Kohzoh Makita

Mucinous adenocarcinoma arising from fistula in ano : MRI findings

OBJECTIVE The purpose of this study was to describe MRI findings in 11 patients with mucinous adenocarcinomas arising from fistula in ano. CONCLUSION More than half of patients had a mass filled with markedly hyperintense content on T2-weighted fast spin-echo images, enhancing solid components within the mass, mesh-like internal enhancement, fluid collections without a thick fibrous capsule, contrast enhancement of peritumoral areas, and a fistula between the mass and the anus. Regional areas of lymph node enlargement were considered indirect findings of locally advanced mucinous adenocarcinoma. These MRI findings may help diagnose mucinous adenocarcinomas arising from fistula in ano.

Cystic islet cell tumors: Radiologic findings in three cases

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.

Clinical evaluation of the effect of percutaneous transluminal angioplasty and intra-arterial papaverine infusion for the treatment of vasospasm following aneurysmal subarachnoid hemorrhage.

The clinical efficacy of percutaneous transluminal angioplasty and intra-arterial papaverine infusion for treatment of vasospasm following subarachnoid hemorrhage was investigated. Between 1990 and 1993, 84 patients were treated for cerebral vasospasm in National Defense Medical College Hospital. Angioplasty was performed for asymptomatic vasospasm in 18 patients and for symptomatic vasospasm in 12 patients. Intra-arterial papaverine infusion was performed for asymptomatic vasospasm in 10 patients and for symptomatic vasospasm in four patients. The other 40 patients were treated with standard conservative therapy including hypervolemic and hypertensive hemodilution. The outcomes of these patients were analyzed using the Glasgow Outcome Scale. The outcome tended to be better for patients treated with angioplasty, but not for those treated with papaverine infusion, than for those treated conservatively. Recurrence of vasospasm was more frequent after papaverine infusion than after angioplasty. Undesirable complications such as abrupt development of unconsciousness were experienced during papaverine infusion but not during angioplasty. We conclude that percutaneous transluminal angioplasty is superior to intra-arterial papaverine infusion for prevention and treatment of vasospasm following aneurysmal subarachnoid hemorrhage.

MRI appearances of calcified regions within intracranial tumours

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.

Retrievable IVC Filter: Preliminary in Vitro and in Vivo Evaluation

PURPOSE To develop an inferior vena cava (IVC) filter that is retrievable even after neointimal formation and incorporation into the caval wall. MATERIALS AND METHODS Eight filters were placed percutaneously in the infrarenal IVC of eight dogs. Four weeks after placement, percutaneous retrieval of the filters was attempted. Vena cavograms were obtained before and immediately after retrieval. Three dogs were killed immediately after the retrieval procedure was completed. In the other five dogs, follow-up vena cavography was performed 4-14 weeks after retrieval, and autopsy was performed. RESULTS The filters were placed and retrieved successfully in all eight dogs. No migration, caval penetration, or tilting occurred. The IVCs were completely patent both before and immediately after retrieval in all eight dogs. In the three dogs killed immediately after retrieval, neointimal hyperplasia was seen around the struts, but there was no detachment. Delayed stenosis was not seen in any of the five dogs that were followed up, and the inner surface of the caval wall was smooth. CONCLUSION This IVC filter can be easily placed and safely retrieved percutaneously, even after neointimal formation.

Moyamoya disease: diagnosis with three-dimensional CT angiography

Our purpose was to assess the value of threedimensional (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.

Contrast-enhanced magnetic resonance imaging of sub- and epidural empyemas

SummaryContrast-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.

A one-stage method for obtaining CT during arterial portography and hepatic arteriography.

We describe a new technique for performing CT during arterial portography (CTAP) and during hepatic arteriography (CTHA) in a one-stage procedure, using a coaxial balloon catheter system and slip-ring CT equipment. This technique was employed in 10 patients with liver neoplasms. Both CTAP and CTHA images were obtained in all patients.

Massive intestinal bleeding caused by an ileal arteriovenous malformation: report of a case.

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.

Embolization with steel coils using a saline flush technique

A method using saline flush to push Gianturco steel coils through catheters is described, and has been successfully used in 45 patients. The saline flush technique requires no precise matching of coils and catheters, solves problems associated with the conventional method and simplifies the coil embolization procedure.