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Biomedical subjects

Naofumi Matsunaga

Publications and source records attributed to Naofumi Matsunaga.

At least 19 recordsLinked to original sources
PubMed2007

Correlation between diffusion in lumbar intervertebral disks and lumbar artery status: evaluation with fresh blood imaging technique.

PURPOSE: To evaluate the correlation of the lumbar artery status with the diffusion values in lumbar vertebral disks in patients with low back problems using a fresh blood imaging (FBI) technique. MATERIALS AND METHODS: First, both digital subtraction angiography (DSA) and MR angiography (MRA) was performed, and the weighted kappa value between DSA and MR angiography in evaluating the status of lumbar arteries was calculated. Then, The sagittal diffusion-weighted MR images in 260 intervertebral disks (L1-2 to L4-5) and MR angiographic images using FBI technique in the corresponding 260 lumbar artery pairs (total of 520 arteries) of the 65 patients with low back problems were separately evaluated by two radiologists. RESULTS: The weighted kappa value between DSA and MRA in evaluating the status of lumbar arteries in both observes indicated good agreement. There were significant correlations between the status of lumbar arteries and the ADC values of the lumbar disks in all orthogonal directions (x, y, and z) at all intervertebral levels except L4-5 by both observers (P < 0.001). CONCLUSION: There is a strong association between the diminished flow in lumbar arteries and the decreased diffusion of lumbar intervertebral disks at all intervertebral levels except at L4-5.

Adult↗
PubMed2007

Small hepatic lesions found on single-phase helical CT in patients with malignancy: diagnostic capability of breath-hold, multisection fluid-attenuated inversion-recovery (FLAIR) MR imaging using a half-fourier acquisition single-shot turbo spin-echo (HASTE) sequence.

PURPOSE: To evaluate the diagnostic capability of breath-hold, multisection fluid-attenuated inversion-recovery (FLAIR) imaging using a half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence in combination with T2-weighted fast spin-echo (FSE) magnetic resonance (MR) sequences for small hepatic lesions found on CT in patients with malignancy. MATERIALS AND METHODS: This study included 48 patients with extrahepatic malignancy who underwent both CT and MR examinations. There were a total of 112 small hepatic lesions (73 cysts and 39 liver metastases, <2 cm in diameter) that showed low attenuation on enhanced CT. Three radiologists independently reviewed the CT and MR (FLAIR-HASTE and T2-weighted FSE) images and assigned a confidence level to their evaluation (cyst or metastasis) on a five-point scale. RESULTS: All three reviewers were significantly better able (P < 0.05) to differentiate small hepatic cyst from liver metastasis with combined FLAIR-HASTE and T2-weighted FSE images (Az values = 0.997-0.999) than with CT (0.917-0.932). The mean values of sensitivity, specificity, and accuracy were significantly higher (P < 0.001) for T2-weighted FSE with FLAIR-HASTE (96.6%, 96.8%, and 96.7%, respectively) than for CT (76.9%, 61.6%, and 67.3%, respectively). A confident diagnosis was rendered in 12 of 112 lesions (10.7%) on the basis of CT, and this rate increased to 83 of 112 (74.1%) on the basis of T2-weighted FSE and FLAIR-HASTE imaging. CONCLUSION: FLAIR-HASTE is considered to be an effective sequence for differentiating hepatic cysts from liver metastases without the use of a contrast agent. With FLAIR-HASTE one can confidently diagnose small hepatic lesions found on CT in patients with a malignancy.

Adolescent↗
PubMed2006

CT lymphography-navigated sentinel lymph node biopsy in patients with superficial esophageal cancer.

BACKGROUND: To evaluate experimentally and clinically the feasibility of a newly developed technique of endoscopic computed tomography (CT) lymphography with endoscopic submucosal injection of iopamidol for esophageal sentinel lymph node (SLN) mapping and biopsy examination. METHODS: Nine anesthetized dogs underwent CT after endoscopic submucosal injection of 2 mL iopamidol; 1.25-mm thick CT images were obtained before and at 1, 3, 5, 7, and 10 minutes after contrast injection. Clinically, 12 patients with superficial esophageal cancer (preoperative imaging stage: cT1, cN0) underwent CT lymphography in a similar fashion at 1, 5, and 10 minutes after peritumoral injection, followed by radical esophagectomy and regional lymph node dissection under CT lymphography guidance. RESULTS: CT lymphography visualized the draining lymphatic vessels and SLNs within 5 minutes after contrast injection. All 14 SLNs in dogs (average, 1.5 nodes per animal; range, 1-2) and 28 SLNs in patients (average, 2.3 nodes per patient; range, 1-4) were found intraoperatively at the correct location under CT lymphography guidance. Lymph node metastasis could be detected with excellent sensitivity and accuracy in this small number of patients with no false-negative findings; metastasis was positive only in the preoperatively identified SLNs in 4 patients and in both SLNs and distant nodes in 1 patient, and was negative in all resected nodes in the remaining 7 patients. CONCLUSIONS: Endoscopic CT lymphography appears to allow accurate identification of direction and locations of lymph flow and SLNs, and has the potential clinical applicability for esophageal SLN mapping and biopsy examination, but will require a large study to determine its accuracy and usefulness.

Aged↗
PubMed2006

Characterization of 133Xe gas washout in pulmonary emphysema with dynamic 133Xe SPECT functional images.

PURPOSE: To characterize regional ventilation impairment of pulmonary emphysema using dynamic 133Xe single photon emission computed tomography (SPECT) functional images, compared with other forms of chronic obstructive pulmonary disease (COPD). METHODS: Dynamic 133Xe SPECT was performed in 34 patients with emphysema and 15 patients with other forms of COPD. Three-dimensional voxel-based functional images of the half-clearance time (T1/2) mainly reflecting the initial rapid washout of 133Xe gas from the large airways, and of the mean transit time (MTT) reflecting 133Xe gas washout from the entire lungs, including the small airways and alveoli, were created based on an area-over-height method. T1/2 and MTT values were compared with the regional extent of low attenuation areas (%LAA) on density-mask computed tomography images and the diffusing capacity of the lungs for carbon monoxide (DLCO). RESULTS: The MTT/T1/2 ratio in each lung in emphysema was significantly higher than that in other forms of COPD (1.60+/-0.74 vs. 1.21+/-0.26; P<0.01). In the selected unilateral lungs with similar T1/2 values, MTT values were also significantly higher in emphysema. MTT values in each lung showed a significantly closer correlation with the corresponding %LAA values compared with T1/2 values in emphysema (R=0.698, P<0.0001 vs. R=0.338, P<0.01; P<0.05); while only the T1/2 values showed a significant correlation in other forms of COPD (P<0.0001). In correlation with DLCO, MTT values showed a significantly closer correlation compared with T1/2 values in emphysema (R=0.909, P<0.0001 vs. R=0.555, P<0.001; P<0.05); while either value did not show a significant correlation in other forms of COPD. CONCLUSION: MTT values are more critically affected in emphysema compared with other forms of COPD without significant alveolar destruction, and MTT and T1/2 values appear to be differently correlated with the regional extent of LAA between these two disorders. Direct comparison of regional T1/2 and MTT values on functional images may contribute to the demarcation of lung pathology of these two disorders.

Administration, Inhalation↗
PubMed2006

Percutaneous radiologic gastrostomy using push-type gastrostomy tubes with CT and fluoroscopic guidance.

OBJECTIVE: The purpose of this study was to evaluate the safety and feasibility of percutaneous radiologic gastrostomy with endoscopic push-type gastrostomy tubes using CT and fluoroscopic guidance. CONCLUSION: Percutaneous radiologic gastrostomy using CT and fluoroscopic guidance with push-type tubes is a safe and effective means of gastric feeding that has few complications and offers an alternative to introducer-placed gastrostomy tubes.

Aged↗
PubMed2005

Dynamic contrast-enhanced perfusion MR imaging of diseased vertebrae: analysis of three parameters and the distribution of the time-intensity curve patterns.

OBJECTIVE: To assess the diagnostic value of perfusion MR imaging of diseased vertebrae by analysis of three parameters and the distribution of the time-intensity curve (TIC) patterns. DESIGN AND PATIENTS: Dynamic MR imaging was performed on 34 patients with 48 lesions. All lesions were assigned to one of four groups: osteoporotic compression fracture, benign lesion without compression fracture, pathologic compression fracture, or metastatic lesion without fracture. Peak enhancement, steepest slope, and slope value were calculated from the TIC of diseased vertebrae. TICs were classified into five types. Comparisons were made among groups by analysis of the three parameters and the distributions of the TICs pattern. RESULT: All parameters of pathologic compression fracture were significantly higher than those of osteoporotic compression fracture (P<0.05). The steepest slopes of metastatic lesions with and without pathologic compression fracture were significantly higher than those of benign lesions without compression fracture (P<0.05). No characteristic distribution of the TIC pattern helpful for the differentiation of benign and metastatic lesions was found. CONCLUSION: In distinguishing osteoporotic from pathologic compression fractures, semiquantitative analysis of the perfusion MR imaging may be useful. However, the analysis of the TIC patterns can not significantly contribute to the differential diagnosis.

Aged↗
PubMed2005

Differentiation between hepatic cyst and hemangioma: additive value of breath-hold, multisection fluid-attenuated inversion-recovery magnetic resonance imaging using half-Fourier acquisition single-shot turbo-spin-echo sequence.

PURPOSE: To evaluate the additive value of breath-hold, multisection fluid-attenuated inversion-recovery (FLAIR) magnetic resonance imaging (MRI) using half-Fourier acquisition single-shot turbo-spin-echo (HASTE) sequence as supplements to moderately and heavily T2-weighted fast-spin-echo (FSE) sequences in differentiating hepatic cyst from hemangioma. MATERIALS AND METHODS: A total of 183 lesions (127 hepatic cysts, 56 hepatic hemangiomas) in 117 patients were evaluated in this study. Three radiologists independently reviewed FLAIR MR images using a HASTE sequence and T2-weighted FSE MR images. Each radiologist used a five-point scale to rate his confidence in determination of hepatic cyst and hemangioma. RESULTS: All three reviewers were significantly better able to differentiate hepatic cyst from hepatic hemangioma with the combination of FLAIR imaging using HASTE and moderately and heavily T2-weighted FSE images (area under the receiver operating characteristic (ROC) curve, 0.99 for each reader) than with moderately and heavily T2-weighted FSE images alone (0.82-0.93; P < 0.05). FLAIR-HASTE imaging in addition to T2-weighted FSE sequences improved the diagnostic performance, including the sensitivity, specificity, accuracy, and confident diagnosis in the differentiation between hepatic hemangiomas and cysts. CONCLUSION: FLAIR-HASTE imaging is useful for distinguishing hepatic hemangioma from hepatic cyst without the use of contrast-enhanced MR images.

Adult↗
PubMed2005

Pre- and postprandial alterations of portal venous flow: evaluation with single breath-hold three-dimensional half-Fourier fast spin-echo MR imaging and a selective inversion recovery tagging pulse.

PURPOSE: To evaluate the influence of food intake on portal flow using unenhanced magnetic resonance imaging (MRI). MATERIALS AND METHODS: The study population included 29 healthy subjects. A selective inversion recovery tagging pulse was used on the superior mesenteric vein (SMV) and splenic vein (SpV) to study the correlation of tagged blood in the portal vein (PV). MRI was performed before and 60-90 min after a meal. RESULTS: The flow signal from the SMV increased in 97% of the subjects after the meal. Before the meal the portal flow was dominated by flow from the SpV in 59% of the subjects, while it was dominated by flow from the SMV in 76% of the subjects after the meal. The most common distribution pattern of the flow signal from the SpV before the meal was in the central part of the main PV (55%), while it was in the left side (45%) after the meal. The most common distribution pattern of the flow signal from the SMV was in the bilateral sides of the main PV both before and after the meal (62%). CONCLUSION: This technique shows potential for evaluating pre- and postprandial alterations of flow from the SpV and SMV in the PV under physiological conditions.

Adult↗
PubMed2005

Does T2-weighted MR imaging improve preoperative detection of malignant hepatic tumors? Observer performance study in 49 surgically proven cases.

The purpose of our study was to determine whether or not the addition of T2-weighted fast spin-echo (SE) imaging to gadolinium-enhanced spoiled gradient-recalled-echo (GRE) imaging improves the observer performance in the preoperative detection of malignant hepatic tumors. Gadolinium-enhanced GRE and fat-suppressed T2-weighted fast SE images obtained in 49 patients with 82 surgically confirmed malignant hepatic tumors (40 hepatocellular carcinomas and 42 metastases) were retrospectively reviewed by three independent off-site observers. In the random review of images, gadolinium-enhanced GRE images were reviewed first; thereafter, T2-weighted fast SE images were added for combined review. Observer performance was evaluated with the McNemar's test and receiver operating characteristic curve analysis. For gadolinium-enhanced GRE images alone vs. combined images, sensitivities for detection were 78% vs. 79% for hepatocellular carcinomas (P>.05), 67% vs. 71% for metastases (P<.05) and 72% vs. 75% for tumors overall (P<.05), respectively. The Az values were 0.892 vs. 0.889 in hepatocellular carcinomas (P>.05), 0.797 vs. 0.828 in metastases (P<.05) and 0.839 vs. 0.846 in tumors overall (P>.05), respectively. Our results showed that the addition of T2-weighted fast SE imaging to gadolinium-enhanced GRE imaging improved the observer performance in the detection of metastases.

Adult↗
PubMed2005

Initial application of respiratory-gated 201Tl SPECT in pulmonary malignant tumours.

AIM: Respiratory-gated thallium-201 chloride (201Tl) single photon emission computed tomography (SPECT) was used in preliminary investigations to reduce the adverse respiratory motion effects observed on standard ungated SPECT images and to obtain reliable fusion images with computed tomography (CT) in patients with malignant lung tumours. METHODS: Fifteen patients with primary lung cancer (n=10) or metastatic lung tumours (n=5) underwent gated SPECT 20 min after intravenous injection of 148 MBq 201Tl, using triple-headed SPECT and laser light respiratory tracking units. Projection data were acquired by a step and shoot mode, with 20 stops over 120 degrees for each detector and a preset time of 30 s for each 6 degrees stop. Gated end-inspiratory and ungated images were obtained from 1/8 data centred at peak inspiration for each regular respiratory cycle and for the full respiratory cycle data, respectively. The degree and size of tumour 201Tl uptake were compared between these images by regions of interest (ROI) analysis. Gated SPECT images were registered with rest inspiratory CT images using an automated three-dimensional (3D) image registration tool. Registration mismatch was assessed by measuring the 3D distance of the centroid of 14 201Tl-avid peripheral tumours. Attenuation correction of gated SPECT images was performed using CT attenuation values of these fusion images. RESULTS: Gated SPECT images improved image clarity and contrast of tumour 201Tl uptakes compared with ungated images, regardless of the decreased count density due to the use of gated images. The lesion-to-normal (L/N) lung count ratios and ROI size in 18 well-circumscribed 201Tl-avid tumours were significantly higher and smaller on gated images (both P<0.0001). Gated images showed positive 201Tl uptakes in two small peripheral tumours, although negative on ungated images, and demarcated 201Tl-avid tumours from adjacent 201Tl-avid lymph node or surrounding focal 201Tl uptakes caused by other pathology, although these were not clearly demarcated on ungated images. On fusion images, gated images yielded a significantly better SPECT-CT matching compared with ungated images (P<0.0001). Fusion images accurately localized 201Tl uptakes of tumour/lymph node and other focal pathological/physiological conditions. Attenuation-corrected gated SPECT images further facilitated the detection of 201Tl uptake in small or deeply located lesions, with significantly increased L/N ratios. CONCLUSION: Gated SPECT images facilitate the detection of tumour 201Tl uptake and provide reliable SPECT-CT fusion images, which contribute to accurate interpretation and attenuation correction of Tl SPECT images.

Adult↗
PubMed2005

Preferential location of acute pulmonary thromboembolism induced consolidative opacities: assessment with respiratory gated perfusion SPECT-CT fusion images.

PURPOSE: Preferential location of acute pulmonary thromboembolism (PTE) induced consolidative opacities (infarction/atelectasis) was determined on respiratory gated perfusion SPECT-CT fusion images. METHOD: Gated end-inspiratory perfusion SPECT images were obtained in 21 patients with acute PTE and 17 patients with inflammatory diseases, using a triple-headed SPECT system and a respiratory tracking device. Anatomical relationships of consolidative opacities and perfusion defects were assessed on gated SPECT-rest inspiratory CT fusion images. The size and radioactivity of perfusion defects with acute PTE consolidative opacities were compared with those of defects without these opacities. The contribution of fusion images for differential diagnosis of acute PTE induced and inflammatory disease induced lesions was evaluated by receiver operating characteristic (ROC) curve analysis. RESULTS: Of the total 56 acute PTE induced consolidative opacities, 42 (75%) were located at the peripheral interface between the severely decreased and adjacent relatively preserved perfusion areas within wedge shaped perfusion defects on fusion images. These defects with consolidative opacities were significantly larger and had taken up less radioactivity compared with those in the 86 defects without these lesions (P<0.0001). In contrast, of the 29 inflammatory disease induced opacities, 14 (48.2%) had the matched defects and 13 (44.8%) were located at the proximal portion of defects. These preferential locations of acute PTE induced and inflammation induced lesions were significantly different (P<0.01). In ROC curves, the combined reading of fusion images showed a significantly higher differential diagnostic accuracy compared with the reading of CT and SPECT images alone (P<0.01). CONCLUSIONS: Acute PTE induced consolidative opacities preferentially occur at the peripheral lung interface between severely decreased and adjacent relatively preserved perfusion areas within relatively large and severely decreased perfusion defects. The fusion images, which provide an accurate assessment of the morphological-perfusion defect relationship could, potentially, provide a differential diagnosis between acute PTE induced and inflammatory disease induced lesions.

Acute Disease↗
PubMed2005

Enhanced perfusion defect clarity and inhomogeneity in smokers' lungs with deep-inspiratory breath-hold perfusion SPECT images.

PURPOSE: Deep-inspiratory breath-hold (DIBrH) Tc-99m-macroaggregated albumin (MAA) SPECT images were developed to accurately evaluate perfusion impairment in smokers' lungs. METHODS: DIBrH SPECT was performed in 28 smokers with or without low attenuation areas (LAA) on CT images, using a triple-headed SPECT system and a laser light respiratory tracking device. DIBrH SPECT images were reconstructed from every 4 degrees projection of five adequate 360 degrees projection data sets with almost the same respiratory dimension at 20 sec DIBrH. Perfusion defect clarity was assessed by the lesion (defect)-to-contralateral normal lung count ratios (L/N ratios). Perfusion inhomogeneity was assessed by the coefficient of variation (CV) values of pixel counts and correlated with the diffusing capacity of the lungs for carbon monoxide/alveolar volume (DLCO/VA) ratios. The results were compared with those on conventional images. RESULTS: Five DIBrH projection data sets with minimal dimension differences of 2.9+/-0.6 mm were obtained in all subjects. DIBrH images enhanced perfusion defects compared with conventional images, with significantly higher L/N ratios (P<0.0001), and detected a total of 109 (26.9%) additional detects (513 vs. 404), with excellent inter-observer agreement (kappa value of 0.816). CV values in the smokers' lungs on DIBrH images were also significantly higher compared with those on conventional images (0.31+/-0.10 vs. 0.19+/-0.06, P<0.0001). CV values in smokers on DIBrH images showed a significantly closer correlation with DLCO/VA ratios compared with conventional images (R = 0.872, P<0.0001 vs. R=0.499, P<0.01). CONCLUSION: By reducing adverse effect of respiratory motion, DIBrH SPECT images enhance perfusion defect clarity and inhomogeneity, and provide more accurate assessment of impaired perfusion in smokers' lungs compared with conventional images.

Artifacts↗
PubMed2005

Breast sentinel lymph node navigation with three-dimensional interstitial multidetector-row computed tomographic lymphography.

OBJECTIVE: Three-dimensional multidetector-row computed tomographic lymphography (3D MDCT-LG) with interstitial injection of a widely available nonionic monometric contrast medium iopamidol was used for navigation of breast sentinel lymph node (SLN) biopsy. METHODS: 3D MDCT-LG was obtained after massage of the interstitially injection sites of a total of 4-5 mL undiluted iopamidol at periareolar and peritumoral areas in 68 consecutive patients with early-stage breast cancer, using a 4 detector-row CT scanner. Drainage lymphatic patterns and SLN anatomy were assessed on 3D MDCT-LG images. 3D MDCT-LG-navigated SLN biopsy with combined use of blue dye was followed by backup axillary lymph node dissection to evaluate accuracy of SLN biopsy. RESULTS: The 3D MDCT-LG images clearly localized primary SLNs by visualizing the direct connection between these nodes and their afferent lymphatic vessels on detailed anatomy of the surrounding structures in all patients. Drainage lymphatic pathways on these images were classified into 4 patterns: single route/single SLN (39 cases, 57%), multiple routes/multiple SLNs (10 cases, 15%), single route/multiple SLNs (9 cases, 13%), and multiple routes/single SLN (10 cases, 15%). Under 3D MDCT-LG navigation, SLNs was found at the accurate location in all patients. With backup axillary lymph node dissection, metastasis was found in 14 (20%) patients, and 8 of these patients had metastasis only in the preoperatively identified SLNs. In other 5 positive patients, metastasis was found both in the SLN and non-SLNs. However, micrometastasis eventually was found only in non-SLN in an elderly patient. Overall, the sensitivity, false-negative rate, and accuracy of 3D CT-L-navigated SLN biopsy were 92% (13/14 patients), 7% (1/14 patients), and 98% (67/68 patients), respectively. CONCLUSIONS: Topographic 3D interstitial MDCT-LG can be a widely available and reliable navigator for breast SLN biopsy.

Adult↗
PubMed2005

Lymphatic drainage from esophagogastric tract: feasibility of endoscopic CT lymphography for direct visualization of pathways.

PURPOSE: To evaluate the feasibility of an endoscopic computed tomographic (CT) lymphography technique with submucosal injection of iopamidol for direct visualization of lymphatic drainage pathways in dogs and in patients with operable esophageal cancer. MATERIALS AND METHODS: With institutional animal committee approval, a total of 2 mL of undiluted iopamidol was injected into the esophageal (n = 6) or gastric (n = 3) submucosa in nine dogs by using a flexible endoscope. Multi-detector row CT images (section thickness, 1.25 mm) were obtained before contrast material injection and during the 10 minutes after injection. The animals were euthanized so that their lymphatic anatomy could be examined. With ethical committee approval and patient informed consent, nine patients with esophageal cancer also underwent CT lymphography with peritumoral injection of 2 mL of iopamidol, followed by esophagectomy and regional lymph node dissection with CT lymphographic guidance. The histopathologic features of dissected nodes, including sentinel lymph nodes (SLNs), were examined. RESULTS: CT lymphography depicted the direct connection of lymphatic drainage vessels with enhanced and/or unenhanced nodes (ie, SLNs) as early as within 5 minutes after contrast material injection in all subjects. All 13 SLNs in dogs (1.4 nodes per animal) and 18 SLNs in patients (two nodes per patient) were found and dissected at the correct location by using CT lymphographic guidance. In patients, histopathologic examination revealed the high predictive value of CT lymphographic-guided SLN biopsy: Only one of the preoperatively identified SLNs in three patients and both SLNs and adjacent nodes in two patients were positive for metastasis; all resected nodes in the remaining four patients were negative. CONCLUSION: Endoscopic CT lymphography is a feasible method for visualizing the direct connection between and the accurate anatomic location of SLNs and lymphatic drainage vessels.

Aged↗
PubMed2005

Diagnosis of gastric cancer with MDCT using the water-filling method and multiplanar reconstruction: CT-histologic correlation.

OBJECTIVE: The purpose of this study was to assess the utility of MDCT with a thin-sliced multiplanar reconstruction (MPR) technique and water-filling method for the diagnosis of gastric cancers. MATERIALS AND METHODS: Sixty-five patients with gastric cancers were preoperatively examined with MDCT using the water-filling method. The abdomen was dynamically scanned at 30 and 80 sec after the start of contrast medium administration. MPR images were reconstructed with a slice width of 1.25 mm and a slice interval of 1 mm. The detection rate and accuracy of T staging for gastric cancer were evaluated on MPR images and compared with 5-mm-slice axial images. In addition, MDCT images were correlated with pathologic findings. RESULTS: The detection rate of all gastric cancers using the MPR technique was 65%. The detection rate of advanced gastric cancers was 96.2% (25 of 26), whereas that of early gastric cancers was 41.2% (14 of 34). There was a statistically significant difference (p < 0.05) in the detection rate of early gastric cancers between MPR and 5-mm-slice axial images. The MDCT appearances of gastric cancers were well correlated with pathologic findings such as mucinous component or differences in infiltration of cancer cells. The overall accuracy of CT staging was 85%. MPR images were superior to axial images for the evaluation of the z-axis extent of tumor. CONCLUSION: MDCT with the water-filling method has advantages in acceptable evaluation of depth invasion of gastric carcinomas and in visualization of histologic changes in the tumors. MPR images may be a useful guide for the evaluation of the z-axis extent of tumor.

Adult↗
PubMed2004

Clinical utility of co-registered respiratory-gated( 99m)Tc-Technegas/MAA SPECT-CT images in the assessment of regional lung functional impairment in patients with lung cancer.

PURPOSE: The aim of the study was to provide preliminary validation of the utility of co-registered respiratory-gated ventilation/perfusion single-photon emission computed tomography-computed tomography (SPECT-CT) images in the assessment of regional lung functional impairment in patients with lung cancer. METHODS: Twenty untreated and three radiotherapy-treated patients with lung cancer underwent gated( 99m)Tc-Technegas/macroaggregated albumin (MAA) SPECT, using a triple-headed SPECT unit and a respiratory synchroniser. Gated SPECT images were obtained from 1/8 data centered at peak inspiration for each regular respiratory cycle and co-registered with tidal inspiration CT images using an automated three-dimensional registration tool. RESULTS: Gated SPECT images detected 10.2% more ventilation defects (205 vs 186) and 9% more perfusion defects (218 vs 200) compared with ungated images, with a significantly higher lesion-to-normal lung contrast ( P<0.0001). Co-registered gated SPECT-CT images accurately visualised the anatomy of ventilation and/or perfusion defects associated with bronchial and/or vascular involvement by tumours, resulting in changes in surgical planning in two patients with lung cancer. In the three patients who had received radiotherapy, perfusion defects along the radiation field were identified even in the lung areas without abnormal opacities on CT images. In the operated patients, the co-registered gated SPECT-CT images allowed accurate placement of regions of interest over the lung lobes to be resected, yielding a significantly better prediction of postoperative forced expired volume in 1 s (FEV(1)) compared with that predicted without use of these images ( R=0.993 vs R=0.890; P<0.05), with an excellent inter-observer reproducibility. CONCLUSION: Detailed functional-morphological correlation on co-registered gated SPECT-CT images contributes to accurate assessment of regional functional impairment, and may be useful for surgical planning, prediction of postoperative function and assessment of external beam radiotherapy effects in patients with lung cancer.

Administration, Inhalation↗
PubMed2004

MRI of bone tumors: Fast STIR imaging as a substitute for T1-weighted contrast-enhanced fat-suppressed spin-echo imaging.

PURPOSE: To compare the usefulness of short inversion recovery (STIR) and T1-weighted, contrast-enhanced, fat-suppressed (T1W-CEFS) sequences for the evaluation of bone tumors. MATERIALS AND METHODS: Eighteen patients with 19 bone tumors who underwent both STIR and T1W-CEFS imaging were evaluated. The tumors were categorized in pairs as follows: bone marrow and soft-tissue components, benign and malignant tumors, and tumors with and without mineralization. The signal difference-to-noise ratio (SDNR), signal-to-noise ratio (SNR), and tumor volume were calculated in each group. An additional qualitative analysis was performed by means of the ratings of imaging contrast. RESULTS: The mean SDNRs of all bone marrow components and bone marrow components without mineralization were significantly higher on fast STIR images than on T1W-CEFS images (P < 0.05). There was no significant difference in the mean SDNR and SNR of the other group (surrounding soft tissue components, bone marrow components with mineralization, benign and malignant lesions) between fast STIR images and T1W-CEFS images. The mean volume of the tumors was significantly higher with STIR than with the T1W-CEFS sequence (P < 0.05). CONCLUSION: The STIR sequence should be used instead of T1W-CEFS imaging for the evaluation of bone tumors.

Adolescent↗