The value of the TIMI frame count method in the diagnosis of coronary no-reflow: a comparison with myocardial perfusion SPECT in patients with acute myocardial infarction.

The state of no-reflow (i.e. inadequate myocardial tissue perfusion despite normal arterial flow proven in angiography after pharmacological or mechanical interventions) is considered to be a marker of a poor prognosis. Although the Thrombolysis in Myocardial Infarction (TIMI) flow grade is a valuable and widely used qualitative measure in angiography trials, it is limited by its subjective and categorical nature. Recently, the TIMI frame count method (TFC) was proposed for detecting no-reflow. In our study we aimed to compare TFC values with myocardial perfusion single photon emission computed tomography (SPECT) findings to investigate the additional role of the former method in the evaluation of no-reflow. Twenty patients (16 men and four women; mean age 58+/-9 years) with first acute myocardial infarction were included in the study after thrombolytic therapy. Coronary angiography (CAG) was performed 5-7 days later. The TIMI flow grade and TFC values were determined in angiography examinations. A TIMI flow of less than grade 3 and a TFC value >27 were considered to be pathologically decreased for coronary artery blood flow. Tc tetrofosmin myocardial rest SPECT was carried out 24 h after coronary angiography. SPECT images were scored on a four-point scale in 20 myocardial segments and the total defect score was calculated from the sum of defect scores in 20 segments. Wall motion was assessed using the wall motion score index in echocardiography (ECWSI). The occurrence rates of angiographic no-reflow, pathological TFC and perfusion defects in SPECT were calculated as 40% (8/20), 47% (8/17; non-measurable in three patients with TIMI grade 0), and 55% (11/20), respectively. Perfusion defects were present and the TIMI frame count value was increased in all patients with angiographic no-reflow (TIMI grade <3). The occurrence rate of perfusion defects and increased TFC was equal (42%) in all 12 patients having TIMI grade 3 flow. Increased TFC was demonstrated in four of five patients having perfusion defects and TIMI grade 3 flow (80% compatibility with SPECT). TIMI frame count and ECWSI values were significantly higher in patients having perfusion defects than in patients with normal perfusion ( <0.05). It is concluded that the TIMI frame count is a valuable method in the detection of patients with TIMI grade 3 flow, with no-reflow, and increases the specificity of coronary angiography in the evaluation of the response to thrombolytic therapy. A pathologically increased TFC value with TIMI grade 3 flow during CAG seems to be a good indication for the use of myocardial perfusion SPECT in the definitive diagnosis and/or follow-up of such patients.

Evaluation of lymphatic drainage of cold thyroid nodules with intratumoral injection of Tc-99m nanocolloid.

PURPOSE: The lymphatic system may show variations throughout the entire body. Knowledge of the variations and aberrant lymph drainage are important when planning surgical treatment and radiotherapy. The aim of this study was to evaluate the intratumoral injection technique in the detection of lymphatic drainage of proved or possibly malignant cold thyroid nodules. MATERIALS AND METHODS: The study group consisted of 13 patients with palpable solitary cold thyroid nodules. None of the patients had cystic nodules on ultrasound examination. After fine-needle aspiration biopsy (at least 3 days later), 15 MBq (0.4 mCi) Tc-99m nanocolloid particles in a small volume (0.2 ml) were injected into the nodule. Dynamic images (60 frame x 1 minute) were acquired during the first hour, followed by static anterior and lateral images at 90 and 120 minutes. RESULTS: Radiopharmaceutical was present in the systemic circulation in two patients, possibly as a result of paratumoral injection. Eleven patients had intratumoral accumulation in early frames. Lymph nodes draining the thyroid nodule were visualized in 10 of 11 patients. In the dynamic acquisition period of 7 of 10 patients, the first draining lymph node could also be identified. Only 5 of 13 patients had malignant nodules. Lymphatic metastases were detected in one patient's specimens. CONCLUSIONS: Preoperative visualization of lymphatic pathways may be used when planning for thyroid cancer surgery. Sentinel node detection could yield valuable additional information in these patients.

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.

Evaluation of metastatic bone disease with pentavalent 99Tc(m)-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.

Bilateral pulmonary artery aneurysms in a patient with Behcet syndrome: evaluation with radionuclide angiography and V/Q lung scanning.

The case of a 14-year-old girl with Behcet syndrome is described. Besides painful and recurrent oral ulcerations, the patient had a cough and intermittent hemoptysis. The initial chest roentgenogram revealed bilateral parahilar opacities. CT and MRI scans of the thorax showed bilateral thrombosing aneurysms of the pulmonary arteries. Pulmonary blood flow imaging was performed after technegas ventilation lung scanning and Tc-99m MAA injection using a first-pass radionuclide angiography procedure. Altered blood flow in the left pulmonary artery was shown. Bilateral and well-defined ventilation/perfusion mismatched areas suggested a high probability of pulmonary embolism. Little additional information was obtained on subsequent contrast pulmonary angiography. The high incidence of pulmonary artery hypertension and associated vascular injury risk makes pulmonary angiography an unsafe procedure in patients with pulmonary Behcet syndrome. The need for pulmonary angiography could be obviated in such cases with the use of high-precision MRI and ventilation/perfusion lung scanning, including radionuclide pulmonary angiography.

Pulmonary Tc-99m tetrofosmin imaging: clinical experience with detecting malignant lesions and monitoring response to therapy.

The authors prospectively investigated the uptake and kinetics of Tc-99m tetrofosmin (Tetro) in benign and malignant lung lesions and the effect of radiotherapy, chemotherapy, or both on Tc-99m Tetro uptake in malignant lung tumors. Dynamic and planar Tetro imaging were performed in 45 patients with pulmonary lesions during a period of 28 months (34 untreated malignant tumors, 11 benign lesions). Tetro uptake was visibly increased in 26 of 34 malignant tumors, with a mean lesion to contralateral normal tissue ratio of 1.44 +/- 0.29 and a tumor washout rate of 28.4 +/- 6.6% 30 minutes after injection. In 3 of 11 benign lesions, Tetro uptake was observed. Of the 26 patients with malignant tumors and positive Tetro uptake, nine had repeated imaging 6 to 8 weeks after therapy. The patients were treated with radiotherapy, chemotherapy, or both. Reduction in radiological tumor size was used as the clinical response parameter. In five of nine patients, the course of Tetro uptake in follow-up imaging was in accordance with that of radiological tumor size. Two of four remaining patients had only slight discordance between the alteration of Tetro uptake and radiological tumor size. The sensitivity of Tetro to detect malignant lung lesions in our patients was 77%. The specificity and accuracy of the method were 73% and 76%, respectively. Tetro has limited diagnostic value in detecting lung cancer. It may be useful to monitor the response to therapy in malignant lung tumors with initial tracer uptake. Broader trials on this matter are needed for further clarification.

Transient reverse ventilation-perfusion mismatch in acute pulmonary nitrofurantoin reaction.

A 67-yr-old woman with a history of myocardial infarct was admitted to emergency for marked dyspnea, nonproductive cough, nausea and fever. The thorax X-ray revealed a bilateral alveolar and interstitial infiltration pattern with basal accentuation. The cardiac examinations were normal. Technegas ventilation and Tc-99m-macroaggregated albumin (MAA) perfusion scans were performed to rule out pulmonary embolism. Bilateral multiple ventilation defects with normal perfusion was observed. The patient had been taking nitrofurantoin for four days for a bladder infection. Hypersensitivity to nitrofurantoin was suspected and the drug was discontinued. An antihistaminic and anxiolytic medication was started. The majority of the clinical symptoms disappeared within 24 hours. The control chest X-rays disclosed a marked improvement. Ventilation and perfusion scans obtained 48 hours after nitrofurantoin withdrawal were normal. The drug-related pulmonary reactions should be taken into account in patients on medication. Reversible ventilation defects can be the only lung-scintigraphic finding encountered in acute pulmonary nitrofurantoin reaction.