Sestamibi Research Articles

Clinical usefulness of intraoperative parathyroid hormone monitoring for primary hyperparathyroidism

PurposeThe availability of intraoperative parathyroid hormone (IOPTH) monitoring allows successful focused parathyroidectomy for primary hyperparathyroidism (pHPT). The objective of this study was to report our initial experience in IOPTH monitoring during parathyroid surgery for primary hyperparathyroidsim.MethodsBetween May 2011 and February 2013, 37 patients underwent focused parathyroidectomy due to pHPT. IOPTH monitoring based on Miami criteria was used to confirm complete excision of hyperfunctioning parathyroid gland during surgery. Medical records of patients were reviewed retrospectively.ResultsPreoperative mean maximal calcium level was 11.7 ± 0.9 mg/dL. Preoperative technetium (99mTc) sestamibi scan and ultrasonography identified 32 of 37 (86.5%) and 29 of 37 (78.4%) of abnormal parathyroid glands, retrospectively. Results of the 2 imaging modalities were discordant for 8 cases (21.6%). The mean pre-excision PTH level was 147.2 ± 201.5 pg/mL. At 5- and 10-minute post tumor resection, PTH levels were 65.3 ± 25.4 pg/mL and 47.5 ± 24.3 pg/mL, respectively. In all cases, IOPTH levels fell by at least 50% after removing all suspected abnormal glands. All patients had a successful return to normocalcemia after surgery (mean follow-up period: 60.2 ± 15.4 months).ConclusionSurgeon could confirm complete excision of abnormal hyperfunctioning parathyroid glands by IOPTH monitoring during surgery for pHPT. IOPTH monitoring can maximize performance of successful focused para thyroidectomy for pHPT, especially when preoperative imaging results are discordant.

In vivo Exposure Effects of 99mTc-methoxyisobutylisonitrile on the FDXR and XPA Genes Expression in Human Peripheral Blood Lymphocytes.

Objective(s):In recent years, the application of radiopharmaceuticals in nuclear medicine has increased substantially. Following the diagnostic procedures performed in nuclear medicine departments, such as myocardial perfusion imaging, patients generally receive considerable doses of radiation. Normally, radiation-induced DNA damages are expected following exposure to a low-dose ionizing radiation. In order to detect molecular changes, high-sensitivity techniques must be utilized. The aim of this study was to assess the effect of a low-dose (below 10 mSv) gamma ray on gene expression using quantitative real-time polymerase chain reaction (qRT-PCR).Methods:Blood samples were obtained from 20 volunteer patients who underwent myocardial perfusion imaging. They were given various doses of Technetium-99m methoxyisobutylisonitrile (99mTc-MIBI). After that, peripheral blood mononuclear cells (PBMNs) were derived, and then total RNA was extracted and reverse-transcribed to cDNA. Finally, the expression levels of xeroderma pigmentosum complementation group-A (XPA) and ferredoxin reductase (FDXR) genes were determinded through qRT-PCR technique using SYBR Green.Results:XPA and FDXR expression levels were obtained following a very low-dose ionizing radiation. A significant up-regulation of both genes was observed, and the gene expression level of each individual patient was different. If differences in the administered activity and radiosensitivity are taken into account, the observed differences could be justified. Furthermore, gender and age did not play a significant role in the expression levels of the genes under study.Conclusion:The up-regulation of FDXR after irradiation revealed the high-sensitivity level of this gene; therefore, it could be used as an appropriate biomarker for biological dosimetry. On the other hand, the up-regulation of XPA is an indication of DNA repair following radiation exposure. According to linear no-threshold model (LNT) and the results obtained from this study, a very low dose of ionizing radiation could bring about adverse biological effects at molecular level in the irradiated person.

The Effect of Long Term Smoking as an Independent Coronary Risk Factor on Myocardial Perfusion Detected by Thallium 201 or Tc99m Sestamibi Spect Study

Objective: The aim of this work was to assess the effect of smoking as an independent coronary risk factor on Myocardial Perfusion detected by Thallium 201 or Tc99m Sesta MIBI SPECT study.Methods: This study included 200 patients, 100 who are smokers only (group A) without any cardiac risks and the other 100 (group B) were nonsmokers, but with single cardiac risk factor as hypertension or diabetes. Each was subjected to Dipyridamole (smokers 53, 47) or exercise (nonsmokers 51, 49) Thallium-201 or Tc99m SestaMIBI SPECT protocol.Results: Comparing smokers versus nonsmokers who have another one risk factor, smokers had : Lower age with ischemic heart disease 55 years versus 60 years; Higher heart rate during peak stress; higher blood pressure during peak stress; More incidence of chest pain during stress test; had the same degree of ischemic perfusion defect, but higher incidence of persistent LV dilatation (43% versus 28%), higher incidence of severe perfusion defects (68% versus 53%) and statistically significant higher incidence of scar tissue (52% versus 30%).Conclusion: Smoking is an independent risk factor equal to hypertension and diabetes but smokers has higher incidence of severe perfusion defects and scar.

Prognostic value of rest gated myocardial perfusion SPECT imaging in male patients with ST-segment elevation myocardial infarction

Objective To investigate the prognostic value of rest gated myocardial perfusion SPECT imaging (GMPI) in male patients with ST-segment elevation myocardial infarction (STEMI). Methods Seventy male patients with acute STEMI were collected from July 2014 to December 2014. General information including age, history of hypertension, diabetes and serum levels of NT-proBNP, cTnI, hs-CRP were recorded. CAG and rest GMPI were performed to measure the LVEDV, LVESV, LVEF, and the percentage of myocardial perfusion defect size (PMPDS) was calculated. All patients were followed at least 180 d and the major cardiac events (MACE) were recorded. According to the follow-up results, patients were assigned to MACE group and non-MACE group, the prognostic value of PMPDS and NT-proBNP for MACE was analyzed by ROC curve. According to the cut-off value of PMPDS, patients were divided into 2 groups, and Kaplan-Meier survival curve were drawn. The data were analyzed by two-sample t test, Mann-Whitney u test, χ2 test, Pearson correlation analysis and log-rank test. Results The PMPDS in STEMI patients was not correlated with cTnI, hs-CRP, LVEDV and LVESV (all P>0.05), while positively correlated with NT-proBNP(r=0.793, P 0.05). The PMPDS, NT-proBNP, and number of stenotic vessels were significantly different between the two groups (t=2.4, z values: -2.1 and -3.6; all P<0.05). ROC curve analysis showed that the AUC of PMPDS was 0.700 with cut-off value of 14.06%, which was better than that of NT-proBNP (z=2.1, P<0.05). When patients were separated according to the cut-off value of 14.06%, there were significant differences in MACE incidence rates between the two groups (P<0.01). Conclusion Compared with NT-proBNP, PMPDS has a better prognostic value for predicting the MACE risk within 180 d in male STEMI patients, and can be used for the risk stratification of STEMI patients. Key words: Myocardial infarction; Male; Prognosis; Myocardial perfusion imaging; Tomography, emission-computed, single-photon; Technetium Tc 99m sestamibi

Dual Parathyroid Pathology; A Common Failure of Technetium-99 Sestamibi Scan for Preoperative Parathyroid Adenoma Localization

Dual Parathyroid Pathology; A Common Failure of Technetium-99 Sestamibi Scan for Preoperative Parathyroid Adenoma Localization

Evaluation of relationship between myocardial injury and left ventricular mechanical dyssynchrony using 99Tcm-MIBI myocardial perfusion SPECT and 18F-FDG myocardial metabolic PET imaging

Objective To investigate the relationship between myocardial injury and damage of mechanical synchrony in the left ventricle of patients with ischemic cardiomyopathy (ICM) using 99Tcm-MIBI MPI and gated 18F-FDG myocardial metabolic PET imaging. Methods A total of 113 ICM patients (100 males, 13 females; average age (58±10) years) underwent 99Tcm-MIBI MPI and gated 18F-FDG myocardial metabolic PET imaging from July 2015 to December 2015 in Fu Wai Hospital were retrospectively analyzed. Three-point scoring system was used for quantitative assessment of myocardial ischemia and myocardial infarction in each segment. Total ischemic score (TIS) and total scar score (TSS) of 17 segments were calculated in each patient. The phase bandwidth (BW) and phase SD were derived from phase analysis. Pearson correlation analysis and logistic regression analysis were used. Results TSS were correlated with BW and SD in all 93 patients with myocardial infarction (r values: 0.517, 0.470, both P 0.05). Logistic regression analysis showed that the number of myocardial infarction segments and TSS were associated with mechanical dyssynchrony. Conclusion Myocardial infarction is the main factor of left ventricular mechanical dyssynchrony in ICM patients, but chronic myocardial ischemia has no significant influence on mechanical dyssynchrony. Key words: Myocardial ischemia; Myocardial contraction; Myocardial perfusion imaging; Tomography, emission-computed, single-photon; Positron-emission tomography; Technetium Tc 99m sestamibi; Deoxyglucose

Influence of different image processing methods on mensuration of cardiac function in myocardial perfusion imaging

Objective To evaluate the influences of FBP and OSEM (with different iteration numbers or subset numbers) on cardiac function parameters with MPI, and to identify a suitable clinical method. Methods The MPI of 66 patients (33 males, 33 females, age range: 18-77 years) from January 2012 to December 2014 were retrospectively analyzed. The imaging data was reconstructed with FBP and 5 different OSEM (4-16 subsets and 2-4 iterations) in order to evaluate if there was any difference of cardiac function parameters calculated by QGS between the different image processing methods. In addition, the results were compared with those of cardiac ultrasonography. One-way analysis of variance was used for data analysis. Results The statistical differences of LVEF, EDV, and ESV(F values: 10.73, 4.89 and 5.97, all P<0.05) were found among 6 reconstructed methods. The values of LVEF were (66.14±11.12)%, (75.05±12.10)%, (70.09±11.27)%, (66.88±10.38)%, (64.97±10.25)%, and (62.58±9.84)%. Those of EDV were (77.32±27.58), (67.97±27.56), (75.10±27.89), (81.03±28.11), (84.94±29.07), and (89.98±29.71) ml, and the ESV values were (28.71±10.04), (19.71±16.51), (25.13±17.66), (29.01±18.47), (32.10±19.63), and (35.83±20.41) ml respectively. The cardiac function parameters measured by OSEM (with 2 iterations, 12 subsets) were much similar to that measured by cardiac ultrasonography. Conclusion Compared with other 5 processing methods of MPI, the OSEM (with 2 iterations, 12 subsets) method may be more suitable for practical clinical application. Key words: Myocardial perfusion imaging; Ventricular function; Tomography, emission-computed, single-photon; Tomography, X-ray computed; Image processing, computer-assisted; Technetium Tc 99m sestamibi

Primary hyperparathyroidism caused by enormous unilateral water-clear cell parathyroid hyperplasia

BackgroundParathyroid water-clear cell hyperplasia (WCCH) and water-clear cell adenoma (WCCA) are rare causes of primary hyperparathyroidism. The frequency of WCCH seems to be less than 1% of all primary hyperplasia.Case presentationWe report a 53-year-old woman with a large unilateral water clear cell parathyroid hyperplasia associated with primary hyperparathyroidism and severe osteoporosis. Ultrasonography showed a 5.4 cm multilobulated hypoechoic well defined mass localized in the lower half of the left thyroid lobe. Technetium sestamibi scanning showed a persistent very large area of increased activity possibly corresponding to a left inferior double parathyroid adenoma. At surgery, two large merged lobulated parathyroid glands were removed from the left superior and inferior aspects of the adjacent thyroid extending to the sub-clavicular area. Histopathology showed polygonal hyperplastic vacuolated cells with abundant water clear cytoplasm. The lesion had lack of capsule or rim of parathyroid tissue and immunohistochemistry was positive for PTH staining. These findings were consistent with diffused water clear cell hyperplasia. After parathyroidectomy, iPTH and calcium levels dropped immediately.ConclusionThe clinical presentation of the patients with water clear cells parathyroid content and hyperparathyroidism is indistinguishable from that of the more common causes of primary hyperparathyroidism of adenoma or hyperplasia and the diagnosis is made only on pathological examination. In conclusion, the distinction of water clear cell hyperplasia from water clear cell adenoma can be challenging in many cases, although clinically significant as far as treatment and follow-up.

Use of Cinacalcet and 99mTc-sestamibi Imaging During Pregnancy.

A case report is reviewed, in which two nontraditional interventions were used in a patient with gestational primary hyperparathyroidism: cinacalcet and technetium-99m methoxyisobutylisonitrile imaging. The rationale for these decisions is considered in view of the available data.

Dual-phase 99mTc-MIBI imaging and the expressions of P-gp, GST-π, and MRP1 in hyperparathyroidism.

ObjectiveThe aim of this study was to further elucidate the mechanisms of dual-phase technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) parathyroid imaging by exploring the association between early uptake results (EUR), delayed uptake results (DUR), and the retention index (RI) in dual-phase 99mTc-MIBI parathyroid imaging and P glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), and glutathione S-transferase-π (GST-π) expression in hyperparathyroidism (HPT).Patients and methodsPreoperative dual-phase (early and delayed) 99mTc-MIBI imaging was performed on 74 patients undergoing parathyroidectomy for HPT. EUR, DUR, and RI were calculated. P-gp, MRP1, and GST-π expressions were assessed using immunohistochemistry in resected tissue from HPT and control patients. The association between P-gp, MRP1, and GST-π expressions and EUR, DUR, and RI in HPT was evaluated.ResultsThe positive rate of dual-phase 99mT c-MIBI imaging was 91.89% (68/74) and the false-negative rate was 8.11% (6/74). P-gp and GST-π expressions were higher in tissues resected from control compared with HPT patients (47.37 and 81.5%, P<0.05); there was no difference in MRP1. EUR were associated with P-gp and GST-π expressions, and DUR were associated with MRP1 expression. There was a significant difference in MRP1 expression between RI greater than or equal to 0 and RI less than 0. There was no relationship between the sensitivity of dual-phase 99mTc-MIBI imaging and P-gp, MRP1, and GST-π expressions in resected parathyroid tissue. The six false-negative HPT cases consisted of three P-gp (−)/MRP1 (−) tissues, three P-gp (−)/GST-π (−) tissues, and four MRP1 (−)/GST-π (−) tissues.ConclusionAs P-gp and GST-π expressions were higher in tissues resected from control compared with HPT patients, 99mTc-MIBI may wash out faster from normal parathyroid tissue surrounding the lesion compared with the lesion itself, facilitating detection.

The Sestamibi Paradox: Improving Intraoperative Localization of Parathyroid Adenomas

Accurate localization of parathyroid adenomas allows for minimally invasive parathyroidectomy. This results in a shorter length of stay and increased patient satisfaction. Preoperative Technetium (99mTc) sestamibi scans accurately localize parathyroid adenomas in 70 to 85 per cent of cases. If a patient has a negative scan, it is logical to believe that with a preoperative sestamibi injection, the gamma probe may fail to help find an adenoma. We hypothesized that the gamma probe would not be useful intraoperatively for patients with primary hyperparathyroidism (PHPTH) and a negative sestamibi scan. We retrospectively reviewed the cases of parathyroidectomy at our institution from 2010 to 2016. We selected patients with PHPTH and negative sestamibi scan. In all cases, an attempt was made to find adenomas intraoperatively with the gamma probe. A frozen section was obtained as well as intraoperative parathyroid hormone levels to confirm removal of hyperfunctioning parathyroid tissue. There were 132 parathyroidectomies of which 22 had PHPTH and a negative sestamibi scan. One case was excluded because of insufficient documentation of the intraoperative use of the gamma probe. In 19 of the 21 patients analyzed, the gamma probe successfully identified the adenoma in the operating room (sensitivity, 90.5%). In two patients, the gamma probe did not aid in localization. There were no false positives. In all cases, the parathyroid resected was confirmed by frozen section. The intraoperative parathyroid hormone levels dropped >50 per cent in all but three cases, two of which corresponded to those cases where the gamma probe did not help. Even in patients with negative sestamibi scans, intraoperative use of the gamma probe after preoperative sestamibi injection is effective in localizing parathyroid adenomas.

Influence of gender, age and weight on the cardiac functional parameters determined by gated myocardial SPECT imaging in patients with low-likelihood coronary heart disease

Objective To derive reference limits of cardiac functional parameters (CFP) determined by gated myocardial SPECT imaging, and to analyze the influence of gender, age and weight on CFP. Methods One hundred and seventy-five consecutive outpatients (89 males with age of (48.3±10.7) years and 86 females with age of (49.8±10.4) years) were defined as patients with low-likelihood coronary heart disease (LCHD). All patients underwent adenosine or exercise stress 99Tcm-MIBI G-MPI from February 2008 to April 2011. The EF, EDV and ESV of the left ventricle were measured by quantitative gated SPECT (QGS) software. The reference limits were derived by means of Gaussian distribution or percentiles. The influence of gender, age and weight on CFP was analyzed by multiple regressions for linear models. Two-sample t test was used to analyze data of 2 groups. Parameters between different age groups were compared by one-way analysis of variance. Results The lower reference limit of EF for males was 50%, the upper limit of EDV and ESV was 112 ml and 49 ml respectively. For females, the corresponding reference limits were 54%, 77 ml and 30 ml. Men had higher EDV, ESV (EDV: (75.8±18.3) ml vs (53.3±11.7) ml, t=9.35, P 0.05). For females, EDV was not different (F=2.408, P>0.05), while ESV and EF were significantly different among 3 groups (F values: 5.010, 6.229, both P<0.05). Conclusions The CFP determined by G-MPI in LCHD patients are significantly affected by gender and age. The age-related changes of CFP in males are different from those in females. Key words: Coronary disease; Ventricular function; Myocardial perfusion imaging; Tomography, emission-computed, single-photon; Technetium Tc 99m sestamibi

Value of 99Tcm-MIBI SPECT/CT in pre-operative diagnosis of primary and secondary hyperparathyroidism

Objective To evaluate the value of pre-operative 99Tcm-MIBI SPECT/CT in patients with HPT by comparing with planar 99Tcm-MIBI and ultrasound imaging. Methods A total of 57 patients (9 males, 48 females; average age: (52.9±15.5) years) were enrolled into this retrospective study. They all underwent 99Tcm-MIBI planar scintigraphy, 99Tcm-MIBI SPECT/CT and ultrasound during March to October in 2016. All patients received parathyroidectomy and the surgical pathology was considered as the gold standard. The diagnostic efficiencies were compared using χ2 test. Results A total of 86 HPT lesions were confirmed, including 47 lesions in 46 PHPT patients and 39 lesions in 11 SHPT patients. The sensitivities of SPECT/CT, planar, ultrasound and combined imaging (planar plus ultrasound) were 87.21%(75/86), 69.77%(60/86), 65.12%(56/86) and 84.88%(73/86), respectively. The overall sensitivity of SPECT/CT was significantly higher than that of individual planar imaging and that of ultrasound (χ2 values: 4.691 and 7.818, both P 0.05). No significant difference was observed among the specificities of all these modalities (χ2=2.219, P>0.05). For PHPT lesions, the sensitivities of SPECT/CT, planar imaging, combined imaging and ultrasound were 95.74%(45/47), 93.62%(44/47), 97.87%(46/47) and 76.60%(36/47), respectively. No statistically significant difference was found in the sensitivity of the former 3 modalities (χ2=1.044, P>0.05), but the sensitivity of ultrasound was the lowest(χ2=16.223, P 0.05). Only SPECT/CT could accurately localize 5 ectopic HPT lesions. Conclusion Compared to planar imaging and ultrasound, SPECT/CT has higher sensitivity for SHPT patients, and could provide precise localization for ectopic lesions, thus facilitating patient planning for minimally invasive surgery. Key words: Hyperparathyroidism; Tomography, emission-computed, single-photon; Tomography, X-ray computed; Technetium Tc 99m sestamibi

Enhancement with coronary artery calcification score in detection of coronary heart disease by myocardial perfusion SPECT imaging

Objective To evaluate the additional value of CACS in detection of coronary artery disease (CAD) with MPI. Methods A total of 188 suspected CAD patients (128 males, 60 females; average age (61.93±9.16) years) who underwent one-step examination of MPI combined with CACS from December 2012 to August 2014 were enrolled in this retrospective study. According to the gold standard of CAG, the diagnostic efficacy of MPI was calculated. ROC analysis was performed to determine the optimal CACS threshold for the detection of CAD. Mann-Whitney u test and χ2 test were used for statistical analysis. Results (1) Seventy-three CAD cases were confirmed (≥50% stenosis) among 188 patients. The sensitivity, specificity, accuracy for CAD diagnosis with MPI were 65.8%(48/73), 75.7%(87/115), 71.8%(135/188), respectively. Twenty-five CAD patients had negative findings with MPI, including 2 with LM disease, 4 with three-vessel disease (LAD+ LCX+ RCA, 3-VD), 3 with 2-VD, 16 cases with 1-VD. Among them 13 cases (52.0%, 13/25) had intermediate lesions of 1-VD (50%≤stenosis 0.05). (3) Of the 25 CAD patients with negative MPI results, 11(44.0%, 11/25) showed abnormal CACS(CACS≥95.1), consisted of 2 cases of LM disease, 4 cases of 3-VD, 2 cases of 2-VD, 3 cases of 1-VD. Diagnosis was corrected by CACS in 8/9 cases of severe CAD (LM CAD or multivessel disease) which were missed by MPI. Conclusion CACS could offer additional information for MPI in detection of suspected CAD patients, which can improve the sensitivity of MPI for diagnosing CAD, especially for severe CAD with LM lesions or multivessel CAD. Key words: Coronary disease; Myocardial perfusion imaging; Tomography, emission-computed, single-photon; Technetium Tc 99m sestamibi

Myocardial perfusion imaging evaluation of left ventricular volume and ejection fraction using a novel semi-conductor SPECT: comparison to conventional SPECT and cardiac MRI

Objective To prospectively compare cadmium-zinc-telluride (CZT) SPECT gated myocardial perfusion imaging (GMPI), conventional SPECT MPI and cardiac MRI for the assessment of left ventricular volume and ejection fraction in patients with heart failure. Methods From July 2016 to October 2016, a total of 35 patients (27 males, 8 females, average age: (52.7±14.9) years) with heart failure were consecutively included. All patients underwent CZT SPECT GMPI, conventional SPECT GMPI and cardiac MRI within 7 d. LVEDV, LVESV and LVEF of three imaging modalities were calculated. One-way analysis of variance, Pearson correlation analysis and Bland-Altman analysis were used. Results CZT SPECT showed excellent correlation with conventional SPECT for LVEDV, LVESV and LVEF (r values: 0.983, 0.986 and 0.910, respectively; all P<0.001). Bland-Altman analysis revealed good agreement between CZT SPECT and conventional SPECT for LVEDV, LVESV and LVEF. The correlation between CZT SPECT and cardiac MRI for LVEDV, LVESV and LVEF were all significant (r values: 0.864, 0.896 and 0.836, respectively; all P<0.001). Compared with cardiac MRI, CZT SPECT showed systemic underestimation of LVEDV and LVESV and good agreement of LVEF by Bland-Altman analysis. Conclusions CZT SPECT has high clinical value for patients with heart failure. Despite underestimating LVEDV and LVESV, it correlated well with cardiac MRI. It also has a good agreement with conventional SPECT on left ventricular volume and LVEF. Key words: Heart failure; Cardiac volume; Stroke volume; Semiconductors; Tomography, emission-computed, single-photon; Magnetic resonance imaging; Technetium Tc 99m sestamibi

Preoperative localization of parathyroid adenoma in video-assisted era: is cervical ultrasound or 99mTc Sesta MIBI scintigraphy better?

Endocrine surgeon localizes solitary adenoma (SA) in preoperative time by cervical ultrasound (c-US) and/or 99mTc Sesta MIBI scintigraphy (MIBI-S), but in clinical practice they often show discordant results. The aim of our study is to verify if c-US and MIBI-S have different sensitivity in preoperative localization of SA, depending on its localization, in planning minimally invasive video-assisted parathyroidectomy (MIVAP). This is a retrospective analysis of data (demographics data, preoperative localization of SA by US and MIBI-S, presence of associated thyroid disease, preoperative calcemia, preoperative serum PTH, surgical time, intraoperative PTH values, day 1 postoperative calcemia, definitive histological report) about patients consecutively submitted to MIVAP because of SA between January 2011 and January 2014 in the department of endocrine and general surgery of the University Hospital of Parma (Italy). The data, expressed as percentages (%) and means (±SD), were analyzed with SPSS Statistics 22.0 program. The c-US detected 56.25% of the superior SA (9/16 patients) and it failed to identify 7 superior adenomas (43.75%); MIBI-S identified 6/16 superior SA (37.5%) and failed in the identification of 10 superior adenomas (62.5%). For inferior SA, c-US was positive in 39/45 patients (86.66%) and falsely negative in 6/45 patients (13.33%); MIBI-S correctly showed 31/45 inferior adenomas (68.88%) and it was falsely negative in 14/45 patients (31.11%). MIBI-S showed decreased sensitivity in the identification of superior SA (P=0.0383). C-US had a high sensitivity in the identification of the inferior SA (P=0.0280). C-US and MIBI-S are the best diagnostic tools for preoperative localization of SA, but both have decreased sensitivity in the presence of a concomitant thyroid diseases. In our experience c-US showed high sensitivity in the identification of inferior SA and MIBI-S showed a decreased sensitivity in the identification of superior SA. Discordant results in the identification of SA did not contraindicate MIVAP. Intraoperative parathormone dosage is fundamental to guide the endocrine surgeon and to verify the completeness of surgical resection.

Influence of single photon emission computed tomography (SPECT) reconstruction algorithm on diagnostic accuracy of parathyroid scintigraphy: Comparison of iterative reconstruction with filtered backprojection.

Background & objectives:Preoperative localization of parathyroid lesions is essential for improving the results in patients with primary hyperparathyroidism. The purpose of this study was to evaluate retrospectively the value of technetium-99m (Tc-99m) methoxyisobutylisonitrile (MIBI) single photon emission computed tomography (SPECT) and to compare the diagnostic accuracy of iterative reconstruction (IR) and filtered backprojection (FBP) reconstruction algorithms about localization of parathyroid lesions.Methods:Forty four patients with primary hyperparathyroidism, in whom histopathological correlation could be performed, were included in the study. Dual-phase Tc-99m parathyroid scintigraphy was performed 20 and 120 min after injection of 740 MBq Tc-99m MIBI in all patients. Tomographic images were acquired 120 min after the administration of radiopharmaceutical. The SPECT data were evaluated using an IR as well as a FBP algorithm. In 23 of 44 patients, SPECT acquisitions were performed in 64×64 matrix; in the remaining 21 patients, tomographic data were collected in 128×128 matrix. The imaging results were compared with pathological findings and sensitivities of both reconstruction algorithms, and planar views were calculated.Results:Using planar MIBI scans, abnormal parathyroid glands were correctly localized in 75 per cent of the cases. Sensitivity increased to 77 per cent using SPECT with FBP and to 84 per cent with IR. When the sensitivities were calculated according to the acquisition matrix, these were 95 per cent (20/21) and 85 per cent (18/21) for IR and FBP, respectively in patients in whom 128×128 matrix was used. The sensitivities were lower in patients who were imaged with 64×64 matrix; these were calculated as 74 per cent (17/23) and 70 per cent (16/23) with IR and FBP, respectively.Interpretation & conclusions:Our findings showed that compared to planar scintigraphy, Tc-99m MIBI SPECT was more sensitive diagnostic modality in the detection of abnormal parathyroid tissues. Image quality and sensitivity may be improved further when larger matrices with IR are used instead of FBP algorithm.

Assessment of ventricular systolic synchrony and ventricular function with gated myocardial perfusion imaging in patients with chronic heart failure

Objective To retrospectively analyze the cardiac systolic synchrony and cardiac function in patients with chronic heart failure (CHF) by gated SPECT myocardial perfusion imaging (GSMPI). Methods (1) From January 2010 to February 2015, 123 cases including 82 CHF patients (57 males, 25 females, age (59.5±11.0) years) and 41 healthy people (control group; 27 males, 14 females, age (33.8±5.2) years) were enrolled in this retrospective study. According to the New York Heart Association (NYHA) classification, the CHF patients were classified into grade Ⅰ-Ⅳ groups. The systolic synchrony and cardiac functional parameters including PHB, PSD, LVEF, EDV, summed rest scores (SRS) were acquired by Emory Cardiac Toolbox software. Differences of PHB, PSD and LVEF were compared between the CHF group and the control group using two-sample t test. The difference among the four CHF groups was compared by one-way analysis of variance. The difference of some clinical factors was compared between the two groups with and without damage of systolic synchrony. The relationship between the cardiac synchrony and myocardial perfusion was analyzed by Pearson correlation analysis. Results There was no obvious difference of PHB and PSD between the grade Ⅰ CHF patients and the control group (t=-1.502 and -0.448, both P>0.05), while LVEF was significant different (t=10.419, P<0.05). Significant difference of PHB, PSD and LVEF existed between the grade Ⅱ-Ⅳ CHF patients and the control group (t values: from -27.250 to 32.723, all P<0.05). There were significant differences of PHB, PSD and LVEF among the 4 CHF groups (F=118.05, 4.13 and 154.37; all P<0.05). The differences of LVEF, EDV and SRS were significant between the patients with and without damage of systolic synchrony (t=9.57, 10.85, 18.87, all P<0.05). The ratios of damage in systolic synchrony in grade Ⅰ-Ⅳ CHF patients were 8.7% (2/23), 60.0%(12/20), 15/18 and 100% (21/21), respectively. PHB and PSD were both positively correlated with SRS (r=0.808 and 0.773, both P<0.05). Conclusions The damage of systolic synchrony are getting severer from patients with NYHA grade Ⅱ to patients with NYHA grade Ⅳ. The damage could be accompanied by the heart failure progression. Diabetes mellitus, LVEF, EDV, ESV, and SRS are related to the damage. The myocardial perfusion damage is positively correlated with the damage of cardiac systolic synchrony. GSMPI is useful to early diagnosis and treatment of heart failure. Key words: Heart failure; Myocardial contraction; Ventricular function; Myocardial perfusion imaging; Tomography, single-photon, emission-computed; Technetium Tc 99m sestamibi

Factors affecting the sensitivity of Tc-99m methoxyisobutylisonitrile dual-phase parathyroid single photon emission computed tomography in primary hyperparathyroidism.

The aim of this study was to investigate the effects of thyroid diseases and regularly used medications on the sensitivity of Tc-99m methoxyisobutylisonitrile (MIBI) dual-phase parathyroid single photon emission computed tomography (SPECT) and to define indicatives of the result of the study. Overall, 218 primary hyperparathyroidism patients (190 women, 28 men, mean age: 57±14 years) with thyroid-parathyroid ultrasonography and Tc-99m MIBI dual-phase parathyroid SPECT were retrospectively enrolled. Patients were divided as follows: a positive SPECT group [119 (54.6%) patients] and a negative SPECT group [99 (45.4%) patients]. The effects of thyroid diseases and use of calcium channel blockers, β-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, oral antidiabetics, thyroid hormone preparates, nonsteroidal anti-inflammatory drugs, and proton pump inhibitors on the sensitivity of Tc-99m MIBI dual-phase parathyroid SPECT were investigated. The frequency of NSAID usage was higher in the negative scan group (P<0.001). No significant difference was detected in terms of coexisting thyroid disease or usage of other medications. Overall sensitivity, specificity, positive, and negative predictive value of Tc-99m MIBI dual-phase parathyroid SPECT were calculated to be 89.6, 92.5, 94.1, and 86.9%. The sensitivity was low only in nonsteroidal anti-inflammatory drug users (75.6%) compared with nonusers (96.5%). Logistic regression showed that ultrasonography was indicative of a positive scan and the possibility of a negative result was increased by regular usage of nonsteroid anti-inflammatory drugs (odds ratio: 0.262, confidence interval: 0.128-0.538; P<0.001) CONCLUSION: Among various drug groups, NSAIDs may decrease the sensitivity of Tc-99m MIBI SPECT and, provided that these novel data are supported by other studies, patient preparation may be modified to stop NSAIDs before Tc-99m MIBI dual-phase parathyroid SPECT.

Evaluation of hypofunctioning thyroid nodules with technetium-99m MIBI and ultrasonography

Background: Fine needle aspiration cytology (FNAC) cannot reliably differentiate follicular adenoma from follicular carcinoma (FC), which requires histological evidence of capsular or vascular invasion. FC is the most predominant thyroid cancer in our loco-regional environment, indicating the need for improvement in preoperative diagnostic accuracy of thyroid nodules to ensure appropriate and timely interventions.Objective: The purpose of this study was to assess the role of technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) scintigraphy and ultrasonography (USG) in the differential diagnosis of thyroid nodules.Methods: Forty-two patients with hypofunctioning thyroid nodules were prospectively studied with 99mTc-MIBI scintigraphy and USG to differentiate benign from malignant nodules. An injection of 740 MBq of 99mTc-MIBI was intravenously administered, followed by semiquantitative analysis of dual-phase scans using a 4-point (0 to 3) scoring system. USG was subsequently performed and interpretation was based on some sonographic criteria for malignancy. In the following days and weeks, patients underwent FNAC followed by surgery and histopathologic examination.Results: All malignant nodules were positive on 99mTc-MIBI and all but two malignant nodules were positive on USG. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy are, respectively, 100%, 70%, 65%, 100%, and 81% for 99mTc-MIBI scintigraphy; 87%, 78%, 68%, 91% and 81% for USG; and 83%, 100%, 100%, 96% and 64% for FNAC. There was no statistically significant difference between 99mTc-MIBI scintigraphy and USG performance for both benign (p = 0.317) and malignant (p = 0.573) nodules.Conclusion: 99mTc-MIBI scintigraphy and USG are important imaging modalities in the evaluation of thyroid nodules, particularly follicular neoplasms which are frequently associated with non-diagnostic cytology.