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Biomedical subjects

M Vorne

Publications and source records attributed to M Vorne.

At least 19 recordsLinked to original sources
PubMed1992

Technetium-99m hexamethyl propylene amine oxine leucocytes in the assessment of disease activity in inflammatory bowel disease.

The inflammatory activity in 108 bowel segments of 40 patients with suspected or known inflammatory bowel disease was assessed macroscopically by endoscopy, histology and technetium-99m hexamethyl propylene amine oxine (99mTc-HMPAO) leucocytes using a numerical grading system (scores 0-3). A 4-h series of scintigrams showed a significant correlation with both histological and macroscopical assessment of disease activity (rho = 0.850, P less than 0.001 and rho = 0.773, P less than 0.001, respectively). Sensitivity, specificity and accuracy of scintigraphy in detecting active inflammatory segments were 85%, 92% and 89%, respectively. A normal scintigram did not completely exclude mild inflammatory activity, especially in the rectosigmoid area. 99mTc-HMPAO leucocytes offer an accurate and non-invasive alternative for the assessment of disease activity in ulcerative colitis and Crohn's disease.

Adult↗
PubMed1992

Tc-99m HMPAO labeled leukocytes superior to bone scan in the detection of osteomyelitis in children.

Seven children (aged 7 to 16 years) with confirmed osteomyelitis underwent imaging with Tc-99m HMPAO labeled leukocytes and with Tc-99m diphosphonates. The patients were scanned at 1/2 hour and at 3 hours. The scans were evaluated visually, and the lesion-to-normal bone ratios were quantitated. All the lesions on leukocyte scans and six out of seven lesions in bone scans were readily detectable 1/2 hour after injection of the radiopharmaceutical, but 3 hours is the better imaging time. In quantitative analysis, the lesion-to-normal bone ratio increased with leukocytes significantly higher than with the bone scans (P less than 0.05). When the scintigraphic findings were compared with surgical and radiologic results, the leukocyte images detected and localized lesions better than the bone scans. According to these preliminary results, Tc-99m HMPAO labeled leukocytes seem to offer a rapid and accurate method for detecting bone infections.

Adolescent↗
PubMed1992

Simple procedure for red blood cell labeling with Tc-99m HMPAO. Preliminary clinical results.

Clinical applications for Tc-99m HMPAO labeled red blood cells have not been previously reported. The authors describe a simple, aseptic, closed, one-step centrifugal procedure for red blood cell labeling with Tc-99m HMPAO and isolation from whole blood, and they report the preliminary results of using these labeled red blood cells to detect acute gastrointestinal bleeding in 11 patients. Whole blood was radiolabeled with Tc-99m HMPAO preparation and blood cells were separated by centrifugation (30 min, 200 g, 20 degrees C) using Polyprep density gradient medium. Red blood cells contained about 50% of the radioactivity. Four out of the 11 patients imaged with a gamma camera after reinjection of labeled autologous red blood cells showed abnormal accumulation, suggesting gastrointestinal bleeding that was verified at surgery and was at the site of abnormal activity in all cases. Image quality with Tc-99m HMPAO was comparable to that of Tc-99m pertechnetate labeled pretinned red blood cells. Tc-99m HMPAO can be used as a red blood cell labeler; however, its elution rate from red blood cells limits its applicability in some investigations.

Adult↗
PubMed1992

Venous thrombosis: a controlled study on the performance of scintigraphy with 99Tcm-HMPAO-labelled platelets versus venography.

Thirty-three patients with symptoms and signs of a deep venous thrombosis (DVT) were examined by contrast venography and radionuclide imaging with 99Tcm-hexamethylpropyleneamineoxime (99Tcm-HMPAO)-labelled autologous platelets. There were 13 patients on heparin therapy and 20 without anticoagulation during the scintigraphy. Scintigraphy consisted of blood pool imaging at 5 to 20 min and accumulation imaging at 2, 4-6 and 18-24 h. In scintigraphy a positive finding was either a defect of radioactivity in the immediate blood pool phase or a hot spot indicative of accumulation of platelets in later phases. Fifteen out of 23 patients positive by venography were also positive by scintigraphy. Five of the eight false negative patients were on heparin treatment, two probably had DVT which were not quite fresh. The venography negative patients were also negative on scintigraphy. Nine out of 12 patients without anticoagulation had positive platelet accumulation compared with two out of 11 patients on heparin therapy. This difference was statistically significant (P less than 0.025). The sensitivity and specificity of platelet scintigraphy were 65 and 100%, respectively, in all patients and 83 and 100% in patients without anticoagulation. Our results suggest that scintigraphy with 99Tcm-HMPAO-labelled platelets is a useful alternative in diagnosing DVT in patients in whom a standard contrast X-ray venograph is contraindicated or otherwise unsuccessful.

Adult↗
PubMed1991

Accumulation of leucocytes labelled with technetium-99m hexamethylpropylene amine oxime in malignant abdominal tumours.

A total of 343 leucocyte scans labelled with technetium-99m hexamethylpropylene amine oxime were reviewed that had been performed in 338 patients suspected of having abdominal infection or inflammation. There was uptake by malignant abdominal tumours in 10 cases (2.9%), which represents 62.5% of known malignancies at the time of the scintigram. Accumulation was seen in 8 patients with adenocarcinoma of the colon associated with a secondary infection in the tumour or pericolic inflammation. A large tumour that had spread beyond the bowel wall was related to a positive scintigram. Accumulation was also found twice in a malignant fibrous histiocytoma in which bleeding and an inflammatory reaction to necrosis were probably responsible for the uptake. The relevant treatment was delayed for 2 weeks-2 months in 4 patients with adenocarcinoma of the colon in whom the positive uptake was regarded as confirmation of the clinically suspected acute diverticulitis.

Abdominal Neoplasms↗
PubMed1991

[99Tcm]MAG3 gamma camera nephrography in epidemic nephritis.

There is a lack of systematic nephrographic studies on epidemic nephritis (EN). We studied 10 patients with EN using [99Tcm]MAG3 gamma camera nephrography and followed up 9 of them 22-68 days later when they had clinically recovered. Variables for renal clearance of [99Tcm]MAG3 and the retention of radioactivity in the kidneys and blood were calculated. In all patients renal function was impaired acutely. There was marked reconstitution of renal function in the control studies. [99Tcm]MAG3 clearance was inversely related to serum creatinine. On visual inspection the nephrograms showed no focal changes. Nephrography was more sensitive than sonography at identifying renal impairment. [99Tcm]MAG3 nephrography is a sensitive method for identifying renal involvement and reconstitution of renal function in EN. It may be a valuable adjunct to the diagnostic arsenal, especially in nonendemic areas where EN occurs only sporadically and where there may be diagnostic uncertainty in patients presenting acutely with EN.

Disease Outbreaks↗
PubMed1991

Scintigraphy with 99mTc-HMPAO labeled leukocytes in acute cholecystitis.

99mTc-HMPAO labeled leukocyte scanning was performed on 38 patients with clinically suspected acute cholecystitis (AC) to evaluate its diagnostic value. The typical finding was an increasing accumulation of the tracer in the gallbladder wall in a 4 hour series of scintigrams. Leukocyte scan was positive in 16 of 17 patients with surgically and histologically confirmed AC. There were no false-positive findings. The sensitivity, specificity, and accuracy of scintigraphy were 94, 100, and 96%, respectively. In 2 patients with acute acalculous cholecystitis true-positive findings were observed. Scintigraphy with 99mTc-HMPAO labeled leukocytes is a valuable new imaging method in AC.

Acute Disease↗
PubMed1991

Fast diagnosis of abdominal infections and inflammations with technetium-99m-HMPAO labeled leukocytes.

The diagnostic value of early 99mTc-HMPAO-leukocyte images (2 min, 0.5 hr, 2 hr and 4 hr) was studied in 87 prospectively performed investigations in 80 patients with a suspicion of abdominal inflammation or infection. Sensitivity, specificity and accuracy were 74%, 85% and 77% in the 2-min scans, 88%, 81% and 86% in the 0.5-hr scans, 95%, 85% and 92% in the 2-hr scans, and 96%, 92% and 95% in the 4-hr scans. Nonspecific bowel accumulation was seen in 7% of patients at 2 hr and in 28% at 4 hr but was easily distinguishable from pathologic activity. The uptake in early images represents an active accumulation of granulocytes at the site of inflammation rather than nonspecific blood-pool activity judged by results of 99mTc-HMPAO-RBC imaging. We found that imaging within 2 hr from injection has a high diagnostic value, and that the activity accumulates in areas of infection and inflammation faster than in the intestinal background.

Abdomen↗
PubMed1991

Chronic prosthetic vascular graft infection visualized with technetium-99m-hexamethylpropyleneamine oxime-labeled leukocytes.

Technetium-99m-HMPAO labeled leukocytes demonstrated chronic femoro-femoral prosthetic vascular graft infection several times during an 18-mo period in a 77-yr-old man. The intensity and distribution of the uptake in the graft were fluctuating in different imaging occasions possibly indicating the strength and location of the infection. Gallium-67-citrate imaging showed negative results twice. The reason for negative 67Ga results remained obscure. The infected graft was removed and the patient did well 5 mo postoperatively.

Aged↗
PubMed1990

Tc-99m labeled leukocytes in imaging of patients with suspected acute abdominal inflammation.

One hundred patients with suspected acute abdominal inflammation were imaged at 0.5, 2-3, 4-6, and 24 hours after the administration of Tc-99m HMPAO labeled autologous leukocytes. Scan findings were retrospectively compared with final diagnosis, serum C-reactive protein (CRP), and antibiotic treatment. Clinical findings were confirmed with surgery, barium enema, or sigmoidoscopy in 61 patients, and diagnosis was based only on clinical findings in 13 patients. In 26 patients, symptoms subsided before a final diagnosis was made. Tc-99m leukocyte images were positive in 45 of the 61 patients with a confirmed diagnosis, including all patients with acute cholecystitis (N = 4) and inflammatory bowel disease (N = 8). They were also positive in nineteen out of 25 patients who had acute colonic diverticulitis and in 6 out of 7 who had intra-abdominal abscesses. Abnormal activity was found in patients with colonic carcinoma, small bowel infarction, and acute appendicitis. Abnormal activity was visualized in 0.5-hour images in all but one of the positive cases. With the exception of two postoperative cases, malignant lymphoma, and a liver abscess, a CRP level of greater than 75 mg/L was associated with positive image findings. Antibiotic treatment did not affect imaging findings. Imaging with Tc-99m labeled leukocytes appears to be valuable for detecting and localizing abdominal inflammation, and three-phase imaging during the first 4-6 hours is recommended. In some cases, 24-hour images may be useful for distinguishing small bowel from large bowel inflammation.

Abscess↗
PubMed1990

Septic Haemophilus influenzae polyarthritis demonstrated best with Tc-99m HMPAO labeled leukocytes.

A 5-year-old girl with fever and tenderness in her left wrist and right ankle was hospitalized. Bone scanning and Tc-99m labeled leukocyte imaging showed increased uptake in these joints and also in her left knee. These radionuclide methods helped determine the diagnosis and were superior to plain radiography and CT scanning. Uptake was greater on leukocyte imaging than it was on the bone scan. The patient had infectious polyarthritis caused by Haemophilus influenzae, which is a very rare cause of acute polyarthritis in children older than 2 years. The patient fully recovered with antibiotic therapy, and no surgical procedure was needed.

Ankle Joint↗
PubMed1989

The visualization of femoral vessels in delayed bone scans--a sign of arteriosclerosis? A comparison of 99mTc-MDP and 99mTc-DPD.

The activity of femoral vessels in delayed bone scans was evaluated visually in 237 consecutive patients and quantified in 40 female patients. In visual analysis the patients were randomly divided into three groups and in quantitative analysis into four groups of equal size. Two different MDP preparations and one DPD preparation were used as bone-seeking agents. With aging, the activity in femoral vessels increased with all agents in visual analysis, significantly with MDPs (P less than 0.001) between patients less than or equal to 60 years and greater than 60 years. In female patients with all agents a significant increase in femoral activity was found (P less than 0.001 with MDPs, P less than 0.05 with DPD). In patients greater than 60 years, the femoral uptake was significantly higher with MDP when compared with the DPD uptake (P less than 0.01 with MDP1, P less than 0.05 with MDP2). Between the MDPs no significant differences were found. In quantitative analysis the femoral vessel to soft tissue ratio was significantly higher in patients greater than 70 years when compared with patients less than or equal to 50 years with MDP. No difference was found with DPD. Histological examination of excised arteries of ten patients with intense femoral uptake of MDP showed arteriosclerosis and calcification in all cases. The findings suggest that the femoral visualization in delayed bone scans is probably related to arteriosclerosis and is not a non specific finding. There may be age-related differences in the distribution of MDP and DPD.

Age Factors↗
PubMed1989

Radiolabelling of human platelets with 99mTc-HMPAO.

The optimum conditions for labelling platelets with lipophilic 99mTc-hexamethyl propylene amine oxime (99mTc-HMPAO) were evaluated. An aseptic closed system was used throughout the procedure in patient studies. 48 ml blood were withdrawn into 12 ml ACD using sterile 60 ml plastic syringes. After mixing, the blood was transferred to sterile 10 ml vacuum tubes and platelets were isolated according to standard centrifugation procedures. The labelling efficiency was not dependent upon incubation temperature (22 degrees C, 37 degrees C) but was greater in saline than in the presence of plasma. The labelling efficiency increased with time up to 60 min in saline. The elution of 99mTc from platelets was about 25% in plasma milieu in vitro but did not increase with time during 160 min. 5 patients with verified fresh deep vein thrombosis in the lower leg were imaged after injection of labelled autologous platelets. All 4 of the patients without anticoagulant therapy showed positive uptake of 99mTc-HMPAO-labelled platelets, but the 5th patient--under heparin therapy--was negative in scintigraphy. Our results are encouraging and 99mTc-HMPAO-labelled platelets offer a promising tool for evaluating various clinical situations.

Blood Platelets↗