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Purpose: This study aimed to enhance the diagnostic accuracy of contrast-enhanced breast magnetic resonance imaging (MRI) using gadobutrol for differentiating benign breast lesions from malignant ones. Moreover, this study sought to address the limitations of current imaging techniques and criteria based on the Breast Imaging Reporting and Data System (BI-RADS)., Materials and Methods: In a multicenter retrospective study conducted in Japan, 200 women were included, comprising 100 with benign lesions and 100 with malignant lesions, all classified under BI-RADS categories 3 and 4. The MRI protocol included 3D fast gradient echo T1- weighted images with fat suppression, with gadobutrol as the contrast agent. The analysis involved evaluating patient and lesion characteristics, including age, size, location, fibroglandular tissue, background parenchymal enhancement (BPE), signal intensity, and the findings of mass and non-mass enhancement. In this study, univariate and multivariate logistic regression analyses were performed, along with decision tree analysis, to identify significant predictors for the classification of lesions., Results: Differences in lesion characteristics were identified, which may influence malignancy risk. The multivariate logistic regression model revealed age, lesion location, shape, and signal intensity as significant predictors of malignancy. Decision tree analysis identified additional diagnostic factors, including lesion margin and BPE level. The decision tree models demonstrated high diagnostic accuracy, with the logistic regression model showing an area under the curve of 0.925 for masses and 0.829 for non-mass enhancements., Conclusion: This study underscores the importance of integrating patient age, lesion location, and BPE level into the BI-RADS criteria to improve the differentiation between benign and malignant breast lesions. This approach could minimize unnecessary biopsies and enhance clinical decision-making in breast cancer diagnostics, highlighting the effectiveness of gadobutrol in breast MRI evaluations., (© 2024. The Author(s).)

Rationale: Duodenal ulcer bleeding is a potentially life-threatening condition commonly caused by the erosion of the duodenal arteries., Patient Concerns: A 55-year-old male was referred to our hospital with abdominal pain for the past 3 days. Contrast-enhanced computed tomography of the abdomen revealed wall thickening in the descending part of the duodenum and a cystic lesion (27 × 19 mm) contiguous with the duodenum, with an accumulation of fluid. An esophagogastroduodenoscopy showed the significantly stenotic duodenum, which prevented passage of the endoscope and evaluation of the main lesion. Based on these findings, duodenal ulcer perforation and concomitant abscess formation were suspected. Two days after admission, he had massive hematochezia with bloody drainage from the nasogastric tube., Diagnoses: Emergency angiography revealed duodenal ulcer bleeding from the gastroduodenal artery and the branch artery of the inferior pancreaticoduodenal artery and middle colic artery (MCA)., Interventions: The patient was treated with transcatheter arterial embolization (TAE) of the gastroduodenal artery, the branch vessel of the inferior pancreaticoduodenal artery, and the main trunk of the MCA., Outcomes: Hemostasis was achieved with TAE. The patient recovered uneventfully and undergone a gastro-jejunal bypass surgery for the duodenal stenosis 2 weeks after TAE. He was discharged without any abnormal complaints on postoperative day 12., Lessons: We have experienced a rare case of duodenal ulcer bleeding from a branch of the MCA. In patients with refractory upper gastrointestinal bleeding, careful evaluation of bleeding sites is recommended considering unexpected culprit vessels., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: To compare the diagnostic performances of contrast-enhanced digital mammography (CEDM) and breast MRI in evaluations of breast cancer, with a focus on the impact of background parenchymal enhancement (BPE) levels., Methods: The present study included women who underwent CEDM and breast MRI to evaluate the disease extent of breast cancer between January 2018 and December 2019. Readers judged BPE levels (minimal-mild or moderate-marked) on CEDM, and were asked to assign findings suggesting malignancy using the following criteria: (1) enhancement other than BPE and (2) BI-RADS 4/5 calcifications without enhancement. On MRI, BI-RADS 3 and BI-RADS 4/5 lesions were evaluated as benign and malignant, respectively. The diagnostic performances of CEDM and MRI were compared separately between women with minimal-mild BPE and those with moderate-marked BPE., Results: Sixty-nine patients comprising 43 postmenopausal and 26 premenopausal women were included in the present study. In total, 195 lesions (94 malignant and 101 benign) were identified. The sensitivity and specificity of CEDM for the diagnosis of all lesions were 90.8 and 91.5% with minimal-mild BPE and 79.3 and 76.2% with moderate-marked BPE, respectively. The sensitivity and specificity of MRI were 90.0% and 71.0% with minimal-mild BPE and 87.5% and 78.1% with moderate-marked BPE, respectively. The accuracy of CEDM was significantly superior to that of MRI in women with minimal-mild BPE on both CEDM and MRI (p = 0.002). Regarding the negative impact of a correct diagnosis on CEDM, the odds ratio of "moderate-marked BPE" was 0.382., Conclusion: In patients with minimal-mild BPE, the diagnostic performance of CEDM was superior to that of MRI., (© 2022. The Author(s), under exclusive licence to The Japanese Breast Cancer Society.)

Purpose: To assess morphology on diffusion-weighted imaging (DWI) and intratumoral signal intensity (SI) on T2-weighted images (T2WI) of breast carcinomas, and to evaluate the association between the combined DWI and T2WI findings and breast cancer subtypes., Methods: Two hundred and eighty breast cancer patients who underwent breast MRI prior to therapy were included in this retrospective study. All had invasive carcinomas, which were classified into five subtypes: Luminal A-like (n = 149), Luminal B-like (n = 63), Hormone receptor-positive HER2 (n = 31), Hormone receptor-negative HER2 (n = 13), or Triple-negative (TN) (n = 24). Based on the morphology on DWI, the tumors were classified into two patterns: DWI-homogeneous or DWI-heterogeneous. If DWI-heterogeneous, an assessment of intratumoral SI on T2WI was performed: tumors with intratumoral high/low SI on T2WI were classified as Hete-H/Hete-L, respectively. The associations between (1) the morphological patterns on DWI and the five subtypes, and (2) the intratumoral SI patterns on T2WI and the five subtypes in DWI-heterogeneous were evaluated., Results: There was a significant association between (1) the morphological patterns on DWI and the five subtypes (p < 0.0001), and (2) the intratumoral SI patterns on T2WI and the five subtypes in DWI-heterogeneous (p < 0.0001). DWI-homogeneous was dominant in Luminal A-like (67.1%), and Hete-H was dominant in TN type (75%). Hete-H, suggesting the presence of intratumoral necrosis, included high proliferative and/or aggressive subtypes more frequently (80%) than Hete-L, suggesting the presence of fibrotic focus. Fibrotic focus was seen more commonly in the luminal subtypes., Conclusion: The combined findings on DWI and T2WI revealed breast carcinomas that were associated with particular subtypes.

There are three types of breast cancer recurrence which can occur after initial treatment: local, regional, and distant. Distant metastases are more frequent than local and regional recurrences. It usually occurs several years after the primary breast cancer, although it is sometimes diagnosed at the same time as the primary breast cancer. Although the common distant metastases are bone, lung and liver, breast cancer has the potential to metastasize to almost any region of the body. Early detection and treatment of distant metastases improves the prognosis, therefore radiologists and clinicians should recognize the possibility of metastasis from breast cancer and grasp the imaging characteristics. In this report, we demonstrate the imaging characteristics of metastases from breast cancer to uncommon sites.

Radical cystectomy with urinary diversion is a common urological procedure performed for the treatment of bladder cancer. Numerous surgical procedures have been developed for urinary diversion. Over the past decade, orthotopic neobladder reconstruction has been used frequently for urinary diversion because of its advantageousness in providing patients with a good quality of life compared with other urinary diversion technique. Knowledge of the indication, surgical procedure, and postsurgical anatomy of orthotopic neobladder reconstruction is essential. While the technique has many advantages, multiple postsurgical complications may occur after reconstruction, including urine leakage, bowel obstruction and fluid collection (lymphocele, urinoma, hematoma, and abscess), neobladder rupture, vesicoureteral reflux, hydronephrosis, urinary tract infection, urinary calculi, abdominal incisional hernia, bowel obstruction, intraneobladder tumor, and tumor recurrence. Radiological imaging including multiple modalities such as intravenous urography, cystography, CT, and MRI plays an important role in the postoperative evaluation of patients with orthotopic neobladder reconstruction and is an accurate method for evaluating complications. In addition, knowledge of appearances on multimodal imaging helps clinicians to select the modality required to achieve an accurate diagnosis of each complication and avoid misdiagnosis.

Diagnostic imaging is undoubtedly important in modern medicine, and final clinical decisions are often made based on it. Fortunately, Japan has the highest numbers of diagnostic imaging instruments, such as CT and MRI devices, and boasts easy access to them as well as a high level of diagnostic accuracy. In consequence, a very large number of imaging examinations are performed, but diagnostic instruments are installed in so many medical facilities that expert management of these examinations tends to be insufficient. Particularly, in order to avoid risks, clinicians have recently become indifferent to indications of imaging modalities and tend to rely on CT or MRI resulting in increasing the number of imaging examinations in Japan. This is a serious problem from the viewpoints of avoidance of unnecessary exposure and medical economy. Under these circumstances, the Japan Radiological Society and Japanese College of Radiology jointly initiated the preparation of new guidelines for diagnostic imaging. However, the field of diagnostic imaging is extremely wide, and it is impossible to cover all diseases. Therefore, in drafting the guidelines, we selected important diseases and focused on "showing evidence and suggestions in the form of clinical questions (CQs)" concerning clinically encountered questions and "describing routine imaging techniques presently considered to be standards to guarantee the quality of imaging examinations". In so doing, we adhered to the basic principles of assuming the readers to be "radiologists specializing in diagnostic imaging", "simultaneously respecting the global standards and attending to the situation in Japan", and "making the guidelines consistent with those of other scientific societies related to imaging". As a result, the guidelines became the largest ever, consisting of 152 CQs, nine areas of imaging techniques, and seven reviews, but no other guidelines in the world summarize problems concerning diagnostic imaging in the form of CQs. In this sense, the guidelines are considered to reflect the abilities of diagnostic radiologists in Japan. The contents of the guidelines are essential knowledge for radiologists, but we believe that they are also of use to general clinicians and clinical radiological technicians. While the number and contents of CQs are still insufficient, and while chapters such as those on imaging in children and emergency imaging need to be supplemented, the guidelines will be serially improved through future revisions. Lastly, we would like to extend our sincere thanks to the 153 members of the drafting committee who authored the guidelines, 12 committee chairpersons who coordinated their efforts, six members of the secretariat, and affiliates of related scientific societies who performed external evaluation.

Background: Increased use of computed tomography (CT) has resulted in greater detection of incidental breast lesions unrelated to the primary diagnostic inquiry., Purpose: To investigate the morphology and clinical significance of breast abnormalities detected incidentally by conventional CT., Material and Methods: A total of 2945 female patients underwent CT examinations of the body, including the chest, from May 2006 to April 2010. Two radiologists interpreted these CT scans independently and pointed out a mass or non-mass-like lesion as abnormalities in the breast. Patients who incidentally showed breast lesions on CT scans were identified by a computer-based search of the diagnostic reports and were enrolled in this study. The morphology and enhancement patterns of CT-detected breast lesions were evaluated according to BI-RADS-MRI., Results: In total, 32 clinically unexpected abnormal breast lesions were found in 31 (1.1%) patients. Twenty-nine of the 32 lesions were detected by contrast-enhanced CT and three by unenhanced CT. Ten breast cancers were found in 10 patients (0.34%), which yielded the prevalence for malignancy of 31% (10/32). Invasive ductal carcinomas accounted for eight lesions, while two were ductal carcinomas in situ (DCIS). Nine lesions were depicted as a mass and one DCIS was a non-mass-like lesion. Good morphological predictors of breast cancers for a mass were an irregular shape, a lobulated shape, and an irregular margin. Benign lesions accounted for 22 lesions from 21 patients (0.71%). Of these, 13 lesions in 13 patients were depicted as a mass and nine lesions in nine patients as a non-mass-like lesion., Conclusion: Unexpected breast lesions can be identified as a mass or non-mass-like lesion on conventional chest CT scans. Among these, breast cancers that are not clinically apparent occur with considerable prevalence. We suggest that careful interpretation of the breast should be a routine part of CT examinations., (© 2013 The Foundation Acta Radiologica.)

Purpose: The purpose of this retrospective study was to evaluate the diagnostic performance of positron emission tomography/computed tomography (PET/CT) with fluorine-18-labeled 2-fluoro-2-deoxy-D-glucose (FDG) in comparison with that of ultrasonography and contrast-enhanced computed tomography (CT) in detecting axillary lymph node metastasis in patients with breast cancer., Materials and Methods: Fifty patients with invasive breast cancer were recruited. They had received no neoadjuvant chemotherapy and underwent PET/CT, ultrasonography and contrast-enhanced CT before mastectomy. The clinical stage was I in 34 patients, II in 15 patients, and III in one patient. The images of these modalities were interpreted in usual practice before surgery and the diagnostic reports were reviewed for analysis. Sensitivity, specificity, positive predictive value, and negative predictive value of each modality were obtained taking histopathological results of axillary lymph node dissection or sentinel lymph node biopsy as the reference standard., Results: Axillary lymph node metastasis was confirmed in 15 of 50 patients by histopathological studies. PET/CT identified lymph node metastasis in three of these 15 patients. The overall sensitivity and specificity, positive predictive value, and negative predictive value of PET/CT in the diagnosis of axillary lymph node metastasis were 20, 97, 75, and 74%, and those of ultrasonography were 33, 94, 71, and 77% and those of contrast-enhanced CT were 27, 97, 80, and 76%, respectively., Conclusions: PET/CT showed poor sensitivity and high specificity in the detection of axillary lymph node metastasis of breast cancer. Diagnostic performance of PET/CT was not superior to that of ultrasonography and contrast-enhanced CT.

Objective: The purpose of this study was to describe the MRI features of the pure and mixed forms of mucinous carcinoma of the breast and the histopathologic correlation., Materials and Methods: Seventeen pure and three mixed mucinous tumors of the breast were examined with T2-weighted MRI and triple-phase dynamic MRI. MR images were reviewed for evaluation of the signal intensity and enhancement patterns of tumors and for correlation with the histopathologic findings., Results: The presence of very high signal intensity on T2-weighted images was a common feature of pure and mixed mucinous tumors. Fourteen pure tumors and one mixed tumor had very high signal intensity, and three pure and two mixed tumors had very high signal intensity and isointensity on T2-weighted images. The enhancement pattern during the early phase varied with the cellularity of pure tumors and with the distribution of nonmucinous components in mixed tumors. Hypocellular pure mucinous tumors had a typical pattern of gradual enhancement., Conclusion: Hypercellular pure mucinous tumors exhibit strong early enhancement and may be difficult to differentiate from mixed mucinous tumors. The distinction between the pure and mixed forms of mucinous carcinoma is important because mixed mucinous carcinoma more frequently undergoes lymph node metastasis and has a poorer prognosis than does pure mucinous carcinoma.

Schistosomiasis is an infection of trematodes, Schistosoma, causing periportal fibrosis and liver cirrhosis due to deposition of eggs in the small portal venules. In schistosomiasis caused by S. mansoni, sonography shows echogenic thickening or fibrotic band along the portal veins. CT shows low-attenuation bands or rings around the large portal vein branches in the central part of the liver with marked enhancement. Hepatoplenomegaly, liver cirrhosis, portal hypertension and gastroesophageal varies are commonly associated. In schistosomiasis caused by S. japonicum, sonography shows echogenic septae in the liver, utlining the polygonal liver lobules, mimicking "fish-scale" network appearance, reflecting fibrosis. CT shows periportal septae in the peripheral part of the liver parenchyma, producing "turtle-back" appearance, representing calcified eggs along the portal tracts. The portal tracts and hepatic capsule are enhanced on contrast-enhanced CT images. The size and shape of the liver are relatively preserved. MR images show fibrous septae as low signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and these fibrous septae are enhanced. CT images of the lungs show multiple scattered nodules with halo of ground-glass opacities. Exudative granulomatous inflammation of the colonic wall may produce inflammatory polyps, fibrous thickening or stenosis of the colonic wall.

Acute tumor lysis syndrome results from a sudden and rapid release of products of cellular breakdown after anticancer therapy. Severe alterations of metabolic profile might occur and result in acute renal failure. We present a patient with a large hepatocellular carcinoma who received transcatheter oily chemoembolization and died subsequently of this syndrome. To our knowledge, there has been only one report of this syndrome induced by chemoembolization for hepatocellular carcinoma. This case illustrates the need to anticipate the development of acute tumor lysis syndrome when chemoembolization is planned for a large hepatocellular carcinoma.

Purpose: In patients with huge leiomyoma and with adenomyosis of the uterus, a peculiar area of hypointensity was occasionally observed on postcontrast magnetic resonance (MR) imaging in the dorsal portion of the enlarged uterus near the sacral promontory. We describe the imaging characteristics of these MR findings and correlate them with histopathological findings to examine whether the areas represent specific pathological changes., Methods: Ten patients with huge leiomyomas and two with huge adenomyotic lesions whose imaging revealed the hypointensity were enrolled. All had enlarged uteri that extended beyond the sacral promontory. MR findings of the hypointense areas were evaluated and correlated with histopathological findings in 5 patients with leiomyoma and two with adenomyosis who had hysterectomy., Results: The ten patients with leiomyoma showed flare-shaped hypointensity arising from the dorsal surface of the uterine body that extended deep into the tumor. The base of the hypointense areas was narrow in 5 patients with intramural leiomyoma and broad in five with subserosal leiomyoma. Two patients with adenomyosis showed nodular-shaped areas of hypointensity in front of the sacral promontory. Precontrast T(1)- and T(2)-weighted MR images showed no signal abnormalities in the portions corresponding to the hypointensity in any of the 12 patients. Pathological examinations showed no specific findings in the portions corresponding to the hypointensity in the 7 patients who had hysterectomy., Conclusion: The areas of hypointensity may represent functional changes, such as decreased localized blood flow caused by compression of the sacral promontory.

Objective: The purpose of this retrospective study was to determine the usefulness of delayed phase imaging for detecting small (< or = 2 cm) hepatocellular carcinomas (HCCs) in patients with liver cirrhosis., Materials and Methods: Triphasic (arterial, portal venous, and delayed phases) dynamic CT was performed in 33 patients with 48 HCCs proven histopathologically and in 65 control subjects. Arterial, portal venous, and delayed phase images were obtained 30 seconds, 68-70 seconds, and 5 minutes after the start of contrast material injection, respectively. Three blinded observers reviewed the images independently and evaluated tumor attenuation. Diagnostic performance for the combination of phases was assessed using receiver operating characteristic (ROC) curve analysis., Results: On arterial phase images, 28 of the 48 HCCs were hyperattenuating, nine were isoattenuating, and 11 were hypoattenuating. On portal venous phase images, three tumors were hyperattenuating, 17 were isoattenuating, and 28 were hypoattenuating. On delayed phase images, five tumors were isoattenuating, and 43 were hypoattenuating. The mean sensitivity for the combination of arterial and portal venous phase imaging was 86.8%, that for the combination of arterial and delayed phase imaging was 90.3%, and that for the combination of all three phase imaging was 93.8%. The area underneath composite ROC curve (A(Z)) for the combination of all three phase imaging (A(Z) = 0.940) was significantly higher than that for the combination of arterial and portal venous phase imaging (A(Z) = 0.917) and for the combination of arterial and delayed phase imaging (A(Z) = 0.922)., Conclusion: Delayed phase imaging is useful for detecting small HCCs and should be included in dynamic CT examinations of patients with liver cirrhosis.

Pulmonary epithelioid hemangioendotheliomas (PEH), also known as intravascular sclerosing bronchoalveolar tumor, is a rare vascular tumor of the lung common among young women. Primitive lumena lined by single cells is the characteristic pathologic feature. The endothelial nature of these cells is confirmed by positive staining with factor VIII and CD34. PEH usually presents as single or multiple pulmonary nodules. The present report describes high resolution CT (HRCT) findings of 2 cases with unusual manifestations of PEH. One case was a 54-year-old woman with multiple pulmonary nodules with irregular thickening of both the bronchovascular bundles and perilobular structures, representing intensive lymphangitic spread on HRCT. The other was an 18-year-old woman who had multiple minute peripheral nodules in the lungs bilaterally. These HRCT findings demonstrated the presence of tumor nodules in the lymphatic spaces, which is quite an unusual histologic presentation for this tumor. Both cases also showed hepatic lesions on abdominal CT; the former showing hypoattenuating masses with coarse calcifications and the latter showing multiple tiny calcifications in the hepatic parenchyma. Recognition of these features in the appropriate clinical setting may allow the clinician and the pathologist to consider this rare tumor.

Purpose: To compare the performance of the phased-array coil (PAC) with that of the single-loop coil (SLC) in magnetic resonance (MR) imaging of the breast., Materials and Methods: MR imaging was performed with a 1.5T MR imager. A phantom study was performed with the right element of the two coils to obtain their signal-to-noise ratio (SNR). MR images of the breasts of 12 patients with breast lesions were obtained with the PAC and SLC, and these images were reviewed by five readers in a blind evaluation employing a scoring system for assessing overall image quality., Results: In the phantom study, the SLC exhibited a SNR 1.82 times higher than that of the PAC at the center of the coil; however, the SLC exhibited an inhomogeneous sensitivity profile and its SNR varied with the distance from the center of the coil in the horizontal and vertical directions. In most of the 12 patients, the MR images obtained with the PAC showed more noise than did those obtained with the SLC, and the PAC obtained lower scores than the SLC in the assessment of overall image quality; however, the difference was significant (p < 0.05) only in coronal imaging. On the other hand, the uniformity of fat saturation in the MR images obtained with the PAC was judged to be significantly superior to that obtained with the SLC (p < 0.05)., Conclusion: Compared with the SLC, the PAC exhibited a lower SNR and was less advantageous at depicting the breast. However, the PAC provided more homogeneous fat saturation and might be useful for reducing artifacts.

Current advances in the diagnostic imaging for lung cancer includes multidetector-row CT (MDCT), lung cancer screening using low-dose MDCT and fluorodeoxyglucose positron emission tomography (FDG-PET) imaging. There is no question about the clinical usefulness of MDCT, and the further development of the hardware and the software of MDCT will open new horizons for CT diagnosis. PET is not an alternative modality to CT but a supplementary one, which adds metabolic information to the morphology. Recently, experimental research on the refraction imaging of human lung specimens has been performed with synchrotron radiation. With progressive refinement, this technique may come to have some practical purpose in diagnosing lung cancer in vivo.

Purpose: The aim of this study was to describe delayed phase dynamic CT findings of advanced (T2-T4) gastric cancer and to correlate with histopathologic findings., Method/materials: Quadruple phase dynamic CT including delayed imaging taken five minutes after the start of injection of contrast material was performed in 43 patients with 45 advanced gastric cancer and 20 control subjects with no gastric lesions. On delayed phase CT scans, the attenuation of the gastric wall was equal to or lower than that of the liver parenchyma in the control subjects, therefore, the presence of higher attenuation in the gastric wall was considered to be abnormal and defined as delayed enhancement. Histopathologic findings in the tumors showing delayed enhancement were compared with those in the tumors without this feature., Results: Delayed enhancement was seen in 26 (57%) of the 45 tumors. Eleven of 25 differentiated-type tumors and 15 of 20 undifferentiated-type tumors showed delayed enhancement (P < .05). Delayed enhancement was seen in one of five medullary type tumors, in 11 of 25 intermediate-type tumors, and in 14 of 15 scirrhous-type tumors (P < .005)., Conclusions: Delayed enhancement was frequently seen in the tumors with abundant fibrous tissue stroma. Delayed phase dynamic CT may be useful for the characterization of advanced gastric cancer.

Purpose: To examine whether the pituitary gland enlarges in patients with spontaneous intracranial hypotension (SIH)., Materials and Methods: All six patients were women ranging in age from 17 to 51 years. They developed severe headache that was completely relieved by lying flat, and MR imaging showed diffuse enhancement of the pachymeninx. They were clinically diagnosed with SIH. The height of the pituitary gland was measured on midsagittal MR image., Results: Pituitary heights ranged from 8 to 11 mm. The measurements were greater than the size of the normal pituitary gland in women described age-matched in the previous report. In one case, follow-up MR images showed that the size of the pituitary gland was decreased from 11 to 5 mm in height., Conclusion: The pituitary gland was enlarged in all six patients with SIH on MR images. SIH may cause enlarged pituitary gland.

To define the frequency of decreased signal intensity (DSI) in cerebral cortex on T2-weighted images relative to aging and to the incidence of identifying white matter pathology, T2-weighted MR brain images of 906 patients consecutively examined between July 1989 and June 1991 were reviewed. MR images of cerebral cortex were divided into five areas: frontal lobe (F), pre- and postcentral gyri (C), parietal lobe (P), occipital lobe (O) and temporal lobe (T). Each area was separately and independently evaluated for the presence or absence of DSI. The frequency of DSI in each area was plotted against patients' ages. The severity of leukoaraiosis was evaluated in relation with DSI in each cortical area. Patients with DSI in area F numbered 61 (5.7%), in area C 236 (26.0%), in area P 174 (15.9%), in area O 428 (47.2%), and in area T 10 (1.1%). The number of patients with DSI in each area increased with age. The greater the severity of leukoaraiosis, the greater the chance of finding DSI of the cerebral cortex. The incidence of DSI in the cerebral cortex increased with the patient's age as well as with the severity of co-existent white matter pathology.

Thallium-201 (201Tl) SPECT was performed 48 times in 26 patients to clarify its usefulness in the evaluation of malignancy and viability of brain tumors. The early counts ratio (ER) and delayed counts ratio (DR) of a lesion compared with normal brain were obtained 10-15 minutes and 3 hours, respectively, after intravenous administration of 185 MBq of 201Tl chloride. Untreated high grade malignant tumors and recurrent tumors did not always show high ER and DR, and they were widely distributed. High grade malignant tumors that showed low ER and DR were not well enhanced on CT or MRI. In low grade malignant tumors, such as pituitary adenoma which was well enhanced on CT, ER and DR were as high as in high grade malignant tumor. Whether a tumor recurred within three months after radiotherapy or not was retrospectively predicted at accuracy rates of 93.8% and 87.5% with cut-off points of 4.0 for ER and 3.5 for DR. Cerebral radiation necrosis showed ring-like increased uptake of 201Tl in proportion to the progress of necrosis and intensity of enhancement on MRI. In conclusion 201Tl SPECT is considered to be less useful for lesions that are well enhanced on CT, because they show high uptake of 201Tl regardless of their malignancy and viability. On the other hand, in tumors that are not well enhanced on CT. 201Tl shows good accumulation in viable and high grade malignant lesions. 201Tl SPECT should be performed in such cases.

Objective: Chronic hepatic schistosomiasis japonica is a disorder characterized by broad fibrous septa in the liver. The ability to recognize these septa on MR images might enable distinction of this lesion from other cirrhotic disorders. The purpose of this study was to analyze the MR appearance of these septa., Materials and Methods: MR images of 18 patients who had typical calcifications of hepatic septa on CT scans were reviewed. The diagnosis was proved by biopsy in six patients. In the remaining 12, stool examinations were positive for schistosomiasis. T1-weighted MR images and T2-weighted and intermediate (long repetition time and short echo time) MR images acquired with the use of gradient-moment nulling were obtained in all 18 patients. In eight of 18 patients, additional T2-weighted and intermediate images were obtained without gradient-moment nulling. Fifteen patients had contrast-enhanced T1-weighted images. The presence of abnormal MR signal and its intensity at sites corresponding to the septa seen on CT scans were studied., Results: MR images showed the septa as linear abnormalities frequently seen in the subdiaphragmatic portion of the right lobe of the liver. On T1-weighted images, septa had low signal intensity and were identified in nine of 18 patients. On T2-weighted images obtained with gradient-moment nulling, septa had high signal intensity and were seen in 13 of 18 patients. On T2-weighted images obtained without gradient-moment nulling, the septa had primarily low signal intensity and were seen in five of eight patients. On intermediate MR images obtained with gradient-moment nulling, the septa had primarily high signal intensity and were seen in nine of 18 patients. On intermediate images obtained without gradient-moment nulling, the septa had primarily low signal intensity and were seen in four of eight patients. In nine of 15 patients, septa were visualized as high-signal-intensity lesions on contrast-enhanced T1-weighted images. In 14 of 18 patients, the septa were detected in one or more sequences., Conclusion: Our experience suggests that MR imaging in patients with chronic schistosomiasis of the liver depicts the morphologic features of hepatic septa. MR signal characteristics of septa are not unique, but use of gradient-moment nulling alters the signal intensity of septa, similar to that of blood vessels, on intermediate and T2-weighted images.

Objective: The purpose of this study was to determine the findings on contrast-enhanced CT scans in patients with hepatic schistosomiasis japonica and to determine their pathologic basis., Materials and Methods: Unenhanced and contrast-enhanced CT scans of 113 patients with histologically proved schistosomiasis were reviewed. Radiologic and pathologic findings were correlated after autopsy in 19 patients., Results: Unenhanced CT scans showed septal calcification in the liver parenchyma in 53 patients (47%) and capsular calcification along the hepatic surface in 29 patients (26%). Twenty-seven patients (24%) had both types of calcification. Fifty-four patients (48%) showed one or more types of enhancement. Septal enhancement (i.e., linear enhancement of hepatic parenchyma looking like septa in the liver) was seen in 52 patients (46%). Forty-seven of the 53 patients who had septal calcification on unenhanced CT scans had septal enhancement on scans obtained after the administration of contrast material. The enhancement was found at sites of septal calcification in 44 patients and at noncalcified sites in 18 (15 had enhancement at both calcified and noncalcified sites). Five of 60 patients who did not have septal calcification on unenhanced CT scans had septal enhancement at noncalcified sites on scans obtained after the administration of contrast material. Amorphous enhancement (i.e., poorly defined and irregularly shaped enhancement) was seen in six patients (5%). Capsular enhancement (i.e., curvilinear enhancement along the hepatic surface) was seen in 12 patients (11%). Histologic studies showed broad fibrous septa at sites of septal enhancement., Conclusion: CT findings in patients with schistosomiasis japonica involving the liver include septal, amorphous, and capsular contrast enhancement. Septal enhancement occurs in broad fibrous septa. CT evidence of septal enhancement may suggest the diagnosis of hepatic schistosomiasis japonica, especially when no calcification is seen on unenhanced CT scans.

Intracavitary irradiation using a high-dose-rate Ir-192 remote after-loading system was applied to 14 advanced or inoperable patients with esophageal carcinoma as a boost therapy. The total dose of external irradiation was 45-70 Gy/15-35 fractions and that of intracavitary irradiation was 11.6-34.0 Gy/2-4 fractions at a point 5 mm deep from the inner surface of the esophageal mucosa. The time-dose-fractionation factor (TDF) of the whole treatment was 116-186 (mean, 146). Six patients (43%) had complete response (CR), three (21%) had partial response and five (36%) had no response. Esophageal carcinoma that showed exophytic growth, was less than 5 cm ling, and showed favorable response to external irradiation was likely to be a good candidate for intracavitary radiation boost therapy. Fistula formation was produced in five patients (36%), four of whom were irradiated at more than 140 TDF. All six CR patients were free from esophageal tumors, but severe esophageal stenosis due to radiation injury developed in five (83%) of them. They were irradiated at more than 135 TDF. One- and two-year survival rates were 28.6% and 14.3%, respectively. The poor prognosis was ascribed to the frequent occurrence of fatal radiation stenosis and fistula formation. An appropriate therapeutic dose for esophageal carcinoma that does not cause severe radiation stenosis was estimated to be under 120 TDF.

Magnetic resonance (MR) features of five primary malignant mesenchymal neoplasms (plasmocytoma, leiomyosarcoma, undifferentiated sarcoma, epithelioid hemangioendothelioma, and angiosarcoma) of the liver were reported. All tumors were hypointense on T1-weighted images and hyperintense on T2-weighted images. No halo and intravenous extension were noted. A target appearance was revealed in epithelioid hemangioendothelioma. MR findings of angiosarcoma were essentially the same as those of cavernous hemangiomas (markedly hyperintense with hypointense linear septa on T2-weighted images). MR findings of these rare hepatic malignancies were nonspecific, although they were quite different from those of typical hepatocellular carcinomas. This study suggested that MR differentiation of primary hepatic mesenchymal tumors from other common benign and malignant neoplasms was difficult; however, the number of studied cases was limited.

Dense accumulation of Lipiodol in hepatic segmental parenchyma was studied by computed tomography (CT) after transarterial chemoembolization (TACE) for hepatic tumor. Six patients showed dense accumulation of Lipiodol in hepatic segmental parenchyma on CT two weeks after TACE. Four of the six showed parenchymal accumulation of Lipiodol as dense as that in a tumor at three weeks after TACE. Therefore, it was considered that evaluation with CT should be performed after one month or more in order to differentiate between Lipiodol accumulation in tumors and that in non-neoplastic liver parenchyma.

Magnetic resonance imaging (MR imaging) provides a sensitive method for mapping the normal and pathological distribution of iron in the brain. High field strength MR imaging (1.5 T) was used to evaluate eight patients with amyotrophic lateral sclerosis (ALS) and 49 neurological normal control patients. All eight ALS patients showed decreased signal intensity in the motor cortex on T2-weighted images, while only one of the normal control patients showed this finding. The results suggested that the decreased signal intensity in the motor cortex in ALS was caused by the deposition of iron in this area.

Direct communication between portal branches and the hepatic vein [macroscopic intra-hepatic portal-hepatic venous shunt (IPHVS)] is a rare entity. We have recently studied five patients with this condition. Magnetic resonance imaging (MRI) clearly demonstrated in each case the portal-hepatic venous shunt due to "flow void." Multiple diffuse shunts were present in one case and a solitary shunt was demonstrated in the others. The solitary shunt was either tubular, focally dilated or racemose in configuration. The MRI findings and clinical significance of this rare entity are discussed.

Patients whose Ga-67 whole-body images showed increased uptake by the bone/bone marrow of the lower extremities were selected and classified into three types according to the extent and the grade of the visualization. These types were then compared with their serum iron levels, iron-binding capacities, and the results of several other serum biochemical tests. Of 374 consecutive whole body 72-hr images reviewed, 59 (15.8%) showed increased uptake of the tracer by the bone/bone marrow of the lower extremities. The three classified types were as follows: type T--visualization of both tibiae and femurs; type S--strong visualization of the femurs; and type W--weak visualization of the femurs. The serum iron concentration was significantly high in type T and low in type S. In conclusion, the pattern of Ga-67 uptake by the bone/bone marrow of the lower extremities fairly closely reflects the status of iron metabolism.

A newly developed instrument based on dual energy X-ray absorptiometry (DEXA), Hologic QDR-1000, was evaluated fundamentally and clinically. Image quality was quite satisfactory though radiation exposure was minimal, 780.2 nC/kg (3.024 mR) for lumbar measurement. Reproducibility of the repeated measurement of a phantom was fairly good; 0.343 CV% in a same day and 0.520 CV% in a long period. Accuracy determined by measurement of potassium phosphate solution was also satisfactory. Bone mineral densities measured by this instrument were fairly correlated with those measured by single energy quantitative CT; coefficient was 0.740 for 17 patients. Mix-DP plates of more than 10 cm thick overestimated the bone mineral densities of a phantom. Bone mineral densities of Japanese normal volunteers were in the normal range (mean +/- 2SD) of the Americans though mostly lower than the mean. In patients with spondylosis deformans or prominent aortic calcification, bone mineral densities might be overestimated. Lateral view was obtainable though its reproducibility was not good. Positioning especially for measuring femoral neck was quite critical for reproducible measurement. In conclusion, this new instrument is quite accurate and satisfactory for clinical application to measuring bone mineral densities.

Thirty-eight Ga-67 scintigraphies have been evaluated in regard to patients with an untreated malignant lymphoma or a recurrent lymphoma after a complete remission. Thirty-four studies (89%) showed positive findings. Waldeyer's ring and lymph node involvement were detected in 66% of the cases. The recurrent type was detected less often than the untreated malignant lymphoma, and there was no significant difference in detectability between Hodgkin's disease and non-Hodgkin's lymphoma. Although the malignancy grade for NHL did not affect the detectability, the intermediate and high grade NHLs tended to show a greater uptake than the low grade NHLs. The detectability was particularly good for neck and intrathoracic lymph nodes. Ga-67 scintigraphy tended to downgrade a malignant lymphoma to a lower stage, especially if in recurrence.

The authors report 4 cases of intestinal calcification detected by computed tomography in patients with Schistosomiasis japonica. The calcification was present in the duodenum in 1 and in the rectum and/or colon in 3.

Ga-67 scintigrams in patients with malignant diseases sometimes reveal uptake of the tracer in the bone metastases. Detectability of Ga-67 scintigraphy for metastatic bone tumors and benign bone lesions was compared with that of Tc-99m bone scintigraphy. Countable bone metastases detected by bone scintigraphy were evaluated whether the lesion showed apparent, faint, or negative Ga-67 uptake. Of 47 lesions 23 (49%) showed apparent uptake and 17 (36%) showed negative uptake. On the other hand, of 71 benign bone lesions, only 7 (10%), mostly fracture/osteotomy, showed apparent uptake of the tracer. Uptake in the other benign lesions such as trauma of the ribs, spondylosis deformans, and arthrosis deformans was rather faint. In patients with multiple bone metastases, 9 patients (82%) out of 11 showed more prominent abnormal findings in Tc-99m MDP bone scintigraphy than in Ga-67 scintigraphy; that is, Ga-67 scintigraphy was not able to reveal all metastatic bone lesions. In patients with untreated or recurrent tumors, relation between Ga-67 uptake in the tumors and that in the bone metastases was evaluated. Of 7 patients with negative Ga-67 uptake in the primary tumors, 5 showed positive Ga-67 uptake in the bone metastases; that is, there seemed to be little relation between Ga-67 affinity to the primary tumors and that to the bone metastases. Mechanisms of the Ga-67 uptake in the bone metastases were discussed. Not only the tumor cells or tissues in the bone metastases but also bone mineral or osteoclasts might be the deposition sites of Ga-67.

67Ga scintigrams in a patient with malignant lymphoma before and after chemotherapy are presented. 67Ga did not accumulate in the mostly necrotic mass with some viable cells. Negative uptake of 67Ga might reflect necrosis of the tumor; however, it is difficult to detect some residual tumor cells. Therefore, negative uptake of 67Ga in the mass seen in X-ray CT may not be totally reliable evidence of eradication of viable tumor cells.