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Biomedical subjects

W C Klingensmith

Publications and source records attributed to W C Klingensmith.

At least 19 recordsLinked to original sources
PubMed2000

Comparative value of 99mTc-sestamibi scintimammography and sonography in the diagnostic workup of breast masses.

OBJECTIVE: This study was conducted to assess the relative roles of 99mTc-sestamibi scintimammography and sonography in the evaluation of breast lesions that are indeterminate or suspicious on mammography or clinical examination. SUBJECTS AND METHODS: Twenty-five patients with 33 biopsy-proven breast lesions underwent both scintimammography and sonography. Lesions were categorized as benign or requiring biopsy on the basis of the absence or presence of a focus of increased activity on scintimammography and the shape, orientation, and echogenicity of the lesion on sonography. RESULTS: Sensitivity and specificity in detecting breast cancer were 92% and 95%, respectively, for scintimammography and 100% and 48%, respectively, for sonography. The higher specificity of scintimammography was statistically significant (p < 0.01). CONCLUSION: Although the overall accuracy of 99mTc-sestamibi scintimammography in the diagnosis of breast cancer was high, it has several disadvantages in comparison with sonography. Scintimammography has a slightly higher false-negative rate for breast cancer, is unable to reveal cysts, is more expensive, takes longer to perform, and involves ionizing radiation. For these reasons, scintimammography with 99mTc-sestamibi is unlikely to either replace sonography or be frequently used in addition to sonography.

Adult↗
PubMed1996

Technetium-99m-MAG3 renal studies in spinal cord injury patients: normal range, reproducibility, and change as a function of duration and level of injury.

UNLABELLED: The normal range, reproducibility, and change as a function of duration and level of injury for Tc-99m-MAG3 renal studies were quantitated in spinal cord injury (SCI) patients. METHODS: Five SCI patients without evidence of renal disease in each of four groups: less than 2 months, 2-12 months, 1-2 years, and greater than 2 years from time of injury, were each studied twice. There were at least two patients with paraplegia and two with tetraplegia in each group. Renal clearance (camera based method), percent function in each kidney, time of peak renal parenchymal activity, and half time of parenchymal activity following the peak were evaluated. The peak and half times were determined with regions of interest (ROIs) over the entire kidney and over just the cortex. All results were compared to normal ranges previously established in normal subjects of the same age range using the same methodology. RESULTS: Renal clearance in the less than 2 month SCI patients was not significantly different from normal subjects in either paraplegic or in tetraplegic individuals. However, clearance in tetraplegics was increased by 28.5% at 2-12 month, increased by 50.6% at 1-2 years, and decreased by 25.9% at greater than 2 years compared to normal subjects (all P < 0.02). Clearance in those with paraplegia showed a similar, but less marked, trend (P = NS). The time of peak parenchymal activity when measured with cortical ROIs did not vary among patient groups or level of injury, but was increased compared to normal subjects (P < 0.05). The percent function in each kidney and half time following the peak were symmetrical, did not differ among patient groups or with level of injury, and did not differ from normal subjects. The parenchymal peak time was significantly shorter with cortical rather than renal ROIs in all patient groups (P < 0.05). In serial studies in the same patient the percent standard deviation in total renal clearance was less than between single studies in different patients, but the decrease was significant for only the right kidney (P < 0.03), and the decrease was not as great as in normal subjects. In addition, the percent standard deviation for percent function in each kidney was significantly less than the percent standard deviations in single studies (P < 0.02). There were no significant differences between intra- and interpatient studies for any other parameter. CONCLUSION: We conclude that: (1) renal clearance measured with Tc-99m-MAG3 in tetraplegic patients increases significantly during the first 2 years following injury and decreases significantly thereafter; there is a similar, but much less marked, trend in paraplegics, (2) parenchymal peak times with cortical ROIs occur later for SCI patients than for normal subjects, and (3) there is more intrapatient variation in total renal clearance and percent renal clearance on a side in SCI patients than in normal subjects suggesting that it may be harder to study SCI patients reproducibly. These findings should be taken into account when performing and interpreting Tc-99m-MAG3 renal studies in SCI patients.

Adult↗
PubMed1996

Magnetic resonance imaging versus bone scan for assessment of vascularization of the hydroxyapatite orbital implant.

We prospectively studied 10 patients who were status postenucleation and primary placement of the hydroxyapatite orbital implant. Both the technetium-99m bone scan and gadolinium-enhanced magnetic resonance images (MRI) were obtained on the same day at variable time points in the postoperative period in order to assess the degree of vascularization. Up to 78% of the bone scans were interpreted as being completely vascularized, while only 10% of the corresponding MRI scans were consistent with complete vascularization. Cost analysis showed that MRI was cost-effective imaging modality. We conclude that contrast-enhanced MRI provides a more accurate assessment of vascularization of the hydroxyapatite orbital implant when compared to bone scan.

Adolescent↗
PubMed1994

Technetium-99m-MAG3 renal studies: normal range and reproducibility of physiologic parameters as a function of age and sex.

UNLABELLED: The normal range and reproducibility of common physiologic parameters for 99mTc-MAG3 renal studies were quantitated in normal subjects. METHODS: Six females and six males in each of three age groups, 21-40, 41-60 and 61-80 yr, were each studied twice. Renal clearance (camera based method), percent function in each kidney, time of peak renal parenchymal activity and half time of parenchymal activity following the peak were evaluated. The peak and half times were determined with regions of interest (ROIs) over the entire kidney and over the cortex only. RESULTS: There were no significant differences between sexes for any parameter. The only significant difference among age groups was a decrease in renal clearance, normalized for body surface area, with increasing age (p < 0.01). The percent function in each kidney, time of peak parenchymal activity and half time following the peak were symmetrical and did not vary with age or sex. The peak times were always less with cortical ROIs (p < 0.05). In serial studies in the same subject the percent s.d. for clearance and percent function in each kidney was less than half of the percent s.d. in single studies, suggesting that at least one half of the error is due to intersubject variation (p < 0.05). CONCLUSIONS: We conclude that: (1) renal clearance decreases with age in normal subjects, (2) cortical ROIs are superior to renal ROIs in measuring peak parenchymal activity, and (3) variation in clearance and percent function per kidney in serial studies is approximately one half the variation in single studies.

Adult↗
PubMed1993

Detection of jeopardized myocardium with Tl-201 myocardial perfusion imaging. Comparison of early and late reinjection protocols.

Reinjection of a second dose of Tl-201 before redistribution imaging has significantly improved the ability of myocardial perfusion imaging to detect jeopardized myocardium. However, PET studies and the results from coronary artery angioplasty and bypass surgery indicate that Tl-201 studies still underestimate the number of ischemic areas at stress that represent viable myocardium. To determine whether an imaging protocol using an early reinjection of Tl-201 immediately after acquisition of the stress images would improve the detection of jeopardized myocardium, 138 patients were studied with an early reinjection protocol and the incidence and magnitude of reversible defects were compared by SPECT to a second group of 143 patients who underwent the standard late reinjection protocol. Two observers independently evaluated 19 standard myocardial segments by visual examination in each patient. They determined the presence or absence of reversible defects, and, when present, their magnitude. The frequency of reversible defects always was less with early reinjection compared to the standard late reinjection; the difference reached statistical significance for one of the two observers (P < 0.05). It is concluded that early reinjection of Tl-201 in myocardial perfusion imaging does not increase and may decrease the sensitivity of the study for jeopardized myocardium.

Adenosine↗
PubMed1992

Lung scan interpretation: a physiologic, user-friendly approach.

A physiologically-oriented, user-friendly algorithm for interpretation of ventilation-perfusion (V/P) lung scans was compared to the widely used Biello criteria. The physiologic algorithm relies primarily on the observer's degree of certainty that a V/P mismatch is present rather than on the size (relative to a whole segment) and number of V/P mismatches. One hundred five patients who had undergone a ventilation study with 133Xe gas, a perfusion study with 99mTc-MAA and pulmonary angiography were reviewed. Each V/P lung scan was interpreted once with the physiologic algorithm and once with the Biello criteria by two observers. Fifty-nine percent of the 105 studies were classified as indeterminate with the physiologic algorithm versus 62% with the Biello criteria. The prevalence of pulmonary embolism in the high probability, indeterminate, low probability and normal categories for the physiologic algorithm were 60%, 26%, 7% and 0%, respectively; and for the Biello criteria were 50%, 31%, 11% and 0%, respectively. Analysis of the data with receiver-operating-characteristic curves indicated that the physiologic algorithm performed better than the Biello criteria (p less than 0.05). In addition, the physiologic algorithm has the advantages of being more intuitive and easier to remember. We conclude that further evaluation of the physiologic approach for the interpretation of V/P lung scans is warranted.

Algorithms↗
PubMed1991

Cholescintigraphy in the diagnosis of intrahepatic cholestasis. How specific is it?

Previous results from tests on a limited number of patients suggested that the combination of relatively normal hepatocyte clearance, prolonged parenchymal transit time, and eventual passage of radiotracer into the intestine or gallbladder without evidence of biliary tract dilatation were relatively specific for intrahepatic cholestasis. We reevaluated the specificity of cholescintigraphy for the diagnosis of intrahepatic cholestasis in an unselected group of patients from a general hospital. Sixteen patients had the cholescintigraphic findings of intrahepatic cholestasis and an established diagnosis of biliary tract dilatation or nondilatation by ultrasound, ERCP, or intraoperative cholangiography. Using 6 mm as the upper limits of normal for the diameter of the common hepatic duct by ultrasonography resulted in a specificity of 63% (10 correct out of 16); using 6 mm plus 1 mm for for every decade over 60 years of age gave a specificity of 75% (12 correct out of 16); and using the more liberal criterion of 8 mm as the upper limits of normal increased the specificity to 81% (13 out of 16). The data suggest that cholescintigraphy alone is unreliable in differentiating intrahepatic cholestasis from extrahepatic obstruction, even when the obstruction is partial and radiotracer eventually passes through the extrahepatic biliary tract.

Aniline Compounds↗
PubMed1990

Cholescintigraphy for acute cholecystitis: false positive results caused by chronic cholecystitis.

We investigated the effect of the severity of chronic cholecystitis on the incidence of false positive cholescintigrams in the diagnosis of acute cholecystitis. In a 4-year period 66 patients underwent cholescintigraphy (without evidence of significant hepatocellular disease or biliary tract obstruction) followed within 6 days by surgical removal of the gallbladder. At histopathology the gallbladders were categorized as normal, acute cholecystitis, or chronic cholecystitis. In addition, the severity of chronic cholecystitis was graded on a three-point scale. Using nonvisualization of the gallbladder for up to 4 h as the criterion for acute cholecystitis, the sensitivity and specificity for acute cholecystitis were 97 and 66%, respectively. Of the 35 gallbladders without acute cholecystitis, 4 were normal and the rest had various grades of chronic cholecystitis. The incidence of false positive studies increased with the severity of chronic cholecystitis (p less than 0.05). In addition, there were no false positive studies among the normal gallbladders and all gallbladders with grade three chronic cholecystitis gave false positive results. The data suggests that the severity of chronic cholecystitis affects the likelihood of obtaining false positive results with cholescintigraphy in the diagnosis of acute cholecystitis.

Acute Disease↗
PubMed1988

Fetal gallstones.

Routine obstetric ultrasound (US) examinations in a 33-year-old woman revealed a normal fetal gallbladder at 24 menstrual weeks but multiple structures in the gallbladder with findings typical of gallstones at 37 menstrual weeks. No other abnormalities were present. Three days after a term delivery, an abdominal US examination again demonstrated multiple gallstones. When the infant was 6 weeks old, a follow-up abdominal US study showed no evidence of gallstones. This case, as well as one previously reported, demonstrates that findings typical of gallstones may be seen in the fetus, and that these structures may spontaneously resolve.

Adult↗
PubMed1986

Measurement of adenosine triphosphate and 2,3-diphosphoglycerate in stored blood with 31P nuclear magnetic resonance spectroscopy.

Conditions for blood storage are chosen to assure adequate levels of adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG). Because of the invasive nature of the techniques, biochemical assays are not routinely used to measure levels of these compounds in stored blood. However, 31P NMR spectroscopy measures phosphorylated intermediates in intact cells and could be used without disruption of the storage pack. We compared levels of ATP and 2,3-DPG measured by 31P spectroscopy and standard enzyme-linked biochemical assays in whole blood (WB) and packed red blood cells (PRBCs) at weekly intervals during a 35-day storage period. NMR demonstrated a marked decrease in 2,3-DPG and an increase in inorganic phosphate after the first week of storage. No significant differences in ATP concentrations were seen in WB during the storage period, but a significant decrease in ATP in PRBCs was documented. There was good agreement in levels of ATP and 2,3-DPG measured by NMR and biochemical techniques. 31P NMR spectroscopy is a noninvasive technique for measuring ATP and 2,3-DPG which has a potential use in quality assurance of stored blood.

2,3-Diphosphoglycerate↗
PubMed1986

Evaluation of a physiologic method of interpreting first circulation time-indicator curves.

A physiologic, mathematically derived method for interpreting first circulation time-indicator curves was used to evaluate 36 proven cases of cerebral pathology taken from the literature. The method of interpretation has been published previously and uses two physiologic parameters to assign each pair of time-indicator curves into one of nine possible categories. Each category is associated with a pathophysiologic state and a list of possible etiologies that were developed on theoretical grounds. Dynamic computed tomography was used in 25 cases and radionuclide angiography in 11; there were a variety of etiologies. Of the 36 cases, 26 (72%) fell in the predicted categories, three (8%) did not fall in the predicted categories, and seven (19%) had etiologies that were not considered in the theoretical classification. Thus, the actual patterns of time-indicator curves in the proven cases from the literature correlated reasonably well with the patterns previously predicted on theoretical grounds. The results give clinical support to this method of interpreting time-indicator curves.

Blood Circulation Time↗
PubMed1986

Schizencephaly: diagnosis and progression in utero.

Schizencephaly is an unusual condition of obscure etiology. Most theories of pathogenesis postulate an in utero insult leading to maldevelopment rather than destruction of brain. The cause has most often been described as vascular or idiopathic dysgenesis. The authors report a case in which two in utero ultrasound (US) examinations performed at 31 and 36 menstrual weeks demonstrated progressive deterioration of the relatively narrow, symmetrical clefts connecting the lateral ventricles with the subarachnoid space into broad defects that corresponded to the entire distribution of the middle cerebral arteries. The findings in this case document progressive destruction of brain tissue in utero and are consistent with a vascular cause rather than a failure of formation of portions of the cerebral mantle.

Adolescent↗
PubMed1986

Cholelithiasis in the morbidly obese: diagnosis by US and oral cholecystography.

Forty-two morbidly obese patients underwent cholecystectomy at the time of gastroplasty, primarily for prophylactic reasons. Preoperatively, 37 patients underwent ultrasonography (US) of the gallbladder and oral cholecystography, four US only, and one oral cholecystography only. There was one indeterminate US study (2.4%) and one indeterminate oral cholecystogram (2.7%). At US study, gallstones were detected in six of the eight patients with gallstones (sensitivity = 75%), and the gallbladders of all 32 patients without gallstones were categorized as normal (specificity = 100%). The gallstones not identified measured 1-2 mm in diameter. Oral cholecystographic study enabled detection of gallstones in three of the seven patients with gallstones (sensitivity = 43%) and categorized as normal all 30 gallbladders without gallstones (specificity = 100%). The gallstones not seen were small and included those not detected by US. The results suggest that US is equal or superior to oral cholecystography for detection of cholelithiasis in obese patients.

Adult↗
PubMed1985

Clinical comparison of technetium-99m-N,N-bis(mercaptoacetyl)-2,3-diaminopropanoate with technetium-99m DTPA for renal imaging.

We studied 14 patients having serum creatinines of 1.0 to 12.8 mg/dl with either Tc-99m-N,N'-bis(mercaptoacetyl)-2,3-diaminopropanoate (CO2-DADS) or Tc-99m DTPA, and within 48 hours with the other agent. Analog and digital images of the kidneys and bladder were acquired for 30 minutes after injection and after voiding. The kidney-to-background ratio at 3 minutes for Tc-99m CO2-DADS was 2.01 +/- 0.79 (mean +/- SD) times that for Tc-99m DTPA (P less than 0.001). The parenchymal transit time for Tc-99m CO2-DADS was 1.34 +/- 0.25 (mean +/- SD) times that for Tc-99m DTPA (P less than 0.005). The percent-excreted dose at 30 minutes for Tc-99m CO2-DADS was 2.57 +/- 1.24 (mean +/- SD) times that for Tc-99m DTPA (P less than 0.001). Analog Tc-99m CO2-DADS images showed spatial resolution comparable to that for Tc-99m DTPA. Hepatobiliary excretion was never seen. Tc-99m CO2-DADS appears to be generally superior to Tc-99m DTPA as a renal radiopharmaceutical.

Alanine↗
PubMed1985

Effect of hydration and dehydration on technetium-99m CO2 DADS renal studies in normal volunteers.

Ten normal volunteers were studied in the hydrated and dehydrated states with the new renal radiopharmaceutical technetium-99m N,N'-bis(mercapto acetyl)-2, 3-diaminopropanoate [( 99mTc]CO2 DADS). The data were used to determine the effect of hydration and dehydration and to determine the normal range in each state. Visual evaluation of the images indicated that the first appearance of tracer in the collecting system was approximately the same in either state, that the concentration of tracer in the collecting system was always higher in the dehydrated state (p less than 0.01), and that the ureters always appeared more segmented in the dehydrated state (p less than 0.01). Quantitative analysis of the images indicated that the kidney to background ratio 1-2 min after injection was somewhat greater in the dehydrated state (13.5 +/- 4.0) than in the hydrated state (9.8 +/- 2.2) (p less than 0.05), that the size of the bladder was always greater in the hydrated state (p less than 0.05), and there was no difference in the amount of tracer in the bladder at 30 min after injection. The results define the normal hydrated and dehydrated [99mTc]CO2 DADS renal study and identify several differences between the two states which can be explained primarily by differences in urine flow rates.

Adult↗
PubMed1984

The multiple coagulopathies of biliary atresia.

Detailed coagulation studies were done prospectively on 43 patients with biliary atresia who had undergone Kasai operation (hepatic portoenterostomy). Patients were divided into three groups based on levels of factor V, factor II, and Echis II and/or response to vitamin K: no coagulopathy (46.5% of patients); coagulopathy of liver disease (30.2% of patients); and coagulopathy of vitamin K deficiency (23.3% of patients). Patients with the coagulopathy of liver disease had significantly lower levels of factors XII, V, and antithrombin III as well as longer thrombin times than patients with no coagulopathy or vitamin K deficiency. Factor V levels were decreased only in patients with more advanced liver disease; normal levels of factor V were not usually helpful in differentiating liver disease and vitamin K deficiency. The prothrombin time, factor VII-X levels, and factor II levels were significantly different for all three groups; the most abnormal values occurred in the vitamin K-deficient group. Comparison of the Echis II level to factor II coagulant activity was helpful in deciding whether a coagulopathy was due to liver disease, vitamin K deficiency, or both. Factor VIII levels were elevated in all groups. Factor VIII coagulant activity was significantly higher by the two-stage (TGT) method than by the one-stage (PTT) method. Hypersplenism causing neutropenia and thrombocytopenia was commonly seen after the age of 5 years. Vitamin E deficiency was more common than vitamin K deficiency; however, all vitamin K-deficient patients were vitamin E deficient. Coagulation status correlated well with hepatobiliary scan data, but not serum bilirubin levels. Recommendations for treatment of patients with vitamin K deficiency and/or liver disease are discussed.

Bile Duct Diseases↗