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Objective: To evaluate the area of the midbrain and pons on mid-sagittal MRI in patients with progressive supranuclear palsy (PSP), Parkinson disease (PD), and multiple-system atrophy of the Parkinson type (MSA-P), compare these appearances and values with those of normal control subjects, and establish diagnostic MRI criteria for the diagnosis of PSP.Methods: The authors prospectively studied MRI of 21 patients with PSP, 23 patients with PD, 25 patients with MSA-P, and 31 age-matched normal control subjects. The areas of the midbrain tegmentum and the pons were measured on mid-sagittal MRI using the display tools of a workstation. The ratio of the area of the midbrain to the area of the pons was also evaluated in all subjects.Results: The average midbrain area of the patients with PSP (56.0 mm2) was significantly smaller than that of the patients with PD (103.0 mm2) and MSA-P (97.2 mm2) and that of the age-matched control group (117.7 mm2). The values of the area of the midbrain showed no overlap between patients with PSP and patients with PD or normal control subjects. However, patients with MSA-P showed some overlap of the values of individual areas with values from patients with PSP. The ratio of the area of the midbrain to the area of pons in the patients with PSP (0.124) was significantly smaller than that in those with PD (0.208) and MSA-P (0.266) and in normal control subjects (0.237). Use of the ratio allowed differentiation between the PSP group and the MSA-P group.Conclusion: The area of the midbrain on mid-sagittal MRI can differentiate PSP from PD, MSA-P, and normal aging.

We report herein the case of a 43-year-old man in whom gastrointestinal bleeding was found to be caused by a large arteriovenous malformation (AVM) in the ileum. Emergency angiography proved invaluable in disclosing the AVM as the bleeding source, after which the patient was successfully treated by surgery. Although the number of reports of AVM has recently been increasing, ileal AVMs are still relatively rare. Moreover, according to the Japanese literature, no other patient has had such marked and large feeding arteries and draining veins as those in the patient described in this report.

We report three cases of cystic islet cell tumors, two caused by gastrinomas and the other by an islet cell carcinoma. All three patients underwent computed tomography (CT) and angiography and two also had magnetic resonance (MR) imaging. Several common radiographic findings were present as follows: thickening of the cyst wall and irregularity of the inner surface on postcontrast CT and MR images, neovascularity and a densely staining hypervascular rim on angiography, and moderately increased signal intensity of the cyst content on T1-weighted MR images, which indicated fluid containing blood and/or necrotic tissue. These findings are helpful in defining the nature of these lesions and strongly suggest that cystic islet cell tumor should be included in the differential diagnosis.

IVL is characterized by a propensity for intravascular tumor cell proliferation. Premortem diagnosis of IVL is difficult because of its nonspecific clinical, laboratory, and imaging manifestations. This study examined cerebral MR imaging patterns of IVL and their changes with and without chemotherapy. Nine of 11 patients studied presented with abnormal findings. We define 5 patterns of abnormal MR imaging findings: 1) infarctlike lesions, 2) nonspecific white matter lesions, 3) meningeal enhancement, 4) masslike lesions, and 5) hyperintense lesions in the pons on T2WI. Seven patients presented with only 1 pattern, while 2 patients presented with multiple patterns. Lesions in 7 treated patients responded to chemotherapy. Pathologic specimens revealed intravascular tumor cell infiltration with associated infarctions, necrosis, congestion, demyelination, vasculitis, and tumor cell extravasation. We conclude that MR imaging patterns can be possible manifestations of intravascular-dominant infiltration by tumor cells with associated occlusion or inflammation, depending on the level of affected vessels.

The MRI appearances of calcification within intracranial tumours was assessed by reviewing MR images of 11 calcified tumours documented by CT. The signal intensity of the calcified regions was varied and nonspecific on both T1- and T2-weighted images. They were seen as signal void exclusively on T2-weighted images in only 2 patients. Gadolinium enhancement of the calcified portion occurred in 7 of 10 patients. These findings reflect the presence of tumour parenchyma within the calcified region, as proved in 5 lesions examined histologically.

Dissection of the superior mesenteric artery (SMA) not associated with aortic dissection is rare. The purpose of this study is to describe the computed tomographic (CT) findings of this condition. We studied the CT findings of six patients with isolated dissection of the SMA. CT demonstrated thrombosis of the false lumen or intramural hematoma (n = 4) and/or intimal flap (n = 4) in all six patients. Other CT findings were enlarged diameter of the SMA (n = 5), increased attenuation of the fat around the SMA (n = 5), and hematoma in the mesentery with hemorrhagic ascites (n = 1). CT is useful for the diagnosis of isolated dissection of the SMA, and increased attenuation of the fat around the artery is considered the key to the diagnosis when no definite findings are evident.

A 67-year-old man was hospitalized at our institution complaining with epiphora and exophthalmos on the left side. Magnetic resonance imaging (MRI) showed an ill demarcated retrobulbar mass in the left orbit. 67Ga scintigraphy revealed avid uptake in the left orbital region. The patient was treated with radiation therapy. One month after the radiation therapy, the size of the mass decreased remarkably on MRI. 67Ga planar imaging after treatment showed no uptake, but 67Ga SPECT showed slightly increased uptake in the left orbital region. One year after the radiation therapy, MRI showed residual mass in the left orbital region. Both 67Ga planar imaging and SPECT showed no uptake in the left orbital region. 1.8 years after the radiation therapy, MRI showed the residual mass with no interval change in size. Both 67Ga planar imaging and SPECT showed no uptake in the left orbital region. The patient remains well with no evidence of local recurrence. 67Ga scintigraphy is useful in assessing the response to radiation therapy of MALT lymphoma in this case.

To evaluate radiation exposure to patients and radiologists during transcatheter arterial embolization(TAE) for hepatocellular carcinoma.In 39 TAE procedures performed at eight institutes, skin doses were evaluated with thermoluminescence dosimeters at the patient's back(entrance surface) and lower abdomen, and at the radiologist's forehead and abdomen. Real-time dosimeters were also used to evaluate patient skin dose.The patients' mean entrance surface dose was 973 +/- 681 mGy(range, 185 to 3543 mGy) with the mean fluoroscopic time of 21 minutes and 6 digital subtraction angiography(DSA) acquisitions. The dose at the patients' lower abdomen was 0.98 +/- 0.77 mGy. Doses for the radiologists were 0.04 +/- 0.04 mGy at the forehead and 0.15 +/- 0.19 mGy and 0.005 +/- 0.01 mGy at the abdomen over and under the apron, respectively. Fifty-six percent of the patients' skin dose was from DSA and 44% from fluoroscopy.Patient skin dose may occasionally exceed the dose for transient erythema. Because a patient may have repeated TAEs, skin doses or X-ray conditions should be recorded. The exposed doses of radiologists were considered to be acceptable with proper techniques. Further efforts to reduce radiation should be directed toward both DSA and fluoroscopy.

Wire-directed detachable balloons were used in embolization treatment of varicoceles in six patients. Advancement of the balloon over a guide wire allowed easy embolization of the internal spermatic vein at the level of the inguinal ring. Additional detachable balloons were used to occlude the collateral vessels to the varicocele. This method proved highly effective in embolization of tortuous veins and in placement of multiple balloons.

Preoperative transhepatic portal vein embolization may not always be sufficient to achieve the desired changes in contralateral hepatic volume and function. The beneficial role of additional transcatheter arterial embolization performed after inadequate response to preoperative transhepatic portal vein embolization is described.Four patients underwent both preoperative transhepatic portal vein embolization and transcatheter arterial embolization, and 6 control patients underwent preoperative transhepatic portal vein embolization only. Changes in right liver lobe volume fraction, residual left lobe volume fraction, and prediction score (low-risk,45; borderline, 45-55; high-risk55); were evaluated.1) The change in right liver lobe volume after both preoperative transhepatic portal vein embolization and transcatheter arterial embolization (volume after/before) was 0.75 times that of the original level whereas after preoperative transhepatic portal vein embolization, they were only 0.81 times that of the original level. 2) The change in residual left liver volume after both preoperative transhepatic portal vein embolization and transcatheter arterial embolization (volume after/before) was 1.40 times that of the original level whereas after preoperative transhepatic portal vein embolization they were only 1.30 times than the original level. The changes in left liver volume after preoperative transhepatic portal vein embolization/transcatheter arterial embolization was more favorable than those after preoperative transhepatic portal vein embolization only. 3) The change in prediction score after both preoperative transhepatic portal vein embolization and transcatheter arterial embolization (after/before) was 0.81 times that of the original level. All prediction score in high-risk patients recovered to the borderline or safety zone. Change after preoperative transhepatic portal vein embolization only (before/after) was 0.87 times that of the original level. 4) All 4 patients who underwent both preoperative transhepatic portal vein embolization and transcatheter arterial embolization received right hepatic lobectomy successfully and returned to their normal life style.Preoperative occlusion of right hepatic inflow vessels increased the volume and function of the contralateral lobe where high-risk patients recovered to the borderline zone for major hepatic resection.

1H-NMR spectroscopy was performed on a 6-month-old boy with pachygyria. A MRI study demonstrated an abnormally thick cortex localized in the right occipital lobe. 1H-NMR spectrums were collected from the lesion and the contralateral cortex that appeared normal on MRI. The N-acetylaspartate (NAA)/Cre (creatine) ratio was markedly lower in the abnormal cortex than in the contralateral cortex and the occipital cortex. NAA localizes to neurons, axons, dendrites and synaptic connections and increases with maturation of neurons. Its decrease is considered to represent the decrease in the number of these structures and/or disturbance of neuronal maturation. We conclude that NAA/Cre can be an important index that reflects the pathogenesis of pachygyria.

The purpose of this study was to evaluate the brain perfusion of neuro-Behçet disease using 99mTc-HMPAO. In total, nine patients (7 men and 2 women) were evaluated. Seven were in the chronic phase, one was acute and the other was subacute. The results of perfusion study were compared with the MRI findings. The findings of chronic-phase neuro-Behçet disease were as follows: 99mTc-HMPAO showed hypoperfusion of the cerebellum in 3, brain stem in 5, and cerebral cortex in 4 patients. Moreover, asymmetry of the basal ganglia and thalamus was seen in 4 cases with 99mTc-HMPAO. MRI showed atrophy of the cerebellum in 4, brain stem in 5 and cerebral cortex in 2 patients. One acute patient showed a perfusion defect with 99mTc-HMPAO that was consistent with the vasculitis shown with MRI. In the remaining subacute patient, perfusion defect was demonstrated with 99mTc-HMPAO, consistent with the infarction shown with MRI. It is concluded that brain perfusion scintigraphy is useful to evaluate the brain blood flow of neuro-Behçet disease.

For the evaluation of brain tumor (n = 15), we performed both dynamic and static 99mTc-ECD (ECD) SPECT studies 201Tl SPECT was also used for comparison with the results of ECD SPECT. Dynamic ECD SPECT was obtained following the injection of 600 MBq of ECD. Five min after the injection of ECD, static ECD SPECT was performed. 201Tl SPECT was obtained 10 min after the injection of 74MBq. Abnormal uptake was recognized in 7 of 15 tumors with dynamic ECD: 5 of 7 meningiomas, 1 of 1 glioblastoma and 1 of 1 astrocytoma. However, no abnormal uptake was seen in 3 of 3 benign tumors (1 low grade astrocytoma, 1 hemangioma, 1 cranio-pharyngioma) and in 2 of 2 brain metastases. In contrast abnormal uptake was seen in 11 of 15 tumors with 201Tl:7 of 7 meningiomas; 2 of 2 brain metastases, 1 of 1 glioblastoma and 1 of 1 craniopharyngioma. No abnormal uptake was seen in 3 of 3 benign tumors (1 hemangioma and 2 low grade astrocytomas). Equivocal uptake was seen in 1 low grade astrocytoma with dynamic ECD and 201Tl. The mechanism of the accumulation of dynamic ECD to brain tumor is unclear. However, it may reflect not only blood flow, but also metabolism.

To determine the factors that may be used to predict outcome of stent placement in patients with malignancies obstructing the superior or inferior vena cava.Gianturco stents were placed in 39 patients with malignant obstruction of the superior (n = 16) or inferior (n = 23) vena cava. Thirteen patients with obstruction of the superior vena cava received radiation therapy and/or chemotherapy at some time in their course of treatment. Computed tomographic (CT) scans were obtained in all patients. The authors analyzed treatment outcome with the location, length, and CT appearance of obstruction.Venous congestive symptoms disappeared after stent placement in 35 patients and remained in four. Symptoms did not recur during 1-13-month follow-up in 32 of the 35 patients in whom the symptoms disappeared. Nonfatal complications were observed in nine patients. Results of multivariate analysis showed that the outcome of stent placement is best predicted by the appearance of obstructions on CT scans irrespective of the location and length of the lesions.Good results can be expected from placement of Gianturco stents except when CT shows the obstruction to be totally enveloped by tumor.

Our purpose was to assess the value of three-dimensional (3D) CT angiography in the diagnosis of moyamoya disease. We studied seven patients with moyamoya disease proved by conventional angiography. Three-dimensional (3D) CT angiography was performed using rapid sequence or helical (spiral) scanning in conjunction with a bolus injection of intravenous contrast medium. All seven patients could be diagnosed as having moyamoya disease on the basis of the following 3D CT angiographic findings: poor visualisation of the main trunks and/or major branches of anterior and middle cerebral arteries (7 patients); dilated leptomeningeal anastomotic channels from the posterior cerebral arteries (4); and demonstration of "moyamoya vessels" in the basal ganglia (2). Although conventional angiography remains the principal imaging technique for demonstrating anatomical changes in detail, less invasive 3D CT angiography provides a solid means of diagnosing moyamoya disease when it is suspected on CT, MRI, or clinical grounds.

We have developed an embolizing material consisting of Y-shaped silicone particles for partial splenic embolization. Wide spaces for blood flow are left around the particles when these are lodged in arterial branches. We embolized one kidney in each of 3 dogs with the particles and observed a slowly induced occlusion of renal arterial branches during one month. The particles were also used for partial splenic embolization in 14 patients. The average portion of infarcted spleen tissue 7 days after embolization was 51% calculated from CT images. In 6 patients who had CT both 2 and 7 days after embolization, the average rate of splenic infarction increased from 29% at 2 days to 60% at 7 days. Our patients required analgesics for only 2.3 days on average. The Y-shaped silicone particles by slowly occluding splenic arterial branches produce ischemia in a gradual fashion which may minimize the pain after embolization.

To compare the clinical value of three-dimensional (3D)-CT angiography using spiral scanning and 3D-time-of-flight (TOF) MR angiography in the diagnosis of cerebral aneurysms, the results of these studies were compared in 12 patients with a total of 17 aneurysms. In seven of the 17 aneurysms, anatomic details were visualized better by 3D-CT angiography than by MR angiography. Both studies demonstrated five aneurysms equally well. MR angiography delineated three aneurysms better than 3D-CT angiography. Both studies failed to demonstrate two very small aneurysms. In 3D-CT angiography, aneurysms were viewed from many view angles, allowing the assessment of the spatial relationship between an aneurysm and the surrounding vascular and bone structures. Considering the use of contrast material and irradiation, 3D-CT angiography is of value in delineating aneurysms which are equivocal on MR angiography. In addition, 3D-CT angiography is a potential preoperative adjunct to conventional angiography.

Gianturco expandable metallic stents were placed in 14 patients with 19 malignant lesions who had tracheobronchial stenosis and/or obstruction together with dyspnea. In all 14 patients, stenotic and/or obstructive changes disappeared immediately after the procedure, and the dyspnea improved. Lumina at the sites of tracheal lesions expanded from a mean of 3.9 mm in diameter before stent placement to a mean of 13.9 mm after stent placement. Lumina at the sites of bronchial lesions expanded from a mean of 2.1 mm to a mean of 10.3 mm. Lumina at the sites of lesions caused by extrinsic compression expanded to a mean of 89.7% of normal, while lumina at the sites of lesions caused by intraluminal tumor growth expanded to a mean of 63.2% of normal. There was improvement of at least one grade of the Hugh-Jones classification in 12 patients. Ten of the patients died; in two of these patients, restenosis developed.

The main pancreatic duct was studied endoscopically by inserting an ultra-thin pancreatoscope into the normal papilla of Vater. Recently, we developed a new pancreatoscope system and improved the image, the durability, and the ease of use. A special video converter was connected to the head of the pancreatoscope. The sequential electronic endoscope images were observed on a TV monitor. We performed examinations with this new system in 52 cases (8 with pancreatic cancer, 19 with chronic pancreatitis and 25 normal cases). We studied the brightness, color and quality of the images on 35-mm film and on videotape. As a result, it has become clear that the images obtained with this system are much better than those obtained by the conventional method. Although further improvement in the ability to angulate the endoscope is necessary, this new pancreatoscope system should help diagnose diseases of the pancreas.

Gianturco expandable metallic stents were placed in 5 patients with dyspnea on exercise due to tuberculous bronchial stenosis. The stents were placed after dilatation with a 10-mm diameter high pressure balloon catheter. In all 5 patients, obstructive changes disappeared following the procedure, and dyspnea on exercise improved markedly. No complications related to the procedure were encountered. At follow-up during a period of up to 38 months, 2 patients showed bronchial restenosis at 11 and 17 months, respectively, after stent placement. Restenosis by granulomatous tissue was successfully treated by laser ablation. One patient showed slight one-day hemoptysis 26 months after stent placement.

The authors report the embolization of an unruptured nondissecting vertebral fusiform aneurysm using a new silicone detachable balloon that they have developed, which is advanced without inflation over a guide wire.

Expandable metallic stents were successfully introduced in 7 patients, including 4 with left main bronchial stenosis caused by bronchopulmonary tuberculosis, 2 with main bronchial stenosis caused by lung cancer and one with tracheal stenosis caused by adenoid cystic carcinoma. The length of stenosis was 1.5-5 cm. The stents were 1.5-2.5 cm long with barbs, and their full expanded diameter was 1.5 cm. Balloon dilatation was performed before stenting in all cases. The stents were inserted by using a 10-12 Fr catheter. In all patients except the one with tracheal stenosis, stents were introduced under local anesthesia without any difficulties. No migration of stents occurred. After stent placement, there were no respiratory difficulties, and radionuclide lung perfusion scan and chest radiographic findings such as lung atelectasis showed marked improvement in three cases. Combined therapy of stent placement and bronchial arterial infusion chemotherapy showed marked effectiveness in one case with lung cancer. Expandable metallic stents were very useful in eliminating tracheobronchial stenosis symptoms.

Expandable metallic stents were successfully introduced in 12 patients; 6 with superior vena cava (SVC) obstruction due to tumor invasion or lymph node metastases, 3 with inferior vena cava (IVC) obstruction or stenosis due to lymph node metastases or hepatic tumor, one with common iliac vein (CIV) obstruction due to lymph node metastases, one with idiopathic obstruction of the hepatic IVC and Budd-Chiari syndrome, and one with CIV obstruction following a dialysis shunt. The length of the lesions was between 2 and 15 cm. Multiple (2–7) stents in tandem were inserted percutaneously from a femoral venous approach through a 12 to 16 F (4.0–5.3 mm) Teflon sheath. Postoperatively, all 12 patients became free from symptoms such as SVC syndrome or IVC syndrome. In 11 patients, the symptoms did not recur during the follow-up periods of 1 to 21 months.

The efficacy of emergent embolotherapy was evaluated in six patients suffering hemorrhage from the small intestine. Hemorrhage was from the jejunum in four patients, from the ileum in one, and from Meckel's diverticulum in one. Superselective embolization of the arcade of the small intestine artery branch was performed in all patients with a coaxial catheter. Embolic materials used were Gelfoam particles alone or Gelfoam particles plus coils in earlier cases and microcoils in recent cases. Complete hemostasis was immediately achieved in all patients, but one patient died of disseminated intravascular coagulation. After stabilization of the patient's condition by hemostasis, elective surgery was performed on three patients suffering small intestine ulcer. Histopathologically, no bowel infarction was noted but mild mucosal inflammation with submucosal edema was found in the jejunum of two patients. We recommend embolization for life-threatening small intestine hemorrhage, preferentially in situations where the blood vessel involved can be super-selectively occluded at the nearest level of the arcade of the vasa recta, lest the vasa recta should be occluded.

Eleven patients with massive duodenal hemorrhage were treated by emergent embolization. Bleeding originated from duodenal ulcer in three patients, from duodenal tumor in one, from ruptured pancreaticoduodenal artery pseudoaneurysm in three, and from ruptured gastroduodenal artery pseudoaneurysm in four. Complete hemostasis was obtained immediately after embolotherapy in all cases. Three of these patients died during the hospitalization period, one of whom from duodenal infarction and pancreas necrosis induced by embolization. In three patients with duodenal ulcer, complete hemostasis was obtained only by the gastroduodenal artery embolization with Gelfoam particles. Seven patients with pseudoaneurysms of the gastroduodenal artery or its branches required not only blockage of blood flow from the celiac artery but also the superior mesenteric artery for complete hemostasis. Therefore, in patients presenting with duodenal hemorrhage, the possibility of dual blood supply to the duodenum should be considered. Emergent embolization represents a useful alternative to surgery for massive duodenal hemorrhage, but it carries a risk of complications in patients with previous gastroduodenal surgery or significant visceral atherosclerosis.

Contrast-enhanced magnetic resonance images (MRI) of three patients with subdural (SDE) and two with epidural empyemas (EDE) were reviewed. In each case, the capsule of the lesion demonstrated enhancement, and distinction between capsule and contents was obvious on contrast-enhanced images. In SDE, contrast-enhanced images clearly depicted thickening of the neighbouring dura mater and a co-existent brain abscess. In EDE, part of the displaced dura mater did not enhance, which facilitated differentiation from SDE. Contrast-enhanced MRI was thus of value in diagnosis.

When lipiodol is injected into the hepatic artery at a dose exceeding a certain level, it flows into the portal vein. On the basis of this feature, an emulsion of Adriamycin with lipiodol was injected into a segmental or subsegmental artery such that it was delivered to the portal vein of the same segment, and the artery was then embolized with Gelfoam. This segmental arterioportal chemoembolization (cement therapy) was performed in 50 patients with localized hepatocellular carcinoma. A posttreatment CT scan showed that almost 100% of the lesions were occupied by lipiodol. The cumulative survival values determined for the 50 patients were very high: 83.4% after 1 year and 62.7% after 2 years.

Intrahepatic tumor staining, which was clearly visualized by common hepatic arteriography, disappeared in balloon-occluded proper hepatic angiography. This finding is interesting in terms of changes in hemodynamics in normal and tumor-bearing livers following hepatic arterial occlusion with balloon catheters.

Gianturco expandable metallic stents were used for treating six patients with inferior vena cava (IVC) obstruction due to compression by large hepatic tumors and three patients with idiopathic obstruction of the hepatic IVC and Budd-Chiari syndrome who showed reocclusion or stenosis 3-21 months after previously performed percutaneous transluminal angioplasty (PTA). In all six patients with compression by hepatic tumors, stents dilated the IVC and debilitating edema of the lower body disappeared. In the three patients with idiopathic obstruction, stents were placed after repeat dilation of the lesions and Budd-Chiari syndrome did not recur during a follow-up period of 7-10 months. In two of the three, cavograms obtained 8 months after placement showed the channels to be open with minimal intimal thickening. Gianturco expandable metallic stents can correct IVC obstruction due to compression by hepatic tumors and are useful in preventing reocclusion of the IVC after PTA for the treatment of idiopathic obstruction. The authors recommend using tanem stents connected by at least two struts.

A 67-year-old man with right upper lobe atelectasis due to squamous cell carcinoma showed positional change of the atelectatic lobe on plain chest radiograph, CT, and fluoroscopic observation. It was considered as lung torsion.

Differences in signal intensity involving lobes of the liver were noted in seven cases of liver tumor. The clinical significance and possible cause of these differences in lobar intensity are discussed.

Dynamic computed tomographic (CT) findings of 42 patients with hepatocellular carcinoma having angiographically proven arterioportal shunt were reviewed. CT findings related to arterioportal shunt were as follows: early enhancement of the portal vein, which showed a time-density curve similar to that of the aorta, markedly prolonged enhancement of the portal vein, dilated, abnormal intrahepatic vessels often accompanied by irregular, transiently enhanced areas, transient high attenuation of lobar or segmental distribution in the lobe contralateral to the main tumor, and transient wedge-shaped enhancement peripheral to the tumor. Dynamic CT usually detected arterioportal shunts involving larger portal veins as represented by any of the first four findings (14 of 17), whereas detection of arterioportal shunts involving smaller portal veins was lower in frequency (8 of 25), but such a shunt could be demonstrated as transient wedge-shaped enhancement peripheral to the tumor.

Computed tomography (CT) was performed after 65 transcatheter arterial embolizations (TAE) in 50 patients with hepatocellular carcinoma. Nonenhanced high-density areas were seen in the tumors within 3 days in 17/25 cases (though they soon disappeared) and low-density areas within 2 weeks in 62/65. Gas bubbles were seen in these areas within 2 weeks in 60% of embolizations. Within 3 to 6 months after the first TAE, enhanced lesions developed around or inside the low-density areas in 15/22 patients. Complications appearing within 2 weeks included non-enhanced low-density areas in the liver and spleen, gallbladder thickening, swelling of the head of the pancreas, contrast retention in the kidneys and gallbladder, ascites, and pleural effusion.

Among 224 hepatomas treated with transcatheter arterial embolization, ten patients who survived for three years are presented. All cases had nodular lesions and the volume ratio of tumor to liver was less than 10% in nine cases. Eight cases had no large venous extension, however, one had 90% occlusion of the portal trunk and the other had tumor thrombus within the inferior vena cava. Laboratory data showed liver function was largely spared in eight cases, whereas the other two had severe liver cirrhosis. CT and/or angiography showed an increase in tumor volume in eight cases after three years of survival. Beneficial factors for long-term survival and the limitations of embolization are also discussed.

Twelve cases of hepatic hemangioma were examined by computed tomography (CT). Dense accumulations of rapidly injected contrast material in or near the periphery of the lesions were demonstrated in early postcontrast scans. They invaded the area of low density and diminished in attenuation value with time. This marked decrease of the low density area noticed in the precontrast scan was also seen in the later postcontrast scan. These findings were recognized in all 10 cases of hemangioma examined with contrast enhancement, while no cases of hepatoma showed such a peripheral high density zone. Most hepatic hemangiomas could be correctly diagnosed by CT alone.

Accuracy and limitations of computed tomography (CT) and sonography in the detection and diagnosis of cavernous hemangioma of the liver were analyzed in 39 cases. In 35 of 38 lesions examined by CT before and after bolus contrast enhancement, findings were dense contrast enhancement spreading in all directions on subsequent scans and/or density (other than capsule or septa) higher than normal hepatic parenchyma after 2 min. Lesions smaller than 1 cm were not detected. Misregistration in sequential scans prevented diagnosis of three of nine lesions smaller than 2 cm. Sonography revealed various patterns of mass, but in the smaller lesions, an extremely hyperechoic pattern was dominant. The contributions of CT and sonography depend on the size of the lesions.

Forty-two patients with hepatocellular carcinoma (HCC) were examined by magnetic resonance (MR) imaging. The presence of tumor was suggested in 41 of 42 cases by a high-intensity area on T2 weighted spin-echo (SE) images with a repetition time (TR) of 1.6 s. Specific findings of HCC such as the presence of a capsule, mosaic pattern, and tumor thrombus in major veins were noted in 10, two, and seven cases, respectively. In six cases the tumor pattern changed from a well-defined mass to an irregular, ill-defined one according to pulse sequence (SE: echo time 35 and 70 ms; TR 1.6 and 0.4 s). In our early experience MR was almost equal to conventional X-ray CT in the detection of main or daughter lesions and in the determination of extent and characterization of HCC.

Twenty-seven gallbladder carcinomas were examined by computed tomography (CT). All patients had abnormal CT findings, suggesting a gallbladder lesion in 26. Based on the major CT findings, gallbladder cancer was classified as "massive," "thickened wall," or "intraluminal." Twenty cases were diagnosed correctly as cancer: on retrospect, definite findings of gallbladder cancer were observed in 24 and equivocal or misleading signs in 3. Some cases of chronic cholecystitis and liver tumor were difficult to differentiate from gallbladder cancer. Direct hepatic extension was easily seen, but lymph-node metastases and bile-duct extension were difficult to distinguish.

Transcatheter arterial embolization (TAE) was performed in 20 patients with ruptured hepatocellular carcinoma (HCC). Bleeding was improved in all patients, but only four survived for over three months. Rerupture occurred in seven patients (35%) and the prognosis was extremely poor. TAE should be considered the treatment of choice for ruptured HCC; however, long-term survival was limited to those patients without portal extension of HCC. The severity of rupture also influenced the prognosis.

Sclerosing hepatic carcinoma (SHC) is one of the variant primary liver carcinomas and is characterized by intense fibrosis which surrounds slender cords of neoplastic cells. We report on a 53-year-old male patient with SHC describing the radiological findings and clinical course after a transcatheter arterial embolization. To our knowledge, this was only the second reported case of SHC in Japan.

In seven primary liver cancers (HCC 5, CCC 1, mixed 1), MR images (0.35 Tesla super-conducting) were compared with macroscopic appearances, and relaxation times (T1 and T2) with microscopic characteristics. MRI was able to reveal the gross appearance of five nodular lesions, but did not reveal one diffuse HCC and one nodular HCC with marked extracapsular extension. T2-weighted SE images could not demonstrate fibrous capsules around the tumor in four nodular HCCs. The T1 and T2 values of the tumors were longer than those of the surrounding liver parenchyma, and the T1 elongation corresponded roughly to the degree of necrosis and fibrosis within the tumors.