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Biomedical subjects

R B Jeffrey

Publications and source records attributed to R B Jeffrey.

At least 91 records · Page 5Linked to original sources
PubMed1993

Adnexal masses: comparison of specificity of endovaginal US and pelvic MR imaging.

In a prospective study, 32 women with suspected pelvic masses at physical examination underwent both endovaginal ultrasound (US) and magnetic resonance (MR) imaging to compare their ability in diagnosis of adnexal masses. Criteria for the diagnosis of various types of adnexal masses with MR imaging and endovaginal US were prospectively defined, and the ability of either modality to allow a specific diagnosis was assessed. For each modality, measures of sensitivity, specificity, and accuracy were obtained. Results indicated higher diagnostic capability of endovaginal US for simple cysts (five of five), hemorrhagic cysts (eight of nine), endometriomas (nine of 14), and ovarian carcinomas (three of three). MR imaging demonstrated higher diagnostic capability for dermoids (three of three). MR imaging and endovaginal US showed equal diagnostic capability for pedunculated fibroids (two of two). For all masses, observers, and observations, the overall sensitivity of endovaginal US was 76% versus 49% for MR imaging, and the overall accuracy of endovaginal US was 83% versus 70% for MR imaging. The authors suggest that endovaginal US is a better modality than MR imaging for the assessment of suspected pelvic masses.

Adnexal Diseases↗
PubMed1993

Dynamic breath-hold multiplanar spoiled gradient-recalled MR imaging with gadolinium enhancement for differentiating hepatic hemangiomas from malignancies at 1.5 T.

PURPOSE: To compare the enhancement patterns of focal liver lesions at dynamic breath-hold gadolinium-enhanced multiplanar spoiled gradient-recalled (SPGR) magnetic resonance (MR) imaging with T2 relaxation times in the differentiation of liver hemangiomas from malignancies. MATERIALS AND METHODS: Forty-seven patients with focal liver lesions underwent MR imaging with spin-echo and gadolinium-enhanced multiplanar SPGR techniques. T2 relaxation times and enhancement patterns were compared for accuracy in liver lesion characterization. RESULTS: Enhancement patterns allowed better characterization of liver lesions than did T2 relaxation times. Only specific patterns of contrast enhancement indicated a hemangioma. Although 18 of the 33 malignancies and 10 of the 12 hemangiomas showed progressive centripetal hyperintense enhancement, only hemangiomas filled in with hyperintense peripheral nodules. Malignancies often filled in with hyperintense thick rinds. CONCLUSION: Gadolinium-enhanced multiplanar SPGR imaging allows more accurate characterization of liver lesions than does T2 relaxation time.

Adult↗
PubMed1993

CT of blunt trauma to the bowel and mesentery.

The high mortality and morbidity rates associated with traumatic rupture of the hollow viscera have been attributed to the clinical difficulty in establishing an early diagnosis. CT has been shown to be accurate for detecting bowel and mesenteric injuries caused by blunt trauma and may be useful in predicting the need for either surgical repair or conservative management. However, many major gastrointestinal injuries have subtle CT findings. In this pictorial essay, we illustrate the broad spectrum of gastrointestinal abnormalities that can be shown by CT in patients with blunt abdominal trauma.

Abdominal Injuries↗
PubMed1993

Fast multiplanar spoiled gradient-recalled imaging of the liver: pulse sequence optimization and comparison with spin-echo MR imaging.

OBJECTIVE: The purpose of this study was to optimize a new rapid-acquisition MR pulse sequence, called fast multiplanar spoiled gradient-recalled (FMPSPGR) imaging, for breath-hold imaging of the liver and to compare unenhanced and contrast-enhanced FMPSPGR with standard spin-echo imaging in detecting liver tumors. MATERIALS AND METHODS: The pulse sequence was optimized at 1.5 T with a healthy volunteer. Various scanning parameters were evaluated, and liver-spleen signal difference/noise measurements were used to estimate lesion contrast-to-noise ratios. We examined 24 patients with hepatic masses using the optimized sequence with spin-echo T1-weighted and T2-weighted imaging as well as unenhanced and gadopentetate dimeglumine-enhanced FMPSPGR imaging. The contrast-to-noise ratio for the hepatic tumors was determined for each sequence. Three radiologists who did not know the biopsy or test results reviewed all images for lesion conspicuity, lesion tissue specificity, and overall image quality. RESULTS: A comparison of unenhanced FMPSPGR images with spin-echo T1-weighted images showed a 40% improvement in mean contrast-to-noise ratio and a 70% improvement in liver signal-to-noise ratio for the FMPSPGR images. A comparison of gadopentetate dimeglumine-enhanced FMPSPGR images with spin-echo T1- and T2-weighted images showed a superior contrast-to-noise ratio for the enhanced FMPSPGR images in 17 (68%) of 25 hepatic lesions, which included all hepatic cysts (n = 3) and all hepatomas (n = 6), and in six of 12 patients with other liver tumors. The results of contrast-to-noise ratio for four patients with hemangiomas were mixed. For the remaining eight lesions, the contrast-to-noise ratio for spin-echo T1- and T2-weighted images predominated in three and five cases, respectively. Contrast-enhanced FMPSPGR images revealed a 40% and 300% increase in contrast-to-noise ratio compared with T2- and T1-weighted images, respectively. All three radiologists preferred the contrast-enhanced FMPSPGR images for overall image quality. For lesion conspicuity and specificity, however, the three radiologists differed, with a preference for the FMPSPGR images in 52%, 80%, and 40% of cases for lesion conspicuity and in 68%, 40%, and 60% of cases for lesion specificity. CONCLUSION: FMPSPGR is a new, ultrafast MR sequence that provides T1-weighted images of the liver during suspended respiration. Contrast-to-noise ratio and liver signal-to-noise ratio are significantly improved over those on conventional spin-echo T1-weighted images. The combination of breath-hold FMPSPGR with gadopentetate dimeglumine is an excellent technique that can be used to rapidly evaluate the liver with superior overall image quality. Contrast-to-noise ratios are generally superior to T2-weighted spin-echo images, making this technique a useful adjunct to conventional spin-echo MR imaging.

Adult↗
PubMed1993

Follow-up sonography in suspected acalculous cholecystitis: preliminary clinical experience.

Fourteen adult patients with clinically suspected AAC and inconclusive initial sonograms underwent follow-up sonography within 24 hours. Eight patients had initial studies demonstrating a normal thickness of the gallbladder wall. Four of these patients demonstrated progressive thickening of the gallbladder wall on follow-up scans and were diagnosed as having AAC. In three of these patients AAC was proved at surgery, and the remaining patient improved clinically after percutaneous cholecystostomy. Four other patients with normal gallbladder wall thickness on both the initial and follow-up sonograms had benign clinical follow-up results without evidence of AAC. The remaining six patients had a thickened gallbladder on the initial sonogram. In one of these patients, the gallbladder wall thickening resolved on follow-up sonography. In the remaining five patients the gallbladder wall thickening did not change. Four of these patients had benign follow-up results but one patient was found to have AAC at surgery. Follow-up sonography may be helpful to confirm AAC if there is progressive edema of the gallbladder wall. A normal gallbladder wall on an initial study does not exclude early AAC. Thickening of the gallbladder wall on initial studies still remains a problem and other ancillary criteria must be used to establish the diagnosis of AAC.

Adult↗
PubMed1993

Hepatic focal nodular hyperplasia: findings with color Doppler sonography.

Color Doppler sonographic images of five patients with a total of six lesions of FNH were reviewed. All cases were confirmed pathologically. All six lesions showed increased intralesional flow in comparison to surrounding liver parenchyma on color Doppler sonography. Four of the six lesions showed significant peripheral flow; two of the six lesions showed central flow radiating peripherally from a central vessel. We conclude that increased color Doppler flow may be a characteristic feature of FNH. Increased internal flow has also been reported in HCC and hepatic metastatic disease. Considerable overlap is seen in color Doppler flow patterns. However, in patients clinically at low risk for malignancy, detection of a liver mass with increased color Doppler flow should suggest the diagnosis of FNH.

Blood Flow Velocity↗
PubMed1993

Three-dimensional spiral computed tomographic angiography: an alternative imaging modality for the abdominal aorta and its branches.

PURPOSE: We sought to apply a new technique of computed tomographic angiography (CTA) to the preoperative and postoperative assessment of the abdominal aorta and its branches. METHODS: After a peripheral intravenous contrast injection, the patient is continuously advanced through a spiral CT scanner, while maintaining a 30-second breath-hold. Thirty-five patients with abdominal aortic, renal, and visceral arterial disease have undergone CTA. RESULTS: Diagnostic three-dimensional images were obtained in patients with aortic aneurysms (n = 9), aortic dissections (n = 4), and mesenteric artery stenoses (n = 4). The technique has also been used to assess vessels after operative reconstruction or endovascular intervention in 18 patients. These preliminary studies have correlated well with conventional arteriographic findings. In aneurysmal disease both the lumen and mural thrombus and associated renal artery stenoses are visualized. The true and false channels of aortic dissections and the perfusion source of the visceral vessels are clearly shown; patency of visceral and renal reconstruction or stent placement are confirmed. CTA is relatively noninvasive and can be completed in less time than conventional angiography with less radiation exposure. CONCLUSIONS: This initial experience suggests that CTA may be a valuable alternative to conventional arteriography in the evaluation of the aorta and its branches.

Adult↗
PubMed1992

Graded compression sonography of abdominal neoplasms mimicking acute appendicitis.

Over a 3-year period nine patients (mean age of 43 years) with acute abdominal pain and unsuspected abdominal neoplasms were referred for graded compression sonography to rule out appendicitis. Six of the nine patients had right lower quadrant neoplasms involving the cecum, terminal ileum, iliacus muscle, or iliac lymph nodes. However, in three patients neoplasm was noted outside the right iliac fossa involving the liver, right kidney, and upper abdominal mesentery. This study underscores the fact that in patients without sonographic evidence of acute appendicitis, a survey of the upper abdomen and right flank should routinely be performed in addition to scanning the right iliac fossa and pelvis. In patients more than 50 years of age neoplasm must also be kept in mind in the differential diagnosis of appendicitis.

Abdominal Neoplasms↗
PubMed1992

Coaxial transthoracic fine-needle biopsy in patients with a history of malignant lymphoma.

Efficacy and safety of coaxial transthoracic fine-needle biopsy were evaluated in 54 patients with a history of malignant lymphoma and new chest lesions. Twenty-one patients had recurrent lymphoma. Correct diagnosis was made in 17 of the 21 patients (81%) after one biopsy. The sensitivity increased to 95% with repeat needle biopsy in three patients. Immunophenotyping (determining phenotype by means of immunologic examination) was essential for a definitive diagnosis of lymphoma in three patients. Non-lymphomatous malignancies were correctly diagnosed in 14 patients. An infectious organism was identified in 11 of 19 patients (58%) with benign lesions. Pneumothorax occurred in eight patients (15%), necessitating placement of a chest tube in two (4%). Mild hemoptysis was observed in four patients (7%). The authors conclude that coaxial transthoracic fine-needle biopsy in patients with a history of lymphoma is safe and accurate. The use of large cutting needles or surgical biopsy can be restricted to patients with false-negative findings at percutaneous biopsy and to patients in whom histologic transformation of lymphoma is suspected.

Adult↗
PubMed1992

Limitations of liver surface US in the diagnosis of cirrhosis.

Ultrasound (US) of the liver surface with a high-frequency, small-parts, short-focused probe has been proposed as a method of diagnosing cirrhosis. US of the liver was performed in 50 consecutive patients undergoing diagnostic liver biopsy to assess the clinical usefulness of this noninvasive procedure in diagnosing hepatic cirrhosis. Eight patients had histologically proved cirrhosis, and 42 had no histologic evidence of cirrhosis. Seven of the eight patients with cirrhosis had a normal liver surface at US, and five of the 42 patients without cirrhosis had an abnormal liver surface. US of the liver surface with this probe was not reliable in this heterogeneous patient population.

Humans↗
PubMed1992

The pelvis: T2-weighted fast spin-echo MR imaging.

Fast spin-echo (SE) T2-weighted magnetic resonance (MR) imaging provides images with highly T2-weighted contrast in substantially reduced imaging times. In a prospective evaluation, fast SE T2-weighted imaging of the pelvis was compared with conventional SE T2-weighted imaging in 30 consecutive patients in whom pelvic pathologic conditions were suspected. Three reviewers independently analyzed the images for (a) overall image quality, (b) pelvic organ definition, (c) conspicuity of pelvic fluid, and (d) conspicuity of pelvic pathologic conditions. Fast SE images were rated superior to conventional SE T2-weighted images in 60% (54 of 90) of the case reviews for overall image quality, in 69% (62 of 90) for pelvic organ definition, in 63% (57 of 90) for conspicuity of pelvic fluid, and in 68% (43 of 63) for conspicuity of pelvic pathologic conditions. The fast SE examinations were typically three to four times faster than conventional SE T2-weighted examinations. No pathologic findings seen on conventional SE T2-weighted images were undetected on fast SE images. Fast SE images may replace conventional SE T2-weighted images in MR imaging of the pelvis.

Abdomen↗
PubMed1992

CT angiography with spiral CT and maximum intensity projection.

The authors describe a technique for obtaining angiographic images by means of spiral computed tomography (CT), preprocessing of reconstructed three-dimensional sections to suppress bone, and maximum intensity projection. The technique has some limitations, but preliminary results in 48 patients have shown excellent anatomic correlation with conventional angiography in studies of the abdomen, the circle of Willis in the brain, and the extracranial carotid arteries. With continued development and evaluation, CT angiography may prove useful as a screening tool or replacement for conventional angiography in some patients.

Abdomen↗
PubMed1992

Arterial and venous blood flow: noninvasive quantitation with MR imaging.

Quantitative measurements of arterial and venous blood flow were obtained with phase-contrast cine magnetic resonance (MR) imaging and compared with such measurements obtained by means of implanted ultrasound (US) blood flow probes in anesthetized dogs. The US flowmeter was enabled during a portion of each MR imaging sequence to allow virtually simultaneous data acquisition with the two techniques. MR imaging data were gated by means of electrocardiography and divided into 16 phases per cardiac cycle. The rates of portal venous blood flow measured with MR imaging and averaged across the cardiac cycle (710 mL/min +/- 230 [standard deviation]) correlated well with those measured with the flowmeter and averaged in like fashion (751 mL/min +/- 238) (r = .995, slope = 1.053). The correspondence in arterial blood flow was almost as good. No statistically significant difference existed between the paired measurements of blood flow obtained with MR imaging and the implanted probe. It is concluded that, as a noninvasive means of accurate quantification of blood flow, phase-contrast MR imaging may be especially useful in deep blood vessels in humans.

Animals↗
PubMed1992

Comparison of iohexol 300 and diatrizoate meglumine 60 for body CT: image quality, adverse reactions, and aborted/repeated examinations.

Six hundred patients were prospectively randomized and given either diatrizoate meglumine 60 or iohexol 300 during dynamic contrast-enhanced body CT in order to compare image quality, contrast reactions, and the number of aborted studies or studies in which images had to be repeated. Three hundred two patients received iohexol 300, and 298 patients received diatrizoate meglumine 60. Thirty-nine percent (119/302) of the patients given iohexol 300 and 63% (188/298) of the patients given diatrizoate meglumine 60 had at least one adverse reaction thought to be related to contrast material during, or within 24 hr of, the body CT scan. When reactions of discomfort (heat or warmth, flushing, bad taste) were excluded, 16% (48/302) of the patients who received iohexol and 33% (99/298) of the patients who were given diatrizoate meglumine 60 had at least one adverse reaction. The differences in both types of reactions between the two agents were significant (p less than .001). Among scans evaluated for study quality, 71% (214/302) of the iohexol 300 group and 62% (184/298) of the diatrizoate meglumine 60 group had optimal enhancement (p = .02). However, when the optimal and adequate categories were combined, 301 of 302 patients given iohexol 300 and 292 of 298 patients given diatrizoate meglumine 60 had diagnostic-quality studies (no statistical difference). Studies were not terminated nor were images repeated in 97% (292/302) of the patients given iohexol 300 and in 94% (280/298) of those given diatrizoate meglumine 60. The CT study was repeated because of movement during the contrast injection or aborted because of contrast-related reactions in 0.7% of the patients given iohexol 300 and in 3.0% of the patients given diatrizoate meglumine 60. This difference was statistically significant (p = .04). Our results suggest that the difference in image quality, number of adverse reactions, and number of aborted/repeated CT scans performed with iohexol 300 or diatrizoate meglumine 60 are not sufficiently different to warrant conversion to nonionic agents for body CT scans.

Diatrizoate Meglumine↗
PubMed1992

Mucocele of the appendix: imaging findings.

Mucocele of the appendix, a cystic mass resulting from a dilated appendiceal lumen caused by abnormal accumulation of mucus, is a rare entity that often is not considered when problems of the right lower quadrant are assessed. Preoperative recognition of mucocele of the appendix is important because of the possibility of rupture at surgery with development of pseudomyxoma peritonei and to predict malignant transformation. The appearances of mucoceles of the appendix on sonography, CT, and barium studies are illustrated.

Appendix↗
PubMed1992

Color flow Doppler characterization of focal hepatic lesions.

OBJECTIVE: The purpose of this study was to determine the sensitivity and specificity of color flow Doppler sonography for the specific diagnosis of focal hepatic lesions. SUBJECTS AND METHODS: Color flow Doppler images of 118 focal hepatic lesions in 108 patients were analyzed prospectively. In most patients, liver disease was suspected or known to be present before the Doppler images were obtained. Experienced sonologists obtained and interpreted all sonograms. The lesions were classified, according to their color flow pattern, into two main categories: lesions with internal vascularity and lesions with no internal vascularity. The color flow Doppler pattern of each lesion was correlated with the diagnosis of the lesion on a lesion-by-lesion basis. One hundred two lesions were proved by biopsy and 16 lesions were confirmed by evaluation with other imaging techniques. Lesions included 29 hepatocellular carcinomas, 64 metastases, one cholangiocarcinoma, and 24 benign lesions. The sensitivity and specificity of vascularity as shown by color Doppler imaging in the diagnosis of hepatocellular carcinoma were determined. RESULTS: The majority of hepatocellular carcinoma lesions (76%) had internal vascularity. Most of the metastases (67%) and benign lesions (75%) had no internal vascularity. When the presence of internal vascularity was used as the discriminating criterion, the sensitivity of color flow Doppler findings for the diagnosis of hepatocellular carcinoma was 0.76. The specificity of internal vascularity for the diagnosis of hepatocellular carcinoma vs other focal lesions was 0.69; for hepatocellular carcinoma vs metastases it was 0.67. CONCLUSION: Although most hepatocellular carcinomas have internal vascularity on color flow Doppler images, a significant number of metastases also have internal vascularity. This overlap limits the usefulness of color flow Doppler imaging for distinguishing hepatocellular carcinoma from metastatic tumors.

Adult↗
PubMed1992

Acute appendicitis confined to the appendiceal tip: evaluation with graded compression sonography.

Focal appendicitis at the tip of the appendix has not been emphasized in the sonographic literature. We present the sonographic findings in four patients with pathologically confirmed acute appendicitis confined to the appendiceal tip. In all four patients, the base of the appendix had a normal appearance with maximal outer diameters measuring 4 to 6 mm. However, the inflamed tip was focally enlarged, measuring greater than 7 mm. The importance of a careful survey of the entire length of the appendix is emphasized to avoid a false-negative examination.

Acute Disease↗