Ultrasonography in the quantification of arterial involvement in Takayasu's arteritis.

OBJECTIVE: To evaluate the accuracy of ultrasonography (US) in the detection and quantification of arterial involvement in Takayasu's arteritis (TA). METHODS: The common carotid and subclavian arteries, and the abdominal aorta of 15 patients with TA were studied by Color Doppler (CD) US and Doppler spectral analysis and compared with angiography. RESULTS: The mean difference (+/-SD) between the percent luminal stenoses measured at angiography and by CD US was 2.0+/-10.3% for the common carotid artery, 4.0+/-23.6% for the subclavian artery and -1.3+/-16.8% for the abdominal aorta. The differences were not statistically significant. However, the agreement of the methods was less than satisfactory as shown by the wide standard deviations. CONCLUSIONS: More efforts are needed to improve the less than optimal agreement of US with angiography regarding the severity of individual stenoses. The technique performs best in the study of carotid arteries.

Measuring visceral adipose tissue content from contrast enhanced computed tomography.

OBJECTIVE: To study whether visceral adipose tissue (VAT) content can be measured retrospectively from routine contrast enhanced computed tomographic (CT) studies in order to avoid extra radiation exposure and to enable epidemiological quantifications of VAT in various diseases. SUBJECTS AND METHODS: Seven patients were examined by CT and the VAT contents (from -150 HU to -50 HU) were quantified both from their corresponding unenhanced and enhanced images (n = 8-18 per patient). RESULTS: The measured VAT volume in enhanced images was smaller (p = 0.016) than in the corresponding unenhanced images, which is most likely due to the adverse accentuation of partial volume effects. By using our bolus technique, VAT (cm2) in an unenhanced image = 1.11 x VAT in an enhanced image + 2.95, p = 0.0001. Alternatively, rising properly the upper limit for VAT density in an enhanced image compensates the use of i.v. contrast media. CONCLUSION: VAT content may be retrospectively quantified from routine abdominal CT images, but the unfavorable effects of i.v. contrast administration on measurements must be taken into account.

Plasma lathosterol as a screening test for bile acid malabsorption due to ileal resection: correlation with 75SeHCAT test and faecal bile acid excretion.

1. Plasma lathosterol concentration, known to reflect cholesterol and bile acid synthesis, was evaluated as a screening test for bile acid malabsorption, comparing it with faecal bile acid measurements, SeHCAT test and Schilling test in 22 subjects of whom six were healthy controls and 16 had Crohn's disease with ileal resections of varying length. 2. Plasma lathosterols and other non-cholesterol sterols were determined by GLC. Faecal bile acids were measured by GLC, and SeHCAT retention times by gamma camera. The study subjects were divided into two groups according to the degree of bile acid malabsorption: controls (faecal bile acids < 10 mg day-1 kg-1, n = 9) and bile acid malabsorption (faecal bile acids > 10 mg day-1 kg-1, n = 13). 3. Faecal bile acid excretion was 5.9 +/- 1.0 mg day-1 kg-1 in control subjects and 45.7 +/- 6.1 mg day-1 kg-1 in the bile acid malabsorption group. The biological half-life of 75SeHCAT (T1/2) was 95.6 +/- 16.3 h and 14.1 +/- 4.1 h, respectively. Plasma lathosterol levels were significantly elevated in patients with bile acid malabsorption (742 +/- 84 micrograms/ml compared with 400 +/- 59 micrograms/ml in control subjects) and correlated closely with faecal bile acid levels (r = 0.779, P < 0.001), with 75SeHCAT T1/2 (r = -0.524, P < 0.05) and with Schilling test (r = -0.591, P < 0.05). Significant correlations were also obtained for delta 8-cholestenol with faecal bile acids (r = 0.784, P < 0.001) and 75SeHCAT (r = -0.505, P < 0.05). The biological half-life of SeHCAT correlated with faecal bile acid excretion (r = -0.702, P < 0.001). Using mean+2 SD of lathosterol (In micrograms/ml cholesterol) as a cut-off value and 10 mg day-1 kg-1 as the upper limit for faecal bile acid excretion, the test gives 100% sensitivity and 82% specificity for plasma lathosterol determination to detect bile acid malabsorption. 4. The results indicate that both the 75SeHCAT test and plasma lathosterol detect bile acid malabsorption in patients with ileal resections for Crohn's disease. However, plasma lathosterol is a simpler and less expensive method.

A low pH 111In-bleomycin complex: a tracer for radiochemotherapy of head and neck cancer.

Bleomycin (BLM) is a well known natural antibiotic. It is toxic to dividing cells and has been used for the treatment of several forms of cancer. BLM has been labeled with various cations, but most of them have turned out be unstable in in-vivo experiments. In-BLM demonstrated high bone marrow uptake, but using 111In-bleomycin complex (BLMC) formed at low pH, the low in vivo stability and high bone marrow seeking behavior of the molecule could be avoided. The idea of using BLMC in combined radiotherapy and chemotherapy is intriguing. In this study we examined the effects of 111In-A'2a-c-BLMC in the treatment of 31 head and neck cancer patients. Findings were compared with those of surgery, and pre-operative radiology. The injected activity was 85-110 MBq, and the specific activity was approximately 100 MBq/mg. The half-life of 111In activity in serum varied from 1.5 to 3.1 hours. Maximum activity in the urine was achieved in all patients within 3 hours, and the average half-life in urine was 2 hours. In most patients 50% was excreted within 3 hours, in some 70%; in all patients > 95% of the activity was excreted within 22 hours. In surgical samples from 24 patients the best tumor-to-tissue ratios were: fat 60:1, bone 17:1, muscle 12:1, blood 3.6:1. All patients were examined on the injection day with ultrasonography of the neck. Using 111In-BLMC we missed a few small lymph nodes in 2 patients, but there were no false positive findings.(ABSTRACT TRUNCATED AT 250 WORDS)

In vivo behavior of 111In-labeled monoclonal anti-prostatic acid phosphatase antibody after intraprostatic and intravenous injections.

The 111In-labeled monoclonal anti-prostatic acid phosphatase (PAP) monoclonal antibody F(ab')2 fragment was used for the radioimmunodetection of prostate cancer in two different patient groups: 15 patients with surgically verified T1-2 prostate cancer were imaged prior to staging lymphadenectomy and total prostatectomy using lymphatic administration (intraprostatic (ipr) injection), and 15 patients with verified metastatic prostatic cancer were imaged after intravenous (i.v.) injection. The patients were studied on several occasions (at 0-180 hours) after injecting a 1 mg MoAb fragment labeled with 75-150 MBq111In (DTPA-chelation). The extirpated tissues were counted for radioactivity, and studied immunohistochemically (IHC) and histologically. The anti-PAP MoAb was labeled with high efficiency (87-99%) and it demonstrated good immunoreactivity (90-95%) and a high affinity to the target antigen. In the excised prostates, cut into 12-18 smaller pieces, there was a clear correlation between the PAP content (as detected by IHC) and absolute radioactivity (% ID of 111In anti-PAP/g prostate). However, there was no correlation between radioactivity and the amount of cancer tissue (% of histological slices) inside the removed prostate tissue. In the pharmacokinetic studies, maximum activity in the serum was obtained within 3-5 hours after ipr injection; after that the kinetic behavior was similar to that after i.v. injection. After i.v. injection, two components could be distinguished the pharmacokinetic curves; the half-lives for mean distribution and elimination were 0.62 and 35.6 hours, respectively. The mean distribution half-life as well as the AUC from the pharmacokinetic curves correlated significantly with serum PAP (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

99mTc-plasmin test in deep vein thrombosis of the leg.

A 99mTc-plasmin test and phlebography were performed on 45 consecutive unselected patients with suspected deep vein thrombosis of the leg. Phlebography showed thrombosis in 15 cases. In fourteen of these patients there was a positive result in the plasmin test. Eleven other patients had a positive plasmin test result as well. The most common causes for a false-positive result in the plasmin test in the diagnosis of deep vein thrombosis were acute inflammatory disease and disturbance in venous flow without fresh thrombosis. The sensitivity of the plasmin test in the diagnosis of deep vein thrombosis was 93% and the specificity was 63%. It is concluded that the plasmin test can be used for the screening of deep vein thrombosis.

Thermography in deep venous thrombosis of the leg.

Thermography, a fast, simple, and sensitive method, was compared with conventional contrast medium phlebography in the diagnosis of acute deep venous thrombosis of the lower extremities in 141 patients. In 84% of the cases, the results with both techniques agreed. Thermograms showed the pathologic findings in 38 of 41 cases with deep thrombosis. In the three cases with false-negative findings, only the anterior surfaces of the legs were studied. In 19 cases, pathologic thermograms were recorded in the absence of deep thrombosis; the main reasons for findings were posttraumatic, postoperative, and postthrombotic states, and insufficiency of the perforant veins. If a patient has no previous history of a venous or other intervening disease, thermography with a negative finding excludes deep venous thrombosis. If it is used as a primary method, it can replace many phlebographies in the diagnosis of acute deep venous thrombosis.