Absent Cerebellar Circulation With Intact Cerebral Blood Flow on a 99mTc Bicisate "Brain Death" Study.

A 55-year old woman presented in an obtunded state and was found to have a subarachnoid hemorrhage. After endovascular repair, her condition deteriorated, and brain death was suspected. A Tc bicisate brain blood flow study was performed, which showed a complete absence of blood flow to the cerebellum despite intact circulation to the cerebral hemispheres.

Thyroid stimulating hormone and cognition during severe, transient hypothyroidism.

Objective: The purpose of our pilot study was to explore the relationship between serum thyroid stimulating hormone (TSH) levels during overt hypothyroidism (OH) and hypothyroid-related neuropsychological symptoms. We hypothesized that TSH level may reflect the degree of 'brain hypothyroidism' such that an inverse correlation may exist between serum TSH and cognitive function in patients experiencing overt hypothyroidism (OH), and sought to explore this hypothesis.

Methods: Eleven thyroidectomized patients underwent neuropsychological and thyroid function testing while overtly hypothyroid, and again following thyroid hormone replacement.

Technetium-99m ethyl cysteinate dimer (ECD) cerebral accumulation and symptom and sign severity during hypothyroidism.

Objective: The purpose of this study was to correlate hypothyroid-related symptomatology with regional cerebral blood flow (rCBF) during hypothyroidism.

Materials And Methods: Nine thyroidectomized patients underwent neuropsychological testing and single photon emission computed tomography (SPECT) of their brains with technetium-99m (Tc-99m) ethyl cysteinate dimer (ECD), a lipophilic cerebral blood flow radiotracer, while hypothyroid, and again following thyroid hormone replacement. Neuropsychological test scores and TSH levels while hypothyroid were correlated with rCBF in hypothyroid-affected areas of the brain.

Symptomatic hyponatremia in association with a low-iodine diet and levothyroxine withdrawal prior to I131 in patients with metastatic thyroid carcinoma.

Background: Strategies to improve I131 uptake in thyroid carcinoma include levothyroxine (LT4) withdrawal or thyrotropin (TSH) administration along with a low-iodine diet. We report five patients with papillary or follicular thyroid carcinoma who developed symptomatic hyponatremia during LT4 withdrawal and low-iodine diet.

Results: Four patients had pulmonary and/or brain metastases.

Exercise-related longitudinal tibial stress fracture in a young person.

A 22-year-old man presented to the Nuclear Medicine Clinic for evaluation of distal right tibial pain. The patient reported recently beginning a rigorous exercise program involving lower extremity impact temporally related to the onset and worsening of the pain. The physical examination was remarkable for significant tenderness to palpation of the distal one-third of his right tibia.

Cerebral accumulation of Tc-99m ethyl cysteinate dimer (ECD) in severe, transient hypothyroidism.

Thyroid dysfunction is a well-known contributor to psychiatric morbidity. To investigate the mechanism(s) by which thyroid hormone availability affects cerebral activity, a group of thyroidectomized individuals were studied at two points in time: when markedly hypothyroid in preparation for a thyroid cancer metastatic survey and when clinically and/or biochemically euthyroid. The analysis consisted of single photon emission computed tomography (SPECT) using a lipophilic radiopharmaceutical, technetium-99m (Tc-99m) ethyl cysteinate dimer (ECD), and measurement of mood, anxiety, and psychomotor function, at both points in time.

Presentation of gastric carcinoma on a radionuclide gastric-emptying study.

We present a case of unsuspected gastric carcinoma discovered as a result of abnormalities seen on a sulfur colloid gastric-emptying study. Considered a functional or physiological analysis, often relatively little attention is given to the morphology of the stomach except for the purpose of drawing a region of interest. This case, in which the images suggested a space-occupying lesion(s), emphasizes the importance of careful examination for "pathoanatomy" as well as pathophysiology in functional imaging.