Usefulness of Technetium-99m Hexamethylpropylene Amine Oxime Lung Scan to Detect Subclinical Lung Injury in Patients with Chronic Renal Failure

We used technetium-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) lung scan to detect subclinical lung injury in patients with chronic renal failure (CRF), on regular hemodialysis (HD), who had normal chest X-ray findings (CXR) and pulmonary function test (PFT). The degree of pulmonary vascular endothelium damage was represented as lung/liver uptake ratios (L/L ratios) calculated by Tc-99m HMPAO lung scan. The L/L ratios of the 20 male CRF patients on HD with normal CXR and PFT were compared with those of the 20 male normal controls. The results show that the L/L ratios on Tc-99m HMPAO lung scans were significantly higher in CRF patients on HD (1.06 ± 0.55) than those in normal controls (0.34 ± 0.09). Using a cut-off value of 0.50, 18/20 [90%] CRF patients had abnormally increased L/L ratios. Our findings concluded that the pulmonary vascular endothelium damage represented as significantly increased L/L ratios on Tc-99m HMPAO lung scan in CRF patients on HD with normal CXR and PFT. In addition, Tc-99m HMPAO lung scan has the potential to be a sensitive, objective and noninvasive method to detect subclinical lung injury of CRF patients on HD, which is different from the traditional studies such as CXR or PFT.     

Assessing Transient Pulmonary Injury Induced by Volatile Anesthetics by Increased Lung Uptake of Technetium-99m Hexamethylpropylene Amine Oxime

Volatile anesthetics such as halothane and isoflurane have long been thought to affect pulmonary function. The purpose of this study was to examine whether volatile anesthetics (halothane and isoflurane) can induce pulmonary vascular endothelium damage. Before surgery, 1 h after surgery, and 1 week after surgery, the degree of pulmonary vascular endothelium damage was represented as increased lung/liver uptake ratios (L/L ratio) and measured on technetium-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) lung scan in 3 groups of the patients. Group 1 included 20 patients undergoing surgery and receiving volatile anesthesia with 1% halothane. Group 2 included 20 patients undergoing surgery and receiving volatile anesthesia with 1.5% isoflurane. Group 3 included 20 patients undergoing surgery with intravenous anesthesia drugs. No significant change of L/L ratio was found from before surgery, 1 h after surgery, to 1 week after surgery in group 3 patients. In groups 1 and 2 patients, significantly transient increased L/L ratio was found 1 h after surgery. We conclude that volatile anesthesia (halothane and isoflurane) can induce transient pulmonary vascular endothelium damage, represented as transiently increased L/L ratios on Tc-99m HMPAO lung scan.     

Usefulness of quantitative Tc-99m HMPAO and Ga-67 citrate lung scans in detecting pulmonary vascular endothelium damage and lung inflammation in patients with systemic lupus erythematosus: a preliminary report

Pulmonary vascular endothelium damage in 34 patients with systemic lupus erythematosus (SLE) was measured by technetium-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) lung scan. The degree of damage was represented as lung/liver uptake (L/L) ratio. The patients were divided into two subgroups according to the following criteria: (a) clinical features, separated as stable or flare stage and (b) chest X-ray findings separated as positive or negative results. Meanwhile, quantitative gallium-67 citrate (Ga-67) lung scan was performed as Ga-67 uptake index (GUI) to evaluate the severity of inflammation in the SLE lungs. The results show (a) no significant statistical differences in the degree of pulmonary vascular endothelium damage (the L/L ratio on Tc-99m HMPAO lung scan) between the two subgroups according to clinical features or chest X-ray findings and (b) no good correlation between the degree of pulmonary vascular endothelium damage and lung inflammation (GUI on Ga-67 lung scan). In conclusion, the change in pulmonary vascular endothelium damage in SLE may be unrelated to the clinical presentation or chest X-ray findings, and its degree is not related to the severity of pulmonary inflammation.     

Objective evidence of impairment of alveolar integrity in patients with non-insulin-dependent diabetes mellitus using radionuclide inhalation lung scan

The alveolar integrity (AI) in 60 patients of noninsulin-dependent diabetes mellitus (NIDDM) who had normal chest X-ray findings and pulmonary function test was measured by technetium-99m (Tc-99m) diethyltriamine pentaacetic acid (DTPA) and Tc-99m hexamethylpropylen amine (HMPAO) radioaerosol inhalation lung scan (lung scan). The degree of AI damage in NIDDM was presented as the clearance rate (%/min) of hydrophilic Tc-99m DTPA and lipophilic Tc-99m HMPAO radioaerosols from the lungs. The AI of NIDDM patients was compared with the AI of 40 normal controls. The results show that (1) the clearance rate of Tc-99m DTPA radioaerosols was faster than those of Tc-99m HMPAO radioareosols in either NIDDM patients or normal controls over any portion of the lungs, (2) the clearance rates of both Tc-99m DTPA and Tc-99m HMPAO radioaerosols were faster in NIDDM patients than those in normal controls over any portion of the lungs. Our findings concluded that (1) at least two different clearance mechanisms of radioaerosols in the lungs are working; and (2) the AI damage in NIDDM patients happened in both hydrophilic and lipophilic parts of the alveoli. In addition, the AI damage found by faster clearance rates of both Tc-99m DTPA and HMPAO radioaerosols may provide the other objective evidence of lung complications in NIDDM patients, which are different from the traditional studies such as chest X-ray or pulmonary function test.     

A pilot trial of quantitative Tc-99m HMPAO and Ga-67 citrate lung scans to detect pulmonary vascular endothelial damage and lung inflammation in patients of collagen vascular diseases with active diffuse infiltrative lung disease

Diffuse infiltrative lung disease (ILD) includes a heterogeneous group of disorders predominantly affecting lung parenchyma and sparing the airway. To assess the degree of pulmonary vascular endothelial damage in active ILD, lung/liver uptake ratios (L/L ratio) on technetium-99m hexamethylpropylene amine oxime (Tc-99m HMPAO) lung scan were determined in 30 patients with active ILD. Meanwhile, the gallium-67 citrate (Ga-67) uptake index (GUI) on Ga-67 lung scan was used to evaluate the severity of lung inflammation in active ILD. In this study, high-resolution CT (HRCT) was used to evaluate disease activity in ILD. The results show statistically significant differences between normal controls and patients with active ILD as shown in L/L ratios and GUI. However, when the patients were divided into two groups of 15 patients with normal chest X-ray findings and 15 with abnormal X-ray findings, there was no significant difference in those parameters. In addition, there was no statistically significant difference between the groups in HRCT scoring. No good correlation between the degree of pulmonary vascular endothelial damage and the severity of lung inflammation was found. In addition, there were no good correlations between HRCT scoring vs GUI and HRCT vs L/L ratio in different study subgroups. In conclusion, L/L ratios on Tc-99m HMPAO and GUI on Ga-67 lung scans differ from chest X-ray findings and have the potential to detect the degree of pulmonary vascular endothelial damage and severity of lung inflammation in active IDL. However, the relationships between HRCT scoring, GUI, and L/L ratio in patients with collagen vascular diseases and active ILD are not significant.     

Technetium-99m Hexamethylpropylene Amine Oxime Lung Scintigraphy Findings in Low-Dose Amiodarone Therapy

Amiodarone (AD)-induced pulmonary toxicity is one of the major complications of long-term AD therapy. Technetium-99m-labeled D,L-hexamethylpropylene amine oxime (Tc-99m HMPAO) scintigraphy has been used to assess lung injury. We designed this study to clarify lung uptake changes of Tc-99m HMPAO using low doses of AD (5 mg/kg/day) during long-term therapy in a rabbit model. Group 1 consisted of 7 rabbits fed with AD by gavage for 6 months. To investigate the effect of ketamine on Tc-99m HMPAO uptake, 5 rabbits were included in Group 2 as a control group. Tc-99m HMPAO scintigraphy was performed in both Group 1 and Group 2 at baseline and after 2, 4, 6, 8, and 12 weeks of AD intake. After 16, 20, and 24 weeks of drug intake, Tc-99m HMPAO scintigraphy was repeated only in group 1. One-min anterior images were acquired 30 min after the injection of 37 MBq of Tc-99m HMPAO. For semiquantitative evaluation, the mean count values were obtained and lung/background and liver/background ratios were calculated. Histopathologic evaluation was performed. No increase in lung and liver uptake of Tc-99m HMPAO was found 2, 4, 6, 8, and 12 weeks after drug intake. There was no significant increase in L/B and H/B ratios of Tc-99m HMPAO in Group 1 compared with Group 2. Both scintigraphic studies and histopathologic examinations showed nonspecific changes. Longitudinal studies investigating Tc-99m HMPAO lung uptake may be planned in patients carrying risk factors for AD-induced lung toxicity.     

Increased lung uptake of technetium-99m hexamethylpropylene amine oxime in diffuse infiltrative lung disease

BACKGROUND: Diffuse infiltrative lung disease (ILD) is a heterogeneous group of disorders which predominantly affect the lung parenchyma and spare the airway. OBJECTIVE: To assess pulmonary vascular endothelium damage in ILD, the lung uptake of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) was determined. METHODS: In 20 ILD patients and 25 controls without ILD, the lung uptake of 99mTc-HMPAO was measured. Anterior lung imaging, including a large part of the liver, was made 10 min after intravenous injection of 20-25 mCi of 99mTc-HMPAO. Regions of interest covered the liver and lung to calculate the lung/liver uptake ratios. The 20 ILD patients included 10 patients with clinically manifest pulmonary disease (group 1) and 10 asymptomatic patients (group 2). All of the study subjects had normal pulmonary function test results. RESULTS: The mean lung/liver uptake ratio in the 25 controls without ILD (0.36 +/- 0.10) was significantly lower than that in the 20 ILD patients (0.97 +/- 0.61). In addition, the mean lung/liver uptake ratio in the 10 ILD patients with clinically manifest pulmonary disease (1.45 +/- 0.51) was higher than that of the other 10 asymptomatic ILD patients (0.49 +/- 0.09). CONCLUSIONS: Our results indicated that determining the lung/liver uptake ratio on 99mTc-HMPAO lung imaging should be an objective method to assess subclinical pulmonary damage in ILD patients.     

Estimation of pulmonary hypertension in lung and valvular heart diseases by perfusion lung scintigraphy]

To estimate pulmonary hypertension, we measured postural differences in pulmonary blood flow for the lateral decubitus positions on perfusion lung scintigrams with Tc-99 m macro-aggregated albumin, applying the method devised by Tanaka et al (Eur J Nucl Med 17: 320-326, 1990). Utilizing a scintillation camera coupled to a minicomputer system, changes in the distribution of pulmonary blood flow caused by gravitational effects, namely, changes in the total count ratios for the right lung versus the left lung in the right and left lateral decubitus positions (R/L), were obtained for 44 patients with lung disease, 95 patients with valvular heart disease, and 23 normal subjects. Mean standard deviation in the R/L ratios was 3.09 +/- 1.28 for the normal subjects, 1.97 +/- 0.89 for the patients with lung disease, and 1.59 +/- 0.59 for the patients with valvular heart disease. The R/L ratios correlated with mean pulmonary arterial pressure and cardio-thoracic ratios in the lung disease and valvular heart disease groups, with pulmonary arteriolar resistance in the former, and with pulmonary capillary wedge pressure in the latter. Defining pulmonary hypertension (> 20 mmHg) as an R/L ratio of less than 1.81, which is the mean-1 standard deviation for normal subjects, the sensitivity and the specificity of the R/L ratio for the diagnosis of pulmonary hypertension were 62.9% and 76.2%, respectively, for the lung disease patients, and 80.3% and 61.8%, respectively, for the valvular heart disease patients. This method seems to be useful for the pathophysiologic evaluation of pulmonary perfusion in cases of lung disease and valvular heart disease.     

Using Technetium-99m Tetrofosmin Chest Imaging to Predict Taxol-Based Chemotherapy Response in Non-Small Cell Lung Cancer but Not Related to Lung Resistance Protein Expression

In vitro studies have shown that technetium-99m tetrofosmin (Tc-99m TF) is a transport substrate for the P-glycoprotein (Pgp) pump. Therefore, Tc-99m TF uptake of tumors can be used to predict chemotherapy response in lung cancers. However, whether lung resistance-related protein (LRP) expression affects tumor accumulation and efflux of Tc-99m TF in lung cancers is not known. Our aim was to use Tc-99m TF uptake of tumors to predict paclitaxel-based chemotherapy response of non-small cell lung cancer (NSCLC) and to compare Pgp or LRP expression. Twenty patients with advanced NSCLC received Tc-99m TF chest images before Taxol-based chemotherapy was used in this study. The chemotherapy response was evaluated by clinical and radiological methods in the third month after completion of treatment. No significant differences of prognostic factors (age, sex, body weight loss, performance status, tumor size, tumor stage, and tumor cell type) were found between the patients with good and those with poor responses. Early and delayed tumor/normal lung (T/L) uptake ratios were calculated on Tc-99m TF chest images. Immunohistochemical analyses were performed on multiple nonconsecutive sections of the biopsy specimens to detect Pgp and LPR expressions. The early and delayed T/L uptake ratios of 10 patients with good response were significantly higher than those of the other 10 patients with poor response. Significantly higher early and delayed T/L uptake ratios were found in patients with negative than those with positive Pgp expression (p < 0.05). However, no significant differences of early and delayed T/L uptake ratios were found between patients with negative and positive LRP expressions (p > 0.05). We found that Tc-99m TF imaging could accurately predict Taxol-base chemotherapy response. In addition, the Tc-99m TF tumor uptake was related to Pgp but not LPR expression in NSCLC.     

Increased lung uptake of technetium-99m hexamethylpropylene amine oxime in systemic lupus erythematosus

BACKGROUND: Systemic lupus erythematosus (SLE) can affect every organ. Involvement of the lungs in this disease is a significant cause of morbidity and mortality. OBJECTIVES: To assess pulmonary vascular endothelium damage in SLE by lung uptake of technetium-99m hexamethylpropylene amine oxime ((99m)Tc-HMPAO). METHODS: Lung uptake of (99m)Tc-HMPAO was measured in 20 SLE patients and for comparison in 25 controls without SLE, referred for brain imaging due to dementia or stroke. Of the 20 SLE patients, 10 had significant clinical pulmonary manifestations. However, all SLE patients had normal chest X-ray findings. Anterior lung image, including a large part of the liver, was taken 10 min after intravenous injection of 20-25 mCi of (99m)Tc-HMPAO. Regions of interest were calculated over the liver and lung. RESULTS: The mean lung/liver uptake ratio in patients without SLE was 0.36 +/- 0.1. The mean lung/liver uptake ratio in SLE patients was 0.79 +/- 0.58. The difference was significant. CONCLUSIONS: Our results indicated that determining the ratio of lung/liver uptake of (99m)Tc-HMPAO may be a useful complementary method to assess pulmonary injury in SLE patients.     

Comparing whole body 18F-2-deoxyglucose positron emission tomography and technetium-99m methylene diophosphate bone scan to detect bone metastases in patients with non-small cell lung cancer

Despite advances in morphological imaging, some patients with non-small cell lung cancer (NSCLC) are found to have non-resectable disease at surgery or die of recurrence within a year of surgery. At present, metastatic bone involvement is usually assessed using conventional technetium-99m methylene diophosphate (Tc-99m MDP) whole body bone scan (bone scan), which has a high sensitivity but a poor specificity. We have attempted to evaluate the usefulness of whole body positron emission tomography with 18F-2-deoxyglucose (FDG-PET) for the detection of malignant bone metastases of NSCLC, and to compare FDG-PET results with Bone Scan findings. Forty-eight patients with biopsy-proven NSCLC and suspected to have stage IV disease underwent whole body bone scan and FDG-PET to detect bone metastases. The final diagnoses of bone metastases were established by operative, histopathological findings or clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/Tc-99m MDP bone scan findings showing progressively and extensively widespread bone lesions. A total of 138 bone lesions found on either FDG-PET or Tc-99m MDP bone scan were evaluated. Among the 106 metastatic and 32 benign bone lesions, FDG-PET and Tc-99m MDP bone scan could accurately diagnose 99 and 98, as well as 30 and 2 metastatic and benign bone lesions, respectively. Diagnostic sensitivity and accuracy of FDG-PET and Tc-99m MDP bone scan were 93.4% and 92.5%, as well as 93.5% and 72.5%, respectively. In conclusion, our data suggest that FDG-PET with the same sensitivity and a better accuracy than those of Tc-99m MDP bone scan to detect metastatic bone lesions in patients with biopsy-proven NSCLC and suspected to have stage IV disease.     

Comparison between technetium-99m hexamethylpropyleneamineoxide labeled white blood cell abdomen scan and abdominal sonography to detect appendicitis in children with an atypical clinical presentation

BACKGROUND/AIMS: Diagnosing acute appendicitis in children with equivocal signs and symptoms is usually difficult. The usual approach to the patient is hospital observation and frequent reexamination. However, many surgeons are reluctant to delay surgery because of the risk of perforation and a negative laparotomy. The aim of this study is to assess and compare the value of the Tc-99m HMPAO (technetium-99m hexamethylpropyleneamineoxide) labeled white blood cell abdomen scan and abdominal sonography in the diagnosis of acute appendicitis in children with an atypical clinical presentation. METHODOLOGY: Forty children with acute abdomen and possible acute appendicitis but atypical findings were included in this study. After an intravenous injection of Tc-99m HMPAO white blood cells, serial anterior abdomen scans at 30 min, 60 min, 120 min and 240 min were obtained using a gamma camera. Meanwhile, at the point of maximal tenderness, abdominal sonography was performed with a graded compression technique for both longitudinal and transverse images. RESULTS: Thirty-three children received operation for surgical and pathological diagnoses. The other 17 children did not receive operation but follow-up of at least a one-month period. The overall sensitivity, specificity, and accuracy of Tc-99m HMPAO white blood cell scan to diagnose acute appendicitis in children with atypical findings is 96.7%, 80.0%, and 90.0%, respectively. The overall sensitivity, specificity, and accuracy for abdominal sonography is 86.6%, 90.0%, and 88.0%, respectively. CONCLUSIONS: The Tc-99m HMPAO white blood cell abdomen scan provides a more sensitive and accurate method for the diagnosis of appendicitis in children with atypical clinical presentation when compared with abdominal sonography.     

Exercise and rest technetium-99m-tetrofosmin lung uptake: correlation with left ventricular ejection fraction in patients with coronary artery disease

Increased lung uptake of thallium-201 (Tl-201) and technetium-99m (Tc-99m) MIBI in myocardial perfusion imaging is a reliable marker of left ventricular dysfunction. The goal of our study was to establish whether the lung-to-heart (L/H) uptake ratio with a newer cardiac imaging agent, Tc-99m tetrofosmin, can also provide valuable information about left ventricular function. We studied 60 patients with recent coronary artery diseases (CAD) undergoing first-pass radionuclide ventriculography to calculate left ventricular ejection fraction (LVEF) and myocardial perfusion imaging to calculate the L/H ratio. Group A consisting of 30 CAD patients with higher LVEF (> or =40%) had a significantly lower L/H ratio than group B consisting of 30 CAD patients with abnormal LVEF (<40%) during exercise and rest. In groups A and B, the exercise and rest L/H ratios did not differ significantly. However, a statistically significant inverse correlation was found between the L/H ratio and LVEF during exercise and rest among the 60 patients. L/H ratios, measured by 99mTc-tetrofosmin imaging, provide clinically useful information with which to predict left ventricular dysfunction in CAD patients.     

Tc-99m MIBI SPECT in detecting metastatic papillary thyroid carcinoma in patients with elevated human serum thyroglobulin levels but negative I-131 whole body scan

Papillary carcinomas are the most common thyroid malignancies. They invade the regional lymphatics and metastasize frequently to local lymph nodes in the neck. Distant metastasis, generally to the lungs, is also common. The aim of this study is to evaluate the effectiveness of single photon emission computed tomography (SPECT) with technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) in detecting metastatic lesions in patients with papillary thyroid carcinoma (PTC) after nearly total thyroidectomy and radioiodine (I-131) treatment who present with elevated serum human thyroglobulin (hTg) levels but negative I-131 whole body scan (WBS). METHODS: Twenty patients of PTC who underwent nearly total thyroidectomy and I-131 treatments were included in this study. All of the 20 patients had negative I-131 WBS results and elevated hTg levels (hTg > or = 20 microIU/mL) under thyroid-stimulating hormone (TSH) stimulation (TSH > or = 30 microIU/mL). Technetium-99m MIBI SPECT was performed to detect metastatic lesions. RESULTS: Technetium-99m MIBI SPECT demonstrated lesions in 10 patients. Technetium-99m MIBI SPECT failed to demonstrate lesions in nine patients including small lymph node and lung metastases. CONCLUSIONS: This study showed that Tc-99m MIBI SPECT is a useful tool to detect metastatic lesions in PTC with elevated hTg but negative I-131 WBS. However, small lymph node and lung metastases may be missed in Tc-99m MIBI SPECT. In the latter circumstance, other imaging studies should be included in the follow-up protocol.     

Technetium-99m isonitrile myocardial uptake at rest. II. Relation to clinical markers of potential viability

To determine the utility of rest-injected technetium-99m methoxybutyl isonitrile (Tc-99m isonitrile) uptake as a marker of myocardial viability, the regional uptake of this agent was compared with regional wall motion by equilibrium gated blood pool scan in 26 patients with previous myocardial infarction and with postrevascularization uptake in 8 patients after coronary bypass surgery. Rest left ventricular Tc-99m isonitrile uptake was assessed qualitatively in three coronary vascular territories as grade 0 (markedly reduced) to grade 2 (normal), and quantitatively by circumferential profile analysis. Wall motion was scored qualitatively in corresponding vascular territories as normal, hypokinetic or akinetic/dyskinetic. There was an overall relation between qualitative Tc-99m isonitrile uptake and wall motion. Abnormal wall motion occurred in 74% of vascular territories with perfusion grade 0, in 61% of those with grade 1 and in 30% of those with grade 2; however, 26% of territories with grade 0 uptake had normal wall motion. In the territories visually assigned perfusion grade 0, quantitative isonitrile uptake (mean value +/- SD) was higher when corresponding wall motion was normal or hypokinetic (62 +/- 15%) than when akinesia was detected by gated blood pool scan (39 +/- 16%, p less than 0.02). Qualitative Tc-99m isonitrile uptake improved after coronary bypass surgery in 12 of 13 territories with reduced uptake preoperatively; this included all 5 territories with a preoperative Tc-99m isonitrile score of 0. Quantitative uptake in these regions increased from 55 +/- 18% to 73 +/- 21% (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Using Tc-99m DMSA renal scan to detect renal damage in Taiwanese women with Type 2 diabetes--a preliminary report

In this preliminary study, we compared control women and Type 2 diabetes mellitus (DM) women for the prevalence and type of renal damage as revealed by technetium-99m dimercapto-succinic acid (Tc-99m DMSA) renal scan. METHODS: A total of 20 control women and 60 women with Type 2 DM received Tc-99m DMSA renal scan were included in this study. The 60 women with Type 2 DM were separated into three groups: 20 women without UTI history, 20 patients with cystitis histories only, and 20 with pyelonephritis histories. RESULTS: All of the control women had normal Tc-99m DMSA renal scan findings. However, 38.3% of Type 2 DM wonmen had abnormal Tc-99m DMSA renal scan findings. Type 2 DM women without UTI history had no abnormal scan findings. The prevalence of abnormal renal scan findings was significantly higher in Type 2 DM women with pyelonephritis (90.0%) than with cystitis alone (25.0%). Renal scar findings were found only in Type 2 DM women with pyelonephritis (40.0%). CONCLUSIONS: Compared with control women, women with Type 2 DM, especially if they had UTI and pyelonephritis histories, have a significantly higher prevalence of abnormal Tc-99m DMSA renal scan findings.     

Value of Tc-99m sestamibi scintigraphy in the detection of bone lesions in multiple myeloma: comparison with Tc-99m methylene diphosphonate

Technetium 99m-2-methoxyisobutylisonitrile (Tc-99m MIBI) is a lipophilic agent that accumulates preferentially within living malignant cells due to the higher transmembrane electrical potential as a consequence of the higher metabolic rate than in the surrounding normal cells. It has been effectively used to detect malignant tumors at diagnosis and follow-up and has been reported to be useful in detecting disease lesions in multiple myeloma. We studied 28 consecutive patients with multiple myeloma at diagnosis to determine the value of Tc-99m MIBI in comparison with Tc-99m methylene diphosphonate (MDP), conventional X-rays, computed tomography (CT) scan, and magnetic resonance imaging (MRI). We found 26 patients with obvious osteolytic lesions in X-rays, 22 patients with positive Tc-99m MIBI scans, and 15 patients with positive Tc-99m MDP scans. There was no coincidence of the positive lesions in the two scans, while in two patients the osteolytic areas were positive in the Tc-99m MDP scans, and in one case the osteolytic area was positive in the Tc-99m MIBI scan. The intensity of Tc-99m MIBI scans correlated with disease activity as determined by lactate dehydrogenase (LDH) (p<0.05), C-reactive protein (CRP) (p<0.01), beta2-microglobulin (p<0.05), and serum ferritin (p<0.01). We believe that Tc-99m MIBI scintigraphy can detect bone marrow lesions in myeloma patients that cannot be detected by other imaging methods and that it can be useful especially in solitary myeloma to exclude other involved sites. In addition, it could be a prognostic factor related to disease activity and multidrug resistance. We believe that a multicenter study is needed to evaluate the usefulness of this agent.     

High resolution computed tomography in early scleroderma lung disease.

Seventeen patients with early systemic sclerosis (SSc) underwent high resolution computed tomography (HRCT) of the chest to evaluate dyspnea and/or abnormal pulmonary function tests (PFT). All patients were assigned a dyspnea score and each had routine chest radiography (CXR). Bronchoalveolar lavage (BAL) was performed on 10 patients. HRCT was abnormal in 15 patients (88%), while CXR was abnormal in only 10 patients (59%). Mediastinal lymphadenopathy was detected in 7 patients (41%). Disease duration, dyspnea score, and forced vital capacity (FVC) did not correlate with HRCT score. However, trends toward higher total BAL cell counts and higher BAL neutrophil counts were noted in patients with ground glass opacities on HRCT, and BAL lymphocyte counts were significantly higher in such cases. HRCT is superior to CXR for detecting early interstitial lung disease in SSc, but patient history and FVC correlate poorly with HRCT findings. Ground glass opacities on HRCT may reflect active alveolitis, and mediastinal lymphadenopathy associated with SSc lung disease may be a consequence of pulmonary inflammation.     

Prediction of pneumothorax rate in percutaneous needle aspiration of the lung

Pneumothorax (PTX) is the most common complication associated with percutaneous needle aspiration (PNA) of the lung. Age, sex, cooperation, and lesion size, location, and depth, as well as needle size, number of passes, and radiographic calculation of total lung capacity all have been implicated in influencing the rate of PTX. Pulmonary function testing to assess PTX risk in PNA has not been previously examined. We retrospectively reviewed 159 patients undergoing PNA who had preprocedure spirometry (PFT) and chest roentgenogram (CXR) interpreted for changes of obstruction or restriction to determine if these classifications could stratify patients at high risk for PTX. We also examined single variables to determine their predictive power. Patients with normal PFT and CXR had a 10 percent risk of PTX, and only one such patient needed intervention to treat the PTX. Obstruction by PFT, regardless of CXR findings, predicted a 50 percent PTX rate. Among single variables, FEV1 proved to be the most significant predictor of PTX. Preprocedure spirometric testing can enhance the assessment of PTX risk and should be routinely performed prior to needle aspiration.     

The subclinical involvement of the lung in rheumatoid arthritis: evaluation by high-resolution computed tomography

Pulmonary involvement is one of the most frequent extra-articular manifestations of rheumatoid arthritis (RA) and represents a serious complication, being the second cause of death after infection. High-resolution computed tomography (HRCT), owing to its increased sensitivity and diagnostic accuracy respect to the conventional chest radiograph (CXR), allows to detect pulmonary abnormalities in RA patients more frequently than CXR. The aim of this study was to assess pulmonary involvement by HRCT in lifelong non-smoking RA patients without symptoms and clinical signs of pulmonary disease. Seventy-two patients (54 women and 18 men) with a mean age of 56.8+/-10.4 years (range, 40-77 years) and mean duration of disease of 6.9+/-4.7 years (range, 2-12 years) entered the study. 52/72 (72%) were positive for rheumatoid factor (> 20 UI/ml). Standard CXR and HRCT were carried out in each patient. CXR showed a mild interstitial fibrosis in 7 patients (9.7%), whereas HRCT demonstrated pulmonary abnormalities in an higher number of them (22/72 = 30.5%). The most frequent abnormal findings on HRCT were irregular pleural margins (13.8%) and septal/subpleural lines (18%), both compatible with pulmonary fibrosis. Ground-glass opacities were found in 8.3% of the patients. Pulmonary nodules (diameter, range 0,5-2 cm) predominantly located in the subpleural portions of the lung, were demonstrated in the same percentage (8.3%) of patients. Small airway involvement, represented by bronchiectasis/bronchioloectasis, was shown in 15.2% of patients. Subpleural cysts were present in two cases (2.8%). No patient had evidence of honeycombing on HRCT. In conclusion, HRCT is an accurate, non-invasive and safe method of diagnosing lung abnormalities in RA patients without signs and clinical symptoms of pulmonary disease.