Prognostic risk factors for rare oncocytic variantin 101 cases of papillary thyroid carcinoma.

OBJECTIVE: Oncocytic variant (OV) is an unusual subtype of papillary thyroid cancer whose histopathologic diagnostic criteria, clinicopathologic features and biological behavior are different and have not been comprehensively studied, characterized in literature. Previous studies present conflicting results upon its prognosis. We investigated demographic and clinicopathologic risk factors affecting its prognosis while presenting our clinical experience. SUBJECTS AND METHODS: This is a retrospective cohort study reviewing 101 patients of OV from an archive of 4500 well-differentiated thyroid cancer patients treated with iodine-131 (131I) between 1991 and 2017. Predefined parameters of age, gender, tumor size (TS), total 131I dose, time to recurrent disease, overall survival, extrathyroidal extension, multifocality, vascular invasion, accompanying other variants, capsular status of thyroid gland, initial cervical lymph node (LN) metastases, preablation stimulated thyroglobulin level, background thyroiditis and stage were evaluated by statistical comparison between metastatic and nonmetastatic groups. RESULTS: Seventeen cases (17%) developed metastases/recurrence, 70% of the recurrences occured before 24 months. Four patients (4%) died during the follow-up. Metastatic sites were usually cervical LN, local recurrence in thyroid bed and lungs. Multivariate analysis revealed stage (IV) and TS were the main parameters impacting recurrence/metastases. In the follow-up, isolated cervical LN metastases were found in 41% of metastatic cases, while 12% had sole recurrence in thyroid bed. Eighty eight percent of the metastatic disease included locoregional (cervical) and/or remote LN. The recurrences were associated with initial thyroid masses greater than 3.5cm in diameter. CONCLUSION: We found that the prognosis of OV is not poor in our series. Stage (IV) and tumor size are the main risk factors in metastatic development.

Risk factors and stratification for recurrence of patients with differentiated thyroid cancer, elevated thyroglobulin and negative I-131 whole-body scan, by restaging 18F-FDG PET/CT.

OBJECTIVE: In nearly 20%-30% of patients with differentiated thyroid carcinoma (DTC) relapse and 7% of them die during the next 10 years after initial diagnosis. In 10%-30% of patients with DTC after ablation therapy during the follow-up show a negative iodine-131 (131I) whole-body screening test (131I WBS) and increased serum thyroglobulin (Tg) level. Loss of ability of DTC metastatic lesions to trap 131I is associated with pure survival and often aggressive disease. Several studies have shown that in DTC cases non trapping 131I, fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG PET) can detect recurrence or metastases with high sensitivity (80%-90%). The purpose of this study was to investigate the clinicopathologic features and other related risk factors of patients with DTC having elevated Tg levels and negative 131I WBS in which recurrence was detected by 18F-FDG PET/CT. We tried to study and stratify patients in this grey zone who could benefit from 18F-FDG PET/CT for the detection of metastases/recurrence according to predefined risk factors not investigated by other researchers. SUBJECTS AND METHODS: We studied retrospectively 165 DTC patients with elevated Tg levels and a negative 131I WBS during their follow-up between 2004-2015. Metastases/recurrence was found in 49% of the patients on restaging with 18F-FDG PET/CT and were compared with nonmetastatic group according to predefined risk factors. These factors were also evaluated in true positive and false negative cases. RESULTS: The sensitivity and specificity of 18F-FDG PET/CT for detecting recurrent/metastatic disease were 90% and 98.5%, respectively. No apparent predefined risk factor impacting a false negative 18F-FDG PET/CT was found. Findings in follicular carcinoma, Hürtle cell carcinoma and papillary carcinoma were not different from positive PET findings. The variants of papillary carcinoma also had no statistically difference with regard to 18F-FDG results. CONCLUSION: The most important factors affecting a true positive 18F-FDG PET/CT study were: ETE, high total 131I dose and the SUVmax values over 4.5.

18F-FDG PET/CT findings in a case of a semantic variant of primary progressive aphasia.

UNLABELLED: Progressive speech and language disorders are commonly referred to as primary progressive aphasia (PPA), which is a clinical syndrome eroding both speech and language. Functional imaging may reveal the cause of this disorder even if structural imaging is absent. Fluorine-18- fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) allows the assessment of neuronal activity by semi-quantitatively measuring glucose metabolism in the brain. In medical literature, (18)F-FDG PET/CT studies show hypometabolic areas in different regions of the brain which are special clues for differentiating the subgroups of PPA. CONCLUSION: This case was reported to demonstrate the characteristic (18)F-FDG PET CT findings for a semantic variant of PPA.

Sonographic Features of Atypical and Initially Missed Parathyroid Adenomas: Lessons Learned From a Single-Center Cohort.

CONTEXT: Awareness of typical and atypical ultrasonographic (US) features of parathyroid adenomas (PAs) is crucial since US is the most widely used first-line imaging modality. OBJECTIVE: The purpose of this study was to describe the atypical features of PAs on US and other possible factors leading to a false negative examination in a large single-center cohort. MATERIALS AND METHODS: The US records of 457 PAs in 445 patients with biochemically proven primary hyperparathyroidism (PHPT) were evaluated in a prospectively maintained database. Atypical size, composition, shape, echogenicity, location, and vascular pattern on US were noted. For patients who previously had at least one negative US examination in referring centers, the main possible reason was defined accordingly. RESULTS: The study group included 359 female and 86 male patients with PHPT. Typical sonographic features were observed in 231 PAs (51%), whereas 226 (49%) had at least one atypical US feature. The most common atypical features were atypical size (29%), followed by atypical echogenicity (19%), shape (8%), location (7%), and composition (7%), respectively. There were 122 initially missed PAs in all groups. The most frequent main atypical US features leading to false negative examinations were atypical size (22.1%) and atypical location (18.8%). Inexperience was third most common reason (16.3%) for false negative US examinations. CONCLUSIONS: Almost half of PAs have at least one atypical feature on US. Awareness of the high prevalence of atypical US features could increase the accuracy of US examination and potentially decrease demand for more expensive second-line imaging modalities.

Initial experience of 3 tesla apparent diffusion coefficient values in differentiating benign and malignant thyroid nodules.

PURPOSE: To evaluate the role of diffusion-weighted magnetic resonance imaging (DWMRI) in differentiating benign and malignant thyroid nodules using a 3 Tesla (T) MRI scanner. MATERIALS AND METHODS: Twenty-eight nodules in 25 patients and 14 healthy control cases were included in the study. DWMRI was acquired with 6 b values with a 3T MRI scanner. The apparent diffusion coefficient (ADC) values of the nodules were calculated from reconstructed ADC map images and were compared with the final histopathological diagnoses. RESULTS: The mean ADC value of the benign nodules was 1548 ± 353.4 (×10(-6) mm(2) /s), and the mean ADC of the malignant nodules was 814 ± 177.12 (×10(-6) mm(2) /s). The normal thyroid tissue had a mean ADC value of 1323.43 ± 210.35 × 10(-6) mm(2) /s (958-1689 × 10(-6) mm(2) /s) in the healthy control group. The ADC values were significantly different among the three groups (P = 0.001). An ADC value of 905 × 10(-6) mm(2) /s was determined to be the cutoff value for differentiating benign and malignant nodules, with 90% (55.5-98.3) sensitivity and 100% (81.3-100.0) specificity. CONCLUSION: This study suggests that the ADC values of nodules measured with a 3T MRI scanner could help in differentiating benign thyroid nodules from malignant nodules.

Low efficacy of clarithromycin including sequential regimens for Helicobacter pylori infection.

BACKGROUND: Sequential treatment for Helicobacter pylori (H. pylori) appears to achieve a better eradication rate than triple therapy. However, most of the data have been reported from the Italy, and studies from different population are needed before it is recommended in clinical practice. The present study aimed to assess and compare the efficacy of two separate clarithromycin including sequential regimens in Turkey which is well known with high clarithromycin and metronidazole resistance to H. pylori. METHODS: Consecutive H. pylori -positive patients with non-ulcer dyspepsia were randomly allocated to one of the two sequential regimens; the first group was given lansoprazole 30 mg b.i.d. plus amoxicillin 1 g b.i.d. for the first week, followed by lansoprazole 30 mg b.i.d., clarithromycin 500 mg b.i.d., and metronidazole 500 mg t.i.d. for the second week (LA-CM). The second arm was given the same regimen but tetracycline500 g q.i.d. instead of metronidazole (LA-CT). H. pylori was detected with urea breath test (UBT) and histology before enrollment. UBT was repeated at 6th weeks after treatment. RESULTS: A total of 200 patients were enrolled in groups and 179 of them completed their protocols. The cumulative per protocol ("PP") and intention-to-treat ("ITT") eradication rates were 74.3% and 66.5% in all patients, respectively. Both "PP" (78.2% vs 70.1%) and "ITT" (72% vs 61%) eradication rates were better in LA-CT group than LA-CM group, but the differences were not statistically significant (p > .05). Both regimens were well tolerated, and the incidence of adverse effects was comparable. CONCLUSION: Two weeks clarithromycin including sequential regimens with metronidazole or tetracycline were not achieved acceptable eradication rates in Turkey.

Efficacy of a modified sequential therapy including bismuth subcitrate as first-line therapy to eradicate Helicobacter pylori in a Turkish population.

BACKGROUND: Eradication rates of Helicobacter pylori with standard triple therapy are not satisfactory. Sequential therapy is an alternative method to overcome this problem. OBJECTIVES: The aim of this study was to assess efficacy of a modified sequential therapy with the addition of a bismuth preparation, as first-line treatment in the eradication of H. pylori infection. MATERIALS AND METHODS: One hundred and forty-two H. pylori-positive patients were included in the study. Patients were given a 14-day sequential therapy program consisting of pantoprazole, 40 mg (b.i.d. for 14 days); colloidal bismuth subcitrate, 300 mg 4 (two tablets before breakfast and dinner, for 14 days); amoxicillin, 1 g (b.i.d.for the first 7 days); tetracycline, 500 mg (q.i.d. for the second 7 days); and metronidazole, 500 mg (t.i.d. for the second 7 days). Eradication was tested by urea breath test (UBT) 6 weeks after completion of treatment. RESULTS: Of the 142 patients included, 131 completed the study. "Per-protocol" and "intention-to-treat" analyses revealed high eradication rates in this group (92.0-95% CI, 87.2-96.8%, and 81.0-95% CI, 74.5-87.4%, respectively). There was no relation to sex and age with this modified sequential therapy. Compliance was satisfactory (11 patients - four women and seven men were unavailable for follow-up), and side effects were minimal (six patients had to stop treatment - metronidazole-related facial swelling and numbness on the face and hands in two patients; tetracycline-related fever and epigastric pain and nausea and vomiting in two patients; and amoxicillin-related diarrhea and vaginal discharge in two patients). These side effects were reversible and resolved after the cessation of the related medication. CONCLUSIONS: This 14-day modified sequential treatment, including bismuth, achieves a significantly high eradication rates in patients with H. pylori infection, with five satisfactory patient compliance and minor side effects.

Giant Abdominal Aortic Aneurysm in Bone Scan

Abdominal aortic aneurysm (AAA) may be incidentally detected in three-phased bone scintigraphy. AAA should be diagnosed prior to the development of symptoms to perform elective repair surgery. We present a rare case who presented with back pain and underwent a 3-phase bone scan with Tc-99m methylene diphosphonate, which revealed a giant AAA on blood-flow and blood-pool phases in addition to bone metastases. F-18-fluorodeoxyglucose positron emission tomography/computed tomography (CT) identified hypermetabolic liver, lung, and bone lesions, and CT component of the study confirmed the diagnosis of AAA with a maximum diameter of 92 mm. The initial two phases of a 3-phase bone scintigraphy are decisive to identify vascular pathologies that may be life-threatening, if left untreated.

Incidental finding of sacral hemiagenesis on the (99m)Tc-MDP bone scan as a casual regression syndrome type II.

A 69 years old woman with chronic low back pain referred to our Department for bone scintigraphy. Patient did not have any other complaint and his physical examination of the patient was normal. Whole-body scan was acquired 3 h after the intravenous injection of 740 MBq of technetium-99m methylene diphosphonate ((99m)Tc-MDP). Distal sacrococcygeal region could not be observed during the visual analysis of the whole-body scan. Pelvic X-rays radiography and pelvic computed tomography of the patient, demonstrated hemiagenesis of the sacrum, which was consistent with type-2 sacral agenesis. Other structural abnormalities were not detected on the pelvic CT scan of the patient. This case is presented to demonstrate the rare congenital anomaly of sacral hemiagenesis causing empty pelvis appearance in the posterior projection of (99m)Tc-MDP whole body bone scan. This congenital anomaly could be associated with extensive abnormalities of the lower vertebrae, pelvis, and spine.

Sphenoid Bone Fibrous Dysplasia Detected Incidentally on Bone Scintigraphy by the Contribution of SPECT/CT Hybrid Imaging.

Fibrous dysplasia (FD) is a benign fibroosseous bone disorder. It has poliostotic and monostotic patterns. Monostotic FD is frequently asymptomatic and is usually discovered incidentally by radiologic imaging performed for other reasons. Bone scintigraphy is valuable for identifying disease extent. Craniofacial FD (CFD) is a form of the disease where lesions are limited to contiguous bones of the craniofacial skeleton. We presented a case with monostotic CFD who was detected incidentally on bone scintigraphy single-photon emission computed tomography/computerized tomography while being investigated for inflammatory arthropaties.

Complementary role of parathormone washout test to 99mTc-MIBI parathyroid scintigraphy and histopathologic analysis of cell types in parathyroid adenomas. / Gammagrafía paratiroidea con 99mTc-MIBI: valor complementario de la paratohormona en el aspirado y análisis histopatológico de los tipos de células en los adenomas paratiroideos.

OBJECTIVE: Parathyroid scintigraphy (PS) can be negative or equivocal (N/E) in a considerable number of cases with highly suspicious clinical findings and biochemical results for parathyroid adenoma (PA). The aims of this study were to investigate the complementary role of parathormone washout test (PWT) to PS in patients with primary hyperparathyroidism (PHPT) and evaluate histopathologic aspects of PAs in comparison with PS results. MATERIAL AND METHODS: Thirty-eight patients with PHPT referred for PS were included in the study. Seventeen patients had both scintigraphic and ultrasonographic findings concordant with PA (Group A). Twenty-one patients having N/E PS, but suspected lesions for PA on ultrasonography (US) formed Group B. PWT was performed for all patients and they underwent the surgical intervention. An adenoma was removed in all patients and the histopathologic cell characteristics were established. RESULTS: The tumor size on US was larger in those patients whose adenomas were seen on the PS (P<.001). The percentages of chief (or principal), oxyphilic and clear cells in PAs were not statistically different between the groups. Serum parathormone level and PWT were not statistically significant between Group A and Group B (P=.095 and P=.04, respectively). CONCLUSION: Although there is not a definitive threshold value, the sensitivity of PS increases with lesion size. While chief cell and oxyphilic cell content of PAs tend to deplete in N/E PS, clear cell rate increases substantially. Combining PS with both US and PWT increases the sensitivity of detection and localization of PAs.

Disseminated metastatic disease of osteosarcoma of the femur in the abdomen: unusual metastatic pattern on Tc-99m MDP bone scan.

A 25-year-old patient with osteosarcoma of the right distal femur underwent a bone scintigraphy with Tc-99m methylene diphosphonate (MDP). Whole-body bone scan revealed extensive metastatic disease in the abdominal region. Abdominal computerized tomography confirmed the presence of ascites and calcified masses on the greater omentum and peritoneal surfaces. Here we describe a case of unusual metastatic pattern of an osteosarcoma showing extensive intraabdominal metastases without prominent lung involvement after intensive chemotherapy.

Fused pelvic kidneys: "hourglass sign" on Tc-99m DTPA diuresis renography.

A 13-year-old girl with fused pelvic kidneys detected on ultrasonographic examination was referred to our department for a diuresis renography to assess urine drainage dynamics and exclude the possibility of urinary tract obstruction. Renal scan demonstrated fused pelvic kidneys functioning normally without obstruction. The authors present this case to demonstrate the diuresis renography findings of the combined position, fusion and rotation anomalies of the kidneys that is a rare congenital anomaly of the urinary tract.

Unilateral temporary functional stasis in the upper urinary tract caused by "a filled bladder" on Tc-99m DTPA diuresis renography: a teaching case.

A 2-year-old girl with recurrent urinary tract infection having slight left pelvicaliceal dilatation on her renal ultrasound underwent a Tc-99m DTPA diuresis renography. During the excretion phase, a prominent and persisting left pelvicaliceal stasis was noticed even after the diuretic injection. However, it disappeared simultaneously with an uncontrolled micturition. This patient is presented to show the effect of filled bladder on the physiological drainage of urine. Since urine flow in the urinary system is more complicated than simple drainage, a thorough understanding of the physiological basis for diuresis renography and the pitfalls of the technique is required for its appropriate use in the management of patients suspected of urinary tract obstruction.

Varices of inferior epigastric veins caused by chronic inferior vena cava obstruction: mimicking normal venous flow pattern on radionuclide venography.

A 21-year-old patient with long-standing inferior vena cava obstruction secondary to idiopathic thrombosis extending from the external iliac veins underwent a radionuclide venography with Tc-99m pertechnetate labeled erythrocytes. The blood pool phase of the study revealed bilaterally distorted inferior epigastric veins mimicking normal venous flow pattern. The authors present this case to discuss the possible alternative routes and the underlying physiopathologic mechanism of this unusual flow pattern in chronic inferior vena cava obstruction.

Clinicopathologic features and prognostic factors of tall cell variant of papillary thyroid carcinoma: comparison with classic variant of papillary thyroid carcinoma.

OBJECTIVE: Tall cell variant (TCV), an aggressive form of papillary thyroid carcinoma (PTC), frequently presents with extrathyroidal disease and recurrence. The aim of this study was to evaluate the clinicopathologic features and outcomes of patients with TCV by comparing them with a larger group of patients with classic variant of papillary thyroid carcinoma (cPTC). PATIENTS AND METHODS: A total of 2500 patients with differentiated thyroid carcinoma were treated and monitored during a 23-year period (1992-2015). Of them, 2250 (90%) had PTC and 235 (9.5%) had follicular thyroid carcinoma. Of the 2250 patients, 862 (38.3%) and 70 (3.1%) had cPTC and TCV, respectively. Cases of TCV and cPTC of PTC were compared on the basis of risk factors. RESULTS: Patients with TCV were significantly older compared with cPTC patients (P<0.001). Tumor size was significantly bigger (P=0.01) and preablation thyroglobulin level was significantly higher (P<0.001) in TCV patients than in cPTC patients. The incidence of capsule invasion, extrathyroidal extension, and vascular invasion was significantly higher in TCV (P=0.003, <0.001, and 0.011, respectively). The incidence of initial lymph node metastasis was significantly higher in TCV (P<0.001). Patients with TCV were mostly at an advanced stage compared with patients with cPTC (P<0.001). Development of local or distant metastasis during the follow-up was significantly higher in TCV than in cPTC. Sex and multifocality were not statistically significant. CONCLUSION: TCV has a higher incidence of local or distant metastasis and mortality rate. Thus, it must be treated with the highest possible I ablation doses and followed up carefully.

Evaluation of variability of phase indices of the left ventricle in the course of time.

OBJECTIVE: Since the effect of time on phase indices is still unclear, the aim of the study was to evaluate the variability of phase indices of the left ventricle which were derived from stress and rest single-photon emission computed tomography (SPECT) imaging acquired at early and late times. METHODS: One hundred twenty-one patients (72 men, 49 women) were included into the study. All stress and rest gated myocardial perfusion imaging (gMPI) acquisitions were acquired at two different time points as early in 15 ± 5 min and late in 45 ± 5 min. The peak of the phase histogram (PP), the standard deviation of the phase distribution (SDPH), the width of the band (BPH), and the symmetry (histogram skewness, HS) and peakedness of the phase histogram (histogram kurtosis, HK) which are the parameters for assessing left ventricular systolic dyssynchrony were calculated in all stress and rest SPECT images acquired twice. RESULTS: The phase indices derived from the late rest scans were smaller than those of the early rest scans but, the differences were not significant. When considering the comparisons of phase indices derived from two different time points after stress, PP showed a tendency to decrease (from 160.8 ± 18.3 to 152.5 ± 17.3; p < 0.001) over time but SDPH (from 20.2 ± 10.6 to 22.4 ± 12.2; p = 0.018) and BPH (from 61.5 ± 36.0 to 66.3 ± 37.3; p = 0.045) tended to increase over time. When the post-stress and the resting dyssynchrony parameters derived at two different time points were compared to each other; PP decreased at early and late times approximately 12 and 9 %, respectively, SDPH increased at early and late times approximately 28.5 and 14 %, respectively, and BPH increased at early and late times approximately 23 and 12 %, respectively. CONCLUSIONS: In resting conditions, phase indices of the left ventricle, and therefore, the phase histogram tend to remain constant over time but, in conditions after exercise, the phase histogram tend to be long and narrow due to changes in phase indices and it shows tendency to return to resting conditions in time. Therefore, it appears that postexercise acquisition times should be standardized if we want to compare the phase indices results of the studies in the literature.

Diagnostic accuracy of whole-body diffusion-weighted magnetic resonance imaging with 3.0 T in detection of primary and metastatic neoplasms.

INTRODUCTION: To discuss the accuracy of the whole-body diffusion-weighted imaging with background body signal suppression (WB-DWIBS) technique performed in the 3.0-T system. METHODS: We studied 17 patients who underwent positron emission tomography (PET)/CT and WB-DWIBS examinations for staging their diseases. The DWIBS pulse and echo-planar imaging-short T1 inversion recovery single-shot pulse sequences were performed for WB-DWIBS. A PET/CT scan was performed with 18-fluorodeoxyglucose. The lesions were localised and counted in both of the examinations, and WB-DWIBS was evaluated for the neoplastic tissue detection rate, while PET/CT was accepted as the reference standard modality. RESULTS: The WB-DWIBS scan had a room occupation time of 32-35 min. All of the metastasis positive patients (n = 12) detected with PET/CT were also detected with WB-DWIBS (100%). In our patient group, there were a total of 109 bone metastases on PET/CT scans, and 93 of them (85.3%) were demonstrated with WB-DWIBS. We detected 128 metastatic lymph nodes on PET/CT, and 123 of them (96.3%) were demonstrated with WB-DWIBS. There were a total of 17 liver metastases on PET/CT, and 15 of them (88.2%) were detected with WB-DWIBS. There was no statistically significant difference between the two imaging modalities in detecting bone, lymph node and liver metastases (P > 0.05). CONCLUSIONS: WB-DWIBS is a non-invasive technique that may successfully detect the spreading of the tumoural tissue in cancer patients when compared with PET/CT.

Can single cIMT measurement during echocardiography affect further investigation decision for coronary artery disease?

OBJECTIVE: This study was aimed to evaluate whether there is any potential role of the measurement of the carotid intima-media thickness (cIMT) in patients with suspected coronary artery disease (CAD) during the echocardiography session on decision-making to refer patients for further diagnostic evaluation such as gated myocardial perfusion imaging (gMPI). METHODS: cIMT of 199 consecutive patients was measured during the echocardiography session and all patients underwent gMPI. According to gMPI results, patients were divided into two groups as CAD and normal groups and according to cIMT measurements patients were divided into four subgroups. RESULTS: Although, there was a good correlation between the age and cIMT values of the patients (r=0.546, p<0.001), the correlation between the summed stress scores and the age of the patients was very weak (r=0.142, p=0.045) and the correlation between the summed stress scores and the cIMT values was very weak (r=0.107, p=0.131). The cIMT measurements of the CAD group (0.74±0.17 mm) were significantly higher than those of the normal group (0.67±0.16 mm) (p=0.012), but after the age correction, the significance between the cIMT measurements of the CAD and the normal groups was not found (p=0.131). Besides, the relationship between the categorical cIMT values of both the CAD and the normal groups was insignificant (p=0.059) and the correlation between the increasing cIMT values and the presence of detectable CAD was also very weak (r=0.187, p=0.08). CONCLUSION: cIMT can predict occurrence of cardiovascular events in subjects, but single cIMT measurement during echocardiographic examination does not seem to have potential role on decision making for further investigation in patients with suspected CAD.

Phase analysis in patients with reversible perfusion defects and normal coronary arteries at angiography.

OBJECTIVE: A count-based new technique from gated myocardial perfusion single-photon emission tomography (gMPS) was developed to allow the phase analysis providing information about the left ventricular (LV) regional discordance in contractility which is a measure of LV dyssynchrony. Since the phase analysis provides data for evaluating the dyssynchronous LV contraction, it has an important role in diagnosis and management of patients with left ventricular dysfunction. The aim of the study was to assess the presence of left ventricular dyssynchrony in patients with reversible perfusion defects on gMPS scans and normal or near normal coronary arteries at angiography. METHODS: 32 patients (19 men, 59 %) with reversible mild perfusion defects on gMPS and normal coronary angiogram were retrospectively enrolled in the study. The peak of the phase histogram, the standard deviation of the phase distribution (PSD), the width of the band (PHB), and the symmetry and peakedness of the phase histogram, which are the assessment parameters for the LV dyssynchrony, were calculated from gMPS scans of patients by means of the phase analysis. RESULTS: Although, five quantitative variables are derived from the phase analysis of gMPS, PSD and PHB are two quantitative indices to assess LV global mechanical dyssynchrony and measurements of PSD (men 24.96 ± 7.31, women 24.26 ± 10.07) and PHB (men 70.1 ± 13.99, women 71.0 ± 30.4) were significantly higher than the those reported in the literature (p < 0.001). No significant differences in gMPS phase analysis indices were found between both sexes except kurtosis. CONCLUSION: As a conclusion, this study provides the phase analysis to detect LV mechanical dyssynchrony as new evidence supporting the concept that an abnormal scintigraphy finding, rather than being false-positive, may be an early marker of vasomotion changes associated with occult atherosclerosis in patients with normal coronary angiography findings.