Murathan Sahin

Comparison of Tc-99m MDP, Tc-99m HSA and Tc-99m HIG uptake in rheumatoid arthritis and its variants.

Tc-99m polyclonal immunoglobulin-G has been shown to be a successful agent in the depiction of active inflammation in rheumatoid arthritis (RA). The objective of this study was to compare the uptake behaviors of Tc-99m HIG and Tc-99m MDP in RA and variants of rheumatoid arthritis (VRA). Seventeen patients with RA and 8 patients with VRA presenting with active inflammation were included in this study. Ten subjects with well-diagnosed degenerative joint disease constituted the control group. All joints in patients were also imaged with Tc-99m HSA to evaluate the vascularization status of the joints. Tc-99m HIG and HSA scans were obtained at 2, 4 and 24 hours after the injection of 555 MBq Tc-99m HIG and 296 MBq Tc-99m HSA. Conventional bone scans were performed 4 hours after the injection of 740 MBq Tc-99m MDP. Target-to-background (T/ B) ratios were obtained exclusively over the joint regions. Tc-99m HIG T/B ratios of the active joints in RA were significantly higher than those of the non-active joints and the control group (p < 0.05). Tc-99m HIG T/B ratios in active joints showed a progressive increase between 2 and 24 hour images (p < 0.05). In contrast, Tc-99m HSA T/B ratios decreased in all active joints significantly (p < 0.05) except the ankle joint region (p > 0.05). The T/B ratios in Tc-99m MDP bone scans were higher in all active joints than in non-active RA joints and joints of controls but significantly differences were only detected in wrist and elbow joints. All clinically active joints in VRA patients accumulated Tc-99m HIG and HSA, and showed increased Tc-99m MDP uptake. These joints had a very similar Tc-99m HIG retention pattern to the RA joints. The detection rate of active joint inflammation with Tc-99m HIG was much higher than that with Tc-99m MDP. The increasing Tc-99m HIG uptake ratio between 2 and 24 hours in contrast to Tc-99m HSA indicates the presence of other binding mechanisms besides increased vascularity in RA.

Evaluation of metastatic bone disease with pentavalent 99Tcm-dimercaptosuccinic acid: A comparison with whole-body scanning and 4/24 hour quantitation of vertebral lesions

The aim of this study was to establish the value of 99Tcm(V)-DMSA scintigraphy in the detection of metastatic bone lesions and compare the results to 99Tcm-MDP bone scintigraphy. Thirty-four patients presenting with metastatic bone disease (Group 1) and 12 controls with degenerative skeletal lesions (Group 2) were studied. Conventional bone scanning and 99Tcm(V)-DMSA whole-body scanning were performed on all patients. All scans were interpreted visually. Furthermore, lesion-to-normal bone ratios (L/N) in vertebral metastases on the 4 and 24 h bone scans were obtained in 58 lesions of cancer patients and in 23 benign (degenerative) vertebral lesions of the control group. 99Tcm-MDP L/N ratios at 24 h (3.08±0.32) were significantly higher than those at 4 h (2.48±0.24) in the malignant foci (P<0.001). No significant difference was observed in benign lesions (P>0.05). In 167 (164 metastatic, 3 traumatic) of 186 99Tcm-MDP positive lesions (90%) of Group 1, 99Tcm(V)-DMSA uptake was observed. The remaining 19 lesions (10%) were 99Tcm(V)-DMSA negative. Fourteen of these 19 sites were diagnosed as benign. The remaining five foci were malignant. In four lung cancer metastases showing no 99Tcm-MDP uptake, 99Tcm(V)-DMSA uptake was observed. There was no 99Tcm(V)-DMSA accumulation in any of the 99Tcm-MDP positive degenerative lesions of Group 2. All quantitatively evaluated (n = 42) vertebral metastatic foci and two compression fractures in Group 1 showed 99Tcm(V)-DMSA accumulation and an increased 99Tcm-MDP L/N ratio at 24 h. A total of 36 degenerative lesions (Groups 1 and 2) and one compression fracture (Group 1) showed neither 99Tcm(V)-DMSA uptake nor an increased 99Tcm-MDP L/N ratio at 24 h. Our results indicate that quantitative 4/24 h analysis of vertebral lesions on 99Tcm-MDP scans has a similar diagnostic value to 99Tcm(V)-DMSA imaging in the detection of bone metastases. However, the accumulation of 99Tcm(V)-DMSA in four lung cancer metastases showing no 99Tcm-MDP uptake is encouraging and justifies further research in patients with proven bone metastases and negative bone scans.

Pentavalent technetium-99m DMSA uptake in pseudofractures of osteomalacia.

Tc-99m MDP and Tc-99m (V) DMSA images are described from a 49-year-old woman with chronic renal insufficiency complicated by osteomalacia. Clinical, biochemical, and radiologic bone profiles were compatible with osteomalacia. Osteomalacia is a condition associated with disorders in which mineralization of the organic matrix is defective. All bone lesions visualized with Tc-99m MDP also showed increased uptake of Tc-99m (V) DMSA. Tc-99m (V) DMSA accumulation has been reported in many malignant and some benign conditions. Pseudofractures in osteomalacia could be included in the spectrum of benign lesions that accumulate Tc-99m (V) DMSA.

Investigation of the vertebrobasilar arterial system in vertigo by vestibulocochlear test, SPECT and angiography

OBJECTIVE Perfusion of the areas of cochleovestibular structures was investigated using Tc-99m HMPAO single photon emission computerized tomography (SPECT) in the young patients with vertigo presumed to have peripheral vestibular abnormalities and compared the results with cochleovestibular test results, and vertebrobasilar angiography findings. METHODS AND PATIENTS The study was performed on 20 patients with vertigo and 17 control subjects who had performed vertebral arteriography due to another disease. The patients with vertigo presumed to be on peripheral vestibular disorder were included in the study. Systemic and otorhinolaryngological examination were carried out. Audiovestibular function was evaluated in all patients and control subjects. Brain SPECT was performed with a one-head rotating gamma camera system from 64 projections into a 64x64 matrix, using low energy and high-resolution fan beam collimators with a sampling time of 30 s. The images taken from cerebellum, temporal, parietal and occipital lobes which are supplied by a vertebrobasilar system were compared visually with the other side and asymmetry in the perfusion was searched. After cochleovestibular tests and laboratory had been completed, vertebral arteriography was performed bilaterally in all patients. Results of digital subtraction angiography (DSA) and the vestibulocochlear test were compared with images of SPECT. Data analysis was done with Yates Chi(2) and percentages of sensitivity and specificity were calculated. RESULTS There was vestibular test and cochlear test abnormalities in eight and ten of the patients with vertigo, respectively. SPECT imaging showed hypoperfusion and decreased regional blood flow in 12 of the patients. There was statistically significant differences between the study and control groups in SPECT (P<0.05). Five patients showed abnormal findings in DSA examinations. CONCLUSION It is believed that SPECT may be helpful in the detection of vascular pathology in the patients with vertigo.

Comparison of gated planar Tc-99m tetrofosmin scintigraphy with radionuclide ventriculography and echocardiography in the evaluation of left ventricular wall motion

Assessment of ventricular function is an important diagnostic and prognostic tool in coronary heart disease (CHD). The objective of this study was to compare radionuclide ventriculography (RVG), echocardiography (ECHO) and gated planar tetrofosmin myocardial scintigraphy (GPTF) in patients with CHD. Radionuclide ventriculography in left anterior oblique (LAO) and left lateral (LLT) projections was performed in 44 patients. Two days later, rest tetrofosmin perfusion tomoscintigraphy (SPECT) and rest GPTF in RVG identical parameters and projections were acquired. Within the two following days, the patients underwent two-dimensional ECHO. GPTF studies were processed and interpreted in original (NI-GPTF) and image inverted, RVG like form (I-GPTF). All visual interpretations were evaluated with a semi-quantitative scoring system. Quantitative analysis was performed on parametric images by means of segmental regions of interest. Linear regression and contingency analysis were carried out in overall analysis and on a segmental basis separately by accepting the RVG as the standard for the whole investigation. In overall cine-mode evaluation, NI-GPTF (r=0.77, p<0.001, complete agreement (CA)=84%) was superior to I-GPTF (r=0.73, p<0.001, CA=82%) and ECHO (r=0.39, p<0.001, CA=78%), compared to RVG. On a segmental basis, NI-GPTF showed the best RVG-correlations except for inferoapical, mid-inferior, mid-anterior and anterobasal segments. In visual analysis of functional images, the best RVG-agreement was observed in I-GPTF (r=0.72, p<0.001, CA=77%). On a segmental basis, I-GPTF showed the best RVG-correlations except for posterolateral, mid-inferior, mid-anterior and anterobasal segments. In overall quantitative evaluation, amplitude values in both I-GPTF (r=0.76, p<0.001) and NI-GPTF (r=0.75, p<0.001) studies were well correlated with RVG amplitude. I-GPTF gave the best RVG-correlation of phase (r=0.59, p<0.001). The mean phase and standard deviation RVG-correlations of I-GPTF were r=0.92, p<0.001 and r=0.53, p<0.001 respectively. In segmental quantification, amplitude values of all segments in I-GPTF were better RVG-correlated than in NI-GPTF. In conclusion, GPTF could be a time saving alternative to ECHO in the evaluation of wall motion by the nuclear medicine physician. Because of differing segmental RVG correlations, NI-GPTF and I-GPTF should be both interpreted to improve the diagnostic value of the method. Cine-mode and parametric image interpretations in GPTF studies should be done simultaneously since the former is more closely correlated to RVG.

Acute gastric dilatation: An incidental finding in a Meckel study

A Meckel study was performed in a patient with melena who at the same time had a peritoneal catheter for dialysis because of renal failure. There was no pathological or abnormal accumulation of Tc-99m pertechnetate in the abdomen, except for the stomach where gastric dilatation was observed. This incidental finding of gastric dilatation which was thought to be a result of irritation of the peritoneal cavity, disappeared 24 hours after the peritoneal catheter was removed.

Intestinal uptake of Tc-99m MDP in a patient with vipoma syndrome.

Vipoma syndrome, or the diarrheogenic syndrome, is often caused by a pancreatic islet cell tumor or a retroperitoneal neural tumor and is mainly characterized by watery diarrhea, hypokalemia, and achlorhydria. Vasoactive intestinal polypeptide (VIP) is generally the mediator in most cases. Intestinal uptakes of Tc-99m MDP in a 32-year-old man with Vipoma syndrome is reported. He had normal calcium and phosphate levels. Multiple intestinal biopsies revealed to metastatic calcifications, necrosis, or amyloidosis, but only diffuse intestinal edema and an 80-centimeter-long ischemic segment in the ileum

Intracoronary versus intravenous injection of 99mTc-tetrofosmin: comparison of myocardial perfusion patterns and wall motion.

ObjectivesThe accuracy of viability and defect size detection by 99mTc-tetrofosmin has been discussed by several authors. The lower myocardial extraction fraction of the latter compared with 99mTc-sestamibi or 201Tl has often been emphasized. We hypothesized that the intracoronary (i.c.) injection of tracer activity, i.e. higher than that theoretically achievable in the case of intravenous (i.v.) administration, could demonstrate the clinical relevance of this finding intra-individually. In this study, myocardial perfusion images obtained after tracer injection down the infarct-related artery were compared with i.v. injection images in the same patients. The trial also provided us with the opportunity to compare the wall motion values calculated using conventional 99mTc-tetrofosmin gated single-photon emission computed tomography (SPECT) studies with those obtained using optimal target/background ratios after i.c. injection. MethodsFourteen patients with acute myocardial infarction, no history of previous cardiac events, single vessel disease and no visible collaterals in the coronary arteriogram were included in the study. Electrocardiogram gated SPECT was carried out separately after i.c. and i.v. injections of the tracer within 5–7 days following thrombolytic therapy. Myocardial perfusion patterns were compared by contingency table analysis after semi-quantitative visual scoring. Segmental wall motion was compared using quantified polar map data in a subset of patients (eight of 14) with normal to moderately hypoperfused myocardium supplied by the left coronary artery. ResultsVisual perfusion scores of both studies showed good concordance (kappa, 0.70), with complete agreement in 94 of 119 segments. Nearly all of the discordant segments (24 of 25) were mildly better scored in i.c. studies than in i.v. studies. The mean wall motion values calculated on polar maps of 78 segments for i.c. and i.v. studies were 8.4±1.2 mm and 8.2±1.3 mm (mean Δ wall motion=0.23 mm), respectively. High segmental wall motion correlation was observed (R=0.90; P<0.0001). ConclusionIt can be concluded that infarct-related myocardial perfusion scores obtained after i.c. and i.v. injections of 99mTc-tetrofosmin compare favourably, with a total agreement rate of 79%. However, the additional information obtained in 21% of the total number of myocardial segments by i.c. injection may indicate a mild underestimation of myocardial viability by i.v. injection. Conventional gated SPECT using i.v. 99mTc-tetrofosmin was demonstrated to be a reliable technique in the detection of true wall motion.

Myocardial uptake of Tc-99m macroaggregated albumin during perfusion lung scanning

The authors present a case of extrapulmonary Tc-99m macroaggregated albumin uptake in a patient with reversed atrial septal defect and cleft lip. Perfusion lung scanning was performed to rule out pulmonary embolism because of dyspnea, cyanosis, and tachy-arrhythmia. Besides minimal systemic activity, significant myocardial uptake of the tracer was observed. Coronary angiography could not be performed because of the severely altered general condition of the patient. It was postulated that this was most probably due to an anomalous origin of the left coronary artery from the pulmonary trunk.

Incidental finding of Tl-201 accumulation in an empyema.

A 47-year-old man with Behcet disease was hospitalized because of abdominal pain. Abdominal ultrasonography revealed a 3 cm x 3 cm hepatic mass and chest x-ray showed an empyema of the right lung. The patient was placed in a protocol for Tl-201 uptake in hepatic tumors. Surprisingly, Tl-201 accumulation was seen in the inferior lobe of the right lung within the empyema.