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Background Recent studies suggest that coexistence of chronic obstructive pulmonary disease (COPD) might be independently related to a worse prognosis for lung cancer. However, because data on the substantial prevalence of COPD and its severity in Asian lung cancer patients remain limited, clinical impact of prevalence and severity of COPD among the population has not been fully evaluated. Furthermore, patients with COPD often have comorbidities. Thus, whether the decision-making process for therapeutic management of lung cancer patients might be independently affected by COPD remains elusive. Methods Clinical impact of prevalence and severity of COPD were evaluated in 270 Japanese patients with newly diagnosed lung cancer who were sequentially registered and underwent bronchoscopy from August 2010 to July 2012 at Nagoya University hospital. Furthermore, to explore whether or not the severity of airflow obstruction might affect the decision to propose thoracic surgery with curative intent, we evaluated data from patients with lung cancer at stage 1A to 3A who underwent spirometry and bronchoscopy. Results The prevalence rate of COPD was 54.4% among Japanese patients with lung cancer who underwent bronchoscopy. The incidence of Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades 1 and 2 was significantly higher than that of GOLD grade 3. Although COPD-related comorbidities were not independent factors for proposing thoracic surgery, the number of thoracic surgeries performed was significantly less in the COPD group than the non-COPD group. Multivariate analysis showed that more severe airway obstruction, advanced clinical staging, and higher age, were independent factors associated with the decision on thoracic surgery. Conclusions We demonstrated a high prevalence of COPD among Japanese lung cancer patients. Based on the knowledge that severity of COPD is one of the most important factors in the therapeutic decision, comprehensive assessment of COPD at bronchoscopy might allow us to implement the optimum management for lung cancer patients.

We compared the efficacies of ¹⁸F-fluoride positron emission tomography (¹⁸F-fluoride PET)/CT, ¹⁸F-fludeoxyglucose PET (¹⁸F-FDG PET)/CT, and ⁹⁹mTc bone scintigraphy [planar and single photon emission CT (SPECT)] for the detection of bone metastases in patients with differentiated thyroid carcinoma (DTC).We examined 11 patients (8 females and 3 males; mean age 6 standard deviation, 61.968.7 years) with DTC who had been suspected of having bone metastases after total thyroidectomy and were hospitalized to be given ¹³¹I therapy. Bone metastases were verified either when positive findings were obtained on both ¹³¹I scintigraphy and CT or when MRI findings were positive if MRI was performed.Metastases were confirmed in 24 (13.6%) of 176 bone segments in 9 (81.8%) of the 11 patients. The sensitivities of ¹⁸F-fluoride PET/CT and ⁹⁹mTc bone scintigraphy (SPECT) were significantly higher than those of ¹⁸F-FDG PET/CT and ⁹⁹mTc bone scintigraphy (planar) (p,0.05). The accuracies of ¹⁸F-fluoride PET/CT and mTc bone scintigraphy (SPECT) were significantly higher than that of ⁹⁹mTc bone scintigraphy (planar) (p,0.05).The sensitivity and accuracy of ¹⁸F-fluoride PET/CT for the detection of bone metastases of DTC are significantly higher than those of ⁹⁹mTc bone scintigraphy (planar). However, the sensitivity and accuracy of ⁹⁹mTc bone scintigraphy (planar) are improved near to those of ¹⁸F-fluoride PET/CT when SPECT is added to a planar scan. The sensitivity of ¹⁸F-FDG PET/CT is significantly lower than that of 18F-fluoride PET/CT or ⁹⁹mTc bone scintigraphy (SPECT).

OBJECTIVES: To compare the accuracy of pulmonary lobar volumetry using the conventional number of segments method and novel volumetric computer-aided diagnosis using 3D computed tomography images. METHODS: We acquired 50 consecutive preoperative 3D computed tomography examinations for lung tumours reconstructed at 1-mm slice thicknesses. We calculated the lobar volume and the emphysematous lobar volume < �950 HU of each lobe using (i) the slice-by-slice method (reference standard), (ii) number of segments method, and (iii) semi-automatic and (iv) automatic computeraided diagnosis. We determined Pearson correlation coefficients between the reference standard and the three other methods for lobar volumes and emphysematous lobar volumes. We also compared the relative errors among the three measurement methods. RESULTS: Both semi-automatic and automatic computer-aided diagnosis results were more strongly correlated with the reference standard than the number of segments method. The correlation coefficients for automatic computer-aided diagnosis were slightly lower than those for semi-automatic computer-aided diagnosis because there was one outlier among 50 cases (2%) in the right upper lobe and two outliers among 50 cases (4%) in the other lobes. The number of segments method relative error was significantly greater than those for semi-automatic and automatic computer-aided diagnosis (P< 0.001). The computational time for automatic computeraided diagnosis was 1/2 to 2/3 than that of semi-automatic computer-aided diagnosis. CONCLUSIONS: A novel lobar volumetry computer-aided diagnosis system could more precisely measure lobar volumes than the conventional number of segments method. Because semi-automatic computer-aided diagnosis and automatic computer-aided diagnosis were complementary, in clinical use, it would be more practical to first measure volumes by automatic computer-aided diagnosis, and then use semi-automatic measurements if automatic computer-aided diagnosis failed.

Differentiation between metastasis-free pancreatic cancer and mass-forming pancreatitis is important to avoid unnecessary operative procedures. This study was aimed at evaluating the efficacy of PET/CT with F-FDG (FDG PET/CT) for the differential diagnosis between them.FDG-PET/CT was performed in 47 study patients with pancreatic masses and without any detectable metastases, 33 of which cases were finally diagnosed as pancreatic cancer and the other 14 as pancreatitis, and the corresponding imaging data were evaluated retrospectively. The maximal SUV (SUVmax) within the masses were determined at 1 hour and mostly at 2 hours after intravenous injection of FDG.SUVmax at 1 hour in pancreatic cancer was significantly higher than that in mass-forming pancreatitis, and the change in SUVmax from 1- to 2-hour time points was more consistent with pancreatic cancer than with mass-forming pancreatitis. However, there remained considerable overlapping between the SUVmax values of both diseases except either at the higher range for pancreatic cancer (7.7 at 1 hour or9.98 at 2 hours) or at the lower range for mass-forming pancreatitis (3.37 at 1 hour or3.53 at 2 hours). No obvious difference was found in the FDG uptake patterns of the mass areas between both diseases.Differentiation between metastasis-free pancreatic cancer and mass-forming pancreatitis is difficult by FDG-PET/CT due to considerable overlapping between the SUVmax values of the two diseases, although the differential diagnosis may be possible either at the higher range of SUVmax (7.7 at 1 hour or9.98 at 2 hours) for pancreatic cancer or at the lower range of SUVmax (3.37 at 1 hour or3.53 at 2 hours) for mass-forming pancreatitis.

Objectives In preoperative segmentectomy simulation for primary lung cancer, it is important to identify the intersegmental pulmonary veins and the relationship between them and the surgical safety margin. We have adopted a method that incorporates a virtual safety margin into three-dimensional computed tomography angiography images in order to plan adequate segmentectomy for lung cancer patients. In this study, we describe the new preoperative planning technique and review cases in which we performed segmentectomy based on its results. Methods We reviewed clinical, radiological, and pathological records and selected patients who underwent segmentectomy for a primary lung cancer lesion with a diameter of 2 cm or less. These segmentectomies were planned using preoperative three-dimensional computed tomography angiography with a virtual safety margin. Results A total of 17 primary lung cancers in 16 patients (11 male and 5 female, aged 52–82 years) were removed by segmentectomy, planned using the new technique. In 6 of 17 tumors (35%) were non-solid type adenocarcinomas, 3 tumors (18%) were partly solid type adenocarcinomas, 6 tumors (35%) were solid type adenocarcinomas and 2 tumors (12%) were squamous cell carcinomas. Pathological examination revealed no positive surgical margins and no lymph node metastases in any patients. Conclusions Three-dimensional computed tomography angiography with a virtual safety margin was able to non-invasively visualize the three-dimensional distances and the relationships between the primary tumor and intersegmental pulmonary veins. It was able to aid in the preoperative planning of a suitable segmentectomy procedure for patients with a primary lung cancer lesion of 2 cm or less in diameter.

A number of variations in the pulmonary arteries and veins have been documented, and the information is very important for performing a safe lung resection. This report describes a case of an anomalous segmental vein of the left upper lobe of the lung. The patient was a 75-year old male who was suspected to have lung cancer in the left upper lobe. A contrast-enhanced computed tomography showed a vessel behind the left lower bronchus. A three-dimensional computed tomography angiography demonstrated that it was an anomalous vein for the apicoposterior segment of the left upper lobe of the lung, draining into the left inferior pulmonary vein. The aberrant vein was readily identified during surgery and was divided without injury, and a left upper lobectomy was successfully performed. Aberrant pulmonary veins for the superior segment of the right upper lobe of the lung are rarely observed, and the same kind of anomaly on the left side has not been reported.

We compared the efficacy of whole-body MRI (WBMRI) with and without diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) using a 3.0-T MR scanner to [18F] fluoro-2-D-glucose positron emission tomography with CT (integrated FDG-PET/CT) for the detection of bone metastases in patients with differentiated thyroid carcinoma (DTC).We examined 23 patients (16 women, 7 men; mean age, 56; range 17-74) with DTC who had undergone total thyroidectomy and were hospitalised to receive [I-131I] therapy. All patients underwent both WBMRI with DWIBS and whole-body FDG-PET/CT. The skeletal system was classified into 13 anatomic segments and assessed for the presence of bone metastases. Bone metastases were verified when positive findings were indicated on at least two imaging modalities: post-treated [131I] whole-body scans, WBMRI without DWIBS (T1-weighted images and short-inversion time inversion recovery images), [18F]-FDG-PET and CT.Bone metastases were confirmed in 78/290 (27%) segments in 20 (87%) of 23 patients. The sensitivities for bone metastases on a segment basis using WBMRI with DWIBS, WBMRI without DWIBS and integrated FDG-PET/CT were 64 of 78 (82%), 50 of 78 (64%) and 62 of 78 (79%), respectively; the difference between values of WBMRI with and without DWIBS was statistically significant (P = 0.0015). The overall accuracies of WBMRI with DWIBS, WBMRI without DWIBS and integrated FDG-PET/CT were 273 of 290 (94%), 261 of 290 (90%) and 272 of 290 (94%), respectively; the difference between values of MRI with and without DWIBS was also statistically significant (P = 0.003). There were only one to three false positive segments and the difference among specificities was not statistically significant in these modalities.Adding DWIBS improved the sensitivity and the overall accuracy of WBMRI using 3.0-T MRI for the detection of bone metastases in patients with DTC. There was no statistically significant difference in diagnostic accuracy between MRI with DWIBS and integrated FDG-PET/CT.

Differentiated thyroid cancers (DTCs) are commonly treated by total thyroidectomy followed by I-131 radioiodine ablation to eradicate any residual thyroid tissue and to detect any metastatic lesions on post-treatment whole body scans (TxWBS). However, some DTCs do not trap iodine, resulting in negative whole body scanning. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) has proven to be a valuable diagnostic technique for detecting many types of malignant tumors and metastases. The purpose of this study was to evaluate FDG-PET performed concurrently with initial I-131 ablation for its ability to detect lymph node metastasis and for its role in the management of DTC patients. A total of 54 patients (16 males and 38 females; median age = 50 years) with histologically proven DTC underwent both FDG-PET and subsequent I-131 ablation. A dose of 3.7 GBq I-131 was administered to 51 patients, 2.96 GBq was administered to 1 patient, and 2.22 GBq was administered to 2 patients. FDG-PET or PET/CT was performed 3–4 days prior to ablation. TxWBS was conducted 1 week after therapy. FDG-PET scans and TxWBS were interpreted by consensus of 2 experienced radiologists. Serum thyroglobulin (Tg) levels at 3–6 months after ablation were compared between PET-positive and PET-negative patients. FDG-PET was positive in 25 sites (thyroid bed: n = 9; cervical lymph nodes: n = 12; mediastinal lymph nodes: n = 3; and axillary lymph nodes: n = 1) of 18 patients (33%). Only 5 of 16 lymph nodes (31%) that were PET-positive were also positive on TxWBS. The success rate of Tg-negative after ablation was significantly lower for patients with PET-positive scans than for those with PET-negative scans (p = 0.026). FDG-PET performed concurrently with I-131 ablation can detect lymph node metastases in which radioiodine does not accumulate and may influence the management and treatment options for DTC patients.

Three-dimensional computed tomography angiography (3D-CTA) is valuable for preoperative simulations for lung cancer. However, when using 3D-CTA alone, it is difficult to identify tumor safety margins, especially for a segmentectomy. We report 2 cases of primary lung cancer for which we performed segmentectomy based on preoperative simulations by 3D-CTA with virtual 3D safety margins. We found this technique easy to use for simulations and useful for safely performing segmentectomy for small tumors in lung cancer.

This paper presents a method for the automated anatomical labeling of bronchial branches extracted from 3D CT images based on machine learning and combination optimization. We also show applications of anatomical labeling on a bronchoscopy guidance system. This paper performs automated labeling by using machine learning and combination optimization. The actual procedure consists of four steps: (a) extraction of tree structures of the bronchus regions extracted from CT images, (b) construction of AdaBoost classifiers, (c) computation of candidate names for all branches by using the classifiers, (d) selection of best combination of anatomical names. We applied the proposed method to 90 cases of 3D CT datasets. The experimental results showed that the proposed method can assign correct anatomical names to 86.9% of the bronchial branches up to the sub-segmental lobe branches. Also, we overlaid the anatomical names of bronchial branches on real bronchoscopic views to guide real bronchoscopy.

Purpose: T1-shortening of labyrinthine fluid on 3-dimensional fluid-attenuated inversion recovery (3D-FLAIR) has been reported in many inner ear disorders. Although semi-quantitative assessment by simple signal intensity ratio between cochlear fluid and brain tissue has been tried, its feasibility using a multi-channel phased-array head coil with an inherently inhomogenous sensitivity distribution has not been fully evaluated. We evaluated the feasibility of measuring simple signal intensity ratio by correlating rapid T1 measurements using an inversion time (TI) scout sequence. Materials and Methods: We evaluated 10 patients with Meniere's disease and 4 patients with sudden deafness. Nine of the patients with Meniere's disease received a unilateral intratympanic injection of Gd-DTPA; the tenth patient received bilateral injections. The 4 patients with sudden deafness received a double-dose intravenous injection. Magnetic resonance (MR) images were obtained 24 hours after intratympanic injections and 4 hours after intravenous injections at 3 tesla using a 32-channel head coil. We measured the ratio (CM ratio) between the signal intensity of the perilymph in the cochlea (C) and that of the medulla oblongata (M) and correlated it with the null-point inversion time (TInull) obtained with the TI scout sequence. The TI scout consisted of 85 images obtained with TI values between 132.5 and 3087.5 ms at increments of 37.5 ms. Results: The correlation coefficient between TInull and the natural logarithm of the CM ratio was −0.88 (P

One important aspect of lung cancer staging is the assessment of mediastinal lymph nodes in 3-D chest computed tomography (CT) images. In the current clinical routine this is done manually by analyzing the 3-D CT image slice by slice to find nodes, evaluate them quantitatively, and assign labels to them for describing the clinical and pathologic extent of metastases. In this paper we present a method to automate the process of lymph node detection and labeling by creation of a mediastinal average image and a novel lymph node atlas containing probability maps for mediastinal, aortic, and N1 nodes. Utilizing a fast deformable registration approach to match the atlas with CT images of new patients, our method can maintain an acceptable runtime. In comparison to previously published methods for mediastinal lymph node detection and labeling it also shows a good sensitivity and positive predictive value.

T-helper (Th)-2 background in the lungs may favor the development of pulmonary fibrosis. We hypothesized that usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP), major pathologic patterns of chronic interstitial pneumonia, would have different expression profiles of T H 1 and T H 2 chemokines. Methods Total RNA was isolated from lung tissues obtained by surgical biopsy (18 cases of UIP and 29 cases of NSIP). The expression of ligands for CXCR3 [T H 1 cells chemoattractant: monokine induced by interferon (IFN)- γ (MIG), IFN- γ -inducible protein of 10 kD, and IFN-inducible T cell α chemoattractant] and ligands for CCR4 [T H 2 cells chemoattractant: thymus- and activation-regulated chemokine and macrophage-derived chemokine (MDC)] were analyzed by real-time reverse transcriptase polymerase chain reaction. Results MIG and IFNy-inducible protein of 10 kD expression were significantly higher in NSIP compared with UIP. MDC expression was increased in UIP compared with NSIP, although the difference was not significant. MIG/MDC is significantly elevated in NSIP but not UIP. Interestingly, MIG/MDC was significantly higher in NSIP group 3 (NSIP with extensive fibrosis) compared with UIP. Conclusions These results may indicate that these 2 diseases have a different pathophysiology. MIG/ MDC may be a useful marker to distinguish these 2 diseases.

We examined a 61-year-old woman with sudden left-side hearing loss accompanied by severe vertigo. High signal in the ampullar endolymph of the left semicircular canal on magnetic resonance (MR) fluid attenuated inversion recovery (3D-FLAIR) images suggested labyrinthine hemorrhage. The patient had been treated for chronic heart failure and prescribed 100 mg/day of acetylsalicylic acid (aspirin) for its antiplatelet effect. The 3D-FLAIR images demonstrated a small amount of focal hemorrhage in the labyrinthine fluid that may have been overlooked on T(1)-weighted images.

To enable volume visualization of endolymphatic hydrops of Ménière's disease via a volume rendering (VR) technique, a three-dimensional (3D) inversion-recovery (IR) sequence with real reconstruction (3D-real IR) sequence after intratympanic injection of Gd-DTPA was optimized for higher spatial resolution using a 32-channel head coil at 3T.Pulse sequence parameters were optimized using a diluted Gd-DTPA phantom. Then, 11 patients who had been clinically diagnosed with Ménière's disease and a patient with sudden hearing loss were scanned. Images were processed using commercially available 3D-VR software. 3D-real IR data was processed to produce endolymph and perilymph fluid volume images in different colors. 3D-CISS data was processed to generate total fluid volume images.While maintaining a comparable signal-to-noise ratio (SNR) and scan time, the voxel volume could be reduced from 0.4 x 0.4 x 2 mm(3) with a 12-channel coil to 0.4 x 0.4 x 0.8 mm(3) with a 32-channel coil. A newly-optimized protocol allowed the smooth, three-dimensional visualization of endolymphatic hydrops in all patients with Ménière's disease.Volumetrically separate visualization of endo-/perilymphatic space is now feasible in patients with Ménière's disease using an optimized 3D-real IR sequence, a 32-channel head coil, at 3T, after intratympanic administration of Gd-DTPA. This will aid the understanding of the pathophysiology of Ménière's disease.

Rationale Radioiodine therapy improves the survival of patients with pulmonary metastases of differentiated thyroid cancer (DTC). It is controversial whether the diagnostic whole-body I-131 scan (DWS) before therapy is essential. We determined whether DWS could predict the efficacy of I-131 therapy for pulmonary metastases. Methods We undertook a retrospective review of records of 42 patients (28 women and 14 men, mean age 52.7 years). The patients had received 62 rounds of I-131 therapy for lung metastases of DTC at our institution between June 2002 and June 2006. On the same day that the DWS (dose of 185 MBq) (5 mCi) was completed, the patient received I-131 therapy (dose of 3700-7400 MBq) (100-200 mCi). Post-therapy whole-body scans (PWS) were performed after 3 to 4 days and 7 to 8 days. For all therapies, chest CT images were obtained before I-131 therapy, and 3 and 6 months after therapy for evaluation of therapeutic effectiveness. In addition, serum thyroglobulin (Tg) values were measured before and after the radioiodine therapy for all treatments. Results In the group demonstrating I-131 accumulation for pulmonary metastases on DWS, 72% of patients showed a reduction of pulmonary metastases on follow-up CT. On the other hand, in the group that failed to accumulate I-131 on DWS, only 5% of patients showed a reduction of pulmonary metastases. After therapy, serum Tg levels decreased significantly in the group that initially showed accumulation of I-131 in DWS (P = 0.045). In contrast, no remarkable changes between pre- and post-therapy Tg levels were observed in patients who failed to accumulate I-131 in DWS. Conclusion A whole-body I-131 diagnostic scan before I-131 therapy has a predictive value for the efficacy of therapeutic radioiodine treatment for pulmonary metastases of differentiated thyroid cancer.

The aim of this study was to evaluate the accuracy of measurements of lung volumes reconstructed using three-dimensional computed tomographic (CT) imaging from thin-section multidetector-row CT images compared to standard pulmonary function testing.Preoperative three-dimensional CT images and pulmonary function test results of 64 patients with solitary pulmonary nodules who were considered candidates for lung resection were reviewed. On the three-dimensional CT images, total lung capacity (TLC(CTV)), emphysematous lung capacity (ELC(CTV)), and normal lung capacity (NLC(CTV)) were calculated. Total lung capacity (TLC), vital capacity, and forced expiratory volume in 1 second were measured using spirometry.There was a strong positive correlation between estimated TLC(CTV) and measured TLC values (r = 0.87, P.001). Estimated ELC(CTV) at the threshold value of -900 Hounsfield units was negatively correlated with forced expiratory volume in 1 second (r = -0.56, P.001). NLC(CTV) values were more strongly correlated with vital capacity values than TLC(CTV) values (r = 0.74, P.001).Lung volume calculated using three-dimensional CT volumetry was well correlated with lung volume measured using spirometry. Three-dimensional CT volumetry can be used to evaluate pulmonary function.

Intratympanic injection of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) has been reported as a procedure to visualize endolymphatic hydrops of Meniere's disease. We frequently noted that cerebrospinal fluid (CSF) in the internal auditory canal (IAC) was also enhanced after this procedure. The purpose of this study was to evaluate how frequently this occurs and to investigate the specific features of patients who lack this communication.A total of 25 patients with clinically suspected endolymphatic hydrops underwent the procedure. After 24 h, three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) and 3D constructive interference in steady state (3D-CISS) were performed. The presence of contrast enhancement in the CSF space of the fundus of the IAC was evaluated.The contrast ratio between CSF of the IAC fundus and cerebellar white matter on the injected side was 1.49 +/- 0.65, and that of the noninjected side was 0.32 +/- 0.16 (P0.01). Enhancement of the CSF space in the IAC fundus was seen in all but two subjects: one had enlarged endolymphatic duct and sac syndrome (EEDS), and the other had cochlear nerve agenesis. In these two patients, the cochlear modiolus seemed to be normal.Intratympanic Gd-DTPA administration can reveal permeability of the modiolus and might facilitate evaluation of functional abnormalities of the modiolus not detected by conventional imaging tests.

We investigated the possibility of using computer analysis of high-resolution CT images to radiologically classify the shape of pulmonary nodules. From a total of 107 HRCT images of solid, solitary pulmonary nodules with prior differentiation as benign ( n =55) or malignant ( n =52), we extracted the desired pulmonary nodules and calculated two quantitative parameters for characterizing nodules: circularity and second central moment. Using discriminant analysis for two thresholds in differentiating malignant from benign states resulted in a sensitivity of 76.9%, a specificity of 80%, a positive predictive value of 78.4%, and a negative predictive value of 78.6%.

We compared the efficacies of (18)F-FDG PET and (99m)Tc-bone scintigraphy for the detection of bone metastases in patients with differentiated thyroid carcinoma (DTC).We examined 47 patients (32 women, 15 men; mean age +/- SD, 57.0 +/- 10.7 y) with DTC who had undergone total thyroidectomy and were hospitalized to be given (131)I therapy. All patients underwent both whole-body (18)F-FDG PET and (99m)Tc-bone scintigraphy. The skeletal system was classified into 11 anatomic segments and assessed for the presence of bone metastases. Bone metastases were verified either when positive findings were obtained on2 imaging modalities--(201)Tl scintigraphy, (131)I scintigraphy, and CT--or when MRI findings were positive if vertebral MRI was performed.Bone metastases were confirmed in 59 of 517 (11%) segments in 18 (38%) of the 47 study patients. The sensitivities (visualization rate) for bone metastases on a segment basis using (18)F-FDG PET and (99m)Tc-bone scintigraphy were 50 of 59 (84.7%) and 46 of 59 (78.0%), respectively; the difference between these values was not statistically significant. There were only 2 (0.4%) false-positive cases in a total of 451 bone segments without bone metastases when examined by (18)F-FDG PET, whereas 39 (8.6%) were false-positive when examined by (99m)Tc-bone scintigraphy. Therefore, the specificities of (18)F-FDG PET and (99m)Tc-bone scintigraphy were 449 of 451 (99.6%) and 412 of 451 (91.4%), respectively; the difference between these values was statistically significant (P0.001). The overall accuracies of (18)F-FDG PET and (99m)Tc-bone scintigraphy were 499 of 510 (97.8%) and 458 of 510 (89.8%), respectively; the difference between these was also statistically significant (P0.001).The specificity and the overall accuracy of (18)F-FDG PET for the diagnosis of bone metastases in patients with DTC are higher than those of (99m)Tc-bone scintigraphy, whereas the difference in the sensitivities of both modalities is not statistically significant. In comparison with (99m)Tc-bone scintigraphy, (18)F-FDG PET is superior because of its lower incidence of false-positive results in the detection of bone metastases of DTC.

The BLADE and PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) techniques have been proposed to reduce the effect of head motion. Preliminary results have shown that BLADE also reduces pulsation artifacts from venous sinuses. The purpose of this study was to compare T1-weighted FLAIR acquired with BLADE (T1W-FLAIR BLADE) and T1-weighted spin-echo (T1W-SE) for the detection of contrast enhancement in a phantom and in patients with suspected brain lesions and to compare the degree of flow-related artifacts in the patients. A phantom filled with diluted Gd-DTPA was scanned in addition to 27 patients. In the phantom study, the peak contrast-to-noise ratio of T1W-FLAIR BLADE was larger than that of T1W-SE, and the position of the peak was shifted to a lower concentration. In patients, the degree of flow-related artifacts was significantly higher in T1W-SE. Among the 27 patients, 9 had metastatic tumor, and 18 did not. On a patient-by-patient basis, the sensitivity and specificity for the detection of metastatic lesions on axial T1W-SE were 100% and 55.6% respectively, while on axial T1W-FLAIR BLADE they were 100% and 100%. T1W-FLAIR BLADE seems to be capable of replacing T1W-SE, at least for axial post-contrast imaging to detect brain metastases.

To clarify whether the benefit of a reduced effective scan width obtained using a smaller pitch outweighs the disadvantage of increased noise in the application of a subsecond helical CT to mass screenings for lung cancer.Twenty-two helical CT scans of the lung were obtained in 11 healthy subjects using the following parameters: 1) scan 1 was performed at 120 kVp, 50 mA, 10-mm collimation, 1-second/rotation, helical pitch of 2.0; and 2) scan 2 was performed at 120 kVp, 50 mA, 10-mm collimation, 0.75-second/rotation, helical pitch of 1.5. Computer-generated nodules measuring 10 mm and 6 mm in diameter showing ground-glass opacity were superimposed on these images. The detectability of each nodule was evaluated by six blinded readers using ROC analysis.Detectability of the 6-mm nodules was significantly higher in scan 2 than in scan 1. Detectability of the 10-mm nodules was not significantly different between scans 1 and 2.The use of a smaller pitch by employing a subsecond rotation scan in a helical CT for lung cancer screenings improves the detection of small lesions without increasing either the scanning time or radiation dose.

To evaluate the degree of contrast enhancement and accuracy of imaging of the circulatory phase in the first-pass, second-pass, and third-pass acquisitions in the pancreato-biliary region with 1-mm collimation obtained by multislice computed tomography (CT).In 53 patients, two sequential acquisitions from the porta hepatis to the pancreas were performed during a single breath-hold, followed by a third-pass acquisition including the liver beginning 15 sec after the second-pass acquisition. Contrast enhancement in each acquisition was measured in the aorta, portal vein and its branches, and pancreas. Four experienced radiologists graded using four-point scoring whether or not each acquisition was appropriate for imaging of the arterial phase, pancreatic phase, and portal venous phase.Aortic enhancement was highest at the beginning of the second-pass acquisition. The portal and splenic veins and pancreas showed maximum enhancement in the second-pass acquisition, while the superior mesenteric vein showed maximum enhancement in the third-pass acquisition. In the visual assessment, significantly higher grades were achieved in the first-pass, second-pass, and third-pass acquisitions with regard to imaging of the arterial phase, pancreatic phase, and portal venous phase, respectively.Multislice CT permits the acquisition of three distinct circulatory phases (arterial, pancreatic, and portal venous phases) in the pancreatobiliary region with 1-mm collimation.

The object of this study was to evaluate the usefulness of high-resolution multiplanar reformatted (MPR) images obtained by multislice CT in demonstrating connection between pancreatic cystic lesions and the main pancreatic duct. The study included 27 lesions with connection to the main pancreatic duct and 12 lesions without. All but one of the former lesions were branch duct-type intraductal papillary mucinous tumors (IPMTs). Oblique and curved MPR images with 0.5 mm continuous slices were generated from pancreatic-phase axial images reconstructed with 0.5 mm or 1 mm thickness at 0.5 mm intervals over a 260 mm field of view. The diagnostic capabilities for demonstrating connection with the main pancreatic duct were compared among axial images, MPR images, and both axial and MPR images in combination using the Brier score. The diagnosis in MPR images for demonstrating connection was more certain than that in axial images (P

The value of automatic bolus tracking in late-arterial and portal-venous phase imaging of the liver with a multislice CT scanner as compared with fixed time-delay examination in patients without circulatory disturbances is evaluated. For the evaluation of known or suspected liver disease, 98 multiphase contrast-enhanced CT examinations including double late-arterial phase imaging were randomized into either scanning with a scan delay of 30 s from the beginning of contrast material injection or scanning with automatic bolus tracking. Contrast material was injected at 0.07 ml/kg body weight/s over 30 s. Contrast enhancement in each acquisition was measured in the aorta, portal vein, liver, pancreas and hepatocellular carcinomas. The density difference between hepatocellular carcinomas and the hepatic parenchyma was calculated. The mean time to the first-pass acquisition as determined by automatic bolus tracking was 29.6 s. No statistically significant difference was observed between the two groups either in any enhancement in any acquisition or in the lesion-to-liver density difference. The use of automatic bolus tracking in late-arterial and portal-venous phase hepatic CT does not significantly improve the degree of contrast enhancement in the aorta, portal vein, liver and pancreas or lesion-to-liver conspicuity in patients without circulatory disturbances.

The purpose of this study was to determine an optimal slice thickness that was efficient in differentiating malignant from benign solitary pulmonary nodules (SPNs) on high-resolution computed tomography (HRCT) images. For a total of 92 SPNs, four radiologist indicated their confidence level for the malignant or benign SPN on the CT images presented in 1-, 3-, and 5-mm slice thickness. HRCT could be used to differentiate more accurately the malignant nodules from the benign ones using 1-mm-thick sections than 3- or 5-mm-thick sections.

A method for changing the tube current during helical scanning was applied to low-dose computed tomography (CT) in the lung. The changing method resulted in significant equalization of image noise in various lung sections compared with that at scanning with constant tube current. Detectability of nodules was equivalent between 60 mA and the changing method, whereas degradation occurred at 20 mA. This method seems feasible for the low-dose CT of lung cancer screening. © RSNA, 2002

A new aluminum filter, 5.8 mm thick at the center, was designed. The effective energy, exposure dose, absorbed dose, and noise were measured by using low-dose technique, very low-dose technique with a conventional filter, and very low-dose technique with a new filter on a chest phantom. Accuracy of very low-dose computed tomography (CT) with a new filter was compared against standard helical CT in 40 patients and against chest radiography in 35 patients. Effective energies were 42.6 keV and 51.6 keV at a conventional filter and the new filter, respectively. Compared against 20mA with a conventional filter, exposure dose was reduced by 17%, and absorbed dose was equivalent, at 30 mA with the new filter. Noise was improved by 9%. Compared with standard helical CT, the sensitivity, specificity, and accuracy of very-low-dose helical CT were 100%, 88%, and 95%, respectively. Very-low-dose helical CT was found to be significantly superior to chest radiography in the detection of lung cancers. Using a smaller tube current and an appropriate filter allows a further reduction in radiation dose in helical CT for lung cancer screening.

To clarify the diagnostic efficacy of color soft-copy computed radiographic (CR) images of the chest in the detection of subtle pulmonary abnormalities. Twenty observers compared 87 soft-copy CR images on four types of CRT monitor (nonmagnified monochromatic CRT, magnified monochromatic CRT, nonmagnified color CRT, and magnified color CRT). Of 87 test images, 45 (including two identical sets of 12 images to test intraobserver variability) were abnormal and 42 (including two identical sets of 12 images) were normal. Of the 45 abnormal images, 15 showed subtle abnormalities, 15 showed mild abnormalities, and 15 showed obvious abnormalities. In the receiver operating characteristic (ROC) analyses, there were no statistically significant differences among the four types of CRT display formats in the detection of subtle abnormalities. Color CRT monitors can replace monochromatic CRT monitors without any loss in the ability to detect subtle interstitial lung disease.

Purpose: The goal of this work was to determine a radiologist's ability to detect solitary pulmonary nodules on helical CT using both video (cine) viewing and film-based viewing. Method: Sixty-five chest helical CT studies were reviewed. Six radiologists searched for 40 lung nodules on CT images presented in three formats. Film-based viewing of images at 10 and 5 mm increments was performed with a light box. Video viewing of the same examinations was performed in 5 mm increments at 2 frames/s. The area under the receiver operating characteristic curve (A z ) measured the observer's ability to detect nodules. Results: The A z was 0.948 for the video viewing, 0.844 for 5 mm increment film-based viewing, and 0.879 for 10 mm increment film-based viewing. There were no statistically significant differences. Conclusion: Lung nodules can be detected with similar detection rates when viewing conventional film or videotaped helical CT images. Videotaped images incur a lower cost, an important consideration in mass screening for lung cancer.

Objective:We compared the efficacies of 18F-fluoride positron emission tomography (18F-fluoride PET)/CT, 18F-fludeoxyglucose PET (18F-FDG PET)/CT, and 99mTc bone scintigraphy [planar and single photon emission CT (SPECT)] for the detection of bone metastases in patients with differentiated thyroid carcinoma (DTC).Methods:We examined 11 patients (8 females and 3 males; mean age ± standard deviation, 61.9 ± 8.7 years) with DTC who had been suspected of having bone metastases after total thyroidectomy and were hospitalized to be given 131I therapy. Bone metastases were verified either when positive findings were obtained on both 131I scintigraphy and CT or when MRI findings were positive if MRI was performed.Results:Metastases were confirmed in 24 (13.6%) of 176 bone segments in 9 (81.8%) of the 11 patients. The sensitivities of 18F-fluoride PET/CT and 99mTc bone scintigraphy (SPECT) were significantly higher than those of 18F-FDG PET/CT and 99mTc bone scintigraphy (planar) (p

Carney triad is a very rare condition with gastrointestinal stromal tumor, pulmonary chondroma, and extra-adrenal paragangliomas. We present the images of a patient with the complete triad, including total gastrectomy for gastrointestinal stromal tumor at the age of 13, and a left pneumonectomy for pulmonary chondroma at the age of 15. Results of F-18 FDG PET/CT that was performed at age of 22 for recurrent pulmonary chondroma also demonstrated new lesions in the neck, mediastinum, and abdomen representing extra-adrenal paragangliomas.