Michael A. Wilson

False-negative bone scan in extensive metastatic disease: CT and MR findings.

A patient is presented with extensive metastatic disease of both the cortex and bone marrow that was demonstrated by CT and magnetic resonance imaging but not by bone scintigraphy.

Utility of SPECT/CT as an adjunct to planar whole body I-131 imaging: liver metastasis from papillary thyroid cancer.

One of the major limitations of planar I-131 imaging is its lack of anatomic precision. SPECT/CT offers the benefit of precise anatomic localization that planar imaging lacks. Whether for confirmation of physiologic uptake or true pathology, SPECT/CT has an important role to play in clarifying equivocal findings. We present a case of papillary thyroid cancer metastatic to the liver, a relatively rare scenario. SPECT/CT allowed definitive lesion characterization at the time of the patients visit to the nuclear medicine department.

A case of periostitis secondary to voriconazole therapy in a heart transplant recipient.

A 66-year-old man with a history of heart transplant for idiopathic dilated cardiomyopathy presented with progressive bone pain and myalgias. He has been on voriconazole for a pulmonary Aspergillus infection for 9 months. He had an elevated alkaline phosphatase of 280. There is no history of rheumatologic disease. Drug-induced periostitis has recently been reported in patients on long-term voriconazole therapy after lung transplantation for prophylaxis and treatment of Aspergillus infection. This case demonstrates the same phenomenon in a heart transplant patient. This patients symptoms improved after discontinuation of voriconazole.

Pitfalls of I-131 whole body scan interpretation: bronchogenic cyst and mucinous cystadenoma.

Whole body iodine scans are routinely performed in the nuclear medicine department as part of the management of differentiated thyroid carcinoma. Similarly, radioactive iodine has a well-established role as an adjunct to thyroidectomy in the treatment of these patients. A thorough understanding of the normal, benign, and pathologic biodistribution of iodine is imperative for the nuclear medicine physician. This knowledge leads to the accurate determination of the presence of metastatic or recurrent carcinoma, and may even facilitate the accurate detection of an undiagnosed condition. Above all, correct image interpretation avoids unnecessary therapeutic doses. The authors describe 2 unusual examples of false positive findings in fluid-filled cavities that showcase the variety of nonmalignant entities one may encounter when interpreting metastatic surveys.

Anatomic and Functional Changes Associated with Crossed Cerebellar Diaschisis in Chronic Brain Injured Subjects

The anatomic and functional changes associated with crossed cerebellar diaschisis (CCD) were examined in chronic brain injured patients to determine if there is evidence that injury to a neuroanatomic tract, such as the corticopontocerebellar tract, could explain the cerebellar diaschisis, and to determine if arm movements would effect the CCD. Four brain injured patients and four normal subjects had MR scans and PET scans using fluorodeoxyglucose. The PET scans were obtained during rest and during left and right arm motor tasks. The PET scans were repeated after six months to determine the reproducibility of the scan findings. Forty-one PET scans were analyzed. Significant crossed cerebellar diaschisis was present in all fourbrain injured patients. One control patient had crossed cerebellar diaschisis, but the cerebellar asymmetry was more subtle than noted in the brain injured patients. MR scans demonstrated atrophy of the cerebral peduncle ipsilateral to the major cerebral cortical injury. One patient had bilateral cerebral cortical and cerebral peduncle atrophy. These findings support the hypothesis that injury to the corticopontocerebellar tract may, in part, be responsible for crossed cerebellar diaschisis in chronic brain injured subjects. Key Words: Brain, injuries—Brain, radionuclide studies—Emission CT—Diaschisis—Degeneration, Wallerian.

Does the Use of IV Contrast Enhanced CT for Attenuation Correction Affect Clinical Interpretation of Head and Neck PET/CT?

Purpose of Report: Evaluate the effect of IV contrast use with FDG PET/CT on clinical interpretation of PET images for head and neck cancer. Procedures: 20 consecutive patients referred for PET/CT and contrast enhanced CT of the head and neck had two sets of PET images obtained. One set used standard low dose CT for attenuation correction, and the other used IV contrast enhanced diagnostic quality CT for attenuation correction. Two blinded nuclear medicine physicians interpreted the results. Results: No statistically significant difference in clinical interpretation of the PET images was found. It was noted that PET scans attenuation corrected with IV contrast CTs had greater incidence of abnormal appearing lesions (P<0.01). Conclusion: It is reasonable to use contrast enhanced CT for attenuation correction in PET/CT of head and neck cancer. This would allow for a reduction in radiation dose delivered to patient.

Visual Cortex Hyperactivity During Arm Movements in Brain Injured Individuals: Evidence of Compensatory Shifts in Functional Neural Systems

Basic neural mechanisms associated with recovery after brain injury were evaluated. Positron-emission tomography (PET) and fluorine-18-labeled fluorodeoxyglucose (18-FDG) were utilized to measure glucose metabolism and associated brain activity in the area of the visual cortex during motor tasks in post-acute brain injured (BI) young adults. Four hemiplegic BI subjects were compared over time to four normal matched controls for affected arm movement, least affected arm movement, and rest conditions. Initial data demonstrated hyperactivity in the visual cortex of the BI group versus the control group. Also, in subsequent data under higher resolution conditions greater visual cortex hyperactivity in the BI group was associated with more difficult movement tasks. These results support the hypothesis that compensatory shifts in functional neural systems occur in the visual cortex of post-acute brain injured adults. Key Words: Brain injury—Visual cortex— Positron-emission tomography.