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D L Miller

Publications and source records attributed to D L Miller.

At least 559 records · Page 31Linked to original sources
PubMedDate not supplied

Update on safety of diagnostic ultrasonography.

Safety considerations for diagnostic ultrasonography have gradually changed as new instruments, not only more powerful in performance but also in ultrasonic exposure, have come into use. Nonthermal cavitational bioeffects of ultrasound have a problematic role in risk assessment for clinical applications, but should serve as cautionary reminders that there potentially could be low-level risks. Recent analyses have indicated possible areas of concern related to the thermal mechanism of bioeffects, particularly if trends for higher intensities continue into the future. The most critical area of concern is in fetal examinations, for which developing bone is unavoidably heated by relatively powerful pulsed-Doppler beams. Fortunately, because of the threshold nature of thermal damage, development of flexible, use-driven upper limits on output should completely resolve this impending safety problem. The ultrasonics community is now responding to these evolving safety issues with improved instrument characterization standards, new bioeffects research, and initiatives in continuing education for sonographers.

Equipment Safety↗
PubMedDate not supplied

Intraarterial calcium stimulation test for detection of insulinomas.

Occult insulinomas are adenomas not visualized by routine preoperative imaging studies, including ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and arteriography. Reliance for detecting occult insulinomas has been placed on portal venous sampling (PVS), a sensitive (> 75%) but invasive procedure that requires considerable experience to enable sampling of small veins about the pancreatic head. For the past 2 years we have attempted to localize insulinomas by stimulating the release of insulin with a selective intraarterial injection of calcium gluconate and sampling for insulin gradients in the hepatic veins. This study replaces PVS by indicating the region of the pancreas within which the tumor lies, although, like PVS, it does not directly visualize the tumor. Our experience in 9 patients with surgically proved insulinomas is reviewed, comparing the results with PVS as well as with US, CT, MRI, and arteriography.

Adult↗