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Biomedical subjects

E Rummeny

Publications and source records attributed to E Rummeny.

At least 37 records · Page 2Linked to original sources
PubMed1993

Experimental liver cancers: Mn-DPDP-enhanced rims in MR-microangiographic-histologic correlation study.

During both animal and clinical studies with manganese (II) N,N'-dipyridoxylethylenediamine-N,N'-diacetate 5,5'-bis(phosphate) (DPDP), enhanced rims around liver tumors on magnetic resonance (MR) images have been observed. To elucidate the origins of these rims and to assess their potential value in the differential diagnosis of liver masses, the authors studied 15 rats with induced hepatocellular carcinoma (HCC), 10 rats with implanted Novikoff hepatomas, and 11 rabbits with implanted VX2 carcinomas. A total of 69 primary and secondary liver cancers from these three animal models were studied. Mn-DPDP- and gadolinium tetraazacyclododecantetra acetic acid (DOTA)-enhanced MR images were compared. On the Mn-DPDP-enhanced images, 34 peritumoral rims of various patterns were displayed, all of which were exclusively related to the presence of highly malignant primary and secondary liver tumors. Peritumoral zones of malignant infiltration, surrounding parenchymal compression, and bile duct proliferation were seen to be the origin of these rims after comparison of MR images with the corresponding microangiograms and histologic specimens.

Angiography↗
PubMed1991

Differentiation of bronchogenic carcinoma from postobstructive pneumonitis by magnetic resonance imaging: histopathologic correlation.

Obstructive pneumonitis frequently occurs distal to hilar bronchogenic carcinomas or in lung adjacent to peripheral tumors. The article evaluates the role of MRI in the differentiation of tumor from pneumonitis. Twelve patients underwent MRI of the thorax before surgery. T1-weighted (SE 310/20) and T2-weighted (SE 2000/60-120) images were obtained through the tumor and presumed areas of pneumonitis. Five histologic types of pneumonitis were identified on pathologic examination of the 12 specimens. Cholesterol pneumonitis, found in 7 patients, was the most common type. Organizing pneumonitis, bronchiectasis with mucus plugs, atelectasis, and abscess were found in 3, 4, 2, and 1 patients, respectively. MRI was able to differentiate tumor from pneumonitis in 5 of 6 patients with a hilar mass and in 5 of 6 patients with a peripheral tumor. This was achieved by a visual difference in signal intensity on heavily T2-weighted (SE 2000/120) images. Cholesterol pneumonitis and bronchiectasis with mucus plugs were always hyperintense relative to tumor, and organizing pneumonitis and atelectasis were isointense and indistinguishable from tumor. MRI can differentiate tumor from pneumonitis provided that pneumonitis is of the cholesterol type or if there are mucus plugs in the collapsed lung.

Aged↗
PubMed1991

Value of sonography in monitoring the therapeutic response of mediastinal lymphoma: comparison with chest radiography and CT.

The aim of this retrospective study was to assess the diagnostic value of mediastinal sonography, compared with that of chest radiographs and CT, in the follow-up of patients with mediastinal lymphomas and in the prediction of clinical outcome. The sonograms, chest radiographs, and CT scans of 40 consecutive patients with Hodgkin (n = 29) and non-Hodgkin (n = 11) lymphoma obtained before and after completion of therapy were analyzed blindly and independently by three radiologists and compared with clinical outcome. Nine patients were treated with radiotherapy, 12 with chemotherapy, and 19 with combined therapy. Therapeutic response was assessed from all available clinical and biochemical findings as well as from the combined results of all imaging studies performed on further follow-up. The sonograms showed obvious changes in the size and echogenicity of the mediastinal lymphomas that corresponded closely with the response to therapy. Sonography showed complete regression of the lymphomas in 30 patients who had complete remission. In five patients with incomplete remission, sonographic diagnoses were correct. All lymph nodes, irrespective of size, detected with sonography after a phase of complete remission indicated recurrence (five patients). Sonographic findings corresponded with those of CT in 25 (81%) of 31 cases. Clinical outcome suggested that the sonographic findings were more reliable in the five cases in which CT and sonographic findings conflicted. Chest radiographs were inadequate for monitoring the response of mediastinal lymphomas to therapy; in 17 (43%) of 40 cases, a false impression was obtained of the extent and therapeutic response of mediastinal lymphomas. The results of this study indicate that sonography is clearly superior to chest radiographs and comparable to CT for monitoring patients with mediastinal lymphomas.

Adolescent↗
PubMed1991

Detection of hepatic masses in patients with carcinoma: comparative sensitivities of sonography, CT, and MR imaging.

To evaluate the sensitivity of sonography, CT, and MR imaging in the detection of hepatic masses in carcinoma patients, we conducted a prospective study of 75 consecutive patients with gastrointestinal tumors who were admitted for surgical resection of the primary tumor. Sonography was performed with convex transducers of 3.5 and 5.0 MHz. Three noninvasive CT techniques were used: unenhanced CT scans, the incremental bolus dynamic scanning technique, and delayed scanning 4-6 hr after bolus injection of 60 g of iodine. MR images (1.5 T) were acquired as presaturated T1- and T2-weighted spin-echo sequences and as breath-holding fast low-angle shot (FLASH) 60 degrees and FLASH 15 degrees sequences. As it is difficult to distinguish benign from malignant masses solely on the basis of morphologic criteria, the techniques for each imaging method were designed to detect and not to characterize hepatic lesions. Each examination was interpreted blindly, and the results were compared with surgical findings, intraoperative sonography, and biopsy of the liver as the gold standard. All focal hepatic masses verified at surgery, malignant or benign, were included in the analysis. Sixty-five (68%) of 95 focal hepatic masses were detected by CT, 60 lesions (63%) by MR, and 50 lesions (53%) by sonography. Although lesions 1-2 cm were shown almost equally well by CT and MR (74% and 77%, respectively), the detection rate of smaller lesions (less than 1.0 cm) decreased more drastically with MR (31%) than with CT (49%). Sonography had a sensitivity of only 20% with the smaller lesions. All imaging techniques had a sensitivity of 100% for focal hepatic masses larger than 2.0 cm. Our results show that CT has a higher overall sensitivity (68%) than MR and sonography for the detection of focal hepatic masses. When the results of the three procedures are combined, the overall sensitivity is 77%. This is unsatisfactorily low, as CT and MR have a size threshold of about 1.0 cm and are relatively unreliable for the detection of smaller lesions.

Adenocarcinoma↗
PubMed1990

Hepatic tumors: quantitative tissue characterization with MR imaging.

To determine which quantitative methods of image analysis are most suitable for the differential diagnosis of benign and malignant hepatic lesions, the authors analyzed magnetic resonance images obtained at 0.6 T in 42 patients with proved hepatic cavernous hemangioma and 63 patients with various hepatic malignancies. The lesion-liver signal-intensity ratio for images obtained with a repetition time of 2,350 msec and echo time of 180 msec was most helpful in distinguishing hemangiomas from cancer (area under the receiving operator characteristic curve [ROC] = 0.99 +/- 0.005). All 38 lesions with lesion-liver signal-intensity ratios greater than 3.5 were hemangiomas, whereas all 57 hepatic tumors with a ratio less than 2.5 were malignant neoplasms. A specificity of 93% and sensitivity of 89% can be achieved with use of quantitative signal-intensity data only. The authors conclude that in conjunction with heavily T2-weighted pulse sequences, signal-intensity ratios are an important adjunct to morphologic analysis in the differential diagnosis of hepatic neoplasms.

Adult↗
PubMed1990

Musculoskeletal neoplasms: fast low-angle shot MR imaging with and without Gd-DTPA.

In 121 patients, image contrast and contrast-to-noise ratios (C/Ns) obtained with gadolinium diethylene-triaminepentaacetic acid (DTPA)-enhanced and nonenhanced fast low-angle shot (FLASH) sequences were compared with those achieved with spin-echo (SE) sequences. Among FLASH sequences, contrast between neoplasms and muscle was sufficient with a flip angle of 90 degrees following administration of Gd-DTPA but was 61% lower than that with the T2-weighted SE sequence. High contrast levels were obtained between tumors and bone marrow or fat in sclerotic, calcified, and fibrotic lesions with the use of a flip angle of 90 degrees and in lytic lesions with a flip angle of 10 degrees, reaching 66% of the contrast level obtained with the T1-weighted SE sequence. C/N between tumor and surrounding tissue was always significantly lower with FLASH sequences than with the ideal SE sequences usually used for tumor delineation. Thus, a replacement of the T2-weighted SE sequences by FLASH sequences cannot be recommended. A replacement of the T1-weighted SE sequences by FLASH sequences seems possible but does not significantly reduce examination time.

Adolescent↗
PubMed1989

Central scars in primary liver tumors: MR features, specificity, and pathologic correlation.

Tumor scars were identified at pathologic study and magnetic resonance (MR) imaging in ten of 17 (59%) primary liver tumors (nine hepatocellular carcinomas, four giant hemangiomas, two hepatic adenomas, and two cases of focal nodular hyperplasia). Histopathologic examination revealed three types of scar tissue. Inflammatory scars (n = 4), with edema, necrosis, hypercellularity, and loose fibrous tissue, appeared hypointense relative to liver on T1-weighted images and hyperintense on T2-weighted images. Vascular scars (n = 3), predominantly composed of vascular channels traversing collagenous tissue, showed MR features similar to those of inflammatory scars. Collagenous scars (n = 3) appeared hypointense relative to liver on both T1-weighted and T2-weighted images. Central tumor scars are a frequent but nonspecific feature of both benign and malignant primary liver tumors.

Adult↗
PubMed1989

Forty-millisecond MR imaging of the abdomen at 2.0 T.

The ability of an ultrafast magnetic resonance (MR) imaging technique to provide abdominal MR images free of motion artifacts was studied. Individual T2-weighted transverse MR images were acquired in as little as 40 msec on a whole-body system operating at 2.0 T. Clinical evaluation was undertaken with fat-suppressed images in which only protons of water molecules contributed to image signal intensity. The ultrafast MR images were compared with conventional MR images obtained at 0.6 T. In 22 patients and two healthy volunteers, ultrafast MR images were of diagnostic quality and free of motion artifacts. Images obtained at an echo time (TE) of 30 msec (imaging time, 40 msec) had liver signal-to-noise ratios of 56.3 +/- 22.6 (n = 19). Because of a smaller data matrix, ultrafast MR images had soft-tissue interfaces that were less sharp than those of the highest-quality conventional MR images in which no motion artifacts were present. However, ultrafast MR images demonstrated high T2-dependent soft-tissue contrast, and pathologic and normal anatomies were readily detected with both imaging techniques. This ultrafast imaging technique has significant promise in whole-body MR imaging, in which motion artifacts often degrade image quality.

Abdomen↗
PubMed1989

Primary liver tumors: diagnosis by MR imaging.

MR features of 153 proved primary liver tumors (95 malignant, 58 benign) in 55 patients with hepatocellular carcinoma (21), cholangiocarcinoma (seven), carcinosarcoma (one), hepatoblastoma (one), hemangioma (16), hepatic adenoma (four), focal nodular hyperplasia (three), leiomyoma (one), and hemangioendothelioma (one) were studied retrospectively to determine which techniques are most reliable for lesion detection and which criteria are most useful for differential diagnosis. MR data were correlated with histologic features such as fatty degeneration, fibrosis, and peritumoral edema. Unlike metastatic cancer, hepatocellular carcinoma was best detected (p less than .01) with T2-weighted pulse sequences. The mean tumor-liver T2 difference was 34.4%, while the mean T1 difference was only 21.8%. A tissue-specific diagnosis of hepatocellular carcinoma was possible in 14 of 21 patients by identification of fatty degeneration of the tumor (eight of 17), tumor capsule (five of 21), and/or vascular invasion (six of 21). MR features of peritumoral edema, present in six of 21 patients with hepatocellular carcinoma and in seven of 25 patients with metastases, were exclusively associated with malignant tumors. The large variation in tissue characteristics (relaxation times and proton density) seen in primary liver tumors necessitates the use of multiple pulse sequences to maximize lesion detection. However, the combined use of T1- and T2-weighted spin-echo and T2-weighted phase-contrast images had the advantage of distinguishing benign from malignant primary liver tumors in 48 of 55 patients in this series.

Adenoma↗
PubMed1989

Detection of hepatic metastases with MR imaging: spin-echo vs phase-contrast pulse sequences at 0.6 T.

The purpose of this study was to compare the sensitivity of T1-weighted and T2-weighted spin-echo (SE) pulse sequences with T2-weighted phase-contrast (PC) imaging techniques for the detection of hepatic metastases. Pulse-sequences performance was evaluated in 52 consecutive patients with 88 hepatic metastases who underwent MR imaging at 0.6 T. Lesion-liver contrast-to-noise ratios (CNR) on SE 260/14 (-12.4 +/- 6.7) and PC 2350/60 (+10.8 +/- 4.2) images were significantly (p less than .05) greater than on SE 2350/60 (+ 7.8 +/- 3.9), SE 2350/120 (+8.1 +/- 4.8), SE 2350/180 (+7.9 +/- 4.5), and PC 2350/30 (+4.6 +/- 2.9) images. Sensitivity for detection of 88 individual metastases was comparable on SE 260/14 (78 of 88 patients) and PC 2350/60 (81 of 88 patients) images and was significantly (p less than .05) greater than on in-phase T2-weighted SE images (TE = 60, 70 of 88 patients; TE = 120, 69 of 88 patients; TE = 180, 65 of 88 patients). Histologic analysis of tumor-free liver showed fatty change in 11 of 13 specimens available for pathologic evaluation. In all 11 of those patients, PC images increased tumor-liver contrast in comparison with the in-phase SE images. This analysis suggests that for detection of hepatic metastases at midfield strengths, the T1-weighted, short TR/short TE (SE 260/14) and the T2-weighted, phase-contrast (PC 2350/60) pulse sequences offer comparable performance.

Adult↗
PubMed1988

Estimation of tumor oxygenation and metabolic rate using 31P MRS: correlation of longitudinal relaxation with tumor growth rate and DNA synthesis.

31P MRS longitudinal relaxation times (T1) were determined for C3H murine fibrosarcomas (FSaII), and mammary carcinomas (MCaIV). Tumors were implanted in the foot dorsum, and were 100-300 mm3 in volume. T1s were repeated after the animal was allowed to breathe 100% oxygen for 30 min and then again 36-48 hr following 30 Gy. The spectrum were obtained using an 8.5 T spectrometer with a 8 cm bore and a 1.4 cm single turn antenna coil. The 31P relaxation times for untreated tumors in air breathing animals were: 3.78 sec for phosphomonoesters, 4.37 sec for inorganic phosphate (Pi), 2.73 sec for phosphocreatine, 1.37 sec for gamma ATP, 1.14 sec for alpha ATP, and 1.18 sec for beta ATP. The Pi T1s were 4.37 and 4.70 sec in control and irradiated tumors in air breathing animals. Respiration of oxygen for 30 min reduced the T1s to 3.02 and 2.62 sec in control and irradiated tumors respectively. The Pi T1 of an anoxic tumor, determined on an in situ tumor 60 min after death was 5.93 sec. The oxygen breathing induced decrease in the T1 of Pi is unlikely to have been caused by the paramagnetic properties of oxygen alone, and suggests a component of increased magnetization transfer secondary to the ATPase reaction. Oxygen breathing following 30 Gy, resulted in a decreased growth time (800 mm3 endpoint) and an increased proportion of cells in S-phase. These results support the hypothesis that the decrease in Pi T1 measured with oxygen breathing is a measure of tumor oxygen tension and metabolic rate, and suggests that T1 measurement may indirectly predict tumor growth rate and DNA synthesis.

Animals↗
PubMed1988

Differentiation of hepatic metastases from hepatic hemangiomas and cysts by using MR imaging.

T1-weighted and T2-weighted pulse sequences were employed for MR imaging of hepatic metastatic tumors (98 patients), hemangiomas (24 patients), and cysts (seven patients); a 0.6-T superconducting magnet was used. In a retrospective study, signal intensity and morphology were used to establish criteria for differentiating metastases from hemangiomas and cysts. The signal intensity of the lesion alone failed to be an etiologic discriminator because over 96% of all masses had a signal intensity less than that of liver on T1-weighted sequences, and at least 90% had a signal intensity greater than that of liver on T2-weighted sequences. Morphologic features depicted on T2-weighted images were more specific than those depicted on T1-weighted images in differential diagnosis. Amorphous, target, and halo signs and a change in morphology were present only in metastatic disease, with a frequency of 45%, 27%, 13%, and 12%, respectively. Two other morphologic patterns--doughnut and lightbulb signs--were found to have overlapping causes. Overall, at least one of the specific signs was observed in 92% of patients with metastatic disease. These data suggest that T2-weighted pulse sequences are essential for discriminating between hepatic metastases and hepatic hemangiomas and cysts. MR imaging is a promising technique for distinguishing these lesions.

Cysts↗
PubMed1988

[Magnetic resonance tomography of focal liver and spleen lesions. Experiences using ferrite, a new RES-specific MR contrast medium].

Superparamagnetic iron oxide (ferrite), a novel, reticuloendothelial cell-specific contrast agent used for magnetic resonance imaging (MRI), was evaluated in the detection of liver and spleen tumors in animal models and in phase I and II clinical trials in 33 patients. The initial results obtained in experimental cancer models showed a dramatic improvement in tumor detection. Our first clinical trials confirmed the experimental results and showed that ferrite-enhanced MRI significantly (p less than 0.05) increases the detection of individual lesions. Furthermore, the threshold of detectable tumor size decreased significantly, to 3 mm, when standard MR spin echo imaging techniques were used.

Animals↗
PubMed1988

Effects of pentobarbital anesthesia on the energy metabolism of murine tumors studied by in vivo 31P nuclear magnetic resonance spectroscopy.

The effects of pentobarbital anesthesia on the energy metabolism of FSaII and MCaIV foot tumors in mice were studied by 31P MRS. Using an 8.5 T spectrometer, in vivo spectra were obtained in 15 animals before and after pentobarbital anesthesia (0.05 mg/g ip). The average phosphocreatine/inorganic phosphate ratios (PCr/Pi) with and without pentobarbital were similar for both tumor histologies. Effects on individual tumors, however, were greater than 20% in 9/15 animals and greater than 50% in 6/15 animals. Pentobarbital anesthesia increased the variability of tumor intracellular pH, and the phosphomonoester/nucleotide triphosphate (PME/NTP) and nucleotide triphosphate/inorganic phosphate ratios (NTP/Pi). When examining the average in a cohort, pentobarbital anesthesia had no significant effect on the PCr/Pi, PME/NTP, NTP/Pi ratios or the pH. However, approximately equal to 50% of individual tumors do have significant changes in these parameters. The anesthesia-induced variability of tumor energy metabolism may explain the decrease in TCD50 observed in previous studies using multifraction radiation.

Anesthesia↗