CT-guided pretreatment biopsy diagnosis in patients with thymic epithelial tumours: diagnostic accuracy and risk of seeding.

AIM: To investigate the diagnostic performance of computed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB) for thymic epithelial tumours (TETs) and the complication rate after PTNB including seeding after PTNB. MATERIALS AND METHODS: This retrospective study identified PTNBs for anterior mediastinal lesions between May 2007 and September 2021. The diagnostic performance for TETs and complications were investigated. The concordance of the histological grades of TETs between PTNB and surgery was evaluated. The factors associated with pleural seeding after PTNB were determined using Cox regression analysis. RESULTS: Of 387 PTNBs, 235 PTNBs from 225 patients diagnosed as TETs (124 thymomas and 101 thymic carcinomas) and 150 PTNBs from 133 patients diagnosed as other than TETs were included. The sensitivity, specificity, and accuracy for TETs were 89.4% (210/235), 100% (210/210), and 93.5% (360/385), respectively, with an immediate complication rate of 4.4% (17/385). The concordance rate of the histological grades between PTNB and surgery was 73.3% (77/105) after excluding uncategorised types of thymomas. During follow-up after PTNB (median duration, 38.8 months; range, 0.3-164.6 months), no tract seeding was observed. Pleural seeding was observed in 26 patients. Thymic carcinoma (hazard ratio [HR], 5.94; 95% confidence interval [CI], 2.07-17.08; p=0.001) and incomplete resection (HR, 3.29; 95% CI, 1.20-9.02; p=0.02) were associated with pleural seeding, while the biopsy approach type (transpleural versus parasternal) was not associated (p=0.12). CONCLUSIONS: Pretreatment biopsy for TETs was accurate and safe and may be considered for diagnosing TETs, particularly when the diagnosis is challenging and histological diagnosis is mandatory.

Identification of chronic obstructive pulmonary disease subgroups in 13 Asian cities.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a heterogeneous condition that can differ in its clinical manifestation, structural changes and response to treatment. OBJECTIVE: To identify subgroups of COPD with distinct phenotypes, evaluate the distribution of phenotypes in four related regions and calculate the 1-year change in lung function and quality of life according to subgroup. METHODS: Using clinical characteristics, we performed factor analysis and hierarchical cluster analysis in a cohort of 1676 COPD patients from 13 Asian cities. We compared the 1-year change in forced expiratory volume in one second (FEV1), modified Medical Research Council dyspnoea scale score, St George's Respiratory Questionnaire (SGRQ) score and exacerbations according to subgroup derived from cluster analysis. RESULTS: Factor analysis revealed that body mass index, Charlson comorbidity index, SGRQ total score and FEV1 were principal factors. Using these four factors, cluster analysis identified three distinct subgroups with differing disease severity and symptoms. Among the three subgroups, patients in subgroup 2 (severe disease and more symptoms) had the most frequent exacerbations, most rapid FEV1 decline and greatest decline in SGRQ total score. CONCLUSION: Three subgroups with differing severities and symptoms were identified in Asian COPD subjects.

Emphysematous phenotype is an independent predictor for frequent exacerbation of COPD.

SETTING: Frequent exacerbation is an important phenotype in chronic obstructive pulmonary disease (COPD), while emphysema is associated with many comorbidities and lung function decline. OBJECTIVE: To investigate unique features of frequent exacerbators and test the hypothesis that emphysematous phenotype is associated with frequent exacerbations of COPD. METHODS: A total of 380 COPD patients were recruited from 16 hospitals in Korea from June 2005 to April 2012 for analysis. We searched for independent predictors of frequent exacerbators in comparison with non-exacerbators. RESULTS: As the severity of emphysema increased, forced expiratory volume in 1 s (FEV1), and FEV1/FVC (forced volume capacity) worsened; hyperinflationary features characterised by higher total lung capacity (TLC) were observed (P < 0.05). Frequent exacerbators had lower body mass index (BMI), higher St George's Respiratory Questionnaire (SGRQ) scores, higher residual volume (RV)/TLC, more severe airflow limitation (lower FEV1 and FEV1/FVC), lower carbon monoxide diffusion capacity, lower serum protein levels and a higher emphysema index than non-exacerbators (P < 0.05). In multivariate analysis, frequent exacerbators were independently associated with a higher emphysema index, lower serum protein levels and higher RV/TLC (P < 0.05). CONCLUSION: Our data show that the severity of emphysema, severe static hyperinflation and serum lower protein levels are independent predictors of frequent exacerbations in COPD patients.

CT findings of pulmonary non-tuberculous mycobacterial infection in non-AIDS immunocompromised patients: a case-controlled comparison with immunocompetent patients.

OBJECTIVE: To describe CT findings of non-tuberculous mycobacteria (NTM) pulmonary infection in non-AIDS immunocompromised patients (ICPs) and to compare these findings with those in immunocompetent patients. METHODS: From July 2000 to August 2007, 369 patients (mean age 58.3 years; 169 males and 200 females) with pulmonary NTM infection were retrospectively reviewed. Of these 369 patients, 24 ICPs (mean age 64.8 years; 15 males and 9 females) were identified. 16 patients had diabetes mellitus, and 6 patients had received long-term steroid therapy. One had received solid organ transplantation and one had received high-dose chemotherapy for haematological disease. 24 age- and sex-matched immunocompetent patients (mean age 64.6 years; 15 males and 9 females) were selected as the control group from the same registry. CT images were reviewed in consensus by three chest radiologists, who were blinded to immune status. Each lung lobe was evaluated in terms of extent of the lesion, bronchiectasis, parenchymal opacity and the presence of ancillary findings. results: A total of 287 lobes were evaluated in ICPs and the control group. The ICPs showed a higher prevalence of ill-defined nodules, with cavities and large opacity >2 cm with/without cavity (p=0.03, 0.04 and 0.02, respectively). Regardless of the immune status, the most common CT findings were bronchiectasis and ill-defined nodules without cavity. CONCLUSION: The most common CT findings of pulmonary NTM infection in ICPs were bronchiectasis and ill-defined nodules, similar to those in the control group. Ill-defined nodules with cavity and large opacity >2 cm with/without cavity were more frequently found in ICPs. ADVANCES IN KNOWLEDGE: In patients affected by NTM infection, large opacities and cavitation in pulmonary nodules are more frequent in ICPs than in immunocompetent patients.

Analysis of initial and follow-up CT findings in patients with invasive pulmonary aspergillosis after solid organ transplantation.

AIM: To assess initial and follow-up CT findings of invasive pulmonary aspergillosis (IPA) in solid organ transplant (SOT) recipients using new diagnostic criteria, and to compare initial CT findings of survivors with those of patients who died. MATERIALS AND METHODS: Forty-six adult SOT patients who met the 2008 EORTC/MSG criteria for proven or probable invasive pulmonary aspergillosis were assessed. Initial CT findings of the 21 survivors and 15 patients who died of IPA-related causes were compared using the internationally recognized thoracic glossary of terms. The extents of the largest lesions in each of 18 surviving were measured and changes of those lesions were recorded. RESULTS: Consolidation or mass was the most common finding, observed in 33 of 46 patients (72%), followed by large nodules (59%), ground-glass opacity (50%), and infarcted consolidation (48%). Consolidation or mass was significantly less frequent in survivors than in patients who died (62% versus 93%). Cavitation was more common (43% versus 13%), and significantly smaller (7.5 cm(2) versus 19 cm(2), p = 0.014) in survivors. Follow-up CT in survivors showed that the halo sign resolved rapidly within 4 weeks. The extent of consolidation, infarcted consolidation, and internal low-density area decreased gradually with time to reduce to half the size in 3 weeks. Large nodules persisted for the first 7 days (84%), followed by slow regression. CONCLUSION: Consolidation or mass is the most common CT finding of IPA in SOT recipients. Absence of consolidation or mass and presence of small cavities may be associated with better prognosis. The time for resolution of each pattern after treatment varies.

Different therapeutic responses in chronic obstructive pulmonary disease subgroups.

SETTING: Eleven referring hospitals in South Korea. OBJECTIVE: To compare therapeutic responses in chronic obstructive pulmonary disease (COPD) subgroups, classified by diffusing capacity of the lung for carbon monoxide (DL(CO)) and lung volume. DESIGN: A total of 130 stable male COPD patients were classified into four subgroups according to baseline DL(CO) and residual volume/total lung capacity (RV/TLC) ratio. We compared therapeutic responses to short acting ß(2)-agonist (SABA) and 3-month combined inhalation of long-acting ß(2)-agonist (LABA) and corticosteroid among patients with these subgroups. RESULTS: Among the 130 COPD patients, 41 (31.5%) had normal DL(CO) and RV/TLC, 28 (21.5%) low DL(CO) and normal RV/TLC, 31 (23.8%) normal DL(CO) and high RV/TLC, and 30 (23.1%) low DL(CO) and high RV/TLC. The normal DL(CO)/high RV/TLC subgroup showed a significantly larger flow response (changes in forced expiratory volume in 1 s) to salbutamol than the normal DL(CO)/RV/TLC subgroups, and a larger volume response (changes in forced vital capacity) than the two normal RV/TLC subgroups. The normal DL(CO)/high RV/TLC subgroup also showed significantly larger flow and volume response to 3-month combined inhalation of LABA and corticosteroid than the two normal RV/TLC subgroups. CONCLUSION: COPD subgroups classified by DL(CO) and RV/TLC may have different pulmonary function responses to pharmacological treatment.

Pulmonary artery pressure in chronic obstructive pulmonary disease without resting hypoxaemia.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) can lead to pulmonary hypertension and cor pulmonale, which are predictors of mortality. OBJECTIVE: To identify predictors of increased pulmonary artery pressure (PAP) in COPD patients without resting hypoxaemia, and to characterise COPD patients with increased PAP. DESIGN: A study of 117 COPD patients from the Korean Obstructive Lung Disease (KOLD) cohort who had measurable tricuspid regurgitant flow under transthoracic Doppler echocardiography and no resting hypoxaemia. RESULTS: The mean patient age was 67 years. Mean forced expiratory volume in 1 second (FEV(1)) was 47% predicted, mean haemoglobin (Hb) concentration was 145 g/l and mean systolic PAP (sPAP) was 33 mmHg. Multiple linear regression analysis showed that Hb was the only factor independently associated with sPAP (beta = -1.752, P = 0.005). Cluster analysis using FEV(1)% predicted, sPAP and Hb concentration as variables indicated three patient clusters: Cluster 1 (n = 36; mean FEV(1) 44% predicted, mean sPAP 39 mmHg, mean Hb 132 g/l), Cluster 2 (n = 45; FEV(1) 35% predicted, sPAP 31 mmHg, Hb 154 g/l), and Cluster 3 (n = 36; FEV(1) 65% predicted, sPAP 29 mmHg, Hb 148 g/l). CONCLUSION: Elevated PAP was linked to low haemoglobin levels in COPD without resting hypoxaemia.

Three phenotypes of obstructive lung disease in the elderly.

SETTING: Eleven referring hospitals in South Korea. OBJECTIVE: To classify the phenotypes in elderly subjects with obstructive lung disease (OLD). METHODS: We analysed 191 subjects aged ≥ 60 years with chronic respiratory symptoms and either obstructive spirometry or bronchial hyperresponsiveness. Factor analysis was performed using commonly measured variables and revealed four significant variables: 1) the ratio of inspiratory capacity to total lung capacity, 2) the total score on the St George's Respiratory Questionnaire, 3) the volume fraction of the lung less than 950 Hounsfield Unit at full inspiration on volumetric computed tomography and 4) post-bronchodilator forced expiratory volume in 1 second (FEV(1)) changes. We performed a cluster analysis on these four variables. RESULTS: The mean age was 68.5 (± 5.2 SD) years and the mean post-bronchodilator FEV(1) was 52.4% (± 16.5) predicted. Three clusters with the following phenotypes were identified: Cluster 1 included subjects with moderate to severe airflow obstruction and bronchodilator reversibility; Cluster 2 subjects had moderate airflow obstruction without bronchodilator reversibility, and Cluster 3 subjects had severe airflow obstruction without bronchodilator reversibility. CONCLUSIONS: We identified three phenotypes in elderly subjects with OLD. Follow-up studies are needed to explore the clinical significance of each phenotype.

Radiological findings and clinical features of thoracic immunoglobulin G4-positive plasma cell granuloma: two cases.

Plasma cell granulomas, inflammatory pseudotumours and myofibroblastomas are synonymous with characteristic plasma cell infiltration in various body organs including the pancreas, liver, retroperitoneum and mediastinal structures causing idiopathic fibrosclerosis. Recently, a new concept has arisen regarding the relationship between immunoglobulin (Ig)G4-positive cell infiltration and idiopathic systemic fibrosclerosis. We report two cases showing IgG4-positive cell infiltration in the lung presenting as lung nodules with or without extrapulmonary manifestations.

Radiological and clinical findings of pulmonary aspergillosis following solid organ transplant.

AIM: To evaluate the radiological and clinical findings in patients with pulmonary aspergillosis after solid organ transplantation. MATERIALS AND METHODS: This study included 13 consecutive patients (five liver, four kidney, and four heart transplant; 10 male and three female; median age 54 years; range 13-63 years) with histologically confirmed pulmonary aspergillosis after solid organ transplantation at a tertiary referral hospital. Chest radiographs and computed tomography (CT) examinations performed for diagnosis were available in all patients. Radiological findings, such as lesion characteristics, location, and associated findings, were assessed retrospectively by two radiologists. The changes in radiological findings and clinical response after treatment were also assessed. Clinical findings, such as time of onset, initial symptoms, clinical course, and laboratory findings, were reviewed. RESULTS: The most common radiographic and CT findings were pulmonary nodules or masses (n=12). The number of nodules or masses was less than 10 in eight patients. Associated findings were surrounding ground-glass opacity (n=4), central low density (n=8), central air cavity (n=5), and air bronchogram (n=3). Follow-up radiographs and/or CT after treatment showed improvement in eight patients, persistence in two, and deterioration in three. The onset time of pulmonary aspergillosis was a median of 32 days (range 15-165 days). The most common symptom at diagnosis was fever (n=6). Ten of 13 patients did not have leucopaenia. There were two aspergillosis-associated deaths during the follow-up period. CONCLUSION: The most common radiological finding of pulmonary aspergillosis after solid organ transplantation is multiple nodules or masses, which commonly appear within 1 month following transplantation.

Newly developed ulcer-like projection (ULP) in aortic intramural haematoma on follow-up CT: is it different from the ULP seen on the initial CT?

AIM: To show whether the clinical and radiological features of newly developed ulcer-like projections (nULPs) in an aortic intramural haematoma (IMH) on follow-up computed tomography (CT) images, are different from those of the initial ULPs (iULPs) on the initial CT images. MATERIALS AND METHODS: A review of the radiological database revealed 98 patients with IMH with at least two follow-up CT examinations with a follow-up period of more than 1 month. The patients were divided into four groups: patients without iULPs or nULPs throughout the follow-up periods (group A); patients with iULPs on the initial CT images (group B); patients with nULPs on follow-up CT images but without iULPs on the initial CT images (group C); and patients with both iULPs and nULPs (group D). The type of IMH, aortic diameter, thickness of the haematoma, and complications were analysed. The clinical and CT findings and complications in the four groups were compared. RESULTS: Forty-two patients had no iULPs nor nULPs (group A); 27 patients had 45 iULPs on the initial CT images (group B); 16 patients had 17 nULPs on follow-up CT images without any ULP on the initial CT images (group C); and 21 nULPs developed in 13 patients with iULPs (group D). There was no significant difference in the demographic or initial CT findings in the four groups. There was no statistical difference in the incidence of complications between groups B (59.3%), group C (62.5%), and group D (69.2%; p=0.830), but there was a significant difference in the incidence of complications between the patients without any ULPs (21.5% in group A) and those with ULPs (62.5% in groups B, C, and D). CONCLUSION: There were no significant differences in the CT findings or complications between the patients with iULPs and nULPs. Regardless of the developing time of the ULPs, the incidence of complications of IMH in patients with ULPs was higher than that in those without ULPs. Careful and regular follow-up CT examinations are needed for patients with ULPs.

Myocardial enhancement pattern in patients with acute myocardial infarction on two-phase contrast-enhanced ECG-gated multidetector-row computed tomography.

AIM: To evaluate the myocardial enhancement pattern of the left ventricle on two-phase contrast-enhanced electrocardiogram (ECG)-gated multidetector computed tomography (MDCT) images in patients with acute myocardial infarction (AMI). METHODS: Two-phase contrast-enhanced ECG-gated MDCT examinations were performed in 16 patients with AMI. The presence, location and pattern of myocardial enhancement were evaluated. MDCT findings were compared with the catheter angiographic results. RESULTS: Subendocardial (n = 9) or transmural (n = 6) area of early perfusion defects of the myocardium was detected in 15 of 16 patients (94%) on early-phase CT images. Variable delayed myocardial enhancement patterns on late-phase CT images were observed in 12 patients (75%): (1) subendocardial residual perfusion defect and subepicardial late enhancement (n = 6); (2) transmural late enhancement (n = 1); (3) isolated subendocardial late enhancement (n=1); and (4) isolated subendocardial residual perfusion defect (n = 2). On catheter angiography, 14 of 15 corresponding coronary arteries showed significant stenosis. CONCLUSION: Variable abnormal myocardial enhancement pattern was seen on two-phase, contrast-enhanced ECG-gated MDCT in patients with AMI. Assessment of myocardial attenuation on CT angiography gives additional information of the location and extent of infarction.

Case report: pericardial rupture and cardiac herniation after blunt trauma: a case diagnosed using cardiac MRI.

Pericardial rupture following blunt chest trauma is rare, and is not usually diagnosed pre-operatively. If pericardial rupture is not recognized and treated promptly, it may be fatal owing to cardiac herniation. We report a case of traumatic herniation of the heart for which a CT scan and MRI made a major contribution to the diagnosis.

Comparison of contrast-enhanced ct angiography and gadolinium-enhanced MR angiography in the detection of subsegmental-sized pulmonary embolism. An experimental study in a pig model.

PURPOSE: To compare contrast-enhanced CT angiography (CTA) and gadolinium-enhanced MR angiography (MRA) for the detection of subsegmental-sized pulmonary emboli in a pig model. MATERIAL AND METHODS: In 5 anesthetized pigs, 3-mm diameter embolic materials made of Konjac, a semisolid food, were introduced through the internal jugular vein into pulmonary arteries. After embolization, CTA and MRA images were obtained. Respiration was suspended during CTA and MRA image acquisition. Two readers reviewed the CTA and MRA images to detect emboli. The pigs were sacrificed, and sliced specimens of inflated lung served as the gold standard. RESULTS: Thirty-six emboli were detected within peripheral arteries. The sensitivity (and 95% confidence intervals) of CTA for the two readers were 57% (39-74%) and 66% (48-81%), and 88% (69-98%) and 92% (74-94%) for MRA. The specificity of CTA was 95% (91-97%) and 98% (96-99%), and that of MRA was 85% (74-93%) and 90% (80-96%). Interobserver agreement was higher for MRA (kappa 0.898) than CTA (kappa 0.574). CONCLUSION: For the detection of subsegmental pulmonary emboli, MRA was superior to CTA, with a higher sensitivity and interobserver agreement by demonstrating perfusion deficits.

Spinal deformities in Noonan syndrome: a clinical review of sixty cases.

BACKGROUND: Skeletal abnormalities, including spinal deformities, in Noonan syndrome have been described, but no detailed and systematic study of such spinal deformities has been presented in the literature. METHODS: The cases of sixty patients with Noonan syndrome were reviewed retrospectively, and the general appearance, growth disturbance, and mental status of the patients were documented. Spinal deformities were evaluated radiographically, and the frequency, pattern, and severity of the curves were documented. RESULTS: Spinal deformity was present in eighteen (30%) of the sixty patients. Two patients had congenital spinal deformity. Of the remaining sixteen patients with scoliosis, nine had a single thoracic curve, four had a single thoracolumbar curve, and three had a double major curve. Thoracic lordosis was also present in three of these sixteen patients. No patient had only increased kyphosis or lordosis. The mean age when the spinal deformities were detected was nine years; seven deformities were detected before the age of seven years. Overall, surgery was recommended to eleven of the eighteen patients; it was recommended for the treatment of scoliosis (mean, 68.5 degrees; range, 45 degrees to 125 degrees ) in eight patients and for the treatment of an associated thoracic lordosis (8 degrees, 15 degrees, and 18 degrees ) in three. Seven of the eleven patients underwent spinal arthrodesis. The operation was deferred in one patient because malignant hyperthermia developed during the induction of anesthesia. CONCLUSIONS: Scoliosis with an associated thoracic lordosis occurs more frequently in Noonan syndrome than has been reported previously. Since the deformities tend to develop early and are relatively severe, a clinical and, if necessary, radiographic assessment of the spine with careful follow-up should be performed for early detection and treatment of spinal deformity. Although malignant hyperthermia is rare, all patients with Noonan syndrome should be considered to be at risk for the development of this complication before operative treatment.

Atypical pulmonary metastases: spectrum of radiologic findings.

Typical radiologic findings of a pulmonary metastasis include multiple round variable-sized nodules and diffuse thickening of interstitium. In daily practice, however, atypical radiologic features of metastases are often encountered that make distinction of metastases from other nonmalignant pulmonary diseases difficult. A detailed knowledge of the atypical radiologic features of a pulmonary metastasis with a good understanding of the histopathologic background is essential for correct diagnosis. Squamous cell carcinoma is regarded as the most common cell type of a cavitating metastasis, but metastatic nodules from adenocarcinomas and sarcomas also cavitate occasionally. Calcification can occur in a metastatic sarcoma or adenocarcinoma, which makes differentiation from a benign granuloma or hamartoma difficult. Peritumoral hemorrhage results in areas of nodular attenuation surrounded by a halo of ground-glass opacity. Pneumothorax commonly occurs in metastases from an osteosarcoma. Air-space consolidation is often seen in cases of metastases from gastrointestinal tract malignancies. Even though tumor emboli in pulmonary arteries can be seen at computed tomography, diagnosis is difficult because they are located in small or medium arteries. A common radiologic appearance of an endobronchial metastasis is an atelectasis. In cases of an endobronchial or a solitary pulmonary metastasis, differentiation between bronchogenic carcinoma and metastasis is difficult. Dilated vascular structures within the mass can be seen in metastatic sarcomas. A sterilized metastasis after chemotherapy is radiologically indistinguishable from a residual viable tumor. Benign tumors such as uterine leiomyomas and giant cell tumors of the bone rarely metastasize to the lung.

Renal and pulmonary lymphangioleiomyomatosis: a case report.

Lymphangioleiomyomatosis (LAM) is a rare disease that most commonly involves the lung. However, extrapulmonary lymphangioleiomyomatosis rarely occurs with or without subsequent involvement of the lung. We report a case of incidentally found renal and pulmonary lymphangioleiomyomatosis in a patient who had no stigmata of tuberous sclerosis.

Digital chest radiography with a selenium-based flat-panel detector versus a storage phosphor system: comparison of soft-copy images.

OBJECTIVE: We compared the soft-copy images produced by a digital chest radiography system that uses a flat-panel X-ray detector based on amorphous selenium with images produced by a storage phosphor radiography system for the visualization of anatomic regions of the chest. MATERIALS AND METHODS: Two chest radiologists and two residents analyzed 46 pairs of posteroanterior chest radiographs on high-resolution video monitors (2560 x 2048 x 8 bits). In each pair, one radiograph was obtained with a storage phosphor radiography system, and the other radiograph was obtained with a selenium-based flat-panel detector radiography system. Each pair of radiographs was obtained at the same exposure settings. The interpreter rated the visibility and radiographic quality of 11 different anatomic regions. Each pair of images was ranked on a five-point scale (1 = prefer image A, 3 = no preference, 5 = prefer image B) for preference of technique. Statistical significance of preference was determined using the Wilcoxon's signed rank test. RESULTS: The interpreters had a statistically significant preference for the selenium-based radiography system in six (unobscured lung, hilum, rib, minor fissure, heart border, and overall appearance) of 11 anatomic regions (p<0.001) and for the storage phosphor system in two regions (proximal airway and thoracic spine) (p<0.05). Chest radiologists strongly preferred selenium-based images in eight regions, and they did not prefer storage phosphor images in any region. CONCLUSION: The soft-copy images produced by the selenium-based radiography system were perceived as equal or superior to those produced by the storage phosphor system in most but not all anatomic regions.

Pulmonary tuberculoma evaluated by means of FDG PET: findings in 10 cases.

PURPOSE: To describe findings of pulmonary tuberculoma at 2-[fluorine 18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET). MATERIALS AND METHODS: Ten consecutive patients who underwent PET and subsequently were proved to have pulmonary tuberculoma were analyzed. Tuberculosis was proved histopathologically in eight by means of wedge resection or lobectomy (n = 7) or needle biopsy (n = 1) and in two by means of clinical follow-up for more than 2 years. PET scans were evaluated by using peak standardized uptake values. Computed tomographic (CT) and histopathologic findings also were reviewed. RESULTS: Nine of 10 tuberculomas showed FDG uptake at PET, and the mean peak standardized uptake value was 4.2 +/- 2.2 (SD). FDG uptake (range, 1. 9-3.7) in lesions adjacent to main abnormalities was demonstrated in four patients. On CT scans, the mean of the longest nodule diameters was 21 mm +/- 8, and there were some areas of branching linear opacities or satellite nodules that suggested pulmonary tuberculosis in seven patients. Histopathologic findings were chronic granulomatous inflammation with caseation necrosis (n = 7) and healed tuberculosis with aspergilloma (n = 1). CONCLUSION: Pulmonary tuberculoma commonly causes an increase in FDG uptake. These results suggest that in geographic regions with a high prevalence of granulomatous lesions, positive FDG PET results should be interpreted with caution in differentiating benign from malignant pulmonary abnormalities.

Factors influencing vascular and hepatic enhancement at CT: experimental study on injection protocol using a canine model.

PURPOSE: The purpose of this work was to evaluate the effects of contrast medium injection parameters on aortic, portal vein, and hepatic enhancement at spiral CT and to assess optimal injection protocol for hepatic CT. METHOD: Ten 15 kg dogs underwent single level dynamic CT through the hepatic hilum at 5 s intervals just after the injection of contrast medium for 3 min. With use of different volumes (1, 2, and 3 ml/kg), injection rates (0.5, 1, and 2 ml/s), and concentrations (150, 200, and 300 mg/ml), a total of 270 spiral CT scans were performed. In each scan, time-attenuation curves of aorta, portal vein, and liver were obtained. The degree of maximum contrast enhancement (Imax), time to maximum enhancement (Tmax), and time to equilibrium phase (Teq) for to each injection protocol were analyzed. RESULTS: Alterations in contrast material volume, injection rate, and concentration had significant impact on contrast enhancement of the liver. With increasing volume of contrast medium, Imax, Tmax, and Teq of aorta, portal vein, and liver increased (p < 0.005). With increasing rate of injection, on the other hand, Imax of aorta and liver increased (p < 0.05), but Tmax and Teq decreased (p < 0.005). Change of concentration of contrast medium had a significant effect on Imax of vessels (p < 0.05). CONCLUSION: Maximum contrast enhancement of liver and vessels was influenced mainly by injection volume of contrast medium and the time to peak enhancement by injection rate of contrast medium. Under given amounts of contrast medium, therefore, the strategy of increasing volume by dilution and faster injection might give better Imax values without penalty for the duration of an optimal temporal window (Tmax and Teq).