Testicular microlithiasis: imaging appearances and pathologic correlation.

PURPOSE: To determine the spectrum of sonographic findings, clinical implications, and pathologic correlation in patients with testicular microlithiasis (TM). MATERIALS AND METHODS: The cases of 42 patients with the characteristic appearance of TM on sonograms were retrospectively evaluated for the number, pattern, and distribution of echogenic foci and for associated intratesticular abnormalities. Medical records and pathologic reports were reviewed. RESULTS: Considerable variation was found in the number and distribution of occurrences of TM (five to 60 echogenic foci per transducer field). In some patients, peripheral clustering was seen. Most patients demonstrated side-to-side symmetry, but asymmetric distribution was seen in eight patients and unilateral foci were seen in one patient. In 17 patients, a germ cell neoplasm was seen. One additional patient had a focal lesion that was proved to be an infarct. CONCLUSION: TM has a characteristic sonographic appearance. Because of the 40% occurrence of primary testicular neoplasm in association with it, TM cannot continue to be considered a benign finding.

Mitochondrial localization and characterization of 99Tc-SESTAMIBI in heart cells by electron probe X-ray microanalysis and 99Tc-NMR spectroscopy.

As the development of targeted intracellular magnetic resonance contrast agents proceeds, techniques for the quantitative analysis of the subcellular compartmentation and characterization of metallopharmaceuticals must also advance. To this end, the subcellular distribution and chemical state of hexakis (2-methoxyisobutyl isonitrile) technetium-99 (99Tc-SESTAMIBI), the ground state of the organotechnetium radiopharmaceutical used for the noninvasive evaluation of myocardial perfusion and viability by scintigraphy, has been determined by a novel application of electron probe X-ray microanalysis (EPXMA) and 99Tc-NMR spectroscopy. In cryopreserved cultured chick heart cells equilibrated in 36 microM 99Tc-SESTAMIBI, EPXMA imaging of mitochondria yielded a respiratory uncoupler-sensitive characteristic 99Tc X-ray peak representing 32.0 +/- 2.9 nmoles Tc/mg dry weight, while EPXMA of cytoplasm or nucleus showed no peak significantly greater than the threshold detectability limit of approximately 1 nmole/mg dry weight. Technetium-99 NMR spectroscopy of heart cells equilibrated with 99Tc-SESTAMIBI showed a single peak at -45.5 ppm with no evidence of significant line broadening or chemical shift compared to aqueous chemical standards, indicating that the majority of the complex exists unbound within the mitochondrial matrix. These data quantitatively demonstrate the localization of this lipophilic cationic organometallic complex within mitochondria in situ, consistent with a sequestration mechanism dependent on membrane potentials. Furthermore, this study establishes the general feasibility of combined EPXMA and NMR spectroscopy for the direct subcellular localization and characterization of metallopharmaceuticals, techniques that are readily applicable to MR contrast agents.

Microprobe analysis of Tc-MIBI in heart cells: calculation of mitochondrial membrane potential.

Hexakis (2-methoxyisobutylisonitrile) technetium-99m (99mTc-MIBI) is a gamma-emitting radiopharmaceutical probe currently in clinical use to evaluate myocardial perfusion. Biochemical and cellular pharmacological studies have suggested that Tc-MIBI, a lipophilic cation, is sequestered in mitochondria in response to transmembrane potentials. To assess directly the subcellular distribution of the probe in heart tissue, cultured chick heart cells were analyzed by electron-probe X-ray microanalysis (EPXMA) following equilibration in micromolar concentrations of carrier-added 99Tc-MIBI, the ground-state radiopharmaceutical. Quantitation of the physiological elements Na, Ca, Mg, K, S, P, and Cl was correlated with exposure to increasing concentrations of 99Tc-MIBI. EPXMA signals indicated that 99Tc-MIBI was concentrated up to 1,000 times into mitochondria in a dose-dependent fashion based on measured Tc content in the mitochondria. Inner membrane potential (delta psi) of individual mitochondria was calculated as -117 mV using the Nernst equation. Concentrations of 99Tc-MIBI > 36 microM caused a significant efflux of K and Mg from the cell, as well as an increase in Cl in the mitochondria. Comparison of cell ultrastructure with conventional electron microscopy at extracellular 99Tc-MIBI concentrations of 36-72 microM showed no changes compared with control. 99Tc-MIBI allows valuable in situ investigation of cellular bioenergetics with EPXMA by quantitation of delta psi.

Lenticulostriate vasculopathy in infants with infections of the central nervous system sonographic and Doppler findings.

Eleven infants had echogenic stripes in the basal ganglia at the location of the lenticulostriate arteries, seen by head ultrasound. Eight patients had proven infection with rubella (2 patients), cytomegalovirus (2 patients), syphilis (1 patient) or bacterial meningitis (3 patients). Two had probable intrauterine infection clinically, but the organism could not be identified; one had trisomy 13. A recent report correlated these echogenic stripes in patients with viral and syphilitic intracranial infection with pathologically proven mineralizing vasculopathy. Our group manifests a wider range of intracerebral infection associated with this finding. Duplex sonography performed in four infants showed these stripes in vivo to be arteries in the basal ganglia. The lenticulostriate arteries are not normally visible by grey scale sonography but their Doppler signal may be elicited in normal children and they are rendered vividly visible by color Doppler. Echogenicity of these vessels is highly suggestive of intracranial infection because it is not encountered normally or in babies with non infectious intracranial disorders except trisomy 13. The prognostic significance of this finding is yet to be determined.

Functional changes during acute rehabilitation in patients with stroke.

The purpose of this study was to analyze functional change levels and determine Spearman rank order correlation coefficients about information gleaned from physical therapy discharge notes for a group of 212 patients with stroke who received physical therapy during an acute rehabilitation stay. Functional changes were determined in the categories of wheelchair skills, transfer ability, bed (mat) mobility, and ambulation. Comparisons also were made between a subgroup of the most severely involved patients and a subgroup of the least involved patients. The correlations between these functional changes and days of physical therapy were determined. Four conclusions were deduced: 1) All patients improved functionally after a stroke, 2) the improvement was related to the amount of time spent in physical therapy, 3) the more severely involved patients exhibited a greater relationship between functional gains and days spent in physical therapy than the least involved patients, and 4) the least involved patients exhibited the most gains in function. The implications of these findings were discussed.