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Biomedical subjects

C C Kuni

Publications and source records attributed to C C Kuni.

At least 55 records · Page 3Linked to original sources
PubMed1988

The significance of poor renal transplant concentrating ability as assessed by I-131 Hippuran imaging.

A pattern of very poor renal allograft concentration of I-131 Hippuran and good bladder activity has been observed by the authors. The kidneys are typically barely visualized and the renogram curve is flat. The significance of this particular finding has not been described in the literature. Accordingly, a retrospective review of all patients exhibiting this scan pattern was performed and the authors attempted to correlate it with clinical, laboratory, and pathological findings at the time of study. Of 11 patients exhibiting this scan pattern, three had very high urine outputs at the time of study. Of the remaining eight patients, five had chronic rejection. In the remaining three patients, the diagnosis was: one each, acute rejection, mixed acute and chronic rejection, and cyclosporine toxicity. The authors conclude that although this pattern is non-specific, if the patient is not in a high output state, it is usually related to chronic rejection.

Adult↗
PubMed1988

Clinical comparison of high-resolution with high-sensitivity collimators in low-count cardiac gated blood pool studies.

We compared high-sensitivity (HS) and high-resolution (HR) collimators for 2.5-minute low-count acquisitions in 13 patients undergoing cardiac gated blood pool studies. High-count acquisitions served as standards. Ejection fractions calculated from low-count acquisitions were plotted against high-count acquisitions for each collimator; the variance of the HS plot was lower, and HS images were superior.

Adult↗
PubMed1987

Splenic reticuloendothelial function after splenectomy, spleen repair, and spleen autotransplantation.

Overwhelming infection after splenectomy remains a problem despite the introduction of vaccine and antimicrobial prophylaxis. To evaluate prospectively various procedures proposed for salvage of the spleen, we measured reticuloendothelial function for two to five years in 51 patients who had initially presented with abdominal trauma and suspected splenic rupture. The mean percentage of pocked erythrocytes and the clearance of antibody-coated autologous erythrocytes in 8 patients who had splenic repair and in 6 who had partial splenectomy were the same as in 11 controls with intraabdominal injury that did not involve the spleen. The mean percentage of pocked erythrocytes remained significantly elevated in 19 patients who had undergone total splenectomy without autotransplantation of splenic tissue. One of seven patients who underwent splenic autotransplantation had a normal level of pocked erythrocytes 18 months after surgery, and a second patient had only a slight elevation at 24 months. The mean (+/- SEM) half-time clearance of labeled erythrocytes was significantly longer in the group that had total splenectomy without autotransplantation (421.1 +/- 74.5 hours) than in the autotransplantation group (91.6 +/- 20.0) or in the controls (5.4 +/- 2.0). We conclude that reticuloendothelial function was better preserved after partial splenectomy and splenic repair than after splenic autotransplantation, but that autotransplantation was superior to total splenectomy and appeared to be safe. Splenic autotransplantation deserves further study in patients who have had splenic trauma when other surgical maneuvers to save the spleen are not possible.

Adolescent↗
PubMed1986

Radionuclide brain perfusion studies in suspected brain death.

The radionuclide brain perfusion study (RPS) has been suggested as a method of confirming suspected brain death. The hospital records and RPSs of 34 patients referred were reviewed because brain death was suspected. In every case but one the RPS showed absent or drastically reduced cerebral blood flow. No patient survived more than five days, and 25 survived less than 24 hours. These findings are consistent with the results of previous reports of a total of 248 patients; only one of 248 survived and was discharged from the hospital after having had a positive RPS. The RPS is highly accurate in confirming brain death.

Brain↗
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↗
PubMed1984

Evaluation of intrahepatic cholestasis with radionuclide hepatobiliary imaging.

Since hepatobiliary imaging with 99mTc=labeled iminodiacetic acid derivatives (HIDA) allows relatively separate, sequential measurement of hepatocyte clearance, parenchymal transit, and biliary excretion, these agents should be useful in differentiating intrahepatic cholestasis (IC) from other hepatobiliary disorders. We studied 18 patients with clinical evidence of IC in whom the parenchymal transit time was increased disproportionately to any decrease in hepatocyte clearance. In a second group of 14 patients with hepatocyte disease but without clinical evidence of IC, the average parenchymal transit time was increased less in relation to the average decrease in hepatocyte clearance than in the IC group. In 15 patients with extrahepatic biliary obstruction, the average hepatocyte clearance was disproportionately increased, as in IC, but large-duct obstruction was identified by scintigrams, ultrasound, or computed tomography. These preliminary results suggest that IC can be diagnosed with hepatobiliary imaging.

Adolescent↗
PubMed1984

Clinical evaluation of Tc-99m N,N'-bis(mercaptoacetyl)-2,3-diaminopropanoate as a replacement for I-131 hippurate: concise communication.

A clinical comparison of Tc-99m N,N'-bis( mercaptoacetyl )-2,3- diaminopropanoate (Component A) (Tc-99m CO2-DADS-A) and I-131 hippurate was conducted in a series of five normal volunteers and 18 patients. Each subject was studied in one session with Tc-99m CO2-DADS-A and I-131-hippurate; digital and analog images were recorded for 30 min and after voiding. In the normal volunteers, digital images with Tc-99m CO2-DADS-A gave a kidney-to-background ratio at 3 min that was greater relative to I-131 hippurate, a leading-edge parenchymal transit time that was similar to I-131 hippurate, and a percent injected dose in the urine at 30 min that was slightly less than I-131 hippurate (p less than 0.05). In patients (serum creatinine 1.0 to 14.3 mg/dl), decreasing renal function impaired excretion of Tc-99m CO2-DADS-A more than that of I-131 hippurate (p less than 0.01). In analog images, Tc-99m CO2-DADS-A always gave superior spatial resolution. No evidence of hepatobiliary excretion was detected with either radiopharmaceutical. We conclude that Tc-99m CO2-DADS-A and similar compounds should be pursued as possible replacements for I-131 hippurate.

Alanine↗
PubMed1983

Work in progress: clinical evaluation of Tc-99m-trimethylbromo-IDA and Tc-99m-diisopropyl-IDA for hepatobiliary imaging.

Six healthy individuals and six patients with a wide range of hepatobiliary function abnormalities were studied with Tc-99m-trimethylbromo-IDA; all normal subjects and four of the six patients were also studied with Tc-99m-diisopropyl-IDA. Visual evaluation of analog images demonstrated a greater liver-to-kidney ratio for Tc-99m-trimethylbromo-IDA (p less than 0.01). Sampling for radiopharmaceutical in urine at three hours following injection demonstrated that Tc-99m-trimethylbromo-IDA had a lower renal excretion rate than Tc-99m-diisopropyl-IDA regardless of whether hepatocyte function was normal or abnormal (p less than 0.01). There were no significant differences between the two radiopharmaceuticals in hepatocyte extraction efficiency or hepatic parenchymal transit time. It is concluded that the lower rate of renal excretion and, therefore, greater hepatocyte specificity of Tc-99m-trimethylbromo-IDA justifies expanded clinical trials and may make it the radiopharmaceutical of choice for hepatobiliary imaging.

Adult↗
PubMed1983

Diagnosis of biliary atresia with radionuclide hepatobiliary imaging.

Sixteen patients with biliary atresia and 11 patients with neonatal hepatitis were studied preoperatively with either Tc-99m-diethyl-IDA or TC-99m-diisopropyl-IDA. Two parameters were evaluated: hepatocyte clearance and time to appearance of radioactivity in the intestine. Two observers, using a visual grading system of 1 to 4, gave the 16 patients with biliary atresia a hepatocyte clearance grade of 1.7 +/- 0.6 (mean +/- SD); intestinal radioactivity was not seen through 24 hours. The hepatocyte clearance grade of the 11 patients with neonatal hepatitis was 2.1 +/- 0.9 (mean +/- SD) (p greater than 0.05); intestinal radioactivity was seen in nine of 11 patients (p less than 0.001). Using both parameters, 91% of the patients were classified correctly, 4% were misclassified, and 6% were classified as indeterminate; sensitivity and specificity for biliary atresia were 97% and 82%, respectively. Radionuclide imaging with the newer technetium-99m-labeled hepatobiliary radiopharmaceuticals appears promising for the noninvasive diagnosis of biliary atresia.

Bile Ducts↗
PubMed1983

Normal appearance and reproducibility of liver-spleen studies with Tc-99m sulfur colloid and Tc-99m microalbumin colloid.

In order to determine the normal biodistribution and reproducibility of Tc-99m sulfur colloid and Tc-99m microalbumin colloid, each of ten normal subjects was studied twice with each of the two agents. In overexposed delayed analog images of the anterior chest, some thyroid radioactivity was demonstrated in all of 20 microalbumin colloid studies and in none of 20 sulfur colloid studies; lung radioactivity was seen in 19 of 20 (95%) sulfur colloid studies and in none of the microalbumin colloid studies (both p less than 0.001). Delayed digital images showed that the sulfur colloid gave a higher lung-to-heart ratio, a higher lung-to-liver ratio, and a lower bone marrow-to-liver ratio compared with microalbumin colloid (all p less than 0.05). In general, reproducibility was poor for both agents. We conclude that while there are some differences between these two radiocolloids, the differences do not indicate a superiority of the newer Tc-99m microalbumin colloid over the established Tc-99m sulfur colloid for liver-spleen imaging.

Adult↗
PubMed1983

Noise reduction in nuclear medicine images.

Common methods of reducing random noise in nuclear medicine use lowpass filtering, which has the disadvantage that it affects high-frequency components of the image. We developed a noise-reduction approach that estimates signal and noise levels in each of several frequency bands and removes the appropriate amount of noise with little effect on the signal in each band.

Radiographic Image Enhancement↗
PubMed1982

Cholescintigraphy in extrahepatic biliary obstruction.

The effect of etiology on findings in cholescintigraphy in patients with extrahepatic obstruction was retrospectively evaluated in 29 patients. Of 11 patients with obstruction secondary to cancer, seven (78%) of nine had complete obstruction (delayed images were not obtained in two) and nine (82%) of 11 had a moderate to severe decreases in hepatocyte clearance. Of 12 patients with obstruction secondary to cholelithiasis, only four (36%) had complete obstruction (delayed images were not obtained in one) (p less than 0.05) and all 11 had normal or only midly decreased hepatocyte clearance (p less than 0.05). All five patients with obstruction secondary to pancreatitis had mild partial obstruction and normal or mildly decreased hepatocyte clearance. One patient had partial obstruction secondary to an abscess adjacent to the common bile duct; hepatocyte clearance was mildly decreased. Cancerous and noncancerous causes of biliary tract obstruction produce significantly different findings in hepatobiliary imaging.

Abscess↗
PubMed1982

Synthesis and biological evaluation of Tc-99m N,N'-bis(mercaptoacetyl)-2,3-diaminopropanoate: a potential replacement for [131I]o-iodohippurate.

A new technetium-chelating agent based on amide and mercaptide donor groups, N,N'-bis(mercaptoacetyl)-2,3-diaminopropanoate, was synthesized as an analog of previously described N,N'-bis(mercaptoacetyl)ethylenediamine (DADS). Complexation of Tc-99m with the new chelating group resulted in two components that were separable by high-performance liquid chromatography. The component that eluted first demonstrated high specificity for renal excretion, with over 90% in the urine of rabbits at 35 min, 87% in the urine of mice at 2 hr, and 1.6% or less in the intestines of mice. Excretion was rapid, with the first component equaling or exceeding [131I]o-iodohippurate in the urine of rabbits at all times. The second or latter component demonstrated comparable specificity but slightly slower renal excretion kinetics. Clinical trials with the first component are probably warranted.

Alanine↗
PubMed1982

Clinical comparison of Tc-99m N,N'-bis(mercaptoacetamido)ethylenediamine and [131I]ortho-iodohippurate for evaluation of renal tubular function: concise communication.

Recent experiments in normal animals have shown that Tc-99m N,N'-bis(mercaptoacetamido)ethylenediamine (Tc-99m DADS) is a potential technetium-99m-labeled replacement for [131I]ortho-iodohippurate(I-131 Hipp). We compared the two agents in eleven patients with renal transplants (serum creatinine range: 0.9--5.7 mg/dl). Digital and analog images were recorded for 30 min and after voiding. The results indicate that the relative extraction efficiency index of Tc-99m DADS is 76% +/- 3 (mean +/- s.e.m.), that the leading-edge parenchymal transit time of Tc-99m DADS is 137% +/- 6, and that the percentage of injected Tc-99m DADS in the bladder at 30 min is 25% +/- 4 of that of I-131 Hipp (all p less than 0.05). Forty percent of patients showed some hepatobiliary excretion of Tc-99m DADS. We conclude that the biologic properties of Tc-99m DADS are inferior to those of I-131 Hipp and that analogs of Tc-99m DADS should be evaluated in an attempt to find a more suitable technetium-99m-labeled replacement for I-131 Hipp.

Animals↗
PubMed1981

Complementary role of Tc-99m-diethyl-IDA and ultrasound in large and small duct biliary tract obstruction.

Fifty-one patients underwent both radionuclide and ultrasound studies of the hepatobiliary system. Eleven patients had large bile duct obstruction, six had intrahepatic diffuse small duct obstruction, and 37 had no obstruction. In all 11 patients with large duct obstruction, the radionuclide images were abnormal, but in nine of these studies the level of obstruction could not be determined. Ultrasound was abnormal in nine studies (with correct identification of level), normal in one, and technically inadequate in one, ultrasound scans were also abnormal in six patients without obstruction. In small duct obstruction, the radionuclide scan was abnormal in all six, but in five patients it could not differentiate small from large duct obstruction. In all six patients, ultrasound showed no large duct obstruction, thus allowing identification of the level of obstruction in patients whose radionuclide scans were equivocal. A cost analysis indicated that in suspected large duct obstruction, the best strategy is ultrasound first, followed by radionuclide imaging in all positive or technically inadequate ultrasound studies. In suspected small duct obstruction, the best strategy is radionuclide scanning first followed by ultrasound in all Tc-99m-diethyl-IDA studies equivocal as to level of obstruction.

Cholestasis, Intrahepatic↗