Multifocal leukoencephalopathy and polyneuropathy after 18 years on interferon alpha.

Multifocal leukoencephalopathy and sensory-motor polyneuropathy have not been reported as side-effects of long-lasting interferon alpha therapy in a single patient. In a 77-year-old man interferon alpha2b and interferon alpha2a were administered subsequently but continuously since 1984 for hairy cell leukemia. Since early 2000, left-sided hemi-hypesthesia occurred and the patient developed gait disturbance, proximal weakness of the lower limbs, bilateral stocking-type sensory disturbances, and restless leg syndrome. Repeated cerebral magnetic resonance images showed multifocal T2-hyperintense white matter lesions supratentorially. The nerve conduction velocity of the peroneal and sural nerve was reduced. After exclusion of various differential diagnoses of leukoencephalopathy and application of a screening program for polyneuropathy, central and peripheral nervous system abnormalities were attributed to the long-lasting interferon alpha therapy. In single patients abnormally long-lasting interferon alpha therapy may cause multifocal white matter lesions supratentorially and sensory-motor polyneuropathy.

[Vascularization of fibroadenomas: contrast harmonic imaging compared with contrast-enhanced power doppler]. / Vaskularisation von Fibroadenomen: Kontrast-Harmonic-Imaging in Vergleich mit kontrastverstärktem Power Doppler.

PURPOSE: To compare contrast material-enhanced harmonic power Doppler ultrasonography (CHI) with conventional contrast-enhanced power Doppler ultrasound (CPD) in depicting the vascularity of fibroadenomas. MATERIALS AND METHODS: Forty patients with fibroadenomas (aged 19-61 years) underwent conventional contrast-enhanced and harmonic power Doppler US. According to a standardized examination protocol, serial dynamic scans were obtained before and at 30, 90 and 150 seconds after injection of contrast agent. Video-taped scans were independently reviewed by three blinded readers with regard to parameter artifacts, degree of Doppler signal enhancement, demarcation of vessels and extent of vessel visualization. RESULTS: The number of intratumoral power Doppler signals depicted was similar with both techniques at 30-90 seconds after contrast administration; however, after 90 seconds, CPD depicted significantly more intratumoral signals than did CHI (p < 0.0001). CHI was superior to CPD with regard to "blooming" or motion-related artifacts (p < 0.0001). CONCLUSION: CHI balances the increased susceptibility of CPD to interference from clutter artifacts and thus allows the depiction of vessels that may have been obscured on CPD at similar system settings.

Rheumatoid arthritis of the craniocervical region: assessment and characterization of inflammatory soft tissue proliferations with unenhanced and contrast-enhanced CT.

The aim of this study was to depict and characterize inflammatory soft tissue proliferations caused by rheumatoid arthritis (RA) in the craniocervical region by unenhanced and contrast-enhanced CT. Computed tomography of the craniocervical region was performed in 35 patients in the axial plane before and after the i.v. administration of contrast material. According to the densities and contrast enhancement of the inflammatory soft tissue proliferations, four groups were classified. Ancillary findings, such as a compression of the dural sac or spinal cord, erosions of the bony structures, and atlantoaxial subluxation, were also evaluated. Inflammatory soft tissue proliferations were depicted in 28 of 35 patients and could be differentiated by unenhanced and contrast-enhanced CT according to the above defined criteria: effusion in 6 patients (17%); hypervascular pannus in 8 (23%); hypovascular pannus in 5 (14%); and fibrous tissue in 9 patients (26%). A compression of the dural sac was seen in 11 (31%) patients; 3 of these had neurological symptoms. Erosions of the odontoid process were found in 20 (57%) patients; 16 (80%) of these also showed erosions of the atlas. Atlantoaxial subluxation was seen in 11 (31%) patients. Inflammatory soft tissue proliferations in the craniocervical region caused by RA can be reliably demonstrated and classified by unenhanced and contrast-enhanced CT, which can differentiate between joint effusion and various forms of pannus and depict ancillary findings. Computed tomography is an alternative method for patients unable to undergo an MRI examination.

Immunoglobulins are effective in pontine myelinolysis.

Although the exact pathogenesis of central pontine myelinolysis (CPM) is unknown, correction of hyponatremia, thyreotropin releasing hormone, plasmapheresis, and corticosteroids seem to be effective. Assuming intravenous immunoglobulins (IVIG) to also be effective in CPM, 0.4 g/kg body weight/d immunoglobulins were applied to a 48-year-old patient who developed CPM with double vision, dysarthria, dysphagia, and left-sided hemiparesis 3 weeks after spontaneous normalization of hyponatremia. After 5 days of IVIG, his symptoms markedly improved, confirmed by improvement in the Norris score (42%), Frenchay score (19%), Kurtzke score (20%), Disability score (54%), vital capacity (26%), and peak torque (69%). The promising clinical effect of IVIG was assumed to be caused by the reduction of myelinotoxic substances, the development of antimyelin antibodies, and the promotion of remyelination. In conclusion, IVIG appear to be a promising therapeutic option in CPM.

[Tissue harmonic imaging sonography. Is the image quality in routine abdominal ulstrasound improved?]. / Tissue Harmonic Imaging Sonographie. Wird die Bildqualität bei Routine-Ultraschalluntersuchungen im Abdomen verbessert?

PURPOSE: Evaluation and statistical analysis of the influence of THI with pulse-inversion technology on image quality in abdominal ultrasound in comparison to conventional sonography. MATERIAL AND METHODS: In 25 patients 398 ultrasound images of the abdomen were evaluated in a prospective, double blind study. 49% of the images were obtained with THI sonography, 51% with conventional sonography, respectively. Image parameter, anatomical region and image plane were kept constant by using a switchable ultrasound probe. Image contrast, delineation of organs, detection of vessels and artifacts in cystic structures were evaluated by four radiologists using a 3-grade scale. The interobserver variability was determined. RESULTS: The results of all groups showed statistically significant improvement compared to conventional sonography. High agreement of the evaluaters was achieved for image contrast and delineation of organs, less agreement in detection of vessels and artifacts in cystic structures, respectively. CONCLUSION: Image contrast and delineation of organs to neighboring structures as well as reduction of artifacts in cystic structures and vessels are statistically significantly improved with THI sonography using pulse-inversion technology in comparison to conventional sonography.

Contrast-enhanced MR imaging of two superparamagnetic RES-contrast agents: functional assessment of experimental radiation-induced liver injury.

The purpose of this study was to compare liver contrast-enhancing characteristics of two superparamagnetic reticuloendothelial system (RES)-directed agents with different particle sizes, polycrystalline iron oxide nanocompounds (PION) and carboxydextran-coated maghemite (DDM128N/389, later referred to as DDM128), in an experimental model of focal radiation-induced hepatitis. PION, for the small particle size (31 nm), and DDM128, for the large particle size (59 nm), RES-directed agents were compared for liver enhancement after radiation-induced liver injury. A single x-irradiation exposure varying from 10 to 60 Gy was delivered to one side of the liver. T2-weighted spinecho magnetic resonance imaging was performed 3 days after x-irradiation at 30 minutes post-contrast. Using the RES-directed PION, the normal, non-irradiated portion of the liver decreased in signal intensity with a maximum negative enhancement of -66%, while the irradiated portion of the liver decreased in signal intensity by -24% (60 Gy). The signal intensity decline of irradiated liver tissue using PION was dose dependent, but was found at all radiation dose levels (10-60 Gy). The difference in signal intensity between irradiated (-63%) and non-irradiated (-82%) portions was also statistically different using DDM128 at 60 Gy. However, lower irradiation doses (10 and 30 Gy) failed to produce a statistically significantly different enhancement in the irradiated and non-irradiated portion of the liver. Sensitivity of liver enhancement with RES-directed agents is size dependent. The smaller particle (PION) is more sensitive for detection of radiation-induced hepatitis than the larger particle (DDM128). The relative insensitivity of DDM128 enhancement for diffuse liver injury will be clinically advantageous for detecting focal lesions in the presence of diffuse hepatic injury.

Magnetic resonance imaging of Achilles tendon in patients with rheumatoid arthritis.

RATIONALE AND OBJECTIVES: The authors characterize the appearance of the Achilles tendon in patients with rheumatoid arthritis and differentiate this appearance from degenerative tendinopathy in patients with chronic pain of the heel using magnetic resonance (MR) imaging. METHODS: Thirty patients with rheumatoid arthritis and 28 patients with chronic pain of the heel underwent MR imaging of the ankle and foot. Three radiologists independently assessed the MR images with respect to size, shape, and intratendinal signal characteristics of the Achilles tendon. The Achilles tendon was considered abnormal on MR imaging when intratendinous signal alterations or an anteroposterior measurement greater than 8 mm was seen. Physical examination of the Achilles tendons was accomplished in both groups. Operation confirmed the diagnosis of 13 patients in the second group with chronic pain of the heel. RESULTS: The Achilles tendon of 83% of patients with rheumatoid arthritis demonstrated various intratendinous patterns (longitudinal, reticular, nodular) of intermediate signal intensity on all pulse sequences on MR imaging. Ninety percent of patients with rheumatoid tendinopathy showed no enlargement of the anteroposterior diameter of the Achilles tendon. In addition, all patients with rheumatoid arthritis had findings compatible with an inflammation of the retrocalcaneal bursa on MR imaging, whereas none of the patients with tendinopathy associated with chronic heel pain had retrocalcaneal bursitis. All patients, however, had enlargement of the anteroposterior diameter of the Achilles tendon. Seventy-nine percent showed various intratendinous lesions of intermediate signal intensity on all pulse sequences. Twenty-one percent of patients had an enlargement of the Achilles tendon without intratendinous changes. CONCLUSIONS: Rheumatoid tendinopathy can be distinguished from degenerative tendinopathy in patients with chronic pain of the heel with MR imaging. Inflammation of the retrocalcaneal bursa and the absence of enlargement of the tendon combined with the presence of intratendinous signal alterations are characteristic findings of rheumatoid tendinopathy.

Quantification of area at risk during coronary occlusion and reperfusion by means of MR perfusion imaging.

PURPOSE: Considerable clinical interest has focused on the size of ischemic myocardium. Fast MR imaging in conjunction with MR contrast media has the potential to identify hypoperfused and infarcted myocardium. This study used MR perfusion imaging to detect and quantify reperfused ischemic myocardium during a brief coronary occlusion and reperfusion, and to characterize the spatial extent of ischemic and reperfused ischemic myocardium relative to the "true" size of the area at risk as defined in histochemical morphometry at post mortem. MATERIAL AND METHODS: The left circumflex (LCX) coronary artery in 8 dogs was occluded for 15 min followed by reperfusion in order to produce regional reversible myocardial ischemia. Perivascular Doppler probes were used to measure blood flow in the left anterior descending (LAD) and LCX coronary arteries. Fast inversion recovery-prepared gradient-recalled-echo images were acquired to delineate the ischemic area during occlusion, and the area of reversible ischemic injury at 1 and 30 min of reperfusion. The size of ischemic and reperfused ischemic myocardium were compared with the area at risk as determined by histochemical morphometry at post mortem. RESULTS: During LCX occlusion, LCX flow decreased from 16+/-1 to 0.2+/-0.1 ml/min. On contrast-enhanced images, ischemic myocardium was evident as a zone of relatively low signal intensity (SI) compared to normal myocardium. The size of the ischemic region was significantly smaller (30+/-2%) than at post mortem (36+/-3%; p<0.05). Immediately after reperfusion, LCX flow increased to 83+/-11 ml/min and the contrast medium caused greater enhancement in the reperfused ischemic region than in the normal myocardium (69+/-3 vs 42+/-3 arbitrary units; p<0.05). The increase in regional SI correlated closely with the increase in regional blood flow (r=0.73). At 1 min of reperfusion, the size of the reperfused ischemic myocardium was larger (48+/-3%, p<0.05) than the area at risk measured at post mortem. At 30 min of reperfusion, when the flow returned to baseline values (16+/-2 ml/min), contrast bolus produced no differential enhancement between the 2 myocardial territories. CONCLUSION: MR perfusion imaging has the potential to detect and quantify the size of ischemic myocardium and the region of post-occlusive hyperemia in the early reperfusion period. There is a significant direct linear relationship between the regional contrast enhancement of reperfused ischemic myocardium and the blood flow during post-occlusive hyperemia. The difference in the size of the area at risk at MR perfusion imaging and at histochemical morphometry may reflect an influence of coronary collateral circulation.

Comparison of albumin-(Gd-DTPA)30 and Gd-DTPA-24-cascade-polymer for measurements of normal and abnormal microvascular permeability.

The purpose of this study was to compare a new MR macromolecular contrast medium (MMCM), gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA)-24-cascade-polymer, to a well-studied prototype MMCM, for the potential of distinguishing tissues of varying endothelial permeability. Three tissue models of varying capillary permeability were studied in a total of 46 rats: normal myocardium (normal capillaries), subcutaneously implanted adenocarcinoma (mild capillary leak), and reperfused infarcted myocardium (high capillary leak). TI-weighted MRI was performed before and dynamically after injection of either albumin-(Gd-DTPA)30 or the cascade polymer (each .02 mmol gadolinium [Gd] per kg). Data analysis based on a two-compartment kinetic model yielded estimates of fractional blood volume (BV) (percentage) and fractional leak rate (FLR) (1 per hour). Permeability to the cascade polymer as reflected in FLR was considerable in normal myocardium (8.24 per hour), of similar value in tumors (8.55 per hour), but significantly greater in infarcted myocardium (39.17 per hour, P < .01) versus normal myocardium. The larger albumin-(Gd-DTPA)30 demonstrated minimal extravasation in normal myocardium (FLR .33 per hour); FLR in tumors was 100% higher (.66 per hour, P < .002) and FLR in reperfused capillaries was significantly greater (7.94 per hour, P < .001). Based on capillary permeability measurements, the cascade polymer may have limited utility for detection of mildly increased microvascular permeabilities. For severe tissue injury, the cascade polymer can resolve abnormal microvascular integrity.

Magnetic resonance imaging in patients with gestational trophoblastic disease.

RATIONALE AND OBJECTIVES: The authors describe the magnetic resonance (MR) imaging characteristics in patients with gestational trophoblastic disease (GTD) before and after therapy and to correlate these findings with human gonadotropin levels and the specific histology of GTD. METHODS: Thirteen women (mean age, 30.1 years) with elevated human chorionic gonadotropin (HCG) levels and histologically proven GTD underwent MR examinations of the pelvis. Magnetic resonance imaging was performed on a 1.5-tesla unit. Axial and sagittal proton density-weighted and T2-weighted and sagittal T1-weighted sequences were obtained. Four patients underwent follow-up studies after 4 and 8 weeks to monitor the response to therapy. Gestational trophoblastic disease was histologically proven with curettage in 11 patients and with hysterectomy in two cases. RESULTS: Nine patients had a diffusely enlarged uterus with pathologic signal intensities. In four patients, a focal tumor mass was observed. All patients showed loss of the zonal anatomy of the uterus in at least one local area. In 11 patients, no uterus zones could be identified throughout the entire uterus. Pathologic dilated tumor vessels were evident in all patients. In all four cases in which follow-up imaging studies were obtained, uterus size, signal intensities, identification of uterus zones, and uterus vessels returned to normal. CONCLUSION: Magnetic resonance imaging shows trophoblastic tumor infiltration as diffuse uterus enlargement, focal tumor masses, loss of zonal anatomy of the uterus, and pathologic uterine vasculature; this seems to be the most reliable MR imaging finding in patients with GTD. No correlation was found between MR imaging changes and HCG levels or specific histologic types of GTD.

Vascular complications in lumbar disk surgery: report of four cases.

Vascular injuries in lumbar disk surgery, although rare, are serious complications which may be overlooked due to a broad range of clinical manifestations. It is important that surgeons and radiologists be aware of these potentially fatal complications and develop an appropriate symptom-based diagnostic paradigm. We reviewed 8099 consecutive cases of lumbar disk surgery, performed over a 14-year period at a single institution, for postoperative vascular complications. We identified four patients (0.05%) with lumbar disk surgery-related vascular complications: intraoperative lacerations of the abdominal aorta and median sacral artery, an arteriovenous fistula between the left common iliac artery and vein detected 19 days postdiskectomy, and a partially thrombosed aortic aneurysm with an arteriovenous fistula between the aneurysm and the inferior vena cava, diagnosed 11 months after surgery. The majority of cases in the literature of vascular injury in lumbar disk surgery were reported prior to 1965. Diagnostic approaches described in that period do not reflect the great range of diagnostic techniques available today. Angiography remains the gold standard for diagnosis and guidance as to surgical repair. However, a high index of suspicion based on clinical signs and/or the use of sonography or CT is important in the detection of these complications.

MR imaging characterization of postischemic myocardial dysfunction ("stunned myocardium"): relationship between functional and perfusion abnormalities.

Stunned myocardium has been detected in patients treated successfully with thrombolytic agents. The hypothesis of this study was that fast gradient echo (GRE) imaging could be used to characterize the regional functional and perfusion abnormalities that are indicative of myocardial stunning. This study was designed to monitor and correlate the extent of wall thickness and perfusion abnormalities as determined by fast (segmented k space) cine and contrast enhanced GRE imaging, respectively. Dogs were subjected to left circumflex (LCX) coronary artery occlusion (15 min) followed by 30-minute reperfusion (n = 8). Perivascular flow probes were used to continuously measure flow in left anterior descending (LAD) and LCX coronary arteries. Short-axis inversion recovery prepared fast GRE and cine images were acquired at baseline, at occlusion, and at 1, 10, and 30 minutes of reflow. Regional signal intensity and percent systolic wall thickening were determined at 26 equally spaced circumferential positions to compare the extent of functional and perfusion abnormalities. During occlusion and reperfusion, the ischemic region was demonstrated on contrast-enhanced images as a hypointense and hyperintense region, respectively. During occlusion, the extent of the perfusion defect (32% +/- 2% of the circumference of the equatorial slice) correlated closely (r = .74) with the extent of contractile dysfunction (35% +/- 2%). After reperfusion, there was transient recovery in the percent wall thickening (26% +/- 4% vs 36% +/- 4% normal), coinciding with the reactive hyperemic response, but this was followed by a significant decline in wall thickening at 10 minutes (19% +/- 4%) and 30 minutes (12% +/- 2%). Fast MR imaging may be useful to monitor postischemic myocardial abnormalities after thrombolytic therapy and the response to pharmacologic interventions.

Contrast-enhanced MR imaging assessment of tumor capillary permeability: effect of irradiation on delivery of chemotherapy.

PURPOSE: To assess the effect of x rays on tumor capillary permeability with macromolecular contrast medium (MMCM)-enhanced magnetic resonance (MR) imaging. MATERIALS AND METHODS: One of paired R3230 mammary adenocarcinomas implanted in the flanks of 48 Fischer rats was treated with a single 5- or 15-Gy dose of x rays. After 1 or 3 days, MR imaging in 30 rats was performed unenhanced and enhanced with albumin-(gadolinium diethylenetriaminepentaacetic acid)30 (0.02 mmol gadolinium per kilogram body weight). Signal intensity enhancement was analyzed to estimate fractional blood volume and permeability-surface area product (PS). In 18 irradiated rats, 2.5 mg/kg cisplatin was injected intravenously, and fractional tumor platinum concentrations were measured spectrometrically. RESULTS: MR imaging showed highest capillary permeability 1 day after 15 Gy (PS 110% above control [P<.001]); PS was elevated 57% 1 day after 5 Gy and 63% 3 days after 15 Gy (P<.05). The largest mean tumor platinum fraction occurred 1 day after 15 Gy: 48% versus 20% (control)(P<.05). CONCLUSION: Transient irradiation-induced increase in tumor capillary permeability to cisplatin can be quantified with MMCM-enhanced MR imaging.

Contrast enhancement in experimental radiation-induced liver injury: comparison of hepatocellular and reticuloendothelial particulate contrast agents.

We compared the liver enhancement of two superparamagnetic agents, polycrystalline iron oxide nanoparticles (PION) and PION coated with asialofetuin (ASF), in an experimental model of focal radiation-induced hepatitis. PION, a reticuloendothelial system-directed agent, and PION-ASF, a hepatocellular-directed agent, were compared for time-dependent liver enhancement in an experimental model of radiation-induced liver injury. Using the reticuloendothelial system (RES)-directed PION, the normal, nonirradiated portion of the liver decreased in signal intensity (SI) with a mean negative enhancement of -66% +/- 4, whereas the irradiated portion (60 Gy, 3 days before imaging) of the liver decreased in SI by -24% +/- 2, significantly less (P <.05). SI changes in irradiated liver tissue using PION were dose-dependent, being more pronounced with lower radiation exposure. The difference in SI changes induced by PION-ASF between irradiated and nonirradiated liver was not statistically different, but SI decreased with a mean negative enhancement of -80% +/- 2. The RES-directed PION is more sensitive for the detection of radiation-induced hepatitis than is the hepatocyte-directed PION-ASF. The insensitivity of PION-ASF enhancement for diffuse liver injury may be clinically advantageous for detecting focal lesions in the presence of diffuse hepatic injury.

Ultrafast computed tomography and three-dimensional image processing of CT sialography in patients with parotid masses poorly defined by magnetic resonance imaging.

The purpose of this study was to determine the efficacy of ultrafast computed tomography (UF CT) in patients with parotid masses poorly defined by magnetic resonance imaging (MRI) and to evaluate the diagnostic potential of three-dimensional (3-D) UF CT sialography when compared with conventional CT sialograms. Thirteen patients with clinical suspicion of a parotid mass, in whom MRI was degraded by motion, underwent UF CT of the parotid region. Two radiologists independently assessed the CT and MR with respect to tumor localization, intraglandular tumor location, tumor margin characteristics, and infiltration of surrounding tissue. In 9 patients, CT sialography was performed using 3-D image processing. Anatomical details and pathologic findings were assessed by three readers using a numerical grad and compared with the findings derived from conventional CT sialography. Histopathologic specimens were obtained in all cases and correlated with the radiographic findings in a consensus manner following the blinded interpretations. UF CT and (suboptimal) MRI provided the same diagnostic information for the evaluation of tumor localization, and intraglandular location. UF CT was superior to MRI in the detection of tumor infiltration, and definition of tumor margins in 2 cases (15%), resulting in a substantial difference in treatment. Three-dimensional CT sialography offered significant improvement in demonstration of anatomic detail (2.5 +/- 0.2 vs 1.5 +/- 0.1, respectively) and pathologic findings (2.6 +/- 0.1 vs 1.3 +/- 0.2, respectively) when compared with conventional CT sialography. UF CT is a viable alternative in uncooperative patients with parotid masses. UF CT 3-D sialography has the potential to allow more precise pre-surgical planning and contributes to the diagnosis and therapy planning of parotid masses.

Three-dimensional processing of ultrafast CT sialography for parotid masses.

PURPOSE: To evaluate the diagnostic potential of three-dimensional image processing of ultrafast CT sialography in comparison with conventional CT sialography in patients with parotid masses. METHODS: In nine patients, CT sialography was done with three-dimensional image processing. The visibility of anatomic details and pathologic findings, derived from three-dimensional images, were graded numerically by three observers and compared with the findings obtained from conventional CT sialograms. Histopathologic specimens were obtained in all cases. RESULTS: Ultrafast CT images showed no motion artifact. Three-dimensional CT sialography offered significant improvement in demonstration of ductal anatomy (2.5 +/- 0.2 versus 1.5 +/- 0.1, respectively) and ductal pathology (2.6 +/- 0.1 versus 1.1 +/- 0.2, respectively) over conventional CT sialography. In two cases, the therapeutic regimen was altered substantially. CONCLUSION: Ultrafast CT three-dimensional sialography has the potential to allow more precise presurgical planning and contributes to the diagnosis and therapy planning of parotid masses, especially in patients in whom MR image quality is degraded by motion artifact.

Tumor angiography using high-resolution, three-dimensional magnetic resonance imaging: comparison of gadopentetate dimeglumine and a macromolecular blood-pool contrast agent.

RATIONALE AND OBJECTIVES: We compared the peritumoral vascular definition in rats using either a paramagnetic extracellular or a macromolecular contrast medium in combination with high-resolution magnetic resonance (MR) imaging. METHODS: High-resolution, three-dimensional spoiled gradient-refocused acquisition in a steady state (SPGR) images were acquired from tumor-bearing Fischer-344 rats before, immediately after, and again 40 min after administration of gadopentetate dimeglumine (0.1 mmol Gd/kg; n = 10) and albumin-(Gd-DTPA)30 (0.05 mmol Gd/kg; n = 5). Small peritumoral vessels were analyzed semiquantitatively on maximum intensity projection angiograms using a 4-point scoring system; quantitative analyses included signal-to-background ratios (SBRs) and signal-to-noise ratios. RESULTS: Gadopentetate dimeglumine caused a transient and low-scoring (0.2 +/- 0.1, SBR = 1.9 +/- 0.2) vessel definition but strong rim enhancement (score = 1.4 +/- 0.2). Albumin-(Gd-DTPA)30 produced persistent, high-quality angiograms (score = 2.6 +/- 0.2, SBR = 7.4 +/- 0.2) but minimal rim enhancement (score = 0.3 +/- 0.2). CONCLUSION: Albumin-(Gd-DTPA)30 combined with high-resolution MR imaging produces time-persistent, detailed angiographic definition of peritumoral vessels. Vascular maps obtained with gadopentetate dimeglumine enhancement are not time persistent or of equal quality.

Technical note: comparison of colour Doppler energy sonography with conventional colour Doppler sonography in detection of flow signal in peripheral renal transplant vessels.

The technical advantage of colour Doppler energy sonography (CDE) results in a higher sensitivity for blood flow detection than in conventional colour Doppler sonography (CDI). We compared the efficiency of CDE versus CDI in the detection of blood flow signals in asymptomatic patients after renal transplantation. 10 asymptomatic voluntary patients after renal transplantation were evaluated with CDI and subsequently with CDE by two examiners. Filter, scale and gate setting were kept constant, the Doppler gain was increased individually in every patient until background noise just did not derange the image. The assessment of blood flow signal was done using a self defined score system. CDI showed Doppler signal in the interlobar vessels in all 10 patients and blood flow signal in arcuate arteries and adjacent portions of interlobular vessels in nine of 10 patients. We were not able to detect blood flow related signal in the more peripheral medullary and cortical vessels. CDE obtained blood flow signal in interlobar and interlobular vessels in all patients. In addition, Doppler signal was observed in all patients in small medullary and cortical vessels. CDE increases detection of blood flow related signal in peripherally located small medullary and cortical vessels. There was no improvement in the evaluation of blood flow in interlobar vessels but marked improvement in blood flow detection in small peripherally located vessels. CDE cannot completely replace CDI in the sonographic evaluation of vascular complications in renal transplants, but should be used as an additional measure to rule out pathology in small peripheral renal vessels.