The structural brain correlates of cognitive deficits in adults with Klinefelter's syndrome.

CONTEXT: Adults with Klinefelter's syndrome (KS) are known to present disturbances of language skills and delayed learning abilities. OBJECTIVES: The aim of this study was to assess brain morphometry in KS and to correlate eventual volumetric changes with performance on neuropsychological tests. PATIENTS: Patients included 18 KS adults and 20 age-matched controls. METHODS: All participants underwent prospectively double-spin-echo brain magnetic resonance imaging and neuropsychological testing of verbal and nonverbal domains. On the axial stack of magnetic resonance imaging slices, regional brain volumes were measured either by automated segmentation (full brain, total cerebrospinal fluid, and ventricular volume) or manual drawing with help of a neuroanatomy atlas (frontal, temporal, and parietal lobes, gray matter component of the lobes, cerebellar hemispheres, and hippocampal complexes). RESULTS: KS patients performed significantly lower than controls on language-related tasks exploring verbal processing speed and verbal executive function. They were diagnosed with significant enlargement of ventricular volume and bilateral reduction of cerebellar hemispheres. Furthermore, after separation of participants according to handedness and after correction of regional brain volumes for atrophy, a significant reduction of left temporal lobe volume was found in KS compared with controls. Ventricular volume was inversely correlated with cognitive function, whereas left temporal lobe volume was positively correlated with language-related tasks. CONCLUSION: This study hypothesizes that supernumerary X-chromosome and/or congenital hypogonadism provoke structural alterations in the subcortical pathways involved in language processing, thus providing a neurobiological substrate for cognitive deficits in KS.

Effect of ecstasy [3,4-methylenedioxymethamphetamine (MDMA)] on cerebral blood flow: a co-registered SPECT and MRI study.

3,4-methylenedioxymethamphetamine (MDMA), an illicit recreational drug, damages serotonergic nerve endings. Since the cerebrovasculature is regulated partly by the serotonergic system, MDMA may affect cerebral blood flow (CBF) in humans. We evaluated 21 abstinent recreational MDMA users and 21 age- and gender-matched healthy subjects with brain SPECT and MRI. Ten of the MDMA subjects also had repeat SPECT and MRI after receiving two doses of MDMA. Abstinent MDMA users showed no significantly different global or regional CBF (rCBF) compared to the control subjects. However, within 3 weeks after MDMA administration, rCBF remained decreased in the visual cortex, the caudate, the superior parietal and dorsolateral frontal regions compared to baseline rCBF. The decreased rCBF tended to be more pronounced in subjects who received the higher dosage of MDMA. Two subjects who were scanned at 2-3 months after MDMA administration showed increased rather than decreased rCBF. Low-dose recreational MDMA use does not cause detectable persistent rCBF changes in humans. The lack of long-term rCBF changes may be due to a non-significant effect of serotonergic deficits on rCBF, or regeneration of serotonergic nerve terminals. The subacute decrease in rCBF after MDMA administration may be due to the direct effect of MDMA on the serotonergic system or the indirect effects of its metabolites on the dopaminergic system; the preliminary data suggest these effects may be transient.

Scintimammographic analysis of nonpalpable breast lesions previously identified by conventional mammography.

BACKGROUND: In randomized trials, screening mammography has led to decreased mortality from breast cancer. However, the low positive predictive value of mammography (i.e., the proportion of patients with a positive test result who actually have breast cancer) results in a large number of unnecessary biopsies. We determined whether scintimammography with technetium-99m-sestamibi is a useful supplemental diagnostic tool for women with nonpalpable breast abnormalities identified by conventional mammography. METHODS: Scintimammography was performed preoperatively on 70 women who were 31-66 years of age (mean age and median age = 51 years). These women had nonpalpable breast abnormalities identified by conventional mammography; subsequently, a needle-localization excisional biopsy of each suspicious lesion was performed. Scintimammographic images were interpreted independently by two nuclear medicine physicians who were blinded to all clinical and pathologic data, and an interobserver variation analysis was performed. RESULTS: Interobserver variation analysis of the scintimammographic findings showed an agreement for breast diagnosis of 97% and a kappa coefficient of 0.90. Comparison of scintimammographic findings and histopathologic results revealed that the sensitivity (proportion of patients with breast cancer who had a positive test result), the specificity (proportion of patients without breast cancer who had a negative test result), the positive predictive value and the negative predictive value (proportion of patients with a negative test result who actually did not have breast cancer) of scintimammography were 56% (95% confidence interval [CI] = 23%-85%), 87% (95% CI = 75%-94%), 38% (95% CI = 15%-68%), and 93% (95% CI = 82%-98%), respectively. Four of nine breast cancers were not detected by scintimammography. CONCLUSION: Because of excellent interobserver agreement, scintimammography provides an objective way of detecting primary breast carcinoma. In view of its low sensitivity and positive predictive value, however, scintimammography is not currently recommended as a screening test in patients with nonpalpable positive mammographic findings.

Scintimammography: the new role of technetium-99m Sestamibi imaging for the diagnosis of breast carcinoma.

Technetium-99-Sestamibi scintimammography has emerged as a new procedure for the imaging of breast tumors. Currently, a large clinical experience has been developed and the results published. At the present time, the major drawback of this procedure appears to be its low sensitivity for the detection of breast carcinomas smaller than 1 cm in diameter. There are other biologic and technical issues that remain to be overcome to optimally image the breasts. Some of these include: development of a dedicated breast imager using nuclear medicine techniques, development of stereotactic needle localization of the abnormalities that demonstrate focal increase uptake in women with normal mammogram and breast physical examination, manufacturing of a breast compression device so that we can immobilize the breast in place for more adequate imaging, overcoming the issue of unilateral or bilateral diffuse breast uptake that is noted in 7-10 percent of the cases and finally, determination of optimal dose and imaging factors. This review includes our experience at Harbor-University of California, Los Angeles Medical Center with the use of this agent for breast imaging since 1992.

Radionuclide-guided stereotactic prebiopsy localization of nonpalpable breast lesions with normal mammograms.

UNLABELLED: Scintimammography with 99mTc-sestamibi can be used as a complementary technique to improve the mammogram's sensitivity and specificity for detection of breast carcinoma. We have observed in some patients focal areas of increased 99mTc-sestamibi uptake with no corresponding abnormalities on physical examination or mammogram. A phantom device and a special needle were designed to stereotactically localize these lesions before biopsy. METHODS: After intravenous injection of 30 mCI (1110 MBq) of 99m Tc-sestamibi, a prone lateral image of the abnormal breast was obtained. With the patient in the prone position, the breast was compressed with two fenestrated plates in the prone position. The x and y coordinates of the abnormal hot spot of the breast were determined. The z coordinate of focal 99mTc-sestamibi uptake was determined by advancing a localizer needle through a selected predetermined hole of the fenestrated plate using real-time visualization on the persistence monitor. The tip of the opturator inside the needle is welded with 57Co to determine the depth of the hot spot in the breast. RESULTS: Three women, all of whom had normal mammogram and breast physical examinations, were studied using 99mTc-sestamibi prone breast imaging. Pre-excisional biopsy needle localization of abnormal focal uptake was performed. Two women demonstrated infiltrative ductal carcinoma, and the third had proliferative fibrocystic disease of the breast. CONCLUSION: Our initial experience demonstrates that nuclear medicine guided stereotactic needle biopsy of the breast in patients with positive scintimammograms is technically feasible. In the future, this technology will enable us to detect breast carcinoma in the absence of clear-cut clinical and mammographic findings.

Parathyroid hyperplasia may be missed by double-phase Tc-99m sestamibi scintigraphy alone.

The authors report two cases of parathyroid imaging with double-phase Tc-99m sestamibi used in conjunction with Tc-99m pertechnetate that detected parathyroid hyperplasia when the wash out rate of MIBI from the glands paralleled normal thyroid tissue. Routine use of thyroid images for comparison may avoid this pitfall. The authors also observed that Tc-99m sestamibi has early uptake in brown tumors.

The bone scan in tarsal coalition: a case report.

Tarsal coalition is abnormal fusion of two or more tarsal bones. The union may be fibrous, cartilaginous, or osseous and can be congenital or acquired in response to infection, articular disorders, trauma, or surgery. We report a case of fibrous talocalcaneal coalition in a 15-year-old boy in whom bone scintigraphy employing pinhole lateral views confirmed the clinical diagnosis when plain radiographs showed minimal changes and computed tomography was equivocal. The diagnosis of symptomatic tarsal coalition is important in that it is a common remediable cause of peroneal spastic flat foot, a frequently encountered condition. Scintigraphy provides important information about the presence and localization of this condition.

Application of nuclear medicine techniques to the study of ARDS.

Radionuclide techniques used for the diagnosis and study of ARDS include the routine clinical procedures of perfusion lung scanning, gallium and white-cell imaging, as well as PET, indicator dilution methods for measuring extravascular lung water, and means of measuring protein accumulation, protein flux, and solute transfer. The techniques that reflect the rate of protein leak from the microvasculature and sensitive measures of rapidly reversible alveolar injury appear most promising. While clinical usefulness remains to be documented, these methods may ultimately assist with the diagnosis of ARDS and with the evaluation of prognosis and therapy.

Bone imaging findings in gangrene.

Review of three-phase bone imaging results in three patients with gangrene of the toes showed a unique pattern of absent perfusion and absent bony and soft-tissue uptake. In one of these patients, characteristic bone imaging findings were present before clear-cut clinical presentation. In our experience, the finding of absent uptake in a particular clinical setting is highly specific for gangrene.

Albumin lung/heart ratio change. A simple clinical means of documenting increased pulmonary endothelial permeability to protein.

We investigated a simple method that can be used at the bedside for documenting the net accumulation of albumin in the lung. The technique employs measurement with a computer-linked gamma camera of the activity ratio in an area of the right lung compared with the same-sized area in the heart at 20 minutes and three hours following intravenous injection of technetium Tc 99m albumin. We applied this measurement to three groups of patients: a control group and patients with roentgenographic evidence of edema classified according to clinically available criteria as either hydrostatic edema or permeability edema to see if we could document differences among these groups. In control patients this ratio did not increase by more than seven units between the 20-minute and three-hour measurements. Of 18 patients classified by other routine clinical means as having hydrostatic pulmonary edema, 89% showed no increase in lung albumin accumulation. In 29 patients with permeability edema associated with the so-called adult respiratory distress syndrome, 31% showed evidence of net pulmonary albumin accumulation. These findings suggest that some patients otherwise classified as having hydrostatic edema have concomitant permeability changes in the microvasculature and that permeability edema represents a spectrum of endothelial damage.

Technetium-99m pyrophosphate imaging in acute renal failure associated with nontraumatic rhabdomyolysis.

Technetium-99m pyrophosphate (Tc-PYP) imaging was performed in five patients with acute renal failure associated with nontraumatic rhabdomyolysis. Four patients had phencyclidine intoxication and one had viral pneumonia. During the acute phase, marked uptake of pyrophosphate was seen in all patients in several muscle groups, but always in the thigh adductors. The results show that phencyclidine intoxication can result in diffuse muscle uptake of Tc-PYP without overt evidence of muscle injury. Tc-PYP imaging may provide a clue to the cause of acute renal failure in patients with suspected rhabdomyolysis in whom elevations of serum creatine phosphokinase concentrations are equivocal.

Carney's triad: radiographic diagnosis, natural history and importance of pulmonary chondromas.

We describe the radiographic findings and benign clinical course of a patient with two components of a triad of unusual neoplasms: pulmonary chondroma, gastric epithelioid leiomyosarcoma, and paraganglioma that may occur together in young women.