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.

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.

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.

Splenic hyperkinetic state and splenic artery aneurysm in portal hypertension.

Forty-eight out of six hundred and thirty patients with portal hypertension undergoing a celiac angiography series were diagnosed as cases of splenic artery aneurysm during the period 1977-1988. The case-control study of patients with portal hypertension with splenic artery aneurysms and those without was designed to characterize the angiological features. The splenic arterial flow was assessed by measuring the radii of the splenic arteries on celiac arteriograms. In the portal hypertensive patients with splenic artery aneurysms, the splenic artery was larger (p < 0.05) and the splenic arterial flow greater (p < 0.05), and these patients were in a more hyperkinetic state, than were those with no splenic artery aneurysm. The study suggests that splenic artery aneurysms in cases of portal hypertension may be the consequence of a hyperkinetic state in the spleen.

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 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.

[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.

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.