The incidence of prostate cancer has been increasing gradually in Japan, and the optimal use of radiation therapy is important to improve therapeutic outcome and quality of life. The clinical trials conducted by RTOG and EORTC have made it clear that dose escalation results in improvement of the local control rate in early stage localized prostate cancer and androgen ablation in combination with radiation therapy improves biochemical control and the progression-free survival rate in locoregionally advanced prostate cancer. To select optimal patients for dose escalation study and to determine the optimal use of androgen ablation, it has become clear that the Gleason score and pretreatment PSA value provide valuable information in addition to clinical stage. In terms of prophylactic irradiation to pelvic lymph nodes, there has been no definitive evidence that prophylactic irradiation of clinically or pathologically uninvolved pelvic lymph nodes improves the overall survival rate. Brachytherapy including 125-I or 103-Pd permanent implants and high-dose-rate brachytherapy is now widely used in the treatment of prostate cancer, but clear indications have not yet been determined because of the lack of clinical trials. In this paper, we summarize evidence concerning the role of radiation therapy in the treatment of prostate cancer and also describe the biological basis of prostate cancer, which influences the optimal selection of treatment modalities.
One year has passed since we started brachytherapy with radioactive iodine-125 seeds for carcinoma of the prostate. During the follow-up of patients, we have relatively frequently found migrated seeds in the lungs. Migrated seeds are reported to reach mainly the pulmonary artery and cause embolization without clinical symptoms. We counted the embolized seeds and determined the proportion of migrating seeds on chest X-ray exam. We found 47 cases of pulmonary embolization in our initial 100 cases. Less than half of the embolization were found in the chest X-ray exam performed on the next day after the implantation. We found more migrated seeds in the lower lung fields than in the upper and middle lung fields. Pulmonary embolization of implanted iodine-125 seeds is not unusual, and cases of prostate brachytherapy are likely to increase in Japan. We will have increased opportunities to observe chest X-ray films with migrated seeds in the future.
PURPOSE:To evaluate the efficacy of the saline flush technique for abdominal multidetector-row computed tomography (CT).METHODS:As a clinical study, 147 patients with chronic hepatic disease were divided into two groups: group A, given 100 cc of contrast material flushed with 50 cc of saline; and group B, given 100 cc of contrast material only. The difference in attenuation values between groups A and B, and cirrhotic liver and non-cirrhotic liver were evaluated. As an in-vitro experimental study, time vs. peak pressure curve was obtained changing injection devices.RESULTS:Group B showed a greater contrast enhancement effect in the early arterial equilibrium phase of the aorta and late arterial phase of the liver. In cirrhotic liver, the aorta showed greater contrast enhancement in the early arterial phase in group A. Attenuation values of hypervascular hepatic nodules showed no statistically significant difference between groups A and B. Time to reach peak pressure was prolonged when using saline flush devices in vitro. Flow of contrast material from the contrast material cylinder to the saline cylinder was also discovered.CONCLUSION:Saline flush causes peak arterial contrast to be strong for a short duration. Abdominal organ attenuation values are not necessarily increased in the saline flush method. It is important to know that contrast enhancement is dependent on the injection device.
This study aimed to evaluate the efficacy of breath-hold three-dimensional (3D)delayed-enhancement MRI using parallel imaging in terms of the effect of parallel imaging on the image quality and visualization of myocardial infarction. Twenty-two patients (17 men and 5 women) with suspected myocardial infarction underwent breath-hold 3D late-enhanced viability examination at least 30 days after occurrence. All patients underwent a Tl-scintigraphy examination. First, 10 patients were examined without applying parallel imaging, then the next 12 patients were studied using parallel imaging. All 3D late-enhanced images at the short axis were acquired 10, 15, and 20 min after an injection of contrast agent, and both the long axis and the four-chamber views were acquired after 15 min. In quantitative analysis, the late-enhanced myocardial images at 10, 15, and 20 min showed higher contrast-to-noise ratios (CNR) in parallel imaging than those with no parallel imaging. During the time-intensity curve of the myocardium, no significant change was observed at 10 or 15 min; however, marked signal reduction was observed at 20 min. In diagnostic evaluation, images obtained with parallel imaging were superior to those without parallel imaging. In general, the application of parallel imaging reduces acquisition time with an expense of reduction in SNR. However, the breath-hold 3D late-enhanced images with parallel imaging showed no apparent SNR reduction. Furthermore, parallel imaging provided clear edge definition between the infarction and the normal region. The reduction of acquisition time with parallel imaging may be less susceptible to fast cardiac motion. In conclusion, breath-hold 3D delayed-enhancement MRI using parallel imaging was highly evaluated in our study and may show promise in clinical application.
A 42-year-old woman with bilateral massive ovarian edema (MOE) is presented. MOE is usually seen in women 6 to 33 years of age. Therefore, accurate re-operative assessment of MOE is important to avoid unnecessary oophorectomy procedures. MR findings of MOE are characteristic and reflect very well the diffuse stromal edema noted on microscopy. The etiology and MR findings of MOE are discussed.
To evaluate the diagnostic ability of multiplanar reformation (MPR) images of the lung in comparison with thin-section source CT images.MPR images were reconstructed for 79 patients with suspected pulmonary disease. Slice thicknesses of source images were 2 mm in 24, 1 mm in 30, and 0.5 mm in 25 cases. The presence of centrilobular nodules, emphysema, bronchiectasis, ground-glass opacity (GGO), consolidation, interstitial thickening, and pulmonary nodule was evaluated on thin-section source images by an experienced chest radiologist to establish gold standards and then subsequently assessed on the MPR images independently by two radiologists. The sensitivity, specificity, and accuracy of each finding were calculated regarding the results of thin-section source images as the gold standards. Accuracy for the detection of findings was also statistically compared among the three groups of different source slice thicknesses using Fisher's exact test.Accuracy for the detection of findings was significantly less (p < 0.05) in 2 mm slice MPR for centrilobular nodule, GGO, and interstitial thickening than in 1 mm or 0.5 mm slice MPR. No statistically significant difference was observed for any of the findings between 0.5 mm and 1 mm slice MPR. Rates of sensitivity, specificity, and accuracy of the MPR images for detection of the findings were 89-100%, 73-95%, and 84-95%, respectively.In comparison with thin-section source images, MPR images are comparably sensitive but not as specific for the detection of findings. When producing MPR images, the slice thickness of source images should be less than 2 mm.
PURPOSE To assess the current practice of pediatric MDCT in Japan, with particular reference to age-related dose adjustment. MATERIALS AND METHODS During the first three months of 2004, a questionnaire was mailed to 996 institutions, among which listed MDCT users ranged from private hospitals to large university-based hospitals. RESULTS We received responses from 348 (34.9%) institutions. Fifty-three percent of the respondents had four-detector MDCT units. Approximately 70% of examinations were head and 22% were body. Scanning parameters were determined by full-time radiologists in 40%, and by CT technologists in 28% of respondents. Eighty-nine percent (head CT) and 85% (abdominal CT) of respondents indicated that they changed parameters for children. More than 90% changed tube current for optimization. Change was based on the technologist's experience (56%, head CT; 43%, abdominal CT), and automatic exposure control has been used as a basis of mAs control in 17% of respondents for head CT and in 34% for abdominal CT. Age-related mAs settings for abdominal CT were almost the same as those published in a United States survey. CONCLUSION Although Japan has approximately 40% of the world's CT units, optimized pediatric MDCT settings might be moved away from a fixed mA protocol as recommended by the FDA and in conformity with the ALARA (as low as reasonably achievable) concept.
We evaluated radionuclide cisternography for the diagnosis of intracranial hypotension in terms of the rate of appearance of abnormal findings in 23 patients, their correlation with therapy, and the most suitable scanning method and timing for visualization of leakage. During the first hour after injection, dynamic lumbar images or consecutively repeated whole-body images were acquired. Whole body images then were acquired at 1, 5, and 24 hours. Until 5 hours after injection, patients were kept in bed resting. Visualization of the leakage (direct finding) and that of the bladder (indirect finding) were observed in 78.3% (18/23) and 60.9% (14/23), respectively. Leakage was visualized most frequently at 5 hours after injection. There were three cases in which the leakage was only visualized at 24 hours. Therefore, there must be cases that show intermittent CSF leakage. To avoid overlooking these cases, a 24-hour whole-body image is also important. The appropriate procedure of radionuclide cisternography is very important to detect CSF leakage, and our procedure proved to be more effective for detecting the abnormal findings.
PURPOSE:To evaluate the usefulness of MR imaging for the detection of severe facial nerve damage in patients with facial nerve palsy.MATERIALS AND METHODS:We retrospectively reviewed 26 consecutive patients with facial nerve palsy (13 non-responders and 13 responders). T1-weighted, T2-weighted, and postcontrast T1-weighted images were obtained in all patients. FLAIR images were also obtained in 3 non-responders.RESULTS:The geniculate ganglion, labyrinthine segment, and tympanic segment or mastoid segment showed high signal intensity on T2-weighted images in 9 of 13 non-responders, whereas high signal intensity of the nerve was only seen in 1 of 13 responders. FLAIR imaging revealed high signal intensity lesions of the distal intrameatal segment in 2 non-responders. Contrast enhancement of the facial nerve showed a similar pattern in non-responders and responders. High signal intensity lesions on T2-weighted or FLAIR images showed enhancement on postcontrast T1-weighted images.CONCLUSION:These results suggest that a high signal intensity area on T2-weighted images is a marker of severe facial nerve damage. FLAIR imaging is useful for identification of T2-prolongation in the distal intrameatal segment.
B-flow imaging is a recently developed ultrasound technique that extends the B-mode imaging quality of blood flow, including high-frame-rate and high-spatial-resolution imaging. The purpose of the present study was to clarify the usefulness of B-flow for evaluation of the hemodynamics of superficial soft tissue tumors. All 33 cases of superficial soft tissue tumors were examined by both B-flow and Color/Power Doppler methods on the same plane. The B-flow images that were obtained were evaluated by comparison with corresponding Color/Power Doppler images. The following four items were compared and evaluated: (1) sensitivity to the detection of tumor vessels; (2) quality of background B-mode imaging; (3) frame rate; and (4) spatial resolution of tumor vessels. B-flow was somewhat inferior to Color/Power Doppler imaging in sensitivity to the detection of tumor vessels. B-flow was clearly inferior in the quality of background B-mode imaging. B-flow provided high-frame-rate imaging. The diameter of tumor vessels on B-flow imaging was clearly thinner than that on Color/Power Doppler images and appeared to indicate the true diameter of tumor vessels. By providing high-frame-rate imaging and high spatial resolution, B-flow makes it possible to clarify the precise vascular structure.
PURPOSETo evaluate the incidence and features of cystic structures adjacent to the frontal horns of neonates using MRI, and to assess the clinical features of the neonates.MATERIALS AND METHODSBetween April 2001 and January 2005, MRI examinations were performed at our hospital in 352 neonates and infants whose postconceptional age was less than 48 weeks. We retrospectively evaluated the MRI findings and the clinical records.RESULTSSeventeen babies (8 males and 9 females) showed cystic structures adjacent to frontal horns, hemilaterally or bilaterally. The incidence of the cysts was 4.8% in total, and was 1.4% (1/74), 9.2% (6/65), and 4.7% (10/213)in term infants, preterm infants born at 33-36 weeks of gestational age, and at less than 32 weeks, respectively. The cysts ranged from 1 to 8 mm in diameter, and were located in the white matter adjacent to ventricular walls and in the portion cephalad to the frontal horns. The cysts resolved in 5 cases (with follow-up ranging from 3 months to 2 years of age), causing slight dilatation of the frontal horn. Developmental disturbances were not observed in patients without other abnormalities.CONCLUSIONCystic structures near the frontal horns in neonates are detected by MRI at a rate of 4.8%. They will resolve spontaneously without causing developmental abnormalities.
The paranasal sinus is an aerated space constructed of bones. Its draining pathway for secreted mucus is narrow and surrounded by structures such as the palate, orbit, and anterior cranial fossa. Many minute openings traverse the bony structure for innervation and blood supply. Therefore, CT and MRI play a complementary role in diagnosing sinonasal disease. When paranasal sinusitis is suspected, CT is conducted to evaluate the drainage passages, deviation of the nasal septum or normal variants, and bone sclerosis for preoperative planning of endoscopic sinus surgery. When a unilateral space-occupying lesion or bone destruction is detected by CT, malignancy may be considered. However, contrast resolution on CT is limited, and the procedure should be complemented by MRI. MRI is superior to CT in contrast resolution, and is more helpful in illustrating tumor extension or invasion into soft tissues such as the masticator space or into the orbital or intracranial space. The present report discusses sinonasal non-neoplastic and neoplastic diseases that have typical and characteristic findings on CT and MRI.
Recognition of which interlobar fissure in the right lung is major or minor is important in chest radiography. Based on assessment of the interlobar fissure, the location of diseases or the degree of expansion of the lobes is comprehensible. As a general rule, the major fissure is not seen in normal cases. However, the major fissure is visualized in the presence of volume loss of the lower lobe. Although the medial end of the minor fissure is at the intermediate artery between the upper and lower lobe bronchi, that of the major fissure is continuous to the central portion of the mediastinum. The following cases will be presented: post-pleuritis, atelectasis of the superior segment of the lower lobe (S6), obstructive pneumonia in the middle and lower lobes due to stenosis of the intermediate bronchus, pneumonia of the upper lobe, and superior accessory fissure with atelectasis of the upper lobe.
PURPOSE To compare rates of accuracy of recognition between experienced dictators and inexperienced ones in using an enrollment-less continuous speech recognition (CSR) system of radiological reporting, and to evaluate the usefulness of the system. MATERIALS AND METHODS Twenty board-certified radiologists were classified into 2 groups: a group of 10 members with more than 6 years' experience of conventional dictation by transcriptionist (group A) and a group of 10 members with no experience of dictation (group B). All radiologists created fresh radiological reports on sets of images using free-style dictation in the reports. We counted errors and total words in the reports individually, and compared the rates of accuracy of word recognition in the two groups. We used a CSR system AmiVoice (Advanced Media, Inc., Tokyo, Japan). RESULTS The average rate of accuracy of word recognition was 96.42 +/- 1.68% in group A and 95.92 +/- 1.15% in group B. There was no significant difference in accuracy rate between the two groups. CONCLUSION The accuracy of word recognition was independent of the experience of dictation, and the enrollment-less CSR system of radiological reporting was considered convenient and useful.
With the increasing demand on picture archiving and communication systems (PACS) to handle larger numbers of images, much research has been conducted on the utilization of lossy compression for efficient communication and storage in PACS systems. The receiver operating characteristics (ROC) method is commonly used to determine the appropriate compression ratio of lossy images. However, conducting an ROC experiment is impractical at actual medical facilities because it is difficult to prepare and interpret images with different compression ratios for each modality, body part, and acquisition method. On the other hand, experienced radiologists have the ability to subjectively assess the level of image quality required for interpretatior and quantitative analysis. Therefore, by simply viewing images, they are able to determine the appropriate criteria for image quality and derive a practical compression ratio for each application. The present study focused on lossy compression as employed in teleradiology systems for medical checkups. Experiments comparing radiologists' subjective assessment of compressed images against the diagnostic results obtained using these images were conducted in order to investigate appropriate compression ratios and efficient methods for determining them.
PURPOSE:To study the frequency of visualization and characteristics of normal thoracic structures on lateral chest radiographs in the Japanese population.MATERIALS AND METHODS:We reviewed 316 lateral chest radiographs of men and women ranging in age from 20 to 90 years. The frequency of visualization and configuration of structures including major, minor, superior and inferior accessory fissures, and orifices of the right and left upper lobe bronchi were reviewed.RESULTS:On lateral chest radiographs, major fissure and minor fissure were visualized in 99.4% and 87.3%, respectively. Superior accessory fissure and inferior accessory fissure were visualized in 1.9% and 9.5%, respectively. Orifices of the right and left upper bronchi were seen in 92.4% and 98.4%, respectively.CONCLUSION:Frequency of visualization and characteristics of various normal anatomic structures on lateral chest radiographs in the Japanese population differ from those reported previously from the West. Familiarity with these normal thoracic structures and variations is important for daily image interpretation.
PURPOSE To compare dual-phase contrast-enhanced multidetector-row CT (MDCT) with high-spatial-resolution MRI using a three-dimensional volumetric interpolated breath-hold examination (VIBE) sequence for evaluation of the extent of ductal carcinoma in situ (DCIS). MATERIALS AND METHODS A retrospective review was conducted in 17 consecutive patients with DCIS in which both MDCT and MRI had been performed. The early phase of MDCT and MRI was started 60 sec after commencing contrast injection. The late phase was started 4 min after the injection. The size of the lesion on MDCT and MRI was measured in coronal images obtained during the early and late phases. Histological evaluation of the size was considered the gold standard, and the deviation in tumor size as measured in the early- and late-phase images from the histologically determined tumor size was calculated. RESULTS The sensitivity rates of MDCT and MRI for the detection of DCIS were 88.2% (15/17)and 100%, respectively, and no lesions were detected in the late-phase images alone. The accuracy of detection of tumor diameters with a deviation of less than 2 cm was 76.5% (13/17) with MDCT and 94.1% (16/17) with MRI. The tumor diameter was overestimated by more than 2 cm in 2 lesions (11.8%) on MDCT and one lesion (5.9%)on MRI, in both early- and late-phase scans. Tumor diameter was underestimated in early- as compared to late-phase scans in 3 cases on MDCT and one case on MRI. CONCLUSION High-spatial-resolution MRI using the VIBE sequence is more accurate for the detection and evaluation of the extent of DCIS than MDCT. In dynamic studies, more accurate evaluation of the extent of DCIS is possible in late-phase images.
PURPOSE:To investigate the usefulness of MRI for predicting pelvic control (PC) of cervical cancer treated with radiation therapy (RT). MATERIALS AND METHODS:Forty-four cervical cancer patients treated with definitive RT were retrospectively analyzed. MRIs were completed before and after RT, and the longest diameter (LD) of the residual tumor was measured on post-RT MRI. Pathologic evaluation for residual tumor was also performed. Therapeutic response was assessed using MRI. Median follow-up time for the 44 patients was 34 months. The correlations between PC rate, MRI, and pathological findings were investigated. RESULTS:The 3-year PC rates of LD = 0 cm (n = 23) after RT, 0 < LD 2 cm (n = 6) were 85%, 80%, and 0%, respectively (p < 0.0001). There was no significant difference in PC according to the presence (n = 8) or absence (n = 36) of residue in the pathologic materials (3-year PC rate: 63% vs. 77%). Three-year PC rates according to therapeutic responses were 85% in complete response (n = 23), 72% in partial response (n = 18), and 0% in stable disease or progressive disease (n = 3) (p < 0.0001). CONCLUSION:MRI is useful for predicting PC in cervical cancer treated with RT, and LD greater than 2 cm after RT is a good marker for poor PC.
PURPOSE:A multicenter study was conducted to evaluate the efficacy of strontium chloride (89SrCl2) for palliation of painful bony metastases using the Visual Analogue Scale (VAS), Brief Pain Inventory (BPI) and Functional Assessment for Cancer Therapy-General (FACT-G).METHODS:Ninety patients received a single injection of 2.0 MBq/kg and were classified as responders if VAS scores decreased without increased use of analgesics or if analgesic consumption decreased without an increase in the VAS.RESULTS:In the 69 subjects that could be evaluated, mean VAS values decreased significantly from 48.0 +/- 20.8 mm at baseline to 24.1 +/- 22.3 mm at last visit(Week 12) (p < 0.0001). VAS decreased more than 10 mm in 58.0% of these subjects, and analgesic consumption was reduced more than 10% in 39.1% of subjects. The response rates were 46.4% (95% confidence interval (CI) 34.3-58.8%) in the 69 subjects that could be evaluated and 43.3% (95% CI 32.9-54.2%) in all subjects. The scoring in BPI for interference in daily life improved together with improvement in its pain scores. Total FACT-G score showed significant improvement, as did its score in the subsection of physical well-being. Both platelets and leucocytes decreased by 22% at nadir (week 8), and such profiles of myelosuppression by 89SrCl2 were similar to those in the previous clinical studies.CONCLUSION:These results suggest the clinical utility of 89SrCl2 for pain palliation, which leads to QOL improvement in patients with painful generalized bone metastases.
