摘要:

Purpose:This study describes a new 1-day protocol with Tc-99m tetrofosmin that requires only 100 minutes to obtain both stress and resting cardiac images by using a double-injection and subtraction method.Methods:This procedure was performed in 48 consecutive patients. Rest-rest double injections were performed in eight patients (five men, three women; mean age, 69 ± 9.8 years) to evaluate count and image reproducibility (subprotocol A), and stress-rest and additional resting perfusion images (true rest) were done on a different day in 11 patients (five men, six women; mean age, 63 ± 5.9 years) to confirm the validity of the new protocol (subprotocol B).Results:Image quality scores of the resting image were excellent (35 of 48, or 72.9%), good (7 of 48, or 14.6%), fair (3 of 48, or 6.3%), and poor (3 of 48, or 6.3%). The scintigraphic findings with the new protocol corresponded closely with those of angiography in 26 of 34 cases (76.5%), with a tendency for underestimation (in 5 of 34 cases, or 14.7%) rather than overestimation (in 3 of 34 cases, or 8.8%). In subprotocol A, count reproducibility between the two resting images was excellent (r = 0.95;P< 0.0001); and in subprotocol B, the early-rest images were concordant visually and quantitatively with the true rest images (r = 0.89,P< 0.0001).Conclusion:Although there are some limitations, this protocol can be used as a routine stress-rest protocol.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

The validity of pharmacologic stress testing and subsequent myocardial perfusion imaging is uncertain in those patients who may have taken caffeine within the 24 hours before testing. For such patients, two new challenge tests have been developed. An intravenous bolus dose of adenosine is given at a dose of 6 mg in a period of 1 or 2 seconds. A physiologic response qualifies the patient to proceed with the scheduled stress test. In the occasional patient who exhibits no pharmacologic symptoms during an infusion test, a similar bolus dose of 6 mg adenosine can validate perfusion tests. These two applications are successful regardless of whether adenosine or dipyridamole infusions are performed. Based on this multicenter experience over 4 years, the authors estimate that 5% to 10% of patients undergoing pharmacologic testing are appropriate candidates for a challenge test.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Myocardial infarction is a rare complication that can occur after blunt chest trauma. The authors describe a 30-year-old man who experienced a fatal anterolateral myocardial infarction after chest trauma in a motorcycle accident. The electrocardiogram and creatine phosphokinase-MB isoenzymes levels suggested myocardial necrosis. Tc-99m phosphate myocardial scintigraphy identified an extensive doughnut-shaped uptake over the cardiac area. An echocardiogram revealed severe left ventricular impairment. Coronary angiography confirmed complete occlusion of the proximal left anterior descending coronary artery.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Purpose:In this study, the authors wanted to determine whether dipyridamole-modulated MIBI (dipyridamole-MIBI) could enhance the prediction of the response to chemotherapy in patients with small cell lung cancer.Methods:Twenty-seven patients with biopsy-proved small cell lung cancer (25 men, 2 women; mean age, 61 ± 7 years) underwent dipyridamole-MIBI SPECT 3 to 7 days before starting chemotherapy (80 mg/m2etoposide and 80 mg/m2cisplatin every 3 or 4 weeks for at least two cycles). Tomographic images before and after dipyridamole (0.84 mg/kg) were acquired 1 hour after injection of 370 (10 mCi) and 1,110 (30 mCi) MBq MIBI, respectively. The response to chemotherapy was grouped as specified as complete response (CR), partial (PR), no change (NC), or progressive disease (PD), according to the change in tumor size on chest roentgenography and CT. Patients showing CR and PR were classified as responders, and those who showed NC and PD were considered nonresponders.Results:Among the 27 patients, 22 were responders (3 CR, 19 PR) and 5 were nonresponders (3 NC, 2 PD). The tumor-to-normal lung ratio (T:NL) of responders was significantly higher than that of nonresponders. The diagnostic accuracy of the T:NL ratio to differentiate responders and nonresponders was 33.3%, with a cutoff value of 2.5, which was significantly improved to 77.8% when an increased T:NL ratio after dipyridamole was assigned to a nonresponder. Furthermore, all patients with CR showed diminished T:NL ratios after dipyridamole, and all patients with NR showed an increased T:NL ratio after dipyridamole.Conclusion:Dipyridamole-MIBI SPECT could enhance the prediction of response to chemotherapy in patients with small cell lung cancer.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

A new cause of a false-positive result of a Meckel's scan is reported. An 11-year-old girl had a 3-week history of constant right lower quadrant pain that was initially managed by laparoscopic appendectomy. A repeated laparoscopy for persistent pain was nondiagnostic. A missed Meckel's diverticulum was considered as the cause of this pain, which prompted a Meckel scan. This scan revealed a periumbilical focus of activity that was interpreted as a Meckel's diverticulum attached to the anterior abdominal wall by a band. The laparotomy showed no Meckel's diverticulum. The false-positive result of the Meckel scan may be the result of inflammation from the periumbilical laparoscopic port site.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Background:Interstitial lung disease (ILD) is characterized by inflammation within the alveolar walls and interstitium of the lungs. This causes increased alveolar-capillary membrane permeability. The diagnosis is made by clinical features, chest roentgenography, lung function tests, and high-resolution CT, and it is confirmed by lung biopsy. Radionuclide aerosol tracers such as Tc-99m DTPA show increased lung clearance in ILD. The clearance rate of microaerosol pertechnegas (modified Technegas) from the lungs in the assessment of ILD was evaluated.Methods:Thirty-two patients (22 with ILD and 10 with non-ILD) were evaluated with pertechnegas. Pertechnegas is formed by adding 3% oxygen to technegas, a microaerosol ventilation agent. Regions of interest were then drawn around the lungs, and clearance rates were determined from the best exponential fit.Results:The mean clearance rate of pertechnegas was significantly increased in ILD and measured 5.78 ± 2.2 minutes compared with non-ILD, which measured 8.53 ± 2.42 minutes (P< 0.001). The sensitivity and specificity rates of pertechnegas clearance (less than 8 minutes) in ILD were 90% and 60%, respectively. When combined with chest roentgenography, the sensitivity and specificity rates increased to 100% and 90%, respectively.Conclusions:Pertechnegas is highly effective in determining the presence of active ILD. It differentiates between active ILD and non-ILD, and it is highly sensitive and specific when combined with chest roentgenography. Its potential role in the management of ILD merits further investigation.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Primary thymic carcinoids are rare tumors in which the tumor cells retain functional somatostatin receptors. In-111-labeled octreotide imaging has been used to diagnose abdominal carcinoids with a sensitivity rate of approximately 87%. The authors describe a case of a recurrent, ectopic cortisol-releasing hormone that produced thymic carcinoid localized as a focal area of increased activity in the upper mediastinum when planar and tomographic octreotide scintigraphy was used. Chest CT and MRI failed to localize the tumor. This may be the first reported case of In-111-labeled octreotide used to identify Cushing's syndrome caused by a cortisol-releasing hormone that produced thymic carcinoid.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Two abscesses were shown on CT in a 72-year-old man: one in the left hip and one in the left pelvic region that resulted from a motor vehicle collision that occurred 8 months earlier. Bone scintigraphy showed increased uptake in the left hip area. On Tc-99m HMPAO leukocyte imaging, the hip area appeared to be photopenic, and the abscess of the left pelvis was not identified. Incidental uptake in the left lung base appeared to be an active acute inflammatory process as evidenced by an infiltrating lesion in the left lower lung on a chest radiograph. Because leukocyte scintigraphy cannot detect the presence of a chronic inflammatory process in the absence of acute inflammatory cells, the patient's abscesses in the left hip and the left pelvis did not localize Tc-99m HMPAO-labeled neutrophils. The cold lesion in the left hip area was most likely caused by the lesion in the reticuloendothelial system (bone marrow); the unidentifiable pelvic lesion was related to the area(s) outside the reticuloendothelial system. In interpreting a labeled leukocyte image, clinicians should be alert to the stage (chronic or acute) and location (regardless of whether in the reticuloendothelial system) of infectious lesion(s). In this patient, a wide spectrum of manifestations was evident on leukocyte scintigraphy.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Tc-99m sestamibi imaging was performed in two patients with multiple myeloma. Focal areas of increased uptake in one patient and diffuse skeletal uptake in the second patient were found. Tc-99m sestamibi appears to identify bone marrow and osteolytic involvement in multiple myeloma.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Purpose:The authors studied the relation between cardiac output (CO) and effective renal plasma flow (ERPF) and compared values from control patients with various cardiac problems with those in a group of study patients who had undergone heart transplantation.Methods:The experimental group was divided into three subgroups according to the interval between the time of surgery and the time of the CO-ERPF studies. Group 1 consisted of patients studied fewer than 10 days after surgery; group 2 consisted of patients studied 10 to 20 days after operation; and group 3 consisted of patients studied more than 20 days after operation. Effective renal plasma flow was determined by the single-injection, single plasma sample method, where 50 μCi I-131 orthoiodohippurate was injected intravenously in a single dose and plasma concentrations of radioactivity were determined. The quotient of injected dose radioactivity divided by plasma radioactivity is highly predictive of global ERPF. Cardiac output was measured by thermodilution.Results:In the control group, a positive linear correlation was found between CO and ERPF; however, the CO: ERPF ratio was elevated, and after heart transplantation, a lag time was observed for as long as 3 weeks in some patients before CO:ERPF ratios returned to control group levels. The regression equation and standard error for the control group was CO = 1.85 + 0.0065 ERPF (±0.62) l/min versus 1.433 + 0.0068 ERPF (±0.64) l/min for group 3. The correlation coefficients comparing CO with ERPF were r = 0.88, 0.23, 0.51, and 0.85, for the control group and groups 1, 2, and 3, respectively.Conclusion:A localized release of catecholamines from the adrenal gland is proposed to cause ERPF damping after abrupt increases in CO.

ISSN:0363-9762    

出版商:OVID    

年代:1999

数据来源: OVID