Serkan Isgoren

Evaluation of post-stress left ventricular dysfunction and its relationship with perfusion abnormalities using gated SPECT in patients with cardiac syndrome X.

ObjectiveCardiac syndrome X defines patients with typical angina, a positive exercise ECG stress test and angiographically documented normal coronary arteries. In previous studies, post-stress prolonged left ventricular dysfunction (PLVD) using gated SPECT (G-SPECT) had been well correlated with myocardial perfusion abnormalities and degree of stenotic vessels in CAG in patients with coronary artery disease. However, evaluation of left ventricular myocardial perfusion, wall motion and left ventricular ejection fraction (LVEF) in patients with cardiac syndrome X, using G–SPECT had not been studied yet. Thus, the aim of this study was to analyse PLVD using 99mTc-MIBI GSPECT in patients with cardiac syndrome X. MethodsOf the patients in whom G-SPECT was performed in our institution between 2004 and 2006, 17 patients with anginal chest pain, positive exercise ECG stress test and normal coronary angiograms were retrospectively included to the study (group I). Fifteen patients with normal myocardial perfusion and another 15 patients with ischaemia on G-SPECT were selected as control groups (groups II and III). 99mTc-MIBI G-SPECT was performed for all patients according to 2 day (stress–rest) protocol. Stress and rest LVEF were derived automatically (SLVEF and RLVEF). Difference LVEF (DLVEF) (stress–rest) was calculated. Semiquantitative analyses were made both for myocardial perfusion and wall motion (WM), using a 20-segment model and a 5-point scoring system. DLVEF, perfusion and WM scores of all groups were compared among three groups and relationship between DLVEF, perfusion and WM scores were evaluated. ResultsAbnormal perfusion were detected in eight (47.1%) of patients, while the remaining nine (52.9%) had normal myocardial perfusion, in group I. Six of 17 (35.3%) patients in group I had post-stress WM abnormalities. Mean of DLVEF values were −3.1±3.0%, 4.4±2.0% and −6.0±5.1% in groups I, II and III, respectively (P<0.05 for group II vs. group I and group III; P>0.05 for group I vs. group III). LVEF response impairment (≤5% increase from rest to post-stress images) was found in 17 (100%), seven (46.6%), 14 (93.3%) of patients in groups I, II and III, respectively. ConclusionAbnormal myocardial perfusion, concordant transient segmental WM abnormalities and LVEF response impairment are not uncommon in patients with cardiac syndrome X of this cohort of the study population. Therefore, post-stress prolonged stunning may be attributed to these findings in some of cardiac syndrome X patients as in true ischaemic patients. However, further studies with larger number of subjects and long-term follow-up are necessary to support these findings.

A doughnut sign of a hydatid cyst of the liver on F-18 FDG PET/CT.

A 59-year-old man underwent a whole-body PET/CT scan to evaluate the metabolic activity of a nodule in the upper lobe of the left lung seen on CT. Slightly increased peripheral activity with a large hypometabolic region centrally, a so-called doughnut sign, was seen in the right lobe of the liver. After the diagnosis of a hydatid cyst of the liver, the patient underwent surgery. This case demonstrates a hydatid cyst that caused increased F-18 FDG uptake as a doughnut pattern.

Comparison of gated SPECT, echocardiography and cardiac magnetic resonance imaging for the assessment of left ventricular ejection fraction and volumes

BACKGROUND Left ventricular ejection fraction (LVEF), end-diastolic volume (EDV) and end-systolic volume (ESV) can be determined non-invasively by two-dimensional echocardiography (ECHO), gated single photon emission computed tomography (GSPECT) and cardiac magnetic resonance imaging (CMRI). This study was designed to analyze the concordance between LVEF, EDV and ESV values derived from ECHO, GSPECT and CMRI. METHODS ECHO, GSPECT and CMRI were performed in a group of 21 patients with suspected coronary artery disease. LVEF, EDV and ESV values were calculated. RESULTS The mean LVEF measured with GSPECT, ECHO and CMRI were 55.9±17.8%, 55.7±16.4% and 56.4±15.7%, respectively. The mean EDV measured with GSPECT, ECHO and CMRI were 109.2±42.4 mL, 127.5±42.2 mL and 91.1±38.0 mL, respectively. The mean ESV measured with GSPECT, ECHO and CMRI were 54.2±41.2 mL, 59.9±37.6 mL and 41.8±26.9 mL, respectively. The results of linear regression analysis showed very good correlation between LVEF and ESV values derived from GSPECT, ECHO and CMRI (r=0.91, r=0.92, r=0.97 for LVEF and r=0.86, r=0.91, r=0.91 for ESV, P<0.01). Good correlations were found between EDV values obtained from GSPECT, ECHO and CMRI (r=0.71, r=0.68, r=0.73, P<0.01). Agreement between these techniques in LVEF values was also good, but not in LV volumes, according to Bland-Altman plots. CONCLUSIONS This study showed good overall correlations between LVEF, EDV and ESV values derived from GSPECT, ECHO and CMRI. LVEF obtained from any of these three imaging modalities could be used interchangeably. However, care should be taken in comparing LV volumes.

Hepatic and splenic uptake of Tc-99m HDP in multiple myeloma: Additional findings on Tc-99m MIBI and Tc-99m sulfur colloid images

The authors present a case of multiple myeloma with intense hepatic and spienie uptake on Tc-99m HDP bone scan and discuss its clinical implications and possible uptake mechanisms. Tc-99m MIBI and Tc-99m sulfur colloid were used to demonstrate bone marrow involvement and focal lesions of multiple myeloma.

Correlation of Cystatin-C and radionuclidic measurement method of glomerular filtration rate in patients with lung cancer receiving cisplatin treatment

Abstract Objective: Cisplatin is a chemotherapeutic agent which affects renal functions adversely. The best indicator of renal functions is glomerular filtration rate (GFR) measurement. Cystatin-C appears to be a good alternative to existing methods of measuring GFR. However, it is controversial whether Cystatin-C demonstrates GFR correctly for patients receiving chemotherapy. This study aimed to investigate the correlation between GFR values calculated by Cystatin-C based formulas, radionuclidic method (multiple blood sampling) and blood Cystatin-C values in patients with lung cancer, receiving cisplatin treatment in both pre-treatment and post-treatment periods. Materials and methods: Thirty-six patients with lung cancer who were going to receive cisplatin treatment were included in this study. However, the evaluation was performed with 20 patients since 16 of them could not complete the treatment. Blood Cystatin-C values, GFR values calculated via Cystatin-C based formulas, and radionuclidic method were investigated before and after the cisplatin treatment. Results: After treatment significant decreases were detected in GFR values, obtained via radionuclidic measuring method. However, there was no significant difference in Cystatin-C values between pre-treatment and post-treatment periods. Also GFR values obtained by Cystatin-C based formulas were not significantly different in pre-treatment and post-treatment periods. There were meaningful correlations between radionuclidic method and Cystatin-C values and Cystatin-C based formulas before treatment. However, all correlations disappeared after the treatment. Conclusion: GFR values, calculated by Cystatin-C may not be reliable in following renal functions in patients receiving chemotherapy. When reliable monitoring of the renal functions is necessary radionuclidic method may be preferred in these patients.

Sentinel lymph node biopsy with a gamma probe in patients with high-risk cutaneous squamous cell carcinoma: follow-up results of sentinel lymph node-negative patients.

ObjectiveLymphoscintigraphy (LS) and sentinel lymph node biopsy have become the standard of care for melanoma and breast cancer. However, the data on patients with cutaneous squamous cell carcinoma (SCC) are limited. We aimed to evaluate and identify the role of LS and sentinel lymph node biopsy in patients with high-risk cutaneous SCC. MethodsNineteen patients (13 men, six women; 47–87 years of age, mean age 67.5±12.3) with SCC were included in the study. LS was performed on all patients after intracutaneous injection of Tc-99m nanocolloid. Primary lesions and sentinel lymph nodes (SLNs) were excised with the help of a gamma probe. ResultsA total of 26 SLNs and 32 secondary lymph nodes were imaged on LS and were marked. During surgery, 29 SLNs, 21 secondary lymph nodes and three nonactive lymph nodes were excised. In total, 53 lymph nodes were removed surgically. A histopathological study revealed that all lymph nodes were negative for metastasis. Patients were followed up for an average of 41.1±22.2 months (7–80 months). Until the time of data collection, 14 patients were alive and had no regional lymph node or distant metastasis. Local recurrence was seen in only one patient. He was reoperated upon 38 months ago. ConclusionThe feasibility of determining SLNs using LS and an intraoperative gamma probe in patients with cutaneous SCC was shown. Unnecessary elective lymph node dissection and possible complications could be avoided in 19 patients.

Comparison of exercise and pharmacological stress gated SPECT in detecting transient left ventricular dysfunction

ObjectiveTransient left ventricular contractile dysfunction (TLVD) is observed owing to post-exercise stunning in patients with coronary artery disease (CAD). Pharmacological stimulation differs from exercise stress because it does not cause demand ischemia. The aim of this study was to determine whether TLVD could also be seen after pharmacological stress (dipyridamole).MethodsOf the patients in whom gated single-photon emission computed tomography (GSPECT) was performed in our institution from January 2004 to April 2007, 439 subjects with known or suspected CAD were included in the study. GSPECT was performed for all patients following exercise (group I, n = 220) or pharmacological stress (group II, n = 219) according to a 2-day (stress-rest) protocol after injection of Tc-99m methoxyisobutyl-isonitrile (MIBI). Stress, rest, and difference (stress-rest value) left ventricular ejection fractions (SLVEF, RLVEF, and DLVEF) and transient ischemic dilatation (TID) ratio were derived automatically. Summed stress score, summed rest score, and summed difference score (SDS) for myocardial perfusion were calculated using a 20-segment model and a five-point scoring system. An SDS > 3 was considered as ischemic. On the basis of the perfusion findings, patients were subdivided into a normal (group A, n = 216) and ischemia group (group B, n = 223). DLVEF and perfusion scores of all groups were compared. Relationships between DLVEF and perfusion, and between TID ratio and DLVEF were also evaluated.ResultsStress-induced ischemia was observed in 223 of 439 patients (50.8%). In group A, the difference between stress and rest LVEF values was not significant (P = 0.670 and P = 0.200 for groups IA and IIA, respectively). However, LVEF was significantly decreased after stress compared with rest values for group B (P < 0.0001 for groups IB and IIB). TLVD (≤−5% for DLVEF) was observed in 20 of 216 (9%) and 81 of 223 subjects (36%) in patients in groups A and B, respectively (P < 0.0001). In group I, we found TLVD in 46 of 119 (39%) and 12 of 101 (12%) subjects, in patients with and without ischemia, respectively (P < 0.0001). On the other hand, in group II, TLVD was detected in 35 of 104 (34%) and 8 of 115 (7%) patients with and without ischemia, respectively (P < 0.0001). And also, we found significant good correlations between TID ratios and DLVEF values in four subgroups (r = −0.55, r = −0.62, r = −0.59, and r = −0.41; for groups IA, IB, IIA, and IIB, respectively, P < 0.0001 for all).ConclusionsDipyridamole is believed to be less likely than exercise to induce ischemia. However, in this study, TLVD after stress was observed following not only exercise but also pharmacological stress, consistent with ischemia.

Double imaging for the diagnostic work-up of alveolar soft part sarcoma with Tc-99m MIBI

The authors report a case of alveolar soft-part sarcoma with lung metastases demonstrated by “double imaging” with Tc-99m HDP and Tc-99m BIBI. The tumor originated in the soft tissue with direct invasion to the right scapula, which was hypoactive on bone scan and hyperactive on Tc-99m MIBI images. A focus of dense accumulation of Tc-99m MIBI in the lungs, suggesting metastasis was also demonstrated.

Pulmonary 18F-FDG microembolism detected on only delayed image in a PET/CT study.

Focal 18F-FDG pulmonary uptake on PET without corresponding abnormality on CT is an incidental and rare finding. This artifact is associated with iatrogenic FDG microembolus as a result of vascular endothelium damage during injection. We present a pulmonary FDG microembolus in a patient evaluated for suspicion of gallbladder cancer not in early (standard 1-hour imaging after FDG injection) but in delayed image. To our knowledge, this is the first case that describes the possibility of FDG microembolism on only delayed image in a PET/CT study.

Obesity control and low protein diet preserve or even improve renal functions in Bardet-Biedl syndrome: a report of two cases.

Summary Background Bardet-Biedl syndrome (BBS) is a rare autosomal-recessive disorder characterized by abdominal obesity, mental retardation, dysmorphic extremities, retinal dystrophy, hypogonadism, and kidney structural abnormalities or functional impairment. It is now considered a significant cause of chronic and end-stage renal disease in children. To the best of our knowledge there have been no previous studies on the role of diet in the management of renal functions in patients with BBS. Case Reports Two siblings, aged 32 and 27 years, with BBS are presented. On admission both patients were obese, with body mass indexes (BMI) of 40 and 39 kg/m2. Their creatinine clearances (CrCl) were 41 and 24 mL/min. After 2 years of follow-up with a diet consisting of 0.6 g/kg/day protein and 1400 kcal/day energy, their BMI’s were decreased to 29 and 27 kg/m2, whereas their CrCl’s were increased to 44 and 32 mL/min, respectively. 99mTc-MAG3 scintigraphy also revealed improved renal function. Conclusions Since this syndrome most likely results in end-stage renal disease, follow-up of renal dysfunction is essential. Low protein diet and/or obesity control may slow the progression of renal failure in patients with BBS.