonstrated in all 32 patients with gastrointestinal inflammatory disorders and in seven of nine patients with neoplasms. No mural flow was demonstrated in four patients with small bowel infarction. The greatest overall degree of flow was noted in patients with Crohn's disease and cytomegalovirus colitis. Flow in tumors was variable, ranging from strikingly increased flow in a giant villoglandular polyp to absent flow in a metastasis from lung carcinoma. Our preliminary experience suggests that the presence of considerable overlap in the color Doppler patterns of mural blood flow in inflammatory and neoplastic lesions. Color Doppler sonography alone without spectral waveform analysis may not distinguish focal inflammatory from neoplastic disorders of the gastrointestinal tract reliably. However, this technique potentially may be useful in diagnosing small bowel ischemia when thickened segments of small bowel are identified with absent flow.

Adult↗
PubMed1994

Sonography of appendicitis and diverticulitis.

Graded compression sonography has gained widespread acceptance as a useful technique to evaluate patients with atypical signs and symptoms of appendicitis. When positive, early surgery can be performed prior to perforation. When there is no sonographic evidence of appendicitis, other alternative diagnoses may be established. CT scans and the contrast enema remain the primary imaging modalities to evaluate suspected diverticulitis; however, sonography may be useful in selected patients with an atypical clinical presentation.

Acute Disease↗
PubMed1993

Experimental hepatic tumor necrosis. Comparison of spin-echo and pulsed magnetization transfer contrast magnetic resonance imaging.

RATIONALE AND OBJECTIVES: We compared the effectiveness of pulsed magnetization transfer contrast (MTC) magnetic resonance imaging (MRI) and spin-echo MRI in detecting tumor necrosis. METHODS: Adenocarcinoma cells were transplanted in the livers of 12 syngenic BDIX rats. To induce various degrees of tumor necrosis, the rats were randomly assigned to the following groups: 1) control; 2) localized hyperthermia; 3) intralesional cisplatin; and 4) hyperthermia plus intralesional cisplatin. At day 7 after treatment, the rats were imaged using a 1.5-T imager with 1) multiplanar gradient-recalled echo sequence (MPGR) 500/8/20 degrees with and without magnetization transfer contrast (MTC); 2) spin-echo 2500/20,80, and 3) spin-echo 300/20 pulse sequences. The rats were then sacrificed and pathologic specimens were prepared using MR images as guidance. T2 and ratios of signal intensity after saturation to signal intensity before saturation (Ms/Mo ratios) of the necrotic and granulation tissues and viable tumors were determined in 10 rats. RESULTS: Compared with standard MPGR images, MPGR images with MTC provided better contrast between the pathologic tissues and normal liver. However, T2 values were more useful than Ms/Mo ratios in distinguishing necrotic areas from viable tumor. The T2 values of coagulative necrosis and granulation tissue were significantly different from that of viable tumor. No significant difference between the Ms/Mo ratios of the different pathologic tissues and normal liver was found. CONCLUSION: Pulsed magnetization transfer contrast MRI was inferior to spin-echo MRI in distinguishing necrotic from viable tumors in rat livers using the pulse sequences described, and none of the sequences studied was thought to be reliable enough for this purpose.

Adenocarcinoma↗
PubMed1993

Three-dimensional spiral CT angiography of the abdomen: initial clinical experience.

Spiral computed tomography (CT) is a new technology that couples continuous tube rotation with continuous table feed. This allows compilation of a data set that has continuous anatomic information without the establishment of arbitrary boundaries at section interfaces as in conventional CT. The unique method of data collection of the spiral scanner has been combined with a dynamic intravenous contrast material bolus to image abdominal vasculature, specifically, the aorta, renal arteries, and splanchnic circulation. Through various techniques of image processing, including surface renderings and maximum-intensity projections, it is possible to obtain excellent anatomic detail of the aorta and its major branches. The authors applied this technique in 15 patients and reliably saw third-order aortic branches as well as third-order splenic-portal venous anatomic detail with remarkable clarity. Pathologic conditions detected include stenotic renal arteries, abdominal aortic dissection, abdominal aortic aneurysm, and celiac bypass graft occlusion.

Abdomen↗