Clinical value of radionuclide small intestine transit time measurement combined with lactulose hydrogen breath test for the diagnosis of bacterial overgrowth in irritable bowel syndrome.

OBJECTIVE: Small intestine bacterial overgrowth (SIBO) may be a pathogenetic factor for irritable bowel syndrome (IBS). This syndrome cannot be explained by structural abnormalities and has no specific diagnostic laboratory tests or biomarkers. We studied quantitatively and semi-quantitatively, using lactulose hydrogen breath test (LHBT), small intestinal transit time (SITT) (99m)technetium-diethylene triamine pentaacetic acid ((99m)Tc-DTPA) in order to examine the mobility of small intestine as an indication of bacterial overgrowth in patients. METHODS: Eighty nine consecutive patients who met Rome criteria for IBS were retrospectively studied. According to the diagnostic criteria, all patients were divided into two groups: the SIBO group and the non-SIBO group. The tracer was a mixture of 10g lactulose, 37MBq (99m)Tc-DTPA and 100mL water. The patient drank the whole mixture during 1min and the SITT study started immediately. The SITT and the LHBT followed every 15min for up to 3h after emptying the urine bladder. Spearman's rank correlation was applied to assess the correlation of oro-cecum transit time (OCTT) between imaging and LHBT. The semi-quantitative index between the SIBO group and the non-SIBO group was analyzed with Wilcoxon's rank sum test. If there was significant group difference, the receiver operating characteristic (ROC) curve was used. P<0.05 was considered significant. RESULTS: The median and inter-quartile range for OCTT for the LHBT (OCTT-L) for all patients was 90min and 60min, respectively, and 75min and 45min for OCTT for the SITT study (OCTT-i). There was positive correlation between OCTT-L and OCTT-i at the 0.05 level (R=0.290, P=0.000). There were no differences in OCTT-i and in the rate of radioactivity (counts of regions of interest ROI) over the abdomen between the SIBO group and the non-SIBO group (P=0.116 and 0.290). There were significant differences in the temporal association of the hydrogen (H2) value with OCTT-i (H2-i) and OCTT-L between the two groups (P=0.000 and 0.000). The areas under the curve (AUC) of H2-i and OCTT-L were 0.749 and 0.138 respectively. CONCLUSION: Small intestinal transit time study using a lactose hydrogen breath test and (99m)Tc-DTPA is a real-time test for small intestine bacteria overgrowth in IBS patients and can be used as an indicator of the disease.

A combined simple bubbling method with high performance liquid chromatography purification strategy, higher radiochemical yield and purity and faster preparation of carbon-11-raclopride.

OBJECTIVE: Carbon-11-raclopride (¹¹C-R) is a positron-emitting radiotracer successfully used for the study of cognitive control and widely applied in PET imaging. A simple automated preparation of ¹¹C-R by using the reaction of carbon-(11)-methyl triflate (¹¹C-MeOTF) or ¹¹C-methyl iodide (¹¹C-MeI) with demethylraclopride is described. METHODS: Specifically we used a simple setup applied an additional "U" reaction vessel for ¹¹C-MeOTf compared with ¹¹C-MeI and assessed the influence of several solvents and of the amount of the percussor for ¹¹C-methylation of demethylraclopride by the bubbling method. The reversal of retention order between product and its precursor has been achieved for ¹¹C-R, enabling collection of the purified ¹¹C-R by using the HPLC column after shorter retention time. RESULTS: By the improved radiosynthesis and purification strategy, ¹¹C-R could be prepared with higher radiochemical yield than that of the previous studies. The yield for ¹¹C-MeOTf was 76% and for ¹¹C-CH3I >26% and with better radiochemical purity (>99% based on both ¹¹C-MeOTf and ¹¹C-MeI) as compared to the previously obtained purity of ¹¹C-R using HPLC method with acetonitrile as a part of mobile phase. Furthermore, by using ethanol as the organic modifier, residual solvent analysis prior to human injection could be avoided and ¹¹C-R could be injected directly following simple dilution and sterile filtration. CONCLUSION: Improved radiosynthesis and HPLC purification in combination with ethanol containing eluent, extremely shortened the time for preparation of ¹¹C-R, gave a higher radiochemical yield and purity for ¹¹C-R and can be used for multiple and faster synthesis of ¹¹C-R and probably for other ¹¹C-labeled radiopharmaceuticals.

[Value of (99m)Tc-MIBI/(18)F-FDG-dual-isotope simultaneous acquisition in diagnosis and treatment of myocardial infarction].

OBJECTIVE: To investigate the value of(99m)Tc-MIBI/(18)F-FDG-dual-isotope simultaneous acquisition (DISA) in diagnosis and treatment of patients with myocardial infarction. METHODS: Sixty-three patients with myocardial infarction who underwent DISA before and after treatment were enrolled in the study. All cases were divided into subgroups based on different treatment and myocardial viability: Group A1 (n = 16) with coronary revascularization and viable myocardium, A2 (n = 9) same as A1 but no viable myocardium; B1 (n = 6) with coronary revascularization + stem cell transplantation and viable myocardium, B2 (n = 7) same as B1 but no vital myocardium; C1 (n = 8) with stem cell transplantation and viable myocardium, C2 (n = 17) same as C1 but on viable myocardium. The changes of uptake rate of (99m)Tc-MIBI/(18)F-FDG before and after treatment were analyzed with SPSS 13.0 software. RESULT: There were statistical significances in DF value of (99m)Tc-MIBI or (18)F-FDG imaging before and after treatment in all groups (P <0.05), except Group A2 (P>0.05). The improvement of blood perfusion and metabolism in cardiac survival groups was more marked than that in non-cardiac survival groups after treatment (P<0.05). Furthermore, Group B1 was superior to Groups A1 and C1; Group B2 was superior to Group A2 and Group C2 (P<0.05 or<0.01). CONCLUSION: (99m)Tc-MIBI/(18)F-FDG DISA can detect myocardial viability and is of value for patients with myocardial infarction to choose appropriate therapeutic strategies. The degree of cardiac improvement after treatment can be evaluated by DISA.

[Intra-operative radionuclide lymphatic mapping in sentinel lymph node biopsy of breast cancer].

OBJECTIVE: To study intra-operative radionuclide lymphatic mapping in sentinel lymph node (SLN) biopsy of breast cancer. METHODS: Forty-two breast cancer (diameter 98%, size of colloid granule 100 approximately 200 nm) was injected into the mammary tissue around the tumor or biopsy site at four points. SLN in breast cancer was detected and dissected with the help of lymphoscintigraphy and intra-operative gamma probe. Routine lymph node dissection was performed for all patients. RESULTS: The detection rate was 88.1% in lymphoscintigraphy and 97.6% in intra-operative gamma probe detection for SLN in breast cancer. The sensitivity, accuracy, false negative and specificity of SLN biopsy were 93.3% (14 in 15), 97.6% (40 in 41), 6.7% (1 in 15) and 100% (26 in 26). CONCLUSION: Sentinel lymph node in breast cancer, detected by preoperative lymphoscintigraphy combined with intra-operative gamma probe, is able to predict regional lymph node metastasis. The successful rate of SLN biopsy can be raised by improvement in the quality of nuclear imaging agent, technic of injection and method of measurement.