The diagnosis of acromegaly: value of inferior petrosal sinus sampling

The early diagnosis of acromegaly may be difficult when serum levels of growth hormone are minimally elevated and imaging of the pituitary gland fails to show an adenoma. However, transsphenoidal surgery has the greatest chance of cure at this stage. We therefore investigated the value of sampling petrosal sinuses for measurement of growth hormone in this group of patients. Simultaneous bilateral sampling of the inferior petrosal sinuses to measure serum concentrations of growth hormone was performed in five patients suspected of having acromegaly but with nondiagnostic CT scans (n = 5) and MR images (n = 3) of the pituitary gland. Levels of growth hormone from the petrosal sinuses were five to 36 times greater than levels in the peripheral veins in all five patients, and three of four showed a marked response to growth hormone-releasing hormone. During transsphenoidal surgery, growth hormone-producing microadenomas were resected completely in four patients. In the fifth patient, a left-sided microadenoma had invaded the cavernous sinus and could not be resected completely. Lateralization of the adenomas within the pituitary gland on the basis of differences in levels of growth hormone between the two petrosal sinuses was not completely reliable. Elevated levels of growth hormone in selective samples from the inferior petrosal sinuses can help support an early diagnosis of acromegaly when peripheral growth hormone levels and imaging are not diagnostic.     

Glycolytic rate (PET) and contrast enhancement (CT) in human cerebral gliomas

A comparison of the glycolytic rate as determined by positron emission tomography (PET) with 18F-deoxyglucose (FDG) and cerebral contrast computed tomography (CT) was carried out in 72 cases of cerebral glioma. FDG-PET is more accurate than contrast CT in predicting tumor grade.     

Meningeal Gd-DTPA enhancement in patients with malignancies

Nineteen patients with malignant diseases and pathologically enhancing meninges were studied by pre- and postcontrast (Gd-diethylene-triamine pentaacetic acid) magnetic resonance (MR) scans. Two patterns of enhancement were recognized: the dural (14 patients) and the leptomeningeal (mainly pial) (5 patients). Positive cytology was found in only 3 of the 14 patients with dural enhancement (21%), whereas in the remaining 11 patients we noted either nonspecific CSF findings such as elevated protein, high white blood cell count, and low glucose or entirely normal CSF. Four patients (80%) in the group with leptomeningeal enhancement showed positive cytology and one had normal CSF analysis. We conclude that meningeal enhancement as seen on MR imaging is a nonspecific finding and correlates well with positive cytology only when the more rare form of leptomeningeal enhancement is encountered.     

Metabolic imaging of the brain stem and spinal cord: studies with positron emission tomography using 18F-2-deoxyglucose in normal and pathological cases

A new high resolution positron emission scanner (Neuro-PET) has made possible clear visualization and quantitation of glucose metabolism in the brain stem and upper cervical cord (above C4) using 18F-2-deoxyglucose. The following mean measurements of the glucose utilization rate are based on studies of 34 normal volunteers and patients with no apparent pathology in the brain stem or cord: 5.0 +/- 1.0 (SD) mg Glu/100 g/min for the mesencephalon-upper pons, 3.2 +/- 1.0 for the pons-medulla, and 1.7 +/- 0.6 for the upper cervical cord. (The first value also includes studies done with the ECAT-II scanner.) Resolution of white-gray matter within these structures was not possible. Whenever possible, a correlation was made with autoradiographic data in monkeys, and good agreement was found. The glucose utilization in cases showing brain stem and cord pathology was altered, with marked elevation (as high as 8.2 mg/100 g/min) in cases of high-grade gliomas, and reduction in cases of low-grade gliomas and one pontine hematoma.     

Resources Required for Semi-Automatic Volumetric Measurements in Metastatic Chordoma: Is Potentially Improved Tumor Burden Assessment Worth the Time Burden?

The Response Evaluation Criteria in Solid Tumors (RECIST) is the current standard for assessing therapy response in patients with malignant solid tumors; however, volumetric assessments are thought to be more representative of actual tumor size and hence superior in predicting patient outcomes. We segmented all primary and metastatic lesions in 21 chordoma patients for comparison to RECIST. Primary tumors were segmented on MR and validated by a neuroradiologist. Metastatic lesions were segmented on CT and validated by a general radiologist. We estimated times for a research assistant to segment all primary and metastatic chordoma lesions using semi-automated volumetric segmentation tools available within our PACS (v12.0, Carestream, Rochester, NY), as well as time required for radiologists to validate the segmentations. We also report success rates of semi-automatic segmentation in metastatic lesions on CT and time required to export data. Furthermore, we discuss the feasibility of volumetric segmentation workflow in research and clinical settings. The research assistant spent approximately 65 h segmenting 435 lesions in 21 patients. This resulted in 1349 total segmentations (average 2.89 min per lesion) and over 13,000 data points. Combined time for the neuroradiologist and general radiologist to validate segmentations was 45.7 min per patient. Exportation time for all patients totaled only 6 h, providing time-saving opportunities for data managers and oncologists. Perhaps cost-neutral resource reallocation can help acquire volumes paralleling our example workflow. Our results will provide researchers with benchmark resources required for volumetric assessments within PACS and help prepare institutions for future volumetric assessment criteria.     

Cerebral mapping of apraxia in Alzheimer's disease by positron emission tomography

The ability to mimic skilled movements or to pantomime them in response to spoken command was compared with psychometric performance and with regional glucose utilization as estimated by [18F]fluorodeoxyglucose positron emission tomography in 17 right-handed patients with Alzheimer's disease and 6 age-matched normal subjects. Apraxia scores, both on tests to command and to imitation, were significantly lower in the Alzheimer patients. Imitation scores correlated best with performance on tests of visual--spatial ability and with cortical metabolism in the right parietal lobe; command scores related most closely with the results of tests reflecting verbal proficiency and with cortical metabolism in the left inferior hemisphere, especially frontally. Apraxia to command and imitation may thus reflect neuronal dysfunction in distinct cerebral regions in patients with Alzheimer's disease.     

Ventricular septa in the neonatal age group: diagnosis and considerations of etiology

Twenty-four patients with ventricular septa are discussed. Seventeen patients had septa acquired during the neonatal period and seven exhibited septations at birth (cogenital septa). Among the acquired septa, there were true intraventricular septa and septa that originated outside the ventricles but later became part of the ventricular system (pseudosepta). Pseudosepta originate in necrotic, cavitating periventricular white matter that, in temporal sequence, becomes ventricularized. Serial use of cranial sonography provided important information about the pathologic mechanisms that govern the development of septa. Intraventricular hemorrhage and infection are the major causes of true intraventricular septa, while periventricular leukomalacia serves as primary cause of pseudosepta. Sonography is the diagnostic method of choice. Septa are associated with a high incidence (62%) of shunt failure.     

Experimental comparison of EOE-13 and perfluoroctylbromide for the CT detection of hepatic metastases

The relative advantages of EOE-13 and perfluoroctylbromide (PFOB) as contrast agents were evaluated using CT scanning in animals with implanted liver tumors. Three criteria were used to compare these compounds: (1)the density difference between liver and tumor, (2)the presence of opacification of intrahepatic vascular structures, and (3)the presence of ring enhancement around the tumors. All three radiographic features were superior in the scans after injection of 5 g/kg of PFOB. When a reduced dose (1.7 g/kg) of PFOB was used, however, the scans obtained with EOE-13 were of approximately equal quality. It is concluded that if toxicity problems prevent administration of PFOB in humans, then EOE-13 will probably remain the contrast agent of choice for tumor imaging in the liver.     

Anti–N‐methyl‐D‐aspartate receptor antibodies,cognitive dysfunction,and depression in systemic lupus erythematosus

Objective

To assess the association of cognitive dysfunction and depression with serum antibodies to N‐methyl‐D ‐aspartate (NMDA) receptor (anti‐NR2) and analyze clinical and neuroimaging correlates in patients with systemic lupus erythematosus (SLE).

Methods

Sixty patients underwent neurocognitive assessment, evaluation for depression with the Beck Depression Inventory II (BDI‐II) and psychiatric interview (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition [DSM‐IV] criteria), brain magnetic resonance imaging, and proton magnetic resonance spectroscopy imaging (¹H‐MRSI). Cognition was assessed in 5 domains: memory, attention/executive, visuospatial, motor, and psychomotor, and adjusted to each individual's best level of prior cognitive functioning estimated from the reading subtest of the Wide Range Achievement Test–3 (WRAT‐3). Serum anti‐NR2 antibodies were measured by enzyme‐linked immunosorbent assay using a pentapeptide from the human NMDA receptor.

Results

Cognitive dysfunction was found in 28 of 60 patients (mild in 8, moderate in 20) before adjustment for WRAT‐3 and in 35 of 60 patients (mild in 15, moderate in 11, and severe in 9) after adjustment for WRAT‐3. The changes were most pronounced in the memory and visuospatial domains. There was no significant association between anti‐NR2 antibody levels and cognition. On ¹H‐MRSI, patients with moderate or severe cognitive dysfunction had significantly higher choline:creatine ratios in the dorsolateral prefrontal cortex and the white matter, compared with patients with mild or absent cognitive dysfunction. Anti‐NR2 antibodies were significantly correlated with BDI scores; patients with BDI‐II scores of ≥14 had higher serum levels of anti‐NR2 antibodies (P = 0.005, 95% confidence interval 0.83, 4.31), and there was a trend toward higher anti‐NR2 antibody levels among patients who fulfilled the DSM‐IV criteria for major depression.

Conclusion

Serum anti‐NR2 antibodies are associated with depressive mood but not with cognitive dysfunction in SLE at a given time point. Larger longitudinal studies are needed to address the possible association between anti‐NR2 antibodies and depression in SLE.