Impact of clinically significant heterotopic ossification on functional outcome after traumatic brain injury.

OBJECTIVE: To assess heterotopic ossification's (HO) impact on functional outcome after TBI. DESIGN: Retrospective with matched control group, single center. SETTING: TBI Model System of Care at the Medical College of Virginia of Virginia Commonwealth University, Richmond, VA. PARTICIPANTS: Twenty-six patients with TBI and triple-phase bone scan confirmed HO were matched with 26 patients without clinical evidence of HO. MAIN OUTCOME MEASURES: Acute and rehabilitation lengths of stay (LOS), Admission and Discharge Functional Independence Measure (FIM) scores, FIM change, FIM efficiency (FIM gains per week), and discharge disposition. RESULTS: The two groups had similar acute care LOS. Patients with HO had significantly longer inpatient rehabilitation LOS and significantly lower FIM mobility and activities of daily living subscale scores on admission and discharge. FIM efficiency was significantly lower for the group with HO. Significantly fewer patients with HO were able to be discharged to home. CONCLUSIONS: HO is associated with a poorer functional outcome; however, it is not clear whether HO causes the decreased function or whether it may serve more generally as an indicator of those patients who will not progress as far or as rapidly during inpatient rehabilitation.

A pharmacokinetic evaluation of 14C-labeled afovirsen sodium in patients with genital warts.

Afovirsen sodium is a 20-mer phosphorothioate oligonucleotide designed to be complementary to the messenger ribonucleic acid sequence for the translation initiation codon of the E2 protein vital to replication of human papillomaviruses types 6 and 11. 14C-Labeled afovirsen was given as a single-dose intradermal injection in each of four warts of five patients to determine the time-dependent changes in concentration of intact afovirsen in genital warts and to determine the systemic absorption and elimination of radiolabeled compound. Intact afovirsen in genital warts was determined by high pressure liquid chromatography analysis of protease K digested extracts. Intact afovirsen was present in wart tissue for at least 72 hours at concentrations several times in excess of the estimated minimal inhibitory concentration of 1 mumol/L. Absorption of radiolabeled afovirsen from the injection site was rapid, with a peak plasma concentration achieved within 1 hour. Clearance of afovirsen was primarily attributable to slow metabolism, with about 30% of the radiolabel eliminated as 14C-CO2 in expired air over a 6-day period after dosing. Radioactivity eliminated in urine represented metabolites of afovirsen. From the clinical pharmacokinetic data presented here and from previously published pharmacokinetic data in rats, the disposition of afovirsen in humans appears to be relatively similar to that in rats. These data suggest that once or twice weekly dosing regimen in the clinic may be appropriate.

Clearance of 131I by hemodialysis.

There are no available data documenting the dialysis clearance of iodide in humans. This work quantitates the hemodialysis clearance of iodide (as 131I) over time and examines certain factors which influence that clearance. In a single-patient study, three dialysis periods were studied over the 24 to 96 hours following administration of 129 mCi 131I given as Na131I. Hemodialysis clearance of 131I was calculated both from the arterio-venous difference of 131I across the artificial kidney and the appearance of 131I in the expended dialysate. Calculations were based on 131I activity in whole blood, whole plasma, and the supernate of plasma treated with 10% trichloroacetic acid (TCA). The hemodialysis clearance of 131I was highest when calculated from the activity of the plasma supernate, 171.3 +/- 6.0 ml/min for the period 24-29 h. post dosing, and fell in a linear fashion with time. The clearance calculated from whole blood activity was always intermediate to that from whole plasma (lowest) or the plasma supernate (highest). The percentage of plasma 131I activity precipitated by TCA rose over the study period and displayed a strong negative correlation to the hemodialysis clearance of 131I. The hemodialysis clearance of iodide, as 131I, is on the order expected for a free ion and is 4-5 times higher than the endogenous renal clearance of the ion. However, the calculated clearance varies with respect to total time of dialysis and the fraction of blood in which the 131I activity is measured.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased transcapillary escape rate of albumin in nondiabetic men in response to hyperinsulinemia.

Diabetic patients manifest increased vascular permeability. To determine whether insulin per se might increase vascular permeability, five nondiabetic men were studied by the hyperinsulinemic-euglycemic clamp technique. Each subject received a 0.72-nmol/kg body wt i.v. insulin bolus, followed by a 72-pmol.kg-1.min-1 insulin infusion for 4 h. Euglycemia was maintained by the Biostator glucose controller. At 7 h of study, 10 microCi i.v. 125I-labeled albumin was injected as bolus dose. Frequent blood samples were drawn during the next 70 min for determination of the transcapillary escape rate (TER) of albumin. Subjects returned 1-2 wk later for a control study, during which 0.45% saline was infused at a rate identical to the dextrose and insulin infusion rates during the hyperinsulinemic clamp. The mean +/- SE serum insulin levels during the hyperinsulinemic clamp and saline infusion were 9786 +/- 126 and 46 +/- 4 pM, respectively, whereas serum glucose during the two sessions was similar (5.0 +/- 0.2 vs. 4.8 +/- 0.1 mM, NS). Identical fluid volumes were infused during the two sessions (1767 +/- 197 ml/7 h), and urine outputs did not differ significantly (1615 +/- 309 vs. 1035 +/- 248 ml/7 h). The TER of albumin was greater in all five men after hyperinsulinemia than after saline infusion (18.3 +/- 2.7 vs. -2.8 +/- 2.3%/h, P = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Persistent splenic visualization on technetium-99m DISIDA hepatobiliary studies.

Tc-99m DISIDA is widely used for studying a variety of biliary conditions. It is generally recognized that the spleen is normally visualized on DISIDA imaging only during the blood pool phase. Upon review of our experience with DISIDA, visualization of the spleen was found more common than generally acknowledged. All DISIDA examinations performed at our two institutions were retrospectively reviewed; 95 studies were performed at Institution #1 and 150 studies at Institution #2. There were 138 men and 107 women. Quality control to confirm radiochemical purity included sephadex gel column chromatography. Of 245 patient studies, persistent splenic visualization was identified in one patient (1.0%) at Institution #1 and in 11 patients (7.3%) at Institution #2. There was no correlation between age, sex or final diagnosis and persistent visualization of the spleen. It is suggested that persistent splenic visualization may be caused by an elevated concentration of reduced hydrolized technetium (colloid) in DISIDA.

Accumulation of Tc-99m MDP in amyloidosis involving the tongue.

Radionuclide bone imaging using Tc-99m phosphates may show accumulation of activity in amyloid deposits. While many sites of amyloidosis have been detected with bone imaging, many reports center on cardiac amyloidosis. The case reported here demonstrates accumulation of Tc-99m MDP in amyloidosis involving the skin and muscle, including the tongue.

Evaluation of technetium-99m disofenin by column and instant thin-layer chromatography: demonstration of radiocolloid as a cause for splenic uptake.

We found persistent splenic uptake in 5% of patients undergoing hepatobiliary imaging with Tc-99m Disofenin when administered within a few minutes after labeling, suggesting the presence of radiocolloid. Hydrolyzed reduced Tc-99m colloid (HR-Tc) present in labeled Disofenin kits is controversial and may be dependent on method of assay and radiochemical kinetics. Kits were therefore evaluated by gel column (GCC) and instant thin-layer (ITLC) chromatographic methods. Tc-99m Disofenin was prepared according to the manufacturer's instructions and was maintained at room temperature (23 degrees C) or was incubated at 37 degrees C for 0.5 hr and then held at 23 degrees C. Aliquots were obtained at intervals over 5 hr and applied to Sephadex G-15 resin columns and ITLC-SG strips, with distilled water as mobile phase. GCC showed 14.9% +/- 3.4% and 11.0% +/- 2.9% initial values of HR-Tc at 23 degrees C and 37 degrees C treatments, respectively. HR-Tc decreased over time with each treatment. ITLC showed 1.2% +/- 0.4% and 1.3% +/- 0.2% HR-Tc, with no change over time. ITLC appears to be an insensitive method for the detection of HR-Tc. Incubation of Tc-99m with Disofenin kits for 30 min at 37 degrees C or for 1 hr at 23 degrees C offers an empiric method to ensure HR-Tc levels acceptable for nuclear imaging.

Preparation and evaluation of a 99mTc-SnF2 colloid kit for leukocyte labeling.

Stannous fluoride colloid (SFC) kits for instant radiolabeling with 99mTc were prepared and evaluated for suitability as a leukocyte radiolabeling agent. Technetium-99m labeling for kits stored at -15 degrees C for up to 3 mo was greater than 95% as determined by instant thin layer chromatography while colloid particles of 1-3 microns were measured by electron microscope for these preparations. Canine leukocyte preparations labeled with [99mTc]SFC and characterized by triple density gradients of metrizamide in plasma demonstrated an 83% leukocyte association. Analysis of labeled cell preparation for up to 3 hr demonstrated label stability. Labeled leukocytes, when readministered in normal dogs, demonstrated bi-exponential blood clearance with uptake and subsequent clearance from lung. There was increasing uptake of labeled leukocytes by the liver until steady state was achieved. Furthermore, when whole blood samples were analyzed by the triple density gradient method, an increasing monocyte-to-granulocyte ratio was observed to occur with time. By 3 hr 95% of the whole blood activity was associated with the leukocyte fraction. Dogs in which a 24-hr sterile abscess was created demonstrated elevated blood-pool activity as compared to control with localization of the labeled cells at inflammatory sites within 3 hr following cell readministration.

Significance of alteration in biodistribution of labeled lymphocytes exposed to stannous ion.

The biodistribution patterns of 99mTc (99mTc-lymph) and 111In-lymphocytes with [111In-(Sn)-lymph] or without (111In-lymph) stannous ion treatment was compared in Lewis rats. Syngeneic lymphocytes were labeled with either 125 microCi (4.63 MBq) 99mTc or 5 microCi (185 kBq) 111In per 2 x 10(7) cells. Mean labeling efficiency for 99mTc and 111In was 68.61% +/- 3.90% (SEM) and 87.22% +/- 2.01% (SEM) respectively. 99mTc-lymph (n = 4), 111In-lymph (n = 6) and 111In-(Sn)-lymph (n = 6) rats received 2 x 10(7) cells and were killed 18 h later. While 99mTc-lymph demonstrated significantly less localization in spleen, lymph nodes, and blood (P(F) less than 0.01) as compared with 111In-lymph, 111In-(Sn)lymph also demonstrated a significant difference (P[F]= 0.0001) in lymph node accumulation when compared to 111In-lymph. As the activity levels utilized are not associated with cell radiation damage, these alterations in biodistribution do not reflect viability or chromosomal damage, but appear related to stannous ion exposure.

Thallium-201/technetium-99m-RP-30A disparity in the course of myocardial infarction after attempted reperfusion.

Recent reports have established that 201Tl may be taken up in areas of recent myocardial infarction after myocardial blood flow is re-established. In addition, there is accelerated 201Tl "washout" from these regions producing a pattern of "reverse redistribution." We present a case in which these phenomena may have contributed to a disparity of findings between a 201Tl stress imaging study and a repeat stress imaging study performed with a [99mTc] isonitrile (99mTc-RP-30A).

Radionuclide bone imaging findings in recurrent calvarial infarction in sickle cell disease.

A patient with sickle cell disease developed bi-parietal calvarial infarctions, and subsequently developed bi-frontal calvarial infarctions. The findings on [99mTc]MDP bone imaging showed decreased activity in the parietal and frontal regions during the phase of acute infarction and increased activity in the parietal region during the later healing phase. Thus the findings on radionuclide bone imaging in cortical infarcts will depend upon the stage of the condition.

Angiographic evaluation of patients with unilateral massive perfusion defects in the lung scan.

Pulmonary embolism is an uncommon cause of a massive unilateral lung scan perfusion defect; other causes may mimic PE clinically. Angiography may, therefore, be essential for accurate diagnosis.

Arthroscintigraphic evaluation of the painful total hip prosthesis.

Arthroscintigraphy was performed in 19 patients with a painful total hip prosthesis by injecting both Tc-99m sulfur colloid and iodinated radiographic contrast material intra-articularly. Scintigraphic and radiographic results correlated exactly in 15 patients, with one false-negative scintigram, one false-positive scintigram, and one false-negative arthrogram. One patient was evaluated by scintigraphy alone. Although arthroscintigraphy is potentially more sensitive than conventional arthrography in the detection of femoral component loosening, acetabular component loosening cannot be evaluated by scintigraphy alone. A combination of scintigraphy and conventional arthrography appears to be the most accurate imaging method in the evaluation of hip prosthesis loosening.

Discordant findings in technetium-99m pertechnetate and iodine-123 thyroid imaging caused by vascular retention in the superior vena cava.

This report demonstrates superior vena cava (SVC) retention of Tc-99m pertechnetate as a cause of discordant findings in thyroid imaging performed with Tc-99m pertechnetate and I-123.

Artifactual focal accumulation of Tc-99m bone imaging tracer in the chest. Technical note (bone imaging artifact).

Four patients undergoing routine bone imaging with a Tc-99m bone imaging agent were observed to have multiple focal areas of increased uptake in the lungs. Delayed or repeat examination demonstrated resolution of the areas. The authors conclude that this was an isolated and bizarre case of aggregate formation.

Pitfall to modified in vivo method of technetium-99m red blood cell labeling. Iodinated contrast media.

Suboptimal labeling of red blood cells with Tc-99m, using the modified in vivo technique, was observed in three patients in whom labeling was attempted following IV administration of iodinated contrast media in the previous 24 hours. The mechanism is not understood, but it may represent a change in either stannous ion distribution or redox potential. It is recommended that studies employing Tc-99m RBC labeling using this technique be performed prior to administration of iodinated contrast media. This effect should be kept in mind in gastrointestinal bleeding studies performed using Tc-99m RBC, as well as in cardiac imaging studies.

Cervical distribution of iodine 131 following total thyroidectomy for thyroid cancer.

The use of postoperative radioiodine thyroid scanning has questioned whether total thyroidectomy is surgically possible. Similar to earlier studies, we have found functioning iodine 131 (131I)-avid thyroid tissue in our patients following total thyroidectomy for thyroid cancer. Preoperative and postoperative thyroid scans were compared in 24 patients to study the cervical location of postthyroidectomy residual thyroid tissue. Thyroid scanning detected 44 distinct sites of uptake. Thirty-eight of these foci were located either at the extremes of the upper poles of the thyroid gland (24) or along the embryonic thyroid descent tract (14). We conclude that these foci of 131I uptake represent incomplete resection of normal thyroid tissue, and that surgical attention to these areas should result more frequently in extirpation of the entire thyroid gland.

Effect of bronchoscopy on localization of gallium-67 citrate.

Bronchoscopy, bronchoalveolar lavage (BAL), and 67Ga lung scans are frequently performed for diagnosis or follow-up of patients with sarcoidosis, interstitial pneumonitis, lymphoma, infections, and bronchogenic carcinoma. Because many patients undergo all 3 of these procedures, it is important to determine what effects bronchoscopy and/or BAL may have on gallium imaging. Because 67Ga accumulates in neutrophils at the site of an inflammatory lesion as well as in those circulating in the vascular compartment, it seems reasonable to postulate that bronchoscopy could cause migration of labeled neutrophils into the lung, resulting in false positive gallium scans. To test this hypothesis, we studied 5 patients with varying chronologic relationships of 67Ga injection, gallium scanning, and bronchoscopy with BAL. In all patients, the repeat 67Ga lung scans remained normal or showed no change after bronchoscopy and BAL. We conclude that bronchoscopy with or without BAL does not cause increased 67Ga uptake by the lung.

Computerized scintigraphic technique for the evaluation of adult respiratory distress syndrome: initial clinical trials.

Eleven patients with suspected adult respiratory distress syndrome (ARDS) and five control patients were studied using a computerized gamma imaging and analysis technique and 99mTc-labeled human serum albumin. The heart and right lung were imaged, lung:heart ratio was plotted vs. time, and a linear regression was fitted to the data points displayed. The slope of this fit was termed the "slope index." An index value of 2 standard deviations greater than the control mean was considered positive. Radiographs from the six positive studies revealed typical diffuse air-space disease. Radiographs from two of the five negative studies demonstrated air-space consolidation. Both of these patients had elevated pulmonary capillary wedge pressure, cardiomegaly, and clinical course consistent with cardiogenic pulmonary edema. These preliminary data demonstrated a good correlation between positive slope index and clinical ARDS.