[Retention of contrast media in the history of radiology : Sequelae of the former use of thorotrast and new challenges].

Detection of gadolinium deposits in patients who have repeatedly been administered intravenous gadolinium chelates have given rise to concern regarding the long-term safety of magnetic resonance imaging (MRI) contrast media. Nevertheless, negative long-term clinical effects have not yet been observed. In some publications parallels have been drawn to the sequelae of thorotrast that was formerly used for arterial angiography.

The German Thorotrast Cohort Study: a review and how to get access to the data.

It is well known that exposures like those from (226)Ra, (224)Ra and Thorotrast(®) injections increase the risk of neoplasia in bone marrow and liver. The thorium-based radioactive contrast agent Thorotrast(®) was introduced in 1929 and applied worldwide until the 1950s, especially in angiography and arteriography. Due to the extremely long half-life of several hundred years and the life-long retention of the thorium dioxide particles in the human body, patients suffer lifetime internal exposure.

[The medical management of high risk individuals. Experiences with persons exposed to chronic internal irradiation].

The medical management and counseling of persons at high risk due to exposure to chemicals or radiation or due to personal disposition, present an additional challenge for physicians and especially radiologists involved. This article is based on own experiences with patients who had been exposed to Thorotrast. They had been injected with the contrast medium Thorotrast, which was in use world-wide until around 1950.

[Therapy-induced effects in normal tissue].

More than 50% of cancer patients survive for more than 5 years, owing to modern and effective treatment. Therefore, long-term sequelae of treatment are more frequently seen than in the past. Such effects on normal tissue may both mimic and obscure tumor recurrences.

Mortality among Thorotrast-exposed patients and an unexposed comparison group in the German Thorotrast study.

Thorotrast was the brand name of a stabilised colloidal solution of thorium dioxide which was used preferentially as an X-ray contrast medium for arteriography between 1930 and 1950. The administration of the medium led to lifelong chronic alpha-particle irradiation by thorium decay products, mainly in the organs of deposition. Several epidemiological follow-up studies were set up after recognition of these side-effects among which the German study was the largest.

[Screening in cardiovascular diseases].

Cardiovascular disease still ranks number one in the mortality statistics in the industrialized world. In Germany the five most common causes of death are all associated with arteriosclerotic changes of the arterial vasculature. As the treatment often extends over long periods and it can be impossible for patients to work, peripheral arterial occlusive disease (PAOD) constitutes a not inconsiderable economic factor.

Computed tomography in various fields outside medicine.

CT has been widely used for non-medical purposes, for which, as in medicine, it has the advantage of being non-destructive and having a high spatial and density resolution. CT may help to generate 3-D views which could otherwise be obtained only by dissecting the object. There is almost no limitation with regard to X-ray exposure and scanning time.

Hepatic phospholipids in alcoholic liver disease assessed by proton-decoupled 31P magnetic resonance spectroscopy.

Background/aims: Alteration of the phospholipid composition of hepatic biomembranes may be one mechanism of alcoholic liver disease (ALD). We applied proton-decoupled (31)P magnetic resonance spectroscopic imaging ({(1)H}-(31)P MRSI) to 40 patients with ALD and to 13 healthy controls to confirm that metabolic alterations in hepatic phospholipid intermediates could be detected non-invasively.

Methods: All patients underwent liver biopsy.

Can pre-operative contrast-enhanced dynamic MR imaging for prostate cancer predict microvessel density in prostatectomy specimens?

The aim of this study was to correlate quantitative dynamic contrast-enhanced MRI (DCE MRI) parameters with microvessel density (MVD) in prostate carcinoma. Twenty-eight patients with biopsy-proven prostate carcinoma were examined by endorectal MRI including multiplanar T2- and T1-weighted spin-echo and dynamic T1-weighted turbo-FLASH MRI during and after intravenous Gd-DTPA administration. Microvessels were stained on surgical specimens using a CD31 monoclonal antibody.

Assessment of focal liver reaction by multiphasic CT after stereotactic single-dose radiotherapy of liver tumors.

Purpose: To characterize and quantitatively assess focal radiation reactions in the liver after stereotactic single-dose radiotherapy for liver malignancies.

Methods And Materials: A total of 131 multiphasic CT scans were performed in 36 patients before and after stereotactic radiotherapy for liver tumors. The examination protocol included a nonenhanced scan and contrast-enhanced scans at different times after contrast injection.

[Comparison of MultiHance and Gadovist for cerebral MR perfusion imaging in healthy volunteers].

To evaluate the weakly protein interacting MR contrast agent MultiHance((R)) and the one-molar agent Gadovist((R)) for cerebral perfusion MR imaging, a randomized intraindividual study was conducted in 12 healthy male volunteers. Perfusion-MRI was performed with single and double dose of each contrast agent on a 1.5T MR system using a gradient-echo EPI sequence.

Cerebral arteriovenous malformations: morphologic evaluation by ultrashort 3D gadolinium-enhanced MR angiography.

The purpose of this study was to evaluate the usefulness of a new ultrashort contrast-enhanced (CE) MR angiography (MRA) for the morphologic evaluation of cerebral arteriovenous malformations (AVMs). The method was compared with conventional X-ray digital subtraction angiography (DSA) and time-of-flight (TOF) MRA in 22 patients to assess the angioarchitecture of the malformations which is essential for treatment planning and follow-up. Two experienced MR readers independently evaluated both techniques with regard to the assessment of feeding arteries, AVM nidus, and venous drainage patterns.

[Successful long-term treatment of multiple metastases from renal cell carcinoma: combination of stereotactically guided percutaneous single-dose convergent beam irradiation and surgery].

The case of a patient suffering from renal cell carcinoma and recurrent brain metastases shows how the survival period can be significantly prolonged by a combination of stereotactically guided percutaneous single-dose convergent beam irradiation and surgery. This 58-year-old man's left kidney was completely excised because of a renal cell carcinoma. After 18 months and 25 months, respectively, a right frontal brain metastasis was operated on.

Differentiation of radiation necrosis from tumor progression using proton magnetic resonance spectroscopy.

We report on a young woman who was treated by stereotactic radiotherapy for recurrence of an initially resected low-grade astrocytoma. MRI follow-up examination 7 months after radiotherapy showed a gadolinium-DTPA-enhancing mass lesion indicative of high-grade tumor progression. This assumption was also supported by positron emission tomography with [2-18F]fluoro-2-deoxy-D-glucose (FDG-PET).

Postoperative fluid-attenuated inversion recovery MR imaging of cerebral gliomas: initial results.

Fluid-attenuated inversion-recovery (FLAIR) imaging has shown to be a valuable imaging modality in the assessment of intra-axial brain tumors; however, no data are available about the role of this technique in the clinically important postoperative stage. The purpose of this study was to evaluate the diagnostic potential of FLAIR MR imaging in residual tumor after surgical resection of cerebral gliomas. Fifteen patients with residual cerebral gliomas were examined within the first 18 days after partial surgical resection of cerebral gliomas.

Bone marrow microcirculation analysis in multiple myeloma by contrast-enhanced dynamic magnetic resonance imaging.

The aim of our study was to investigate the quantitative microcirculation parameters amplitude A (hypothetical intravascular volume) and exchange rate constant k(21) (hypothetical vascular permeability) by contrast-enhanced dynamic magnetic resonance imaging (dMRI) as markers of angiogenesis in multiple myeloma (MM). Therefore lumbar spine and spina iliaca superior posterior of 16 normal controls and 41 patients with active MM were assessed using a dMRI protocol with a pump controlled bolus infusion of Gadolinium-DTPA. Pharmacokinetic parameters, amplitude A and exchange rate constant k(21) were calculated according to a 2-compartment model.

Proton MR spectroscopic evaluation of suspicious brain lesions after stereotactic radiotherapy.

Background And Purpose: The radiologic assessment of suspicious brain lesions after stereotactic radiotherapy of brain tumors is difficult. The purpose of our study was to define parameters from single-voxel proton MR spectroscopy that provide a probability measure for differentiating neoplastic from radiation-induced, nonneoplastic lesions.

Methods: Seventy-two lesions in 56 patients were examined using a combined MR imaging and MR spectroscopy protocol (point-resolved spectroscopy, TE = 135 ms).