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Biomedical subjects

J A Borrello

Publications and source records attributed to J A Borrello.

At least 19 recordsLinked to original sources
PubMed2000

Efficacy and safety of mangafodipir trisodium (MnDPDP) injection for hepatic MRI in adults: results of the U.S. Multicenter phase III clinical trials. Efficacy of early imaging.

The efficacy of contrast-enhanced magnetic resonance imaging (MRI) for detecting and characterizing, or excluding, hepatic masses was assessed in 404 patients, following the intravenous administration of mangafodipir trisodium (MnDPDP) injection, a hepatic MRI contrast agent. An initial contrast-enhanced computed tomography (CT) examination was followed by unenhanced MRI, injection of MnDPDP (5 micromol/kg IV), and enhanced MRI at 15 minutes post injection. Agreement of the radiologic diagnoses with the patients' final diagnoses was higher for enhanced MRI and for the combined unenhanced and enhanced MRI evaluations than for unenhanced MRI alone or enhanced CT using the clinical diagnosis as the gold standard. Mangafodipir-enhanced MRI uniquely provided additional diagnostic information in 48% of the patients, and patient management was consequently altered in 6% of the patients. MnDPDP-enhanced MRI was comparable or superior to unenhanced MRI and enhanced CT for the detection, classification, and diagnosis of focal liver lesions in patients with known or suspected focal liver disease.

Adult↗
PubMed2000

A prospective assessment of breath-hold fast spin echo and inversion recovery fast spin echo techniques for detection and characterization of focal hepatic lesions.

The purpose of this study was to prospectively assess two breath-hold T(2)-weighted fast spin-echo sequences and two breath-hold inversion recovery fast spin-echo sequences to determine their relative ability to detect and characterize focal hepatic lesions. Fourteen patients with a total of nineteen proven focal hepatic lesions were imaged with two breath-hold T(2)-weighted (T2W) fast spin echo sequences (HASTE TE = 66 and HASTE TE = 120), two breath-hold inversion recovery fast spin echo sequences (IRFSE TE = 64 and IRFSE TE = 95), and a nonbreath-hold T(2)-weighted fast-spin echo sequence (FSE TE = 96-120). Contrast-to-noise ratios (CNRs) were measured for all proven lesions on all sequences. Both IRFSE sequences and the HASTE sequence with TE = 66 showed an improvement in lesion-liver and liver-spleen CNRs compared to the nonbreath-hold T2W sequence. The mean difference in CNR between benign and malignant lesions was largest for the HASTE TE = 120 sequence. These preliminary results suggest that a breath-hold IRFSE sequence (TE = 64 or 95) has an equal ability to detect focal hepatic lesions as a nonbreath-hold T2W FSE sequence (TE = 96-120). The HASTE TE = 120 showed the greatest ability to discriminate between benign and malignant lesions.

Adult↗
PubMed1999

A retrospective analysis of the accuracy of T2-weighted images and dynamic gadolinium-enhanced sequences in the detection and characterization of focal hepatic lesions.

The aim of this study was to determine the relative ability of T2-weighted and dynamic gadolinium-enhanced T1-weighted gradient-echo sequences to detect and characterize focal hepatic lesions. We retrospectively studied 37 patients with proven focal hepatic lesions using the following sequences: a T1-weighted spin-echo sequence (T1), a T2-weighted sequence (T2), and a series of breath-hold dynamic gadolinium-enhanced T1-weighted gradient-echo sequences (Gd). Two observers were asked to determine retrospectively the number and type of focal hepatic lesions present using images from three combinations of sequences (T1+T2, T1+Gd, T1+T2+Gd). Proof of the number and diagnosis of focal lesions in each patient was established using a consensus read. Both readers detected more focal lesions when both the T2-weighted sequences and the gadolinium-enhanced sequences were available than on either sequence alone, although this improvement reached statistical significance (P<0.05) only for one of the readers. There was no significant difference (P<0.05) in the ability to characterize lesions between any of the sets of sequences. The combination of dynamic gadolinium-enhanced images and T2-weighted images was shown to assess focal hepatic lesions better than either of these sequences alone.

Adolescent↗
PubMed1997

Characterization of focal hepatic masses by dynamic contrast-enhanced MR imaging: findings in 311 lesions.

This study aimed to determine the overall accuracy of known enhancement patterns for the characterization of a large series of focal hepatic masses on dynamic contrast-enhanced magnetic resonance (MR) images. Breath-hold T1-weighted images of the liver acquired before intravenous gadolinium administration and serially over 6-10 min after contrast injection were acquired in < 25 a using FLASH or rapid spin-echo pulse sequences. A total of 311 proven focal hepatic masses in 128 patients were analyzed, including 192 malignant lesions (166 metastases and 26 hepatomas) and 119 benign lesions (48 cavernous hemangiomas, 45 hepatic cysts, and 26 other abnormalities). The lesions were evaluated for a variety of characteristics independently by two reviewers who were blinded to results. Cavernous hemangiomas showed early peripheral nodular enhancement (80% sensitivity and 99% specificity) and hepatic cysts showed no enhancement (100% sensitivity and 95% specificity). Hepatic metastases showed variable, moderate enhancement (47% by one reviewer and 74% by the other). Metastatic lesions from hypervascular primary neoplasms displayed peak enhancement during the hepatic artery dominant (bolus) phase, while other malignant neoplasms showed later peak enhancement (72% sensitivity and 77% specificity). Five metastatic foci with early homogeneous enhancement showed a delayed peripheral washout of contrast (rim sign), while no nonmetastatic foci displayed this finding (3% sensitivity and 100% specificity). Characteristic enhancement patterns of focal hepatic lesions were described in a large series of patients. This study confirms results of previous investigators who have shown that early nodular peripheral enhancement was highly specific for hemangiomas and lack of enhancement was highly specific for hepatic cysts. Hypervascular metastatic foci show earlier peak enhancement than other malignant lesions. Some (2-3%) metastatic lesions display a peripheral washout of contrast on serial images, with 100% specificity.

Adolescent↗
PubMed1997

Renal MR angiography.

MR angiography is a noninvasive technique for evaluating blood vessels. Its main use in the renal vasculature has been for evaluating the renal arteries for stenoses and for diagnosing renal vein thrombosis. Different methods of renal MR angiography, including gadolinium-enhanced MR angiography, are described, including guidelines for their use. The utility of MR angiography is discussed for a variety of clinical indications.

Humans↗
PubMed1995

Dynamic contrast-enhanced MR imaging of the liver: parenchymal enhancement patterns.

A retrospective study of 164 patients undergoing dynamic contrast-enhanced magnetic resonance (MR) imaging was performed to assess hepatic parenchymal enhancement patterns and to correlate these patterns with hepatic function and disease. Rapid T1-weighted images were acquired before and after gadolinium administration. Hepatic enhancement patterns were analyzed blindly by two observers. Medical records were reviewed to document known liver pathology and liver function test results. A total of 72% of patients had homogeneous enhancement of the liver parenchyma; 28% had heterogeneous enhancement. Of the latter group, 61% of patients had enhancement conforming to segmental or lobar boundaries. Patients with heterogeneous enhancement patterns were more likely to have abnormal liver function test results and hepatic morphological abnormalities on their MR examinations than patients with homogeneous enhancement patterns. Heterogeneous hepatic enhancement on dynamic MR images is associated with a higher likelihood of liver disease and biochemical evidence of hepatic dysfunction than homogeneous enhancement.

Adult↗
PubMed1995

Large angle spin-echo imaging.

A study was undertaken to assess the use of excitation flip angles greater than 90 degrees for T1 weighted spin-echo (SE) imaging with a single 180 degrees refocusing pulse and short TR values. Theoretical predictions of signal intensity for SE images with excitation pulse angles of 90-180 degrees were calculated based on the Bloch equations and then measured experimentally from MR images of MnCl2 phantoms of various concentrations. Liver signal-to-noise ratios (SNR) and liver-spleen contrast-to-noise ratios (CNR) were measured from breathhold MR images of the upper abdomen in 16 patients using 90 and 110 degrees excitation flip angles. The theoretical predictions showed significant improvements in SNR with excitation flip angles > 90 degrees, which were more pronounced at small TR values. The phantom studies showed reasonably good agreement with the theoretical predictions in correlating the excitation pulse angle with signal intensity. In the human imaging studies, the 110 degrees excitation pulse angle resulted in a 7.4% (p < .01) increase in liver SNR and an 8.2% (p = .2) increase in liver-spleen CNR compared to the 90 degrees pulse angle at TR = 275 ms. Increased signal intensity resulting from the use of large flip angle excitation pulses with a single echo SE pulse sequence was predicted and confirmed experimentally in phantoms and humans.

Abdomen↗
PubMed1995

Renal arteries: clinical comparison of three-dimensional time-of-flight MR angiographic sequences and radiographic angiography.

PURPOSE: To prospectively compare three magnetic resonance (MR) angiographic techniques in the renal arteries. MATERIALS AND METHODS: Twenty-five adult patients underwent three-dimensional time-of-flight MR angiography with three different sequences: conventional, tilted optimized nonsaturating excitation (TONE), and selective inversion-recovery rapid gradient-echo (SIR-RAGE). Fifteen also underwent radiographic angiography. Stenosis grade measured with each MR angiographic technique was compared with that measured with radiographic angiography by using correlation coefficients. Visible artery lengths with each MR angiographic technique were compared by using the Turkey method. RESULTS: Correlation between stenosis grades with each MR angiographic technique and with radiographic angiography was good (P < .01). Stenosis was correctly excluded with SIR-RAGE findings in six patients. Mean visible artery length was greatest with SIR-RAGE (P < .01). CONCLUSION: SIR-RAGE depicts a greater length of renal artery than does conventional MR angiography. TONE also improved depiction of distal arteries. Normal SIR-RAGE findings were highly predictive of normal arteries.

Adult↗
PubMed1995

MR imaging of the biliary system.

MR imaging has a distinct role to play in two areas of hepatobiliary imaging that continue to challenge the radiologist--evaluation of the gallbladder and evaluation of the jaundiced patient. The distinction between primary gallbladder carcinoma and chronic cholecystitis remains a diagnostic dilemma for all cross-sectional imaging modalities. MR imaging may be useful in detection of local invasion or metastatic disease. Gallstones are commonly seen coincidentally on cross-sectional imaging studies; the imaging characteristics of gallstones must be well-understood for the interpretation of routine abdominal MR examinations. The evaluation of jaundice is a multimodality process, often requiring three or four separate imaging techniques to determine the cause of biliary obstruction. MR may supplant more invasive techniques for anatomic depiction prior to therapeutic intervention.

Biliary Tract↗
PubMed1994

Differentiation of hepatomas from nonhepatomatous masses: use of MnDPDP-enhanced MR images.

Manganese (II) N,N'-dipyridoxylethylenediamine-N,N' diacetate 5,5'-bis(phosphate) (MnDPDP) is a hepatobiliary agent that is incorporated into the hepatocyte. We retrospectively reviewed our experience with 39 focal liver lesions in 20 patients studies with MnDPDP-enhanced hepatic magnetic resonance (MR) imaging to determine whether hepatocellular carcinoma (HCC) could be differentiated from tumors of nonhepatocyte origin (metastases, cavernous hemangiomas, etc.) For all cases, liver parenchyma enhanced significantly following MnDPDP administration. All HCCs (6) showed significant tumor enhancement resulting in decreased tumor conspicuity compared to precontrast images [average 37% decrease in tumor-liver contrast to noise ratio (C/N)]. In contradistinction, other focal liver lesions showed little or no tumor enhancement resulting in increased lesion conspicuity (average 100% increase in tumor-liver C/N ratio). Our preliminary data suggest that MnDPDP-enhanced MR images may enable differentiation of HCC from other focal liver masses of nonhepatocyte origin.

Carcinoma, Hepatocellular↗
PubMed1994

Chemical shift misregistration artifact: increased conspicuity following intravenous administration of gadopentetate dimeglumine.

We have observed increased conspicuity of chemical shift misregistration artifact (CSMA) associated with enhancing structures on MR images after the intravenous administration of gadopentetate dimeglumine compared with corresponding unenhanced images. In this study, we investigate the influence of gadopentetate dimeglumine administration on the conspicuity of CSMA in MR imaging of the kidneys. Nine gadopentetate-enhanced and unenhanced T1-weighted images of the kidneys were evaluated in a side-by-side fashion for the conspicuity of both the high and low signal intensity (SI) components of CSMA. A phantom study of saline in a bath of oil and increasing concentrations of gadopentetate dimeglumine in a bath of oil was performed. There was increased conspicuity of both the high and low SI components of CSMA in gadopentetate-enhanced images compared with unenhanced images in all study cases and in the phantom samples containing gadopentetate compared with the saline control. In conclusion, the administration of gadopentetate dimeglumine results in increased conspicuity of CSMA on MR images of the kidneys.

Aged↗
PubMed1994

Pediatric knee MR imaging: pattern of injuries in the immature skeleton.

PURPOSE: To evaluate the frequency of various cartilaginous and ligamentous knee injuries with magnetic resonance (MR) imaging in a large pediatric population. MATERIALS AND METHODS: The authors reviewed 104 consecutive MR imaging studies acquired in patients 4-18 years of age with open physes. Frequency of various injuries was compared by using a chi 2 test. The frequency of each injury was compared with published adult data by using the Student t test. Arthroscopic follow-up in 30 patients was used to calculate sensitivity and specificity. RESULTS: The medial meniscus was found to be injured more frequently than the lateral meniscus or the anterior cruciate ligament (ACL). Both menisci were injured less frequently than in adults. Sensitivity and specificity of MR imaging for meniscal tears were 83% and 95%, respectively, and for ACL tears were 64% and 94%, respectively. CONCLUSIONS: These results show that medial meniscal tears are the most common cartilaginous or ligamentous injury in children and adolescents. The frequency of specific injuries, however, is different from that in adults.

Adolescent↗
PubMed1990

Regional phase correction of inversion-recovery MR images.

Many MR imaging systems are limited in their ability to successfully display inversion-recovery images. The reason is that part of the contrast is encoded as phase differences between pixels, whereas in the more commonly used spin-echo pulse sequence all the information is contained in the pixel magnitude. Inversion-recovery images are often displayed in magnitude form, resulting in loss of potentially useful phase information contained in the data. Before this phase information can be used, phase errors which result from scanner imperfections must be removed. While most of the necessary correction can be accomplished using data obtained by scanning a uniform phantom, this approach has several disadvantages. An alternative method by which phase errors can be readily removed without phantom data is described. This method has been applied to images of the head, knee, and liver with good results. It is concluded that this technique is useful for producing phase corrected inversion-recovery MR images.

Algorithms↗
PubMed1988

Mediastinal lymph nodes: relaxation time/pathologic correlation and implications in staging of lung cancer with MR imaging.

The authors measured the T1 and T2 relaxation times of freshly excised human mediastinal lymph nodes to determine whether the times are clinically useful in distinguishing benign from malignant nodes. All measurements were performed at 20 MHz and 40 degrees C, within 45 minutes of lymph node excision. Mean T1 and T2 relaxation times of 99 benign nodes were 566 msec (standard deviation [SD], 117 msec) and 92 msec (SD, 29 msec), respectively. For the 16 malignant nodes, these times were 640 msec (SD, 138 msec) and 105 msec (SD, 26 msec), respectively (P less than .05 for difference in T1 times, P greater than .05 for difference in T2 times). Histograms showed considerable overlap in the relaxation times of benign and malignant nodes such that absolute measurement of these times will likely be of limited clinical value.

Humans↗
PubMed1987

Chemical shift-based true water and fat images: regional phase correction of modified spin-echo MR images.

The process of separating water and fat signal in magnetic resonance images with the Dixon pulse sequence is hindered by phase errors in the water-fat opposed image. These errors arise from static field inhomogeneities, varying magnetic susceptibilities of different body tissues, and other causes. Phase correction performed with data from phantom imaging can compensate for static field inhomogeneities but not for the other effects. A regional phase-correction algorithm is presented that removes non-chemical-shift phase effects and produces true water and fat images. The technique has been applied with good results to 21 patients and healthy volunteers. The images include ones of the abdomen, knees, hips, spine, and head. This method of regional phase correction is an efficacious way of producing separate water and fat images with the Dixon pulse sequence.

Adipose Tissue↗
PubMed1981

Oblique-angle tomography: a restructuring algorithm for transaxial tomographic data.

A set of contiguous transaxial tomographic sections obtained with a rotating-camera tomograph represents the full three-dimensional distribution of activity within a volume of the body. Tomographic sections in planes other than the origianl transverse plane can be produced from these data merely by resorting the data appropriately. The paper presents a simple and efficient algorithm for producing tomograms of the heart oriented either at right angles to the long axis of the left ventricle, or parallel to it. Tomograms in these orientations have specific advantages for imaging the heart and avoid some of the limitations seen in comparable tomograms obtained by the seven-pinhole technique.

Heart↗
PubMedDate not supplied

MR imaging of Crohn disease: use of perflubron as a gastrointestinal contrast agent.

This study was undertaken to evaluate the use of perflubron (perfluorooctylbromide) as an oral contrast agent for magnetic resonance (MR) imaging of patients with Crohn disease. MR examinations were performed before and after perflubron administration in 12 patients with documented Crohn disease. Glucagon was administered intramuscularly before the post-perflubron examinations. Each patient also underwent abdominal computed tomography within 48 hours of MR imaging. The imaging studies were analyzed for effectiveness of bowel marking with oral contrast agent, clarity bowel wall visualization, and presence of bowel wall thickening and extraluminal manifestations of Crohn disease such as abscess or fistula formation. Analysis of the imaging studies showed effective marking of the bowel with perflubron and improved bowel wall visualization on postcontrast MR images. Detection of bowel wall thickening and extraluminal complications of Crohn disease was not significantly improved on postcontrast MR images. The authors conclude that perflubron administration effectively marked the bowel and increased the clarity of bowel wall visualization but did not significantly increase the detection of abnormalities related to Crohn disease in the study population.

Adult↗