Role of (111)In-DTPA-pentetreotide scintigraphy in accurate diagnosis of neuroendocrine gastroenteropancreatic tumors.

Most gastroenteropancreatic neuroendocrine tumors contain high-affinity binding sites for somatostatin, and somatostatin-receptor scintigraphy has been introduced for the in-vivo evaluation of such tumors. We report two patients with gastroenteropancreatic neuroendocrine tumors, in whom it was quite difficult to localize the tumors by conventional techniques, and in whom we found that (111)In-DTPA-pentetreotide scintigraphy was useful for accurate information on tumor localization. In the first patient, who had gastrinoma, multiple tumors were shown in the gastrinoma triangle, but we could not clarify whether there were any tumors in the pancreatic body. The selective arterial secretin injection (SASI) test diagnosed that the gastroduodenal artery was the feeder of the gastrinomas, and (111)In-DTPA-pentetreotide scintigraphy with single-photon emission computed tomography indicated the absence of tumors in the pancreatic body. In the second patient, who had insulinoma, multiple liver tumors and a large mass in the hilum of the spleen were shown. (111)In-DTPA-pentetreotide scintigraphy was useful in determining that there was no secretion of insulin from the tumor in the hilum of the spleen. In conclusion, X-ray computed tomography is superior for detection of neuroendocrine tumors, because not all neuroendocrine tumors have somatostatin receptors; however, somatostatin receptor scanning, as well as the SASI test, may be useful for the surveillance of patients with known primary tumors, for monitoring patients with disseminated disease, and for following the treatment of these patients.

[Dynamic MR hepatocholangiography with the SIP Fast GRE (saturation inversion projection fast gradient echo) method].

The purpose of this study was to assess the utility of dynamic MR hepatocholangiography with the Gd-EOB-DTPA enhanced SIP Fast GRE sequence in the hepatobiliary system. The SIP Fast GRE sequence was used for sequential imaging of the hepatobiliary system with a frame rate of 3 sec in a 256 x 192 matrix. Dynamic sequential acquisition was performed for 51 min before and after the injection of 30 mu mol/kg of Gd-EOB-DTPA in a rabbit. Dynamic images of the hepatobiliary system were obtained in the rabbit study. Dynamic MR hepatocholangiography provides better functional information than conventional MR cholangiography.

Assessment of breast cancer with dynamic gadolinium-enhanced MR imaging combined with magnetization transfer contrast using a newly developed breast surface coil for the supine position.

To assess the value of dynamic gadolinium-enhanced MR imaging combined with magnetization transfer contrast (MTC) of breast cancer by SPGR sequence, 15 patients with breast cancer were imaged in the supine position with the newly developed breast coil in a 1.5 Tesla imager. Dynamic gadolinium-enhanced MR imaging combined with MTC (10 cases) and conventional dynamic gadolinium-enhanced MR imaging (5 cases) were performed after the administration of Gd-DTPA (0.2 ml/kg). Sagittal images were obtained every 22 seconds during the first 264 seconds. Thus, a total of 15 images were obtained in each lesion. The signal intensity ratio (SIR) of lesion to mammary glarid was calculated for each image as follows: (SI lesion/SI mammary gland)/(SI (pre)lesion/SI (pre)mammary gland). Dynamic gadolinium-enhanced MR imaging with MTC always allowed better SIR at 88 seconds than conventional dynamic gadolinium-enhanced MR imaging after bolus injection (p < 0.01). Dynamic gadolinium-enhanced MR imaging with MTC improved detection of the boundary of the lesion and mammary gland.

[Clinical significance of whole body thallium-201 chloride scintigraphy in multiple myeloma].

This study attempts to characterize the findings of thallium-201 chloride (201TlCl) uptake in patients with multiple myeloma and to evaluate its clinical significance. Twenty-four patients (including 10 untreated cases, 5 relapsed cases and 9 cases in stable course after initial treatment) were evaluated. Whole body 201Tl scintigraphy was performed 10 minutes after intravenous administration of 111 MBq of 201TlCl. Abnormal scintigraphic findings in whole body scanning varied from solitary focal uptake to extensive diffuse bone marrow visualization, but fell into the following 3 broad types; 1) skeletal visualization type, 2) predominant focal uptake type and 3) mixed type. Diffuse bone marrow uptake could be classified according to the skeletal distribution into 5 gradings (grade 0-4) between normal and entire skeletal visualization. This grading was roughly related to estimated tumor mass classification by tumor mass staging system (Alexanian, 1985). Furthermore, serum beta2-microglobulin level, that is widely confirmed as the reliable parameter of tumor burden and response to treatment except for patients with renal dysfunction, showed significant difference between grade 2 and grade 3 (p < 0.05), grade 2 and grade 4 (p < 0.01). The detectability of focal myelomatous lesions was compared to those of plain radiographs and 99mTc-HMDP scintigraphy in the untreated cases. Whole body 201Tl scintigraphy demonstrated 32 lesions among 46 focal lesions which included lesions revealed on either X-ray CT or MR imaging. In contrast to whole body 201Tl scintigraphy, plain radiographs and 99mTc-HMDP scintigraphy demonstrated 23 lesions and 22 lesions, respectively. All focal lesions exceeding 5 cm3 in tumor size were detectable on whole body 201Tl scintigraphy. Whole body 201Tl scintigraphy additionally showed 12 focal lesions that were demonstrated on MR imagings but failed to be detected on plain radiographs. However, detection of small lesions confined within the vertebral body was difficult. In conclusion, whole body 201Tl scintigraphy is a useful non-invasive tool to investigate the patients with multiple myeloma.

Theory and Practice of Rapid Flow-Through Analysis Based on Optode Detection and Its Application to pH Measurement as a Model Case.

Rapid flow-through analysis (RFA) based on optode (optical chemical sensor) detection is proposed, and its performance is discussed using the RFA system equipped with a pH-sensitive optode as a model case. To demonstrate and understand the usefulness of the RFA system, long-lifetime pH-sensitive optodes were prepared using a hydrophilic poly(hydroxyethyl methacrylate) (poly-HEMA) membrane covalently immobilized with a dye containing an amino group such as Congo Red or Nile Blue. The response equation for the optode with the RFA system was proposed, and satisfactory estimation for rapid pH analysis was obtained. The proposed RFA can stand as an advanced method for conventional flow injection analysis.

[Clear skeletal visualization on whole body 201Tl-chloride scintigraphy: a case of prostatic cancer with diffuse bone metastases].

A 70-yr-old man who was diagnosed as early gastric cancer showed leukocytopenia after total gastrectomy. Osteosclerotic findings on radiography were not remarkable. 99mTc-HMDP bone scintigraphy showed diffusely increased uptake in the axial skeleton, but visualization of the kidney and urinary bladder was apparent. However, whole body 201Tl-chloride scintigraphy showed diffuse abnormal visualization of axial skeleton. Physical and ultrasonographic examination indicated no abnormality in prostate. Afterward, further investigation, including bone marrow biopsy and immunohistochemical study, confirmed the diagnosis of bone metastasis from prostatic cancer. Microscopically, metastatic tumor cells were located in the intertrabecular space. Furthermore, no osteoclastic bone resorption or new trabecular bone formation was seen in this biopsy specimen. These findings suggest that whole body 201Tl-chloride scintigraphy can be a useful non-invasive diagnostic tool to investigate patients with suspicious malignancy in the bone marrow.

Dynamic MRI with slow injection of contrast material for the diagnosis of pituitary adenoma.

Magnetic resonance (MR) imaging of pituitary adenoma is usually carried out in dynamic studies with bolus contrast material injections, with the result that few strong images are obtained. Dynamic studies using a slowly injected contrast material were carried out in 14 cases of pituitary adenomas. The examinations were performed with a 1.5 Tesla superconducting MR imaging system using the spin-echo technique. Gd-DTPA (0.1 mmol/kg) was slowly injected (within 90 sec) by hand, providing seven to nine dynamic images during 350 sec from the start of injection. The average time to reach the maximum signal intensity was 170.6 sec in adenoma and 156.2 sec in normal gland tissue. The maximum contrast signal intensity ratio of adenoma to normal gland was 0.527 in the fifth image. The contrast of adenoma to normal gland tissue was calculated by the following formula: ASII (adenoma signal intensity index) = (adenoma signal intensity-tissue signal intensity)/tissue signal intensity. The most remarkable contrast between adenoma and normal tissue was obtained from the fourth to eighth images. In other words, we could obtain the strongest contrast at 144.8 sec to 299.6 sec from the start of contrast injection. Our results with slow injection suggest that stronger images can be obtained a longer period after contrast injection.

[Current imaging techniques in multiple myeloma].

The detection of skeletal involvement in multiple myeloma (MM) is often difficult. Plain radiographs have a very low yield in depicting skeletal lesions when they are confined to the bone marrow. The major advantage of bone scintigraphy is the ability to evaluate the entire skeletal system and to detect the bone lesions with a single examination. However it is well known that the false negative bone scan may occur frequently in MM. The advantage of magnetic resonance imaging (MRI) is the availability to detect myeloma foci within the spine, particularly early epidural involvement and spinal cord compression due to fracture. MRI is becoming increasingly routine in the work-up of patients with MM. Further investigations are required for the improved assessment of therapeutic response, correct diagnosis of diffuse bone marrow infiltration and distinction between pathologic and osteoporotic compression fractures.

Mechanical factors and patellofemoral osteoarthrosis.

This paper investigates the possible role of mechanical stress in the development of the osteoarthrotic lesions frequently observed in the patellofemoral compartment of the knee joint. First the location of these destructive lesions was determined by studying the location and pattern of contact in the patellofemoral joint. The study was carried out on 39 cadaveric knees for the range of flexion 0 degrees -120 degrees. It was shown that the lesions were localised to the areas corresponding to the range of flexion 40 degrees -80 degrees. These areas have been shown to be subjected to a low stress for most of the time and to a much higher stress for only part of the time. This mode of stressing this area of the cartilage is a consequence of the style of life of the average Western man in which the most predominant activity is level walking, during which the load and in turn the stress are much lower than they are during other ambulatory activities such as ramp and stair ascent and descent. The same area of the cartilage seems to be subject to a similar mode of stress during sedentary occupations. It is suggested that this mode of stressing the cartilage conditions it chemically, and hence mechanically, to transmit low stresses, so that when the much less frequent but higher stresses are applied it cannot transmit them without sustaining some damage.