Early-Phase SPECT/CT for Diagnosing Osteomyelitis:A Retrospective Pilot Study

Objective@#The aim of this pilot study was to investigate the potential of early-phase single-photon emission computed tomography (SPECT)/computed tomography (CT) using technetium-99m methyl diphosphonate ( 99m Tc-MDP) for diagnosing osteomyelitis (OM). @*Materials and Methods@#Twenty-one patients with suspected OM were enrolled retrospectively. Three-phase bone scan (TPBS), early-phase SPECT/CT (immediately after blood pool planar imaging), and delayed-phase SPECT/CT (immediately after delayed planar imaging) were performed. The final diagnoses were established through surgery or clinical follow-up for over 6 months. We compared three diagnostic criteria based on (I) TPBS alone, (II) combined TPBS and delayed-phase SPECT/ CT, and (III) early-phase SPECT/CT alone. @*Results@#OM was diagnosed in 11 of 21 patients (nine surgically and two clinically). Of the 11 OM patients, criterion-I, criterion-II, and criterion-III were positive in six, seven, and 10 patients, respectively. Of the 10 non-OM patients, criterion-I, criterion-II, and criterion-III were negative in five, five, and seven patients, respectively. The sensitivity/specificity/ accuracy of criterion-I, criterion-II, and criterion-III for diagnosing OM were 54.5%/50.0%/55.0%, 63.6%/50.0%/57.1%, and 90.9%/70.0%/87.5%, respectively. @*Conclusion@#This pilot study demonstrated the potential of using the early-phase SPECT/CT to diagnose OM. Based on the results, prospective studies with a larger sample size should be conducted to confirm the efficacy of early-phase SPECT/CT.

Usefulness of cyclic thermal therapy and red blood cell scintigraphy in patients with chemotherapy-induced peripheral neuropathy

Background@#Pharmacological and non-pharmacological therapies have been used to treat patients with chemotherapy-induced peripheral neuropathy (CIPN). However, the effect of therapies in cancer patients has yet to be investigated comprehensively. We hypothesized that cyclic thermal therapy would improve blood flow and microcirculation and improve the symptoms driven by CIPN. @*Methods@#The criteria of assessment were blood volume in region of interest (ROI) in the images, and European Organization for Research and Treatment of Cancer–Quality of Life Questionnaire–Chemotherapy-Induced Peripheral Neuropathy 20 questionnaire scores. The blood volume was quantified by using red blood cell (RBC) scintigraphy. All patients were treated 10 times during 10 days. The thermal stimulations, between 15° and 41°, were repeatedly delivered to the patient’s hands. @*Results@#The total score of the questionnaires, the score of questions related to the upper limbs, the score of questions closely related to the upper limbs, and the score excluding the upper limbs questions was decreased. The blood volume was decreased, and the variance of blood volume was decreased. During cooling stimulation, the blood volume was decreased, and its variance was decreased. During warming stimulation, the blood volume was decreased, and its variance was decreased. @*Conclusions@#We suggest that cyclic thermal therapy is useful to alleviate CIPN symptoms by blood circulation improvement. RBC scintigraphy can provide the quantitative information on blood volume under certain conditions such as stress, as well as rest, in peripheral tissue.

Early-Phase SPECT/CT for Diagnosing Osteomyelitis:A Retrospective Pilot Study

Objective@#The aim of this pilot study was to investigate the potential of early-phase single-photon emission computed tomography (SPECT)/computed tomography (CT) using technetium-99m methyl diphosphonate ( 99m Tc-MDP) for diagnosing osteomyelitis (OM). @*Materials and Methods@#Twenty-one patients with suspected OM were enrolled retrospectively. Three-phase bone scan (TPBS), early-phase SPECT/CT (immediately after blood pool planar imaging), and delayed-phase SPECT/CT (immediately after delayed planar imaging) were performed. The final diagnoses were established through surgery or clinical follow-up for over 6 months. We compared three diagnostic criteria based on (I) TPBS alone, (II) combined TPBS and delayed-phase SPECT/ CT, and (III) early-phase SPECT/CT alone. @*Results@#OM was diagnosed in 11 of 21 patients (nine surgically and two clinically). Of the 11 OM patients, criterion-I, criterion-II, and criterion-III were positive in six, seven, and 10 patients, respectively. Of the 10 non-OM patients, criterion-I, criterion-II, and criterion-III were negative in five, five, and seven patients, respectively. The sensitivity/specificity/ accuracy of criterion-I, criterion-II, and criterion-III for diagnosing OM were 54.5%/50.0%/55.0%, 63.6%/50.0%/57.1%, and 90.9%/70.0%/87.5%, respectively. @*Conclusion@#This pilot study demonstrated the potential of using the early-phase SPECT/CT to diagnose OM. Based on the results, prospective studies with a larger sample size should be conducted to confirm the efficacy of early-phase SPECT/CT.

Usefulness of cyclic thermal therapy and red blood cell scintigraphy in patients with chemotherapy-induced peripheral neuropathy

Background@#Pharmacological and non-pharmacological therapies have been used to treat patients with chemotherapy-induced peripheral neuropathy (CIPN). However, the effect of therapies in cancer patients has yet to be investigated comprehensively. We hypothesized that cyclic thermal therapy would improve blood flow and microcirculation and improve the symptoms driven by CIPN. @*Methods@#The criteria of assessment were blood volume in region of interest (ROI) in the images, and European Organization for Research and Treatment of Cancer–Quality of Life Questionnaire–Chemotherapy-Induced Peripheral Neuropathy 20 questionnaire scores. The blood volume was quantified by using red blood cell (RBC) scintigraphy. All patients were treated 10 times during 10 days. The thermal stimulations, between 15° and 41°, were repeatedly delivered to the patient’s hands. @*Results@#The total score of the questionnaires, the score of questions related to the upper limbs, the score of questions closely related to the upper limbs, and the score excluding the upper limbs questions was decreased. The blood volume was decreased, and the variance of blood volume was decreased. During cooling stimulation, the blood volume was decreased, and its variance was decreased. During warming stimulation, the blood volume was decreased, and its variance was decreased. @*Conclusions@#We suggest that cyclic thermal therapy is useful to alleviate CIPN symptoms by blood circulation improvement. RBC scintigraphy can provide the quantitative information on blood volume under certain conditions such as stress, as well as rest, in peripheral tissue.

Prognostic Value of Restaging F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography to Predict 3-Year Post-Recurrence Survival in Patients with Recurrent Gastric Cancer after Curative Resection

Objective@#The aim of this study was to investigate the prognostic value of the maximum standardized uptake value (SUVmax) measured while restaging with F-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/ CT) to predict the 3-year post-recurrence survival (PRS) in patients with recurrent gastric cancer after curative surgical resection. @*Materials and Methods@#In total, 47 patients with recurrent gastric cancer after curative resection who underwent restaging with 18F-FDG PET/CT were included. For the semiquantitative analysis, SUVmax was measured over the visually discernable 18F-FDG-avid recurrent lesions. Cox proportional-hazards regression models were used to predict the 3-year PRS. Differences in 3-year PRS were assessed with the Kaplan–Meier analysis. @*Results@#Thirty-nine of the 47 patients (83%) expired within 3 years after recurrence in the median follow-up period of 30.3 months. In the multivariate analysis, SUVmax (p = 0.012), weight loss (p = 0.025), and neutrophil count (p = 0.006) were significant prognostic factors for 3-year PRS. The Kaplan–Meier curves demonstrated significantly poor 3-year PRS in patients with SUVmax > 5.1 than in those with SUVmax ≤ 5.1 (3-year PRS rate, 3.5% vs. 38.9%, p < 0.001). @*Conclusion@#High SUVmax on restaging with 18F-FDG PET/CT is a poor prognostic factor for 3-year PRS. It may strengthen the role of 18F-FDG PET/CT in further stratifying the prognosis of recurrent gastric cancer.

Comparison of Image Quality and Semi-quantitative Measurements with Digital PET/CT and Standard PET/CT from Different Vendors / 대한핵의학회잡지

Purpose@#This study aimed to evaluate the concordance and equivalence of results between the newly acquired digital PET/ CT(dPET) and the standard PET/CT (sPET) to investigate possible differences in visual and semi-quantitative analyses. @*Methods@#A total of 30 participants were enrolled and underwent a single 18F-FDG injection followed by dual PET/CT scans, by a dPET scan, and immediately after by the sPET scan or vice versa. Two readers reviewed overall image quality using a 5-point scale and counted the number of suggestive 18F-FDG avid lesions. The SUV values were measured in the background organs and in hypermetabolic target lesions. Additionally, we objectively evaluated image quality using the liver signal-to-noise ratio (SNR). @*Results@#The dPET identified 4 additional 18F-FDG avid lesions in 3 of 30 participants with improved visual image quality. The standard deviations of SUV of the background organs were significantly lower with Digital PET than with sPET, and dPET could acquire images with better SNR (11.13 ± 2.01 vs. 8.71 ± 1.32, P < 0.001). The reliability of SUV values between scanners showed excellent agreement. Bland-Altman plot analysis of 81 lesions showed an acceptable agreement between scanners for most of the SUVmax and SUVpeak values. No relationship between the SUV values and time delays of dual PET/CT acquisition was found. @*Conclusions@#The dPET provides improved image quality and lesion detectability than the sPET. The semi-quantitative values of the two PET/CT systems of different vendors are comparable. This pilot study will be an important basis for possible interchangeable use of either system in clinical practice.

Genetic features associated with ¹⁸F-FDG uptake in intrahepatic cholangiocarcinoma

PURPOSE: In intrahepatic cholangiocarcinoma (iCCA), genetic characteristics on ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG)-PET scans are not yet clarified. If specific genetic characteristics were found to be related to FDG uptake in iCCA, we can predict molecular features based on the FDG uptake patterns and to distinguish different types of treatments. In this purpose, we analyzed RNA sequencing in iCCA patients to evaluate gene expression signatures associated with FDG uptake patterns. METHODS: We performed RNA sequencing of 22 cases iCCA who underwent preoperative ¹⁸F-FDG-PET, and analyzed the clinical and molecular features according to the maximum standard uptake value (SUVmax). Genes and biological pathway which are associated with SUVmax were analyzed. RESULTS: Patients with SUVmax higher than 9.0 (n = 9) had poorer disease-free survival than those with lower SUVmax (n = 13, P = 0.035). Genes related to glycolysis and gluconeogenesis, phosphorylation and cell cycle were significantly correlated with SUVmax (r ≥ 0.5). RRM2, which is related to the toxicity of Gemcitabine was positively correlated with SUVmax, and SLC27A2 which is associated with Cisplastin response was negatively correlated with SUVmax. According to the pathway analysis, cell cycle, cell division, hypoxia, inflammatory, and metabolism-related pathways were enriched in high SUVmax patients. CONCLUSION: The genomic features of gene expression and pathways can be predicted by FDG uptake features in iCCA. Patients with high FDG uptake have enriched cell cycle, metabolism and hypoxic pathways, which may lead to a more rational targeted treatment approach.

Low Dose versus High Dose Radioiodine Therapy / 대한갑상선학회지

Since 1946, radioiodine (I-131) therapy has been one of the standard treatments for differentiated thyroid cancer (DTC). Recently the occurrence of thyroid cancer was markedly increasing and most of them were limited disease. Several reports said that there is no significant difference of outcome between low and high dose radioiodine therapy in patients with low to intermediate risk category of thyroid cancer. In this review, current effectiveness and toxicity of radioiodine ablation will be compared between low and high dose radioiodine in patient with low to intermediate risk DTC.

Effect of Isotretionin for Refractory Solid-pseudopapillary Tumor of the Pancreas which Previously did not Respond to Anticancer Drugs and Radiation Therapy / 계명의대학술지

Solid pseudopapillary neoplasm (SPN) of the pancreas is an exocrine tumor with low malignant nature. Although it's treatment of choice is complete surgical resection, the patients who are not eligible for surgical therapy need other kinds of therapy and there are little reports. Vitamin A and its derivatives in some tumors are known to be prohibiting the tumors' growth by reducing the manifestation of transcription factors. We present one case of SPN of the pancreas, which was not eligible for resection and was not responding to chemotherapy and radiation therapy, but, responded with the administration of Isotretionin (Roaccutan(R)). Therefore, for inoperable SPN of the pancreas, we consider Isotretionin therapy can be used as treatment and, in the future, new studies with more of Isotretionin treatment implemented cases should be conducted to identify their anticancer mechanism.

Recent Trends in Nuclear Cardiology Practice / 전남의대학술지

Over the past three decades, radionuclide myocardial perfusion scintigraphy (MPS) has become established as the main functional cardiac imaging technique for ischemic heart disease. It is currently appropriate for all aspects of detecting and managing ischemic heart disease, including diagnosis, risk assessment and stratification, assessment of myocardial viability, and evaluation of left ventricular function. The purpose of this article was to review recent trends in nuclear cardiology practice, excluding positron emission tomography. The past few years have brought several rapid developments that have increased photon sensitivity in nuclear cardiology scanner hardware. Additionally, software applying new methods of single photon emission tomography (SPECT) reconstruction on conventional and dedicated systems has preserved or even improved SPECT image quality with lower count statistics. On the other hand, much interest has been shown in lowering the radiation dose by the stakeholders of MPS.

Recent Trends in Nuclear Cardiology Practice / 전남의대학술지

Over the past three decades, radionuclide myocardial perfusion scintigraphy (MPS) has become established as the main functional cardiac imaging technique for ischemic heart disease. It is currently appropriate for all aspects of detecting and managing ischemic heart disease, including diagnosis, risk assessment and stratification, assessment of myocardial viability, and evaluation of left ventricular function. The purpose of this article was to review recent trends in nuclear cardiology practice, excluding positron emission tomography. The past few years have brought several rapid developments that have increased photon sensitivity in nuclear cardiology scanner hardware. Additionally, software applying new methods of single photon emission tomography (SPECT) reconstruction on conventional and dedicated systems has preserved or even improved SPECT image quality with lower count statistics. On the other hand, much interest has been shown in lowering the radiation dose by the stakeholders of MPS.

A Case of Cyclic Vomiting Syndrome Responding to Gonadotropin-Releasing Hormone Analogue

Cyclic vomiting syndrome (CVS) is a disorder characterized by recurrent episodes of incapacitating nausea and vomiting interspersed with symptom free periods. Common triggers of cyclic vomiting include noxious stress, excitement, fatigue and menstrual period. Here, we report a case of cyclic vomiting syndrome in adult patient characterized by stereotypical vomiting attack, occurring in every menstruation period. Recurrent vomiting episodes began 6 years ago and we treated this patient with subcutaneous injection of goserelin, a gonadotropin-releasing hormone analogue (GnRHa) and oral estrogen. After 4 months of therapy, she was symptom free for the following 5 years, even with the resumed normal menstruation. Recurrence of vom - iting attack with same pattern occurred 1 month before readmission. Treatment with intravenous lorazepam aborted vomiting, but could not prevent recurrences of vomiting and epigastric pain. We treated the patient with GnRHa and oral estradiol again which effectively prevented recurrence of the symptoms.

Efficacy Assessment of Endovascular Stenting in Patients with Unilateral Middle Cerebral Artery Stenosis Using Statistical Probabilistic Anatomical Mapping Analysis of Basal/Acetazolamide Brain Perfusion SPECT / 핵의학분자영상

PURPOSE: The aim of this study was to evaluate the hemodynamic changes after endovascular stenting in patients with unilateral middle cerebral artery (MCA) stenosis using statistical probabilistic anatomical mapping (SPAM) analysis of basal/acetazolamide (ACZ) Tc-99m ECD brain perfusion SPECT. MATERIALS AND METHODS: Eight patients (3 men and 5 women, 64.8+/-10.5 years) who underwent endovascular stenting for unilateral MCA stenosis were enrolled. Basal/ACZ Tc-99m ECD brain perfusion SPECT studies were performed by one-day protocol before and after stenting. Using SPAM analysis, we compared basal cerebral perfusion (BCP) counts and cerebrovascular reserve (CVR) index of the MCA territory before stenting with those after stenting. RESULTS: After stenting, no patient had any complication nor additional stroke. In SPAM analysis, 7 out of the 8 patients had improved BCP counts of the MCA territory and 7 out of the 8 patients had improved CVR index of the MCA territory after stenting. Before stenting, the mean BCP counts and CVR index in the affected MCA territory were 47.1+/-2.2 ml/min/100 g and -2.1+/-2.9%, respectively. After stenting, the mean BCP counts and CVR index in the affected MCA territory were improved significantly (48.3+/-2.9 ml/min/100 g, p=0.025 and 0.1+/-1.3%, p=0.036). CONCLUSION: This study revealed that SPAM analysis of basal/ACZ brain perfusion SPECT would be helpful to evaluate hemodynamic efficacy of endovascular stenting in unilateral MCA stenosis.

Radiation Induced Rib Fractures on Bone Scan after Breast Cancer Surgery and Radiation Therapy / 핵의학분자영상

PURPOSE: This study is to evaluate rib fractures on bone scan in breast cancer patients treated with breast cancer surgery and radiation therapy and to evaluate its relation with radiation therapy and operation modality. MATERIALS AND METHODS: Two hundred seventy cases that underwent serial bone scan after breast cancer surgery and radiation therapy were enrolled. Bone scan and chest CT findings of rib fracture were analyzed. RESULTS: The rib uptake was seen in 74 of 270 cases (27.4%) on bone scan and 50 cases (18.5%) were confirmed to have rib fracture by chest CT. The rate of modified radical mastectomy in patients with rib fracture was significantly higher than that in patients without rib fracture (66.0% vs. 27.0%, p=0.000). The rate of additional radiation therapy to axillar or supraclavicular regions in patients with rib fracture was significantly higher than that in patients without rib fracture (62.0% vs. 28.6%, p=0.000). Rib fracture was seen most frequently at 1-2 years after radiation therapy (51.9%) and single rib fracture was seen most frequently (55.2%). Of total 106 rib fractures, focal rib uptake was seen in 94 ribs (88.7%) and diffuse rib uptake was seen in 12 ribs (11.3%). On one year follow-up bone scan, complete resolution of rib uptake was seen in 15 ribs (14.2%). On chest CT, the rate of fracture line in ribs with intense uptake was significantly higher than that in ribs with mild or moderate uptake (p=0.000). The rate of presence of fracture line in ribs with focal uptake was significantly higher than that in ribs with diffuse uptake (p=0.001). CONCLUSION: Rib fracture in breast cancer patients after radiation therapy was related to radiation portal and operation modality. It should be interpreted carefully as a differential diagnosis of bone metastasis.

Diagnosis of Coronary Artery Disease Using Myocardial Perfusion SPECT / 핵의학분자영상

Myocardial perfusion scintigraphy is currently by far the most commonly performed cardiac nuclear study, constituting approximately one third of all nuclear medicine procedure. It plays an important role in the diagnosis, prognosis, risk assessment and management of heart disease. Aim of this review is to describe recent evolution of myocardial perfusion imaging on the focus of diagnosis of coronary artery disease. In addition, current status of other imaging modalities will be reviewed.

Added Value of 3D Cardiac SPECT/CTA Fusion Imaging in Patients with Reversible Perfusion Defect on Myocardial Perfusion SPECT / 핵의학분자영상

PURPOSE: Integration of the functional information of myocardial perfusion SPECT (MPS) and the morphoanatomical information of coronary CT angiography (CTA) may provide useful additional diagnostic information of the spatial relationship between perfusion defects and coronary stenosis. We studied to know the added value of three dimensional cardiac SPECT/CTA fusion imaging (fusion image) by comparing between fusion image and MPS. MATERIALS AND METHODS: Forty-eight patients (M:F=26:22, Age: 63.3+/-10.4 years) with a reversible perfusion defect on MPS (adenosine stress/rest SPECT with Tc-99m sestamibi or tetrofosmin) and CTA were included. Fusion images were molded and compared with the findings from the MPS. Invasive coronary angiography served as a reference standard for fusion image and MPS. RESULTS: Total 144 coronary arteries in 48 patients were analyzed; Fusion image yielded the sensitivity, specificity, negative and positive predictive value for the detection of hemodynamically significant stenosis per coronary artery 82.5%, 79.3%, 76.7% and 84.6%, respectively. Respective values for the MPS were 68.8%, 70.7%, 62.1% and 76.4%. And fusion image also could detect more multi-vessel disease. CONCLUSION: Fused three dimensional volume-rendered SPECT/CTA imaging provides intuitive convincing information about hemodynamic relevant lesion and could improved diagnostic accuracy.

F-18 FDG PET/CT Finding in Solid Pseudo-papillary Tumor of the Pancreas 6 years After Initial Diagnosis / 핵의학분자영상

Solid pseudo-papillary tumor (SPT) is a rare pancreatic neoplasm with low malignant potential, which tends to occur predominantly in younger females. Only a few cases of SPT seen on F-18 FDG PET scan have been reported, and the findings are not fully evaluated. A 33 year-old woman underwent F-18 FDG PET/CT study for staging of renal cell carcinoma. She was diagnosed with SPT of the pancreas 6 years ago, and has not had any treatment so far. Recent PET/CT showed marked F-18 FDG uptake in the peripheral solid portion and relatively less F-18 FDG uptake to the central calcified portion of SPT. We report one case of SPT of the pancreas on F-18 FDG PET/CT.

The Clinical Efficacy of Lung to Heart Ratio in 1 Hour Delayed Tc-99m Tetrofosmin Gated Myocardial SPECT after Adenosine Stress: Comparison with Coronary Angiography / 핵의학분자영상

PURPOSE: It is well known that lung to heart ratio (LHR) is one of the high risk findings in Tl-201 myocardial perfusion SPECT. We evaluated the clinical efficacy of LHR to identify severe coronary artery disease in adenosine stress Tc-99m tetrofosmin gated myocardial perfusion SPECT (gSPECT). MATERIALS AND METHODS: The study population was 157 patients who underwent both adenosine stress Tc-99m gSPECT and coronary angiography (CAG) within one month. According to the results of CAG and gSPECT LHR and the incidence of increased LHR were compared. RESULTS: Among 53 patients with normal coronary arteries increased LHR was found in 2 patients (3.8%) and 0 in 44 patients (0%) with one vessel disease, 2 in 27 with two vessel disease (7.4%) and 8 in 33 with triple vessel disease (24.2%). Significant differences were found in LHR between subgroups of summed stress score, summed rest score and LV ejection fraction (LVEF). There were weak negative correlation between LHR and LVEF and weak positive correlation between LHR and SSS and SRS. CONCLUSION: Increased LHR had higher incidence in patients with triple vessel disease, severe LV dysfunction and/or extensive perfusion defect than those of normal group. Although its sensitivity might be low to identify severe coronary artery disease, LHR could be helpful in abnormal myocardial perfusion SPECT to stratify risk and prognosis.

PET Imaging for Gynecologic Malignancy / 한양의대학술지

The utility of positron emission tomography (PET) in gynecologic malignancy has increased rapidly in recent years. This review examines publications in this area. PET scans in gynecologic malignancy are mostly performed using F-18 FDG. It is valuable in primary staging of untreated advanced cervical cancer, for post-treatment unexplained tumor marker elevation, and restaging of potentially curable recurrent cervical cancer. However, its value in early-stage cervical cancer is limited. In ovarian cancer, sequential imaging predicts response to neoadjuvant chemotherapy and survival. It is also very useful when increases in CA 125 or CT/MRI defined recurrence is noted, but biopsy deemed infeasible. The role of PET or PET/CT has evolved from a iagnostic tool into a potential indicator of response to treatment and prognosis. Evaluating PET or PET/CT using clinical impact is an attractive new endpoint.

Importance of Carbon Monoxide Transfer Coefficient (KCO) Interpretation in Patients with Airflow Limitation / 결핵및호흡기질환

BACKGROUND: The single-breath carbon monoxide diffusion capacity (DLCO) and the per unit alveolar volume (KCO; DLCO/VA) gave discordant values when there was an abnormal alveolar volume (VA). However, the clinical significance of the discordant values in patients with airflow limitation has not been examined. This study investigated the DLCO and KCO changes after improving the airflow limitation. METHOD: The baseline DLCO and KCO with lung volume were measured in patients with an airflow obstruction. The effective alveolar volume was measured using the single-breath CH4 dilution method. The patients divided into two groups according to the baseline values: (1) increased KCO in comparison with the DLCO (high discordance) (2) decreased or not increased KCO in comparison with the DLCO (low discordance). The diffusion capacity and lung volume were measured after treatment. RESULTS: There was no significant difference in the baseline lung volumes including the FEV1 and FVC between the two groups. The FEV1 and FVC were significantly increased in the high discordance group compared with the low discordance group after treating the airflow limitation. The DLCO and alveolar volume were significant higher in the high discordance group compared with the low discordance group while the TLC was not. CONCLUSION: The discordance between the DLCO and KCO could be translated into an airflow reversibility in patients with an airflow limitation