[Show abstract][Hide abstract] ABSTRACT: Purpose:
Myocardial perfusion imaging (MPI) using gated single-photon emission tomography (gSPECT) may underestimate the severity of coronary artery disease (CAD). This study aimed to evaluate the significance of combined parameters derived from gSPECT, as well as treadmill stress test parameters, in the detection of severe CAD.
A total of 211 consecutive patients referred for exercise MPI between June 2011 and June 2013 (who received invasive coronary angiography within six months after MPI) were retrospectively reviewed. Exercise MPI was performed with Bruce protocol and 201Tl injected at peak exercise. Gated SPECT was performed using a cadmium-zinc-telluride camera and processed by QPS/QGS software. Perfusion defect abnormalities such as sum stress score (SSS); sum difference score, algorithm-derived total perfusion deficits, transient ischemic dilatation ratios of end-diastolic volumes and end-systolic volumes, post-stress changes in ejection fraction, and lung/heart ratio (LHR) were calculated. Treadmill parameters, including ST depression (STD) at the 1st and 3rd minutes of recovery stage (1'STD and 3'STD), maximal STD corrected by heart rate increment (ST/HR), heart rate decline in 1st and 3rd minutes of recovery stage, recovery heart rate ratio (HR ratio), systolic and mean blood pressure ratios (SBP ratio and MAP ratio) during recovery phase were recorded. Diagnostic performances of these parameters were analyzed with receiver operating characteristic (ROC) analysis and logistic regression for detection of left main (≥ 50%) or 3-vessel disease (all ≥ 70% luminal stenosis) on invasive angiography.
Among various MPI and treadmill parameters used for detection of severe CAD, SSS and ST/HR had the highest AUC (0.78, 0.73, p = NS) and best cut-off values (SSS > 6, ST/HR > 17.39 10-2mV/bpm), respectively. By univariate logistic regression, all parameters except 1'HRR, 3'HRR, SBP and MAP ratios increased the odds ratio of severe CAD. Only increased L/H ratio, 3'STD, and HR ratio remained significant after multivariate regression. The predicted values of combined MPI and treadmill parameters (LHR, 3'STD, and HR ratio) gave the best ROC (AUC: 0.91) than any individual parameter or parameter combination.
Of all treadmill and gSPECT parameters, the combination of MPI and treadmill parameters can offer better diagnostic performance for severe CAD.
PLoS ONE 08/2015; 10(7):e0134485. DOI:10.1371/journal.pone.0134485 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of the study was to examine the patterns of lymph node metastases from esophageal squamous cell carcinoma (ESCC) and compare the laterality of lymphatic metastasis in cervical, supraclavicular, and paratracheal areas using F-FDG PET/CT.
The data of 75 patients who underwent F-FDG PET/CT for staging of ESCC between January 2011 and March 2012 were reviewed. Fourteen groups of lymph nodes from the neck to abdomen were defined. Lateralization of the upper thoracic lymph nodes was defined in reference to the midline of the trachea. Frequencies of positive lymph nodes were used to determine the pattern of lymphatic spread and compare the lateralization of metastases in the cervical and upper thoracic regions.
The right paratracheal region was the most frequent site of metastasis among all patients. Left paratracheal and paragastric nodes were more frequent in upper and lower third ESCC, respectively. Upward and downward lymphatic spread was equal in mid third ESCC. In all patients, there was a trend toward more frequent lymph node metastasis on the right side than the left side for the supraclavicular and paratracheal regions. Further stratified analysis with tumor location found that right paratracheal node metastasis was significantly associated with mid third ESCC (P = 0.03). Remote nodal metastasis was found in 10.5% of patients with upper third ESCC and 13% of patients with lower third ESCC, respectively. Remote nodal metastasis was associated with higher SUV of the primary tumor (P = 0.02) and worse survival (P = 0.03). Receiver operating characteristic analysis showed a cutoff SUV of 14.8 for predicting remote lymph node metastases.
PET/CT provides important information before radiotherapy planning. Mid and lower third ESCC tends to metastasize to the right paratracheal/supraclavicular lymph nodes. Remote nodal metastases on PET/CT correlated with higher primary tumor SUV and worse survival.
Clinical Nuclear Medicine 02/2015; 40(5). DOI:10.1097/RLU.0000000000000714 · 3.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
This study described a method for tracking and compensating respiratory motion in cadmium-zinc-telluride (CZT) cameras. We evaluated motion effects on myocardial perfusion imaging and assessed the usefulness of motion compensation in phantom and clinical studies.
SPECT studies were obtained from an oscillating heart phantom and 552 patients using CZT cameras with list-mode acquisition. Images were reformatted in 500-ms frames, and the activity centroid was calculated as respiratory signal. The myocardial perfusion, left ventricular (LV) wall thickness, and LV volume were assessed before and after the motion compensation technique.
In phantom studies, we documented only minimal bias between simulated and measured shifts. Significantly reduced tracer activity, increased wall thickness and decreased volume in scans with 15 mm or more axial shifts were noted. In clinical studies, there was a higher prevalence of significant motion after treadmill exercise. The motion compensation technique could successfully compensate those motion artifacts.
The described method allows for tracking and compensating respiratory motion in CZT cameras. Significant respiratory motion is still not uncommon using CZT cameras, especially in patients who underwent treadmill tests. Motion blurring can be compensated using image processing techniques and image quality could be significantly improved.
[Show abstract][Hide abstract] ABSTRACT: Background and aim:
Instant oatmeal has been proposed as a good alternative to the standardized low-fat egg white test meal for gastric emptying studies. We aim to establish normal values of oatmeal-based gastric emptying scintigraphy and test its correlation with gastroparesis symptoms in the Chinese population.
This study prospectively enrolled 60 healthy volunteers, 30 functional dyspepsia and 30 diabetes patients with gastroparesis symptoms. All participants were evaluated using the Gastroparesis Cardinal Symptom Index. Each participant ingested instant oatmeal mixed with 1 mCi of (99m) Tc diethylenetriaminepentacetic acid, and serial imaging was immediately acquired for 3 h in the supine position using a left anterior oblique projection. Time-activity curves were generated and quantitative parameters were determined. Normal values were established from healthy volunteers and further applied in the symptomatic patients.
All participants finished the test meal and tolerated the procedure well. All gastric emptying parameters were not significantly affected by age or gender. Values above the 95th percentile of T1/2 , gastric retention at 1, 2, and 3 h (85 min, 65%, 28%, and 8%, respectively) were indicative of delayed gastric emptying. Values below the 5th percentile of gastric retention at 0.5 and 1 h (40% and 15%, respectively) were indicative of rapid gastric emptying. The lower gastric retention limit at 0.5 and 1 h were 40% and 15%, respectively. Four (13.3%) diabetes and four (13.3%) functional dyspepsia patients had delayed emptying while three diabetes patients (10%) had rapid emptying. Gastric emptying parameters correlated best with vomiting (r = 0.621) and nausea (r = 0.566) in diabetes patients.
We established normal values of oatmeal-based gastric emptying scintigraphy and observed good correlation with cardinal gastroparesis symptoms in the Chinese population.
Journal of Gastroenterology and Hepatology 06/2014; 29(11). DOI:10.1111/jgh.12640 · 3.50 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Primary aldosteronism (PA), characterized by an excessive production of aldosterone, affects 5-13 % of patients with hypertension. Accurate strategies are needed for the timely diagnosis of PA to allow curability and prevention of excessive cardiovascular events and related damage. This study aimed to evaluate the usefulness of semiquantification of (131)I-6β-iodomethyl-norcholesterol (NP-59) single photon emission computed tomography (SPECT)/CT in differentiating aldosterone-producing adenoma (APA) from idiopathic adrenal hyperplasia (IAH) and in predicting clinical outcomes after adrenalectomy.
We retrospectively reviewed 49 PA patients who had undergone adrenalectomy after NP-59 SPECT/CT within 1 year. A conventional visual scale (VS) and two semiquantitative parameters generated from SPECT/CT, adrenal to liver ratio (ALR) and lesion to contralateral ratio of bilateral adrenal glands (CON), with cutoff values calculated by receiver-operating characteristic (ROC) analysis, were compared with pathology results and postsurgical outcomes to determine the accuracy.
An ALR cutoff of 1.84 and a CON cutoff of 1.15 showed an ability to distinguish adenoma from hyperplasia similar to VS (p = 0.2592 and 0.1908, respectively). An ALR cutoff of 2.28 and a CON cutoff of 1.11 yielded the highest sensitivity and specificity to predict postsurgical outcomes, and an ALR of 2.28 had an ability superior to VS (p = 0.0215), while a CON of 1.11 did not (p = 0.1015). Patients with either ALR or CON greater than the cutoff had a high probability of positive postsurgical outcomes (n = 36/38), while patients with both ALR and CON less than the cutoff had a low probability of positive postsurgical outcomes (n = 2/11).
Semiquantification of NP-59 scintigraphy has an ability similar to VS in differentiating APA from IAH, but an excellent ability to predict postsurgical outcomes of adrenalectomy. An ALR or CON greater than the cutoff strongly suggests benefits from adrenalectomy, and both ALR and CON less than the cutoff implies a reduced chance of improvement in postsurgical outcome.
European Journal of Nuclear Medicine 02/2014; 41(7). DOI:10.1007/s00259-014-2692-z · 5.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: At present, there is no ideal imaging modality for the diagnosis of periampullary lesions. We prospectively evaluated the preoperative diagnostic usefulness of PET/CT for differentiating malignant from benign periampullary lesions.
A total of 62 patients aged 27-86 years with periampullary lesions scheduled for surgical resection were consecutively recruited. Dual-phase F-FDG PET/CT was performed in all patients. An additional 3'-deoxy-3'-[F]fluorothymidine (FLT) scan was performed in 21 patients (33.9%). The relationship of visual interpretation, SUV, and lesion to background ratio (LBR) with surgical histopathology diagnosis was evaluated.
There were 36 patients with malignancies, 15 with benign neoplasms, and 11 with benign non-neoplasms. Using visual analysis, FDG PET/CT had good sensitivity (86.1%; 31/36), lower specificity (57.7%; 15/26), and fair accuracy (74.2%; 46/62). Regional lymph node metastases were identified in 7 of 11 patients by FDG PET/CT and only in 1 patient by abdominal CT. On the other hand, hepatic metastasis was detected in 1 patient by FDG PET/CT. Dual-phase FDG (P < 0.001) and FLT (P < 0.05) SUVmax and LBR were significantly higher in malignant than in benign lesions, and in malignant neoplasms than in benign neoplasms. Although average FLT SUVmax was significantly lower than the average FDG SUVmax (P < 0.001), the specificity and accuracy of the former were significantly better.
FDG PET/CT may help identify patients with periampullary malignancy. FDG SUVmax and LBR appear to aid in the differential diagnosis and add diagnostic confidence. In addition, higher specificity and diagnostic accuracy may be achieved by additional FLT PET/CT.
Clinical nuclear medicine 06/2013; 38(9). DOI:10.1097/RLU.0b013e31829b266a · 3.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Abscess formation inside adenomyosis rarely occurred. A 49-year-old woman had adenomyosis for several years with the symptoms of menorrhagia and dysmenorrhea. She presented with fever of unknown etiology for 3 weeks. Ga SPECT/CT demonstrated increased tracer accumulation inside the uterus, which was confirmed as pyoadenomyosis after hysterectomy, and her fever subsided dramatically thereafter. For women with adenomyosis and fever of unknown origin, pyoadenomyosis is a rare but possible cause. Ga SPECT/CT is a valuable tool for accurate diagnosis.
Clinical nuclear medicine 05/2013; 39(4). DOI:10.1097/RLU.0b013e318292f118 · 3.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A 56-year-old woman, who had already suffered from systemic sclerosis and primary biliary cirrhosis, was presented with progressive pain at the right lower quadrant of abdomen, lower-grade fever, and leukocytosis for 4 days. Blood cultures did not yield pathogens. Abdominal ultrasonography revealed a right iliac artery aneurysm compressing the right kidney resulting in right hydronephrosis. Ga SPECT/CT demonstrated an intense hot area at the right common iliac artery, suggestive of an infected aneurysm. Contrast-enhanced CT showed concordant findings. This case illustrates the value of Ga SPECT/CT in discriminating pathologic uptake of the abdomen from physiologic activity of the bowels.
Clinical nuclear medicine 04/2013; 38(7). DOI:10.1097/RLU.0b013e318286c00c · 3.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Lymphoscintigraphy is a useful and safe tool for the diagnostic evaluation of a swollen extremity as well as sentinel lymph node biopsy in malignancies. Here, we report a 34-year-old woman who developed progressive abdominal distention and bilateral lower limb edema 3 months after simultaneous pancreas and renal transplantation. Color Doppler-duplex ultrasound revealed patent deep veins of bilateral lower extremities without evidence of thrombosis. Lymphoscintigraphy demonstrated a large area of tracer accumulation at left lower quadrant of abdomen, suggestive of a postoperative lymphocele. SPECT/CT successfully localized the lesion near the renal graft.
Clinical nuclear medicine 04/2012; 37(4):374-6. DOI:10.1097/RLU.0b013e31823eac5e · 3.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We describe the case of a 4-month-old girl who was admitted for bilateral legs swelling for several weeks. Lymphoscintigraphy revealed the absence of the radiotracer proximal to the ilioinguinal nodes up to 6 hours postinjection. In light of the clinical and image findings, a diagnosis of congenital lymphedema was compatible. Systemic corticosteroid was given, and physical massage was applied at the lower extremities for 3 weeks. Repeat lymphoscintigraphy revealed faster lymphatic flow and liver visualization, demonstrating improvement in lymphatic function. This case illustrates the usefulness of lymphoscintigraphy in diagnosis and evaluating therapy response of lymphedema in children.
Clinical nuclear medicine 04/2011; 36(4):e11-2. DOI:10.1097/RLU.0b013e31820aa35a · 3.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An 80-year-old woman, who had suffered from end-stage renal disease under peritoneal dialysis, was presented with intermittent fever, leukocytosis, and elevated C-reactive protein for 4 months. She did not have symptom of abdominal pain. Culture of ascites showed Klebsiella pneumoniae. Abdominal utrasonography was negative. Whole-body gallium-67 imaging showed a segmental uptake mimicking bowels in right abdomen. SPECT/CT revealed the uptake in a soft tissue density beneath the abdominal wall instead of bowels. Contrast-enhanced CT demonstrated a low-density mass with peripheral enhancement at the aforementioned area. Her clinical condition stabilized gradually after CT-guided percutaneous drainage of pus from the abscess.
Clinical nuclear medicine 03/2011; 36(3):258-60. DOI:10.1097/RLU.0b013e3181f9e025 · 3.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Infiltrative hepatic lesions in conventional imaging modalities are a continuing diagnostic challenge in clinical practice, especially in an endemic area of viral hepatitis. The purpose of this study isto prospectively assess the role of F-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography/computed tomography (PET/CT) in indeterminate infiltrative hepatic lesions seen in conventional CT or magnetic resonance imaging (MRI).
Dual-phase FDG-PET/CT was performed on35consecutive patients with indeterminate infiltrative hepatic lesions in CT or MRI. The variables analyzed included visual score and maximum standardized uptakevalue. Final diagnosis was histopathology orclinicalfollow-up for at least 12 months.
Malignancy was proven in 28 patients and there were benign strictures in seven patients. Sensitivity, specificity, and overall diagnostic accuracy of FDG-PET/CT using visual score were 85.7% (24/28), 71.4% (5/7), and 82.9% (29/35). Early and delayed maximum standardized uptake values were significantly higher in infiltrative hepatic malignancies than in benign lesions. Furthermore, PET/CT detected 13 unexpected distant metastatic foci notseen in other imaging studies. Thirteen patients (37.1%)had the plans of clinical treatment altered by FDG-PET/CT alone.
FDG-PET/CT can help to clarify the diagnosis of indeterminate infiltrative hepatic lesions in CT or MRI. Inthis patient population, FDG-PET/CT may hold promisein the detection of unsuspected occult metastases, facilitating decision making and treatment planning.
Nuclear Medicine Communications 02/2011; 32(4):252-9. DOI:10.1097/MNM.0b013e32834368bf · 1.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The left ventricular (LV) ejection fraction (EF) and end-diastolic and end-systolic volumes are strong predictors for prognosis of cardiac death. Quantitative-gated myocardial perfusion single-photon emission computed tomography (SPECT) is widely used to measure LV functional parameters. However, systematic differences may exist between referred populations. We sought to derive sex-specific normal values for LV functional parameters obtained using two quantitative methods.
Among 1044 consecutive patients who underwent dipyridamole stress myocardial perfusion-gated 201Tl SPECT in 2008, a total of 140 (56 men) with normal perfusion imaging were selected. None had cardiac diseases or experienced cardiac events during 1-year follow-up. LV EF and end-diastolic and end-systolic volumes were calculated by quantitative-gated SPECT (QGS) and four-dimensional-myocardial single photon emission computed tomography (4D-MSPECT), respectively.
There was excellent intrareader and interreader reproducibility for both QGS and 4D-MSPECT algorithms. The differences in LV volumes and EF between the software packages were small. High prevalence of small heart was noted in the study population, especially in women (>60%). Volumetric measures were significantly greater (P<0.001) in men than in women, even after adjustment for body surface area. Women had a higher LV EF than men when using QGS methods, but not when using the 4D-MSPECT method. Compared with 4D-MSPECT, sex remained significantly associated with EF determined by QGS methods, independent of age and body weight.
LV functional parameters determined by means of gated 201Tl SPECT need to be corrected for sex and algorithms. Separate reference values of LV EF and volumes need to be applied in both women and men depending on the software package used.
Nuclear Medicine Communications 02/2011; 32(2):113-20. DOI:10.1097/MNM.0b013e3283422838 · 1.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this prospective study is to evaluate the diagnostic and prognostic usefulness of F-18 sodium fluoride (NaF) positron emission tomography-computed tomography (PET-CT) relative to Tc-99m methylene diphosphonate (MDP) planar bone scintigraphy with no CT (BS) for hepatocellular carcinoma (HCC) patients with suspicious bone metastasis.
Both Tc-99m MDP BS and F-18 NaF PET-CT were performed for 34 consecutive Taiwanese HCC patients (five female and 29 male; mean age, 61.0+/-12.0 years) within a time span of 1 month (mean: 11.3+/-10.4 days). The accuracies of BS and PET-CT were determined by comparing their results with the finalized clinical data in a lesion-by-lesion manner.
According to the pathological and/or follow-up results, the accuracy for detecting metastatic bone lesions by Tc-99m MDP BS is 75.4% and that by F-18 NaF PET-CT is 95.7%, respectively. F-18 NaF PET-CT is significantly more accurate than Tc-99m MDP BS (P=0.0001). Furthermore, there is a significant correlation between the presence of F-18 NaF PET-CT-positive bone lesions and the survival time of HCC patients. On the other hand, the diagnostic results from BS are not correlated with the survival time of these HCC patients.
F-18 NaF using PET-CT system has significantly better sensitivity and specificity than conventional Tc-99m MDP BS in detecting metastatic HCC bone lesions that are predominantly osteolytic. The diagnostic result of PET-CT also serves as a more effective prognostic indictor for HCC patients.
Nuclear Medicine Communications 04/2010; 31(7):637-45. DOI:10.1097/MNM.0b013e3283399120 · 1.67 Impact Factor