Magnetic Resonance Imaging Compared with Computed Tomography and Angiography in Moyamoya Disease

Magnetic resonance (MR) imaging performed in 13 patients with moyamoya disease was reviewed and compared with computed tomography (CT) and angiography. The MR findings consisted of occlusion of arteries, collateral vessels and parenchymal changes. Narrowing or occlusion of the middle cerebral artery and the supraclinoid portion of the internal carotid artery were seen in all hemispheres but one. Collateral vessels, cerebral infarcts and atrophy with dilatation of the ventricles were observed on MR imaging. In general, the MR findings correlated well with angiography regarding occlusive changes and moyamoya vessels but was less sensitive in a few cases. Because of its higher sensitivity in detecting occlusive changes and collateral vessels, MR imaging was superior to CT in the diagnosis of this disease.

Transcatheter Embolization of Testicular Vein for Varicocele Testis

Percutaneous transcatheter embolization of the testicular vein was performed on 28 patients with angiographically proven varicocele testis. In 2 patients bilateral and in 26 only the left vein was embolized using 3-, 5-, or 8-mm stainless steel coils. All patients had clinically palpable varicoceles and male infertility. The grade of varicoceles improved after embolization in 23 of 28 cases (82%). Effective sperm count increased significantly from 34.5 ± 44.6 to 65.1 ± 71.0 following embolization. However, pregnancy was achieved only in one of 28 cases. Technically, the basilic vein approach was felt to be superior to the femoral vein or jugular vein approach for this procedure.

Retroperitoneal bronchogenic cyst: a rare case showing the characteristic imaging feature of milk of calcium

Bronchogenic cysts are rare congenital anomalies of the primitive foregut that are usually found above the diaphragm, and a retroperitoneal location is extremely unusual. Due to the low prevalence of these pathologies, their imaging features have seldom been described. We report a rare case of retroperitoneal bronchogenic cyst showing characteristic imaging features of milk of calcium on plain abdominal radiography and computed tomography.

[A case of severe stenosis of bilateral distal vertebral artery successfully treated with anastomosis operation]

A 65-year-old male complained of loss of consciousness for several minutes, transient diplopia and dizziness. He had no neurological deficits nor abnormalities in MR imaging. However, flow velocity of bilateral vertebral artery on ultrasonography indicated severe stenosis of bilateral distal vertebral artery. Brain angiography revealed severe stenosis of bilateral distal vertebral artery as well as occlusion of right middle cerebral artery (MCA). Single photon emission CT (SPECT: ECD-RVR method with acetazolamide loading) showed decreased cerebral blood flow and poor perfusion reserve in bilateral cerebellar hemisphere and right MCA territory. Superficial temporal artery-superior cerebellar artery (STA-SCA) anastomosis was performed. The patient turned out to have no episodes of unconsciousness attack, transient diplopia and dizziness after operation. Cerebral blood flow (CBF) in the posterior circulation was also improved. Evaluating quantitative CBF measurement by means of ECD-RVR method was useful for evaluating CBF. In cases who have severe stenosis of bilateral distal vertebral artery with complaints of vertebrobasilar insufficiency, STA-SCA anastomosis may be one of the most effective treatments.

Autoimmune pancreatitis: radiologic findings in three histologically proven cases

We describe the radiologic findings of autoimmune pancreatitis, a rare variant of pancreatitis. The radiologic findings of autoimmune pancreatitis are pathognomonic and very different from those of ordinary types of acute or chronic pancreatitis. This condition is a new clinical entity that is effectively treated with steroid therapy. It is important to recognize the radiologic characteristics of autoimmune pancreatitis to avoid surgical resection and start steroid therapy.

Spectrum of CT findings in nonmalignant disease of the adrenal gland

Computed tomography (CT) plays a leading role in the evaluation of nonmalignant disease of the adrenal gland. CT is highly accurate in the localization of adrenal masses in patients with diseases associated with hyperfunctioning adrenal glands such as Cushing syndrome and Cushing disease, Conn syndrome, adrenal tumors leading to virilization or feminization, and pheochromocytomas. CT permits a specific diagnosis of acute or subacute adrenal hematoma and myelolipoma. Hematomas are round to oval and have increased attenuation (50-90 HU) that decreases on follow-up CT scans. Myelolipomas typically manifest as a well-defined suprarenal mass with an attenuation of-30 to -115 HU. Adrenal cysts are usually round to oval and manifest as a hypoattenuating mass with a smooth, thin wall. CT is useful in the evaluation of patients with Addison disease, particularly the subacute form secondary to tuberculosis or disseminated histoplasmosis. Findings typically include bilateral adrenal enlargement with a central necrotic area of hypoattenuation and peripheral enhancement. Thin-section unenhanced CT permits accurate measurement of attenuation and can be used to differentiate adrenal adenoma from metastasis in a cancer patient with an indeterminate mass: Attenuation of 10 HU or less usually indicates adenoma rather than cancer. If the mass is found incidentally at contrast material-enhanced CT, delayed scans obtained as early as 5-15 minutes after intravenous administration of contrast material appear to have comparable accuracy.

[Selective intra-arterial injection of calcium for localization of insulinomas: proposed new criteria]

To elucidate whether noninvasive arterial stimulation venous sampling (ASVS) is helpful for localizing insulinomas, calcium gluconate (0.02-0.025 mEq Ca2+/kg) was injected directly into the gastroduodenal, splenic and superior mesenteric arteries of six patients with episodic hypoglycemia. In all six patients, there was a greater than 26-fold increase in serum insulin levels in blood samples obtained from the hepatic vein after the infusion of calcium into the artery supplying the tumor. However, in four of the six patients, such an injection into an artery not supplying the tumor resulted in a greater than twofold increase in insulin concentration. Accurate localization of the insulinomas was verified at surgery in all patients. We believe that these false positive results were caused mainly by the influx of calcium via branches of intrapancreatic anastomoses. In order to minimize false positive results, we have recommended the following new criteria for ASVS: maximum insulin concentrations exceeding 150 microU/ml in blood samples obtained from the hepatic vein, and greater than twofold increases in insulin concentration. We concluded that noninvasive ASVS is helpful in determining the location of insulinomas.

Management of tracheal and bronchial stenoses with the Gianturco stent

Thirty-six cancer patients with symptomatic tracheobronchial stenoses received Gianturco tracheobronchial stents over a 9-year period. Symptoms improved in 28 patients (78%). The overall median survival was 1 month 3 weeks (range, 4 days to 35 months). The median survival for patients who showed improvement after receiving stents was 3 months compared with 1 week for those who did not respond. Complications were minimal. The Gianturco stent may palliate symptoms of tracheobronchial compression in selected cancer patients.

MRI of the brain in chronic carbon monoxide poisoning

We examined 13 patients with chronic carbon monoxide (CO) poisoning by magnetic resonance imaging (MRI); all of them had been in an explosion in a coal mine 25 years previously. Symmetrical globus pallidus lesions were observed in 12, as was degeneration of the white matter, with focal cortical atrophy. The temporal parietal and occipital lobes were usually affected, the parietooccipital region being the most frequently and extensively damaged. Of the 12 patients with white matter degeneration 7 had definitely asymmetrical cortical and subcortical lesions. There were 6 patients with dilated temporal horns, probably due to atrophy of the hippocampal gyri. A history of CO inhalation and an awareness of the typical distributions of lesions are important for recognition of the effects of CO poisoning, especially when patients are in the chronic stage.

Hepatocellular carcinoma: correlation of CT, angiographic, and histopathologic findings

PURPOSE

To elucidate the causes of various enhancement patterns of hepatocellular carcinomas (HCCs).

MATERIALS AND METHODS

Computed tomographic (CT) scans of 68 surgically resected HCCs (62 patients) were obtained 45 seconds and 6 minutes after administration of contrast material. These scans were compared with angiographic and histopathologic findings.

RESULTS

On the early images, 24 HCCs (35%) were hypoattenuating, 33 were totally or partially hyperattenuating (48%), and 11 were isoattenuating (16%) compared to adjacent liver. On the delayed images, 55 HCCs (81%) were hypoattenuating and 13 (19%) were isoattenuating. Twenty-nine of the 48 very hypervascular or hypervascular tumors (60%) were hyperattenuating or partially hyperattenuating at early CT. Sixteen of the 20 slightly hypervascular or hypovascular tumors (80%) were isoattenuating or hypoattenuating.

CONCLUSION

Although there was relatively good agreement between tumor vascularity and enhancement pattern (60% correlation for hypervascular tumors, 80% correlation for hypovascular tumors), hyperattenuation of the large HCCs (> or = 5 cm) at CT appeared to be a function of dilated sinusoids within the tumor (peliotic changes) as well as vascularity. In patients with advanced cirrhosis, hypovascular HCCs could be hyperattenuating at CT.

Placement of covered self-expanding metallic stents in the common bile duct: a feasibility study

PURPOSE

Gianturco self-expanding metallic stents have been useful in cases of benign biliary stenoses; however, the stents have not worked well in the presence of intraluminal tumor because of tumor growth between the wire struts. Stents were covered with polymeric membranes, which may prevent tumor ingrowth, and the feasibility of using these covered stents in the common bile duct was studied in healthy adult dogs.

MATERIALS AND METHODS

Initially, stents (10 x 6 mm) covered with polycaprolactone (PCL), segmented polyether polyurethane (SPP), and silicone were placed in the common bile duct of dogs and were followed up for 3-12 months. Subsequently, four types of modified silicone-covered stents were evaluated. Rough-surface, small-diameter (3-mm), half-covered, and tapered stents were placed and followed up for 3 months.

RESULTS

In the initial study, the SPP and silicone membranes remained intact, but the PCL covering broke in all dogs. In all but two dogs, luminal narrowing caused by varying degrees of papillary mucosal hyperplasia at both ends of the stent was observed. In the subsequent study, mucosal hyperplasia was considerably reduced by using half-covered stents and was virtually eliminated with tapered stents. All small-diameter stents migrated into the bowel.

CONCLUSION

These studies suggest that tapered Gianturco self-expanding stents covered with silicone may be useful in the biliary tract in cases of intraluminal tumor.

MRI of primary lymphoma of the liver

OBJECTIVE

The MR findings in two cases of primary lymphoma of the liver (PLL) are presented.

MATERIALS AND METHODS

MR of two cases of primary lymphoma of the liver were reviewed and its features were estimated.

RESULTS

Both cases showed a solitary large liver mass. On T1-weighted imaging the tumor was isointense in one and homogeneously hypointense to the liver parenchyma in the other. On T2-weighted imaging both tumors were homogeneously hyperintense. In one case the margin of the tumor was poorly defined, and portal branches were identified within the tumor, an unusual finding in other liver neoplasms.

CONCLUSION

In patients with liver masses with homogeneous intensity on MR but without liver dysfunction and other malignancies, PLL should be included in the differential diagnosis.

Hepatocellular carcinoma: prospective assessments of the T-factor with CT, US, and MR imaging

The capabilities of computed tomography (CT), ultrasonography (US), and magnetic resonance (MR) imaging were studied in order to determine the role of each of these noninvasive examinations for estimating the T-factor of hepatocellular carcinomas (HCCs). Fifty-one patients with surgically proven HCCs received CT (50 patients), US (46 patients), and MR (44 patients). The images of CT, US, and MR were prospectively evaluated for main tumor size, intrahepatic metastases, and vascular invasion, which compose the T-factor of HCC, and compared to pathological results. The sizes of the main tumor were estimated correctly by all examinations. For estimating intrahepatic metastases, US (74%) and MR (73%) were superior to CT (65%). For estimating portal invasion, CT (79%) was superior to US (70%) and MR (66%), because CT could demonstrate the segmental staining caused by portal invasion. The estimates of hepatic venous invasion were difficult during any of the examinations. We conclude that presurgical evaluations of the T-factor require the use of US and CT or MR and CT.

Intrahepatic peripheral cholangiocarcinoma: two-phased dynamic incremental CT and pathologic correlation

To elucidate the characteristic CT findings of intrahepatic peripheral cholangiocarcinoma, two-phased dynamic incremental CT scans of 20 cholangiocarcinomas in 16 patients were carefully analyzed. Dynamic incremental CT scanning was performed after intravenous administration of 100 ml iodinated contrast medium at a rate of 2 ml/s using a power injector. The CT scans (8-16 sections) were obtained during 45-110 s (early phase) and 6-7 min (delayed phase) after commencement of the injection of the contrast medium. On CT, 55% (11 of 20) of intrahepatic peripheral cholangiocarcinomas appeared hypodense in both phases. Most of the tumors (80%) appeared hypodense in the early phase and had increased CT numbers in their delayed images. Lymphadenopathy was observed in 69% (11 of 16) of patients whose main tumors exceeded 3 cm in diameter. All tumors appeared irregular or indistinct. Twenty percent (4 of 20) of the cholangiocarcinomas were difficult to distinguish from hepatocellular carcinomas or hemangiomas.

Atypical arteriographic features of myositis ossificans circumscripta (MOC)

Earlier reports on the angiographic features of MOC concluded that there may be hypervascularity and tumor stain but no A-V shunting, pooling, or vessel amputation as a result of the lesion. However, our cases demonstrated A-V shunting in MOC, and showed that the vascularity of this lesion can closely mimic that of malignant neoplasms. Therefore, the possibility of MOC should not be excluded because of the presence of A-V shunts or "tumor vessels" in suspected MOC lesion on plain radiography. These points are underscored by the findings in two MOC patients, whose cases are described.

Rupture of embolised coeliac artery pseudoaneurysm into the stomach: is coil embolisation an effective treatment for coeliac anastomotic pseudoaneurysm?

An elderly woman with an anastomotic pseudoaneurysm of the coeliac artery, after previous treatment of a thoraco-abdominal aortic aneurysm, was treated by stainless steel coil embolisation. One year later, the embolised pseudoaneurysm ruptured into the stomach and total gastrectomy and aneurysmorraphy was necessary. She is leading a normal life 6 months later.

[MR imaging in paranasal and intracranial aspergillosis]

The MR findings in three patients with paranasal and intracranial aspergillosis were analyzed. Two patients had sphenoid sinus aspergillosis with mucocele, and one had aspergillosis in the maxillary sinus and pachymeningitis in the posterior fossa. In all patients with aspergillosis of the paranasal sinuses, a markedly hypointense area was present within the lesion on T2-weighted images. In the patient with pachymeningitis, contrast-enhanced MR images clearly demonstrated the extent of the lesion.

Hemifacial spasm caused by CP angle AVM associated with ruptured aneurysm in the feeding artery--case report

A 66-year-old male presented with clinical features of hemifacial spasm. Cerebral angiograms disclosed an arteriovenous malformation (AVM) in the cerebellopontine angle. The hemifacial spasm was caused by a dilated feeding artery of the AVM compressing the facial nerve at the root exit zone. Surgery was not initially performed because of his age and absence of AVM rupture. However, the AVM was associated with a small aneurysm in the feeding artery, which rapidly grew during 20 days after discharge and ruptured causing subarachnoid hemorrhage. The aneurysm was clipped and the feeding artery of the AVM partially obliterated. Careful angiographic examination for associated aneurysms and consequent surgical obliteration to prevent hemorrhage are suggested in cases of AVM.

Transcatheter embolization of testicular vein for varicocele testis

Percutaneous transcatheter embolization of the testicular vein was performed on 28 patients with angiographically proven varicocele testis. In 2 patients bilateral and in 26 only the left vein was embolized using 3-, 5-, or 8-mm stainless steel coils. All patients had clinically palpable varicoceles and male infertility. The grade of varicoceles improved after embolization in 23 of 28 cases (82%). Effective sperm count increased significantly from 34.5 +/- 44.6 to 65.1 +/- 71.0 following embolization. However, pregnancy was achieved only in one of 28 cases. Technically, the basilic vein approach was felt to be superior to the femoral vein or jugular vein approach for this procedure.

MR imaging of pituitary hypertrophy due to juvenile primary hypothyroidism: a case report

We present a case of pituitary hypertrophy due to juvenile primary hypothyroidism with subsequent return to normal size after therapy. This clinical entity is well known, but there are few reports on its magnetic resonance (MR) findings. We stress the usefulness of Gadolinium-DTPA-enhanced (Gd-DTPA-enhanced) MRI in the differential diagnosis of pituitary hypertrophy and pituitary adenoma.

Arterioenteric fistulae: diagnosis and treatment by angiography

Two cases of massive gastrointestinal haemorrhage caused by arterioenteric fistulae are presented. In both cases, bleeding was controlled by interventional angiography. In the first case, a fistula between an aberrant right subclavian artery and a reconstructed oesophagus was temporarily occluded with a balloon catheter as a pre-surgical measure. In the second case a communication between the external iliac artery and the colon in a patient with invasive cervical cancer was treated by embolization. An arterioenteric fistula should be considered as a possible cause of acute gastrointestinal haemorrhage in post-operative or cancer patients and aortography or pelvic arteriography may be required to make the diagnosis.

Lateral ventricular arteriovenous malformations: natural history and surgical indications

The authors report 21 cases of lateral ventricular arteriovenous malformation (AVM) focusing on their natural history and surgical indications. Eighteen of 21 patients (86%) had bleedings prior to admission. We performed definitive surgery in 9 patients and conservative treatment in 12 patients. In 7 of 9 patients (78%) in the operative group and in 5 of 12 patients (42%) in the non-operative group, the nidus of the AVM was less than 4 cm in diameter. The other 2 AVMs in the operative group, more than 4 cm in diameter, were located in the temporal lobe and widely extended to the temporal horn of the lateral ventricle. The nidi of the AVMs were totally removed in all 9 cases in the operative group. All patients have been doing well except one who had a mental breakdown 6 years after surgery. In 10 patients in the non-operative group, AVMs were located in the left cerebral hemispheres. Three patients in the non-operative group had rebleeding of the AVM. Two of the 12 patients in the non-operative group (17%) died of the recurrent haemorrhages. The rate of bleeding of the lateral ventricular AVM seems to be higher than that of the cerebral cortical AVM, but the mortality due to recurrent bleeding might be similar between the two. The operative indications we made depended on the sizes and locations of the AVMs. For AVMs in the temporal horn, even though they were large, we performed total removals of the nidi and had good results. We did not perform any definitive surgery for AVMs more than 4 cm in diameter except for those in the temporal horn. The mortality and morbidity of the 21 cases were 10% and 14%, respectively. Patients with AVMs in the temporal horn and patients with small AVMs in the frontal horn were good candidates for definitive surgery. We undertook conservative treatment for patients with large AVMs, and the results were acceptable.

[MRI of brain abscesses]

Four cases of brain abscess were examined on 1.5T MR and their findings were evaluated retrospectively. Preoperative cases had relatively characteristic findings, such as 1) peripheral edema producing hypointensity on T1-weighted images (T1WI) and hyperintensity on T2-weighted images (T2WI); 2) central necrosis with abscess fluid hypointense relative to white matter on T1WI and hyperintense on T2WI; 3) abscess rim iso- to hypointense on T2WI. Gd-DTPA enhanced T1WI carried further information; comparison of iso- to hypointense rim on T2WI (abscess rim) and enhanced area by Gd-DTPA on T1WI suggested that the former represented zone of macrophage infiltration.

MR imaging of pituitary dwarfism

The purpose of this study was to determine whether the MR findings of idiopathic pituitary dwarfism correlated with a clinical history of perinatal abnormalities and abnormal levels of pituitary hormones. MR examinations of 18 patients with pituitary dwarfism were performed; these patients were divided into two groups: those with ectopic posterior lobes (group 1) and those with normal posterior lobes (group 2). Among the seven patients in group 1, MR showed hyperintense signal at the median eminence of the hypothalamus, which was regarded as the ectopic posterior lobe of the pituitary gland. The mean anteroposterior length and height of the pituitary gland in group 1 patients were significantly smaller than those dimensions in the normal control group; the pituitary stalk was not detected in three of seven patients. Six of seven patients were products of breech presentation with perinatal asphyxia. The peak serum growth hormone level was less than 5 ng/ml when assessed by insulin-induced hypoglycemia or the clonidine test. MR findings in the 11 patients with pituitary dwarfism and normal posterior lobes were normal except that the mean size of the pituitary gland was slightly smaller than that of normal controls. The clinical history of these patients was normal except for perinatal asphyxia in one case. Our findings in patients with pituitary dwarfism, with or without an ectopic posterior pituitary lobe suggest that the ectopic lobe, visualized as a bright spot at the median eminence of the hypothalamus, may be common when pituitary dwarfism follows perinatal anoxic/ischemic episodes.

[A case of demyelinating disease showing a peculiar honeycomb-like and lamellar structure on magnetic resonance imaging]

A case of subacute demyelinating disease showing large honeycomb-like and lamellar lesions in bilateral cerebral white matter on MRI was reported. A 22 year-old woman felt general fatigue on sept. 30, 1988, and developed complete quadriplegia and mutism in about 10 days. She recovered shortly after high-dose corticosteroid therapy. She had neither fever nor meningeal irritation. There were no inflammatory changes in examinations of blood and CSF. On MRI, high and low signal areas of irregular shape in the cerebral white matter and brainstem, were observed on T2 and T1 weighted images, respectively, suggesting that the lesions are of demyelinating nature. These lesions appeared lamellar or honeycomb-like structures on T1 and T2 weighted image. This patient was diagnosed as having a subacute type of demyelinating disease similar to Balo's disease (concentric sclerosis).

Neuronal migration anomalies causing extensive ventricular indentation

Neuronal migration disorders include various anomalies of the brain, and cortical heterotopia is the most common type. In this report, we present the radiological findings of two adults with unusually large cortical heterotopia associated with fused-lip schizencephaly that caused extensive ventricular indentation. The lesion showed density on a computed tomographic scan and signal intensity on a magnetic resonance imaging scan similar to normal gray matter. Perifocal edema, contrast enhancement, and calcification were not seen. An abnormally decreased volume of the ipsilateral cerebral hemisphere, the presence of adjacent microgyri, and deep fissures that contained blood vessels were also characteristic findings, indicating abnormal development. Knowledge of this entity is important in differentiating true intracerebral neoplasms.

Magnetic resonance imaging compared with computed tomography and angiography in moyamoya disease

Magnetic resonance (MR) imaging performed in 13 patients with moyamoya disease was reviewed and compared with computed tomography (CT) and angiography. The MR findings consisted of occlusion of arteries, collateral vessels and parenchymal changes. Narrowing or occlusion of the middle cerebral artery and the supraclinoid portion of the internal carotid artery were seen in all hemispheres but one. Collateral vessels, cerebral infarcts and atrophy with dilatation of the ventricles were observed on MR imaging. In general, the MR findings correlated well with angiography regarding occlusive changes and moyamoya vessels but was less sensitive in a few cases. Because of its higher sensitivity in detecting occlusive changes and collateral vessels, MR imaging was superior to CT in the diagnosis of this disease.

Angiographically undetected small hepatocellular carcinoma: clinicopathological characteristics, follow-up and treatment

We studied 36 cases (38 nodules) of small hepatocellular carcinoma with special attention directed to detectability using angiography and histology. Among the 38 nodules, 31 nodules (81.6%) were evident. The remaining seven (18.4%) were not evident angiographically but were detected using ultrasonography and/or computed tomography, prior to angiography. An elevated level of serum alpha-fetoprotein also suggested a diagnosis of hepatocellular carcinoma. When comparisons were made between angiographically detected and undetected nodules, there was no statistically significant difference in parameters, including sex of the patient, tumor size, location of the tumor, positive rate for hepatitis B surface antigen, history of liver disease and values of alpha-fetoprotein. The small hepatocellular carcinomas not detected angiographically and evidenced only histologically had the following characteristics: (i) no fibrous capsule surrounding the nodules; (ii) well-differentiated tumors; (iii) replacing growth pattern of cancer cells, and (iv) remains of portal tracts within the tumor. The replacing growth pattern and the presence of portal tracts may correlate with the low detectability in angiography. When a definite diagnosis of angiographically undetectable tumors cannot be made using close surveillance with ultrasonography or alpha-fetoprotein and/or needle biopsy under ultrasonic guide, surgical intervention should be considered, particularly for patients at high risk for hepatocellular carcinoma.

Gd-DTPA administered MR imaging of intracranial mass lesions: a comparison with CT and precontrast MR

Magnetic resonance (MR) images of 13 intracranial mass lesions taken with the intravenous administration of gadolinium-DTPA were evaluated in comparison with precontrast computed tomography (CT), postcontrast CT, and precontrast MR. In the MR images taken with Gd-DTPA, tumor delineation improved in eight of 13 cases (62%) in comparison with precontrast MR images, and in seven of 13 cases (54%) in comparison with the overall evaluation of precontrast CT, postcontrast CT, and precontrast MR images. Tumor demarcation was unchanged in the remaining cases; no deterioration was observed with Gd-DTPA administration. MR imaging with Gd-DTPA should be performed to better evaluate the extent of intracranial mass lesions and to provide additional information.

Magnetic resonance imaging of jugular foramen neurinomas

Four cases of jugular foramen neurinoma, extending from the posterior fossa into the temporal bone through the jugular foramen, are reported. The information provided by magnetic resonance imaging was compared with that by computed tomography. Due to the excellent sensitivity, the absence of bone artifacts, and the ease of imaging in any plane, magnetic resonance imaging gave better information particularly about the location of the tumour than X-CT scan did. It included the dumb-bell shaped tumour through the jugular foramen, the extra-axial nature of the tumour, and the precise anatomical relationships between the tumour and the facial and acoustic nerves or the internal carotid artery. Sagittal and coronal views clearly demonstrated the superior and inferior margins of the tumour. The information is very useful not only for preoperative diagnosis but also for planning the surgical approaches and postoperative follow-up.

[Eight cases of non-resectable hepatocellular carcinoma surviving for more than 3 years after Lipiodol administration]

From December 1982 to February 1986, selective regional cancer chemotherapy using Lipiodol plus anticancer drug (Lipiodolization) was prescribed for 87 patients with non-resectable hepatocellular carcinoma (HCC). Eight out of 87 cases survived for more than 3 years. The mean age of the 8 long survivors was 52.6. In the liver function, 2 cases were in Child A, 5 cases in Child B, and 1 case in Child C. The largest diameter of HCCs was 5.3 cm, and the number of the tumors was one in 6 cases, two in one case, and three in one case. No vascular invasion was detected on hepatic angiography. These findings suggested that long survivors in lipiodolization are not in far advanced HCCs. For these 8 cases, lipiodolization was repeatedly prescribed from two to 6 times. The largest amount of adriamycin was 192 mg/case. The longest survivor has lived for 5 years and 6 months after first lipiodolization. After lipiodolization, one tumor vanished, and three tumors decreased in size. Although seven tumors increased in size after lipiodolization, the tumor doubling time of seven tumors were 64, 265, 313, 317, 350, and 1943 days (average 539 +/- 639 days). It is possible that lipiodolization remarkably inhibited tumor growth. Nevertheless, in 5 out of 7 cases, the daughter lesions increased in size and number, although the main tumors grew slowly. Lipiodolization was less effective for newly arising daughter lesions than main lesions.

[Relationship between angiographical manifestations and operative findings in 100 cases of hemifacial spasm]

Relationship between angiographical manifestations and operative findings of hemifacial spasm was studied in 100 cases. Vertebral angiography was performed, and Towne, straight AP, and lateral projections were routinely studied. The anterior inferior cerebellar artery (AICA) directly compressed the facial nerve root exit zone in 54 instances, the posterior inferior cerebellar artery (PICA) in 38, and the vertebral artery (VA) in 11. Compressions by multiple vessels were observed in 3 cases. Anatomical variations of the AICA and the PICA were classified into 3 groups according to their origins and their distributions of blood supply: Type I, normal distribution of AICA and PICA; Type II, common trunk anomaly with dominant AICA (basilar artery origin); and Type III, common trunk anomaly with dominant PICA (vertebral artery origin). In our cases, 35% of them showed normal distribution, 34% dominant AICA, and 35% dominant PICA. Analyses of the angiograms revealed significantly increased numbers of common trunk anomalies when compared with normal angiograms studied by Takahashi. In 60 of the 65 cases with common trunk anomalies, facial nerves were compressed by the main trunk or the branches of the dominant artery. There were 35 cases which belonged to Type I anatomical classification. They were subdivided into 2 groups according to the size of the AICA and PICA: 1. AICA greater than PICA, and, 2. PICA greater than AICA. In the AICA greater than PICA subgroup, the AICA was the offending artery in all but one case. In the PICA greater than AICA subgroup, the PICA was responsible in 9 of 17 cases. In 31 cases, angiograms showed a redundant VA with lateral elongation into the cerebellopontine angle.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiographic observations in idiopathic trigeminal neuralgia

Twenty-four patients with idiopathic trigeminal neuralgia were treated by neurovascular decompression surgery. All patients underwent preoperative vertebral angiography. After surgery, the vertebral angiograms of these patients were retrospectively reviewed. In 23 of the 24 patients, the superior cerebellar artery (SCA) and/or the anterior inferior cerebellar artery (AICA) compressed the trigeminal nerve. In the remaining case, no such compression by vessels was observed. On review of the angiograms, most of the compressing arteries, and the sites and numbers of compression points could be identified. Most of the caudal points of the SCAs which did not compress the trigeminal nerve were located higher than the compression points of the SCAs. It was therefore concluded that vertebral angiography is useful in the preoperative evaluation of compressing arteries. Since superimposition of arteries could be avoided, the straight AP projection was the most valuable of the three projections employed.

Oligodendrogliomas of the lateral ventricle: computed tomography and angiography

Computed tomographic (CT) and angiographic findings in four cases of oligodendroglioma of the lateral ventricle are reported. CT showed a midline nodular intraventricular mass containing punctate calcifications and cysts. The tumors were slightly to markedly enhanced after the infusion of contrast media. Angiography showed slightly increased vascularity in the mass, and displacement of subependymal veins near the tumor. Oligodendrogliomas of the lateral ventricle are rare but should be included in the differential diagnosis of intraventricular tumors near the foramen of Monro.

Computed tomography and angiography in MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes); report of 3 cases

Among mitochondrial encephalomyopathies, MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes, Pavlakis et al. 1983) is recognized as a distinct syndrome characterized by generalized convulsions and recurrent stroke-like episodes. The neuroradiological findings of three patients with MELAS are reported here. Retrospective review shows that MELAS should be included in the differential diagnosis of infarct-like lesions of the cerebrum.

Posttranscatheter embolization computed tomography in hepatocellular carcinoma. Evaluation of embolization effects

The postcontrast CT scans and angiography of 26 lesions in 23 patients with hepatomas who underwent transcatheter arterial embolization therapy were reviewed. Newly developed low density and high density areas and gas were noted on CT scans of the tumors after embolization in 100, 8 and 58% of the lesions, respectively. The CT findings of residual tumors correlated well with those of follow-up angiography. When discrete smooth round low density zones were observed on CT, there was no residual neovascularity on follow-up arteriography. When there were nodular or thick septum-like structures in low density lesions, arteriography revealed residual tumor vascularity in the lesions. CT proved useful not only in evaluating the effects of embolization, but also in providing important information about residual tumors.