[99m-Technetium-mercaptoacetyltriglycine (MAG3) for the demonstration of the kidney changes following extracorporeal shockwave lithotripsy. A prospective study of 117 patients]. / 99mTechnetium-Mercaptoacetyltriglycin (MAG3) zum Nachweis von Nierenveränderungen nach extra-korporealer Stosswellenlithotripsie. Eine prospektive Untersuchung bei 117 Patienten.

Extracorporeal shock wave lithotripsy (ESWL) has become the treatment of choice for urinary calculi. 117 patients were studied prospectively with 99mTc mercaptoacetyltriglycine (MAG3) before and after ESWL. 79 (66%) of the 119 kidneys treated had abnormal findings. Of these 63/119 (53%) had abnormal scans. 41 (65%) had focal lesions with a delayed intrarenal transport. The remaining 22 had a diffuse delay of intrarenal transport. A loss of relative renal function of 3% and more compared to the pretreatment values was observed in 50/119 (42%) patients. 99mTc MAG3 should be done routinely together with radiologic tests (CT or MRI) before and after ESWL to select the patients at risk for post ESWL hypertension.

Nuclear medicine studies in the differential diagnosis of diseases with spinal involvement.

Plain X-rays computed tomographic and magnetic resonance images all yield information on the pathophysiology of diseases with spinal involvement. Descriptions of the following nuclear medicine methods are presented: Bone scanning with 99 m-technetium labeled phosphonate complexes used for the evaluation of skeletal metastases, primary bone tumors, traumatic, degenerative, and postoperative changes as well as in inflammatory conditions. Specific radionuclides used for the localization of inflammatory conditions are radioactive labeled leucocytes. Iodine total body scans used to detect spinal metastases of follicular and papillary thyroid carcinoma. 201-thalliumchloride is used as a tumor-marker with high affinity and sensitivity in malignant thyroid tumors. 131- or 123-iodine-meta-iodobenzylguanidine scans used in the detection of metastases of pheochromocytoma and neuroblastoma. Immunoscintigraphy with radioactive labeled anti-CEA antibodies used for the specific labelling of metastases of gastrointestinal tract tumors, melanoma, breast, and ovarian carcinoma. The value of the various nuclear medicine methods in the diagnostic schedule is illustrated in case reports.

SPECT bone scintigraphy of benign and malignant lesions of the spine.

70 patients were examined with planar and SPECT bone scintigraphy. SPECT proved to be superior over planar bone scanning for imaging of traumatic, inflammatory, and malignant bone lesions. SPECT provides three-dimensional information and, therefore, delineates the exact location and extension of lesions. It also has a higher sensitivity than planar bone scintigraphy. The three-dimensional bone scan generates complementary diagnostic information which often facilitates an adequate therapy protocol.

RCBF-quantification with 99mTc-HMPAO-SPECT: theory and first results.

The activity concentrations of 99mTc-HMPAO in brain after intravenous injection were evaluated in 25 patients using SPECT. With additional first pass studies of heart and brain with the short lived isotope 195mAu, the cardiac output and the mean cerebral transit times of the patients were measured a short time before the HMPAO injection. The time dependence of 99mTc-HMPAO activity in the brain was registered during the first 5 min after injection over both hemispheres. Using a simplified three compartment model it was possible to calculate the mean retention fraction of HMPAO in brain from the time activity curves. It could be shown that the regional cerebral blood flow in ml/min per 100 g can be calculated from the activity concentration of HMPAO in the brain, the cardiac output and the retention fraction. In 15 of the 25 cases the rCBF was measured using the planar 133Xe inhalation method as a reference. We found a significant correlation between the mean hemisphere CBF from our method and the mean hemisphere grey matter CBF from the Xenon method with a correlation coefficient of 0.73.

[Intraoperative measurement of radiation dosage following 123-iodine meta-iodobenzylguanidine scintigraphy in surgical therapy of metastatic pheochromocytoma]. / Intraoperative Strahlendosismessung nach 123-Jod-MIBG-Szintigraphie zur operativen Therapie des metastasierenden Phäochromozytoms.

We investigated whether preoperative injection of 123-Jod-MIBG might be useful for intraoperative staging of chromaffine tumor cells. This was performed in a 46 year old patient in whome the diagnosis of a malignant pheochromocytoma had been established by 123-Jod-MIBG image and in catacholamine secretion. The rational for intraoperative staging of this patient was a discrepancy between computer tomography (CT) and the radio nuclide imagine. Intraoperative the tumor mass was identified with an activity of 10 x 10(4) Imp/sec as compared to normal tissue (15 x 10(2). A lymph node metastasis was found to be identified only by prior MIBG imagine and not by CT scanning. We thus conclude that intraoperative employment of this single probe measurement method might help to identify chromaffine tumor cells that have not been located fully by CT.

Intraoperative localization of malignant pheochromocytoma by 123-I-metaiodobenzylguanidine single probe measurement.

Metaiodobenzylguanidine (MIBG) imaging is a well-established method for locating intra- and extraadrenal pheochromocytomas. We investigated whether preoperative injection of 123-I-MIBG might be useful for intraoperative staging of chromaffine tumor cells. This was performed in a 46-year-old patient in whom the diagnosis of a malignant pheochromocytoma had been established by 123-I-MIBG imaging and enhanced catecholamine secretion. The rationale for intraoperative staging in this patient was a discrepancy between computed tomography (CI) of the abdomen and the radionuclide imaging, because scintigraphy revealed a mass with MIBG uptake in the right lower abdomen that could not be visualized by CT. We thus applied a preoperative dose of 4 mCi 123-I-MIBG and determined tissue activity by direct organ measurement. A right abdominal mass was thus identified with an activity of 10 x 10(4) impulses/s as compared to normal tissue (15 x 10(2)). The left-sided tumor was found to be identified correctly by prior CT and MIBG imaging. We thus conclude that intraoperative application of this single probe measurement might help to identify chromaffine tumor cells that have not been located fully by CT.