Mozafareddin K. Karimeddini

Unilateral adrenal hyperplasia causing primary aldosteronism: limitations of I-131 norcholesterol scanning

Primary aldosteronism is a disorder that is commonly considered in patients referred to the hypertension clinic. The ease of measuring the random aldosterone-to-renin ratio in conjunction with an elevated serum aldosterone level has led to an increased screening for this disorder. Typically, patients undergo a confirmatory test after a positive screening test. However, once primary aldosteronism is confirmed, subtype delineation is critical to decide on the optimal treatment. We report a patient with resistant hypertension and primary aldosteronism with a normal computed tomographic scan of the adrenal glands, a left-sided uptake on adrenal scintigraphy, and a right-sided lateralization of aldosterone after adrenal vein sampling. A repeat adrenal vein sampling confirmed the aldosterone lateralization to the right adrenal gland, which was then removed laparoscopically. The patient had a good clinical and biochemical response, and unilateral adrenal hyperplasia was discovered at histology. Excessive reliance on adrenal scintigraphy without adrenal vein sampling may lead to serious errors in patient management.

Potential role of a hybrid intraoperative probe based on OCT and positron detection for ovarian cancer detection and characterization

Ovarian cancer has the lowest survival rate of the gynecologic cancers because it is predominantly diagnosed in the late stages due to the lack of reliable symptoms and efficacious screening techniques. A novel hybrid intraoperative probe has been developed and evaluated for its potential role in detecting and characterizing ovarian tissue. The hybrid intraoperative dual-modality device consists of multiple scintillating fibers and an optical coherence tomography imaging probe for simultaneously mapping the local activities of 18F-FDG uptake and imaging of local morphological changes of the ovary. Ten patients were recruited to the study and a total of 18 normal, abnormal and malignant ovaries were evaluated ex vivo using this device. Positron count rates of 7.5/8.8-fold higher were found between malignant and abnormal/normal ovaries. OCT imaging of malignant and abnormal ovaries revealed many detailed morphologic features that could be potentially valuable for evaluating local regions with high metabolic activities and detecting early malignant changes in the ovary. These initial results have demonstrated that our novel hybrid imager has great potential for ovarian cancer detection and characterization during minimally invasive endoscopic procedures.

Breast milk content of 131I in a hypothyroid patient.

An oral dose of 185 MBq of 131I (sodium iodide) was administered to a lactating mother for whole body scanning. Breast milk was collected at several points in time, and assayed for radioactivity. The radioiodine concentration in the milk was found to be 4 MBq/dL at 6 h (about 2% of the dose). The radioactivity in breast milk decreased with a biological half-life of about 15 h in this hypothyroid patient. Following ingestion of radioiodide (such as [131I]sodium iodide), the appearance of radiolabel in breast secretion has been well documented. However, data do not appear in the literature on this process in the grossly hypothyroid state. We, therefore, are reporting our experience with such a situation.

Matching ventilation/perfusion images in fat embolization

Forty-eight hours after fracture of the tibia and fibula, a 27-year-old man developed the triad of findings noted in the fat embolism syndrome (neurologic changes, respiratory distress, and petechlae). An initially normal chest-x-ray, which progressed to one of bilateral fluffy diffuse infiltrates, aided in making the diagnosis. Ventilation/perfusion lung images were performed at the time of the radiographic changes and showed “matching” defects. Transcapillary passage of lipid breakdown products was considered to be the cause. While all parts of the lung showed reduced ventilation/perfusion, the upper half of the lung fields was affected more prominently, as opposed to emboli of venous origin, which most frequently involve the lung bases.

Positive Tc-99m MIBI breast study related to a psoriatic lesion.

A woman was examined because of a painful left breast accompanied by excoriation and ulceration of the areola and nipple and some deformity. Because of the pagetoid changes in the nipple, a Tc-99m Miraluma (Tc-99m sestamibi) imaging study was performed. This revealed uptake in the areola and a small area near the chest wall. Biopsy of the areola revealed psoriasis. She was treated with an antipsoriatic cream, which healed the skin lesion. Two months after the initial Tc-99m Miraluma image, the results of another study were negative in both the areola and deep regions.

Radiogallium hot spleen in Trousseau's syndrome with splenic vein occlusion.

A 75-year-old man had multiple findings that indicated thromboembolic disease. A radiocolloid study showed splenic defects. The remainder of the spleen was hot on radiogallium imaging. The patient had Trousseaus syndrome (tumor-associated thromboembolism) due to carcinoma of the pancreas. The splenic vein was obstructed. Vascular compromise should be considered in the differential diagnosis of the radiogallium hot spleen.

Mastoid bone as a single site of metastasis of neuroendocrine tumor.

A man was examined for bleeding from the right ear. Four years earlier, he had resection of a neuroendocrine tumor from high on the right cerebrum, followed by radiation therapy. A primary focus had not been identified. Currently, an In-111 octreotide study of the whole body revealed no accumulation outside of the head. However, massive uptake occurred in the right mastoid bone. Biopsy of the area revealed a tumor identical to the neuroendocrine lesion that had been resected from the right brain 4 years before. A single metastasis was identified but the primary site was not.

Ineffective splenosis detected on Tc-99m labeled white cell imaging

A Tc-99m HMPAO WBC study, in an 84-year-old woman, showed mottled uptake in the posterior left upper quadrant. This finding corresponded to splenosis. However, despite the presence of these splenic cells, Howell-Jolly bodies had not been cleared from circulating RBCs. Either the volume of splenic cells was insufficient, or they were ineffective.

Bone agent and radiogallium deposition around infiltrated calcium gluconate.

Intravenous administration of calcium gluconate partially infiltrated the hand of a neonate. Because of subsequent redness and swelling, bone and radiogallium studies mere performed. Both sets of images showed uptake in the hand crossing the wrist; there was no radiogallium excess of subtracted views. A radiograph showed calcium deposition in the hand, likely accounting for uptake of the imaging agents. The redness in the hand gradually decreased

Nuclear medicine studies of aging—VIII. Bone to soft-tissue ratio of 99mTc labeled MDP and HMDP vs age

An objective approach to determine whether there was an advantage of using 99mTc-MDP or 99mTc-HMDP for bone imaging, particularly in elderly subjects, was evaluated by measuring the bone to soft-tissue ratio in relation to age. This was done by quantifying analog images of the femoral region by using an optical densitometer. A ratio (mean for right and left thighs) was determined for mid-femur to adjacent soft-tissue. These values were analyzed in relation to the age of patients studied with either MDP or HMDP. Little correlation with age was observed. An analysis at 10-year intervals of age indicated a decline in the ratio after 70 years, without any significant difference between MDP and HMDP.