Anthony M. Passalaqua

A Spectrum of Diseases of the Thyroid Gland as Imaged by Gray Scale Water Bath Sonography

A method of performing gray scale thyroid echography with a 3.5 MHz focused transducer and an open water bath is described. A preliminary echographic classification of abnormalities and representative echograms illustrating various thyroid disorders are presented.

Managing the solitary thyroid nodule: echography's role.

Improved preoperative thyroid diagnosis and reduction of needless thyroid surgery are achieved by employing gray scale echography in patients whose solitary thyroid nodule is cold on scintillation scanning. It is highly useful in distinguishing solid tissue from a cyst, identifying degenerative changes, guiding needle biopsy, and monitoring changes in a nodule during suppressive therapy.

Bone Scanning in Metastatic Calcification to the Lungs

A case of pulmonary metastatic calcification demonstrated by bone scanning is presented. It appears that the sensitivity of bone scanning in the detection of these calcific deposits depends upon the nature of their crystalline structure. The nature of these calcific deposits and their relationship to bone scanning is discussed.

Posterior Fossa: A Clinical Comparison of Radionuclide Scanning and Computed Tomography

&NA; CT and RN imaging both appear to be less sensitive in detecting lesions in the posterior fossa than in the supratentorial area. This study compares the accuracy of these two modalities in 27 patients with a variety of proven posterior‐fossa lesions, all studied by both methods. The overall yield of RN studies in these cases was 59%. The yield of CT without contrast was 67%. The combination of RN and noncontrast CT detected 85% of the cases. The combination of CT with and without contrast had, at best, the same accuracy. When used as a screening test, the small but established risk of IV contrast material must be considered. CT, both with and without contrast, plus RN still missed two out of 27 cases.

Uptake of 99mTc Pyrophosphate in Chest Wall Tissues Due to Defibrillation

A case is presented in which uptake of 99mTcpyrophosphate occurred due to local injury to the chest wall by the electrodes following defibrillation. It is important to differentiate this from myocardial accumulation of the agent.

Nuclear medicine and ultrasound in the evaluation of neurologic diseases

Echoencephalography and radionuclide brain imaging are used to aid in the diagnosis of a variety of intracranial abnormalities. Because of technical considerations, A-mode rather than B-mode echography must, under most circumstances, be employed for examination of the head. There are technical limitations to echoencephalography, and it tends to be relatively subjective and dependent on the skill of the sonographer. These factors have, to some extent, been responsible for the more limited application of ultrasound to neurologic diagnosis, as compared to the application of radionuclides. The most common use of echoencephalography is in the detection of midline shifts associated with various sequelae of head trauma. Ultrasound has also been used to detect space-occupying lesions, either directly or more usually by determing associated midline displacements. The characterization and follow-up of known lesions with ultrasound has also been described. In the above instances its usefulness is usually as a noninvasive technique complementary to nuclear medicine studies, which under most circumstances are more effective than ultrasound. The evaluation of ventricular enlargement, which is not usually possible per se with radionuclides, is possible with ultrasound. Computerized transverse tomography (CTT) can be applied more efficiently in a routine way in many of the above circumstances, including evaluation of ventricular size. The combination of CTT and nuclear medicine procedures in the brain area is so effective and comprehensive that where these are both available the demand for ultrasound will probably decrease but will not be eliminated.

Liver/pleural cavity scan for diagnosis of subphrenic abscess.

The interpretation of a combined liver/lung scan can be difficult in patients with pleural or pulmonary disease. A procedure is suggested to circumvent these difficulties by injecting 99mTc-sulfur colloid into the pleural cavity. A scan of the pleural cavity can then replace the lung scan in the conventional liver/lung scan. Two examples of liver/pleural cavity scans are shown.