Symptomatic peripheral vascular disease: selection of imaging parameters and clinical evaluation with MR angiography

In the first phase of this study, seven healthy subjects underwent examination with two-dimensional time-of-flight (TOF) magnetic resonance (MR) angiography to develop a protocol for evaluation of peripheral arterial vasculature from the infrarenal aorta to the foot. In the second phase, 73 patients with symptomatic peripheral vascular disease underwent examination with both conventional contrast material-enhanced arteriography and two-dimensional TOF MR angiography to evaluate the clinical usefulness of MR angiography. Postinterventional and intraoperative angiography or direct surgical exploration was the standard of reference. In 32 patients, discrepancies occurred between findings on arteriograms and those on MR angiograms; most of these discrepancies were caused by improved depiction of runoff vessels on MR angiograms. The demonstration with MR angiography of blood vessels not seen on conventional arteriograms, unidentified stenoses, or misidentified blood vessels altered surgical management in 12 patients (16%). Metal-clip artifacts obscured clinically important disease on MR angiograms in two patients. It is concluded that two-dimensional TOF MR angiography is very useful in preoperative assessment of patients with severe peripheral vascular disease.     

Solid localization marker for MR imaging

A solid, stable material that can be easily cut into unique, identifiable shapes was compared with other localization markers used in magnetic resonance imaging to determine relaxation characteristics and chemical shift. The solid marker and the conventional oil-based markers caused substantial chemical shift artifacts and so should never be used when high levels of spatial accuracy are necessary, such as in stereotaxy. Although it had the lowest T2 of all the substances tested, the solid marker was useful in identifying structures when different coils, sequences, and fields of view were used.     

A case of infective endocarditis with the mycotic aortic valve aneurysm

A 49-year old man was admitted with a complaint of syncopal attack. Transient A.V block was detected and permanent pacemaker (DDD) was implanted. Five months later he was re-admitted because of dyspnea and palpitation. Infective endocarditis with aortic regurgitation and mycotic aortic valve aneurysm was diagnosed by echocardiography and cineangiography. The aortic valve and valve aneurysm were resected and AVR was performed using Bj?rk-Shiley disc valve (23A) in the usual manner. But 6 months later he suffered from acute cardiac failure due to perivalvular leakage. He died in spite of re-AVR with translocation method.     

Radionuclide angiography as an adjunct in diagnosis of ruptured aortic aneurysm: case report

Radionuclide angiography is a rapid, safe, and reliable method of imaging aneurysms of the abdominal aorta in patients who are too ill to undergo contrast angiography or when time is a critical factor.     

MR imaging of adult colo-rectal intussusception. A case report

MR imaging of an intussuscepted sigmoid cancer misinterpreted as a rectal carcinoma is described. High-resolution technique with pelvic-phased array coils and fast spin-echo was used. The diagnosis is discussed in relation to the MR findings.     

Fibromuscular dysplasia associated with intracranial giant aneurysm: report of a case

Although the correlation between fibromuscular dysplasia (FMD) and intracranial aneurysm is well established, the combination of FMD with a giant aneurysm is rare. This paper reports a patient with extracranial FMD associated with a giant intracavernous aneurysm compromising the trigeminal and abducens nerve. A review of the literature uncovered only four documented cases of FMD with concurrent giant intracranial aneurysms. The present case adds further weight to the argument for including FMD in the differential diagnosis list when confronted with a patient with a giant intracranial aneurysm. Absence of adequate collaterals in this patient eliminated ligation as a treatment strategy for the aneurysm.     

Renal artery aneurysm: case report of a ruptured calcified renal artery aneurysm

Renal artery aneurysms constitute one per cent of all aneurysms. To our knowledge, this is the first reported case of a calcified saccular arteriosclerotic renal artery aneurysm rupturing. Because the patient was in hemorrhagic shock, nephrectomy was performed. The postoperative course was complicated by acute renal failure, pneumonia, and small-bowel fistula, which responded to hemodialysis, antibiotics, and central hyperalimentation, respectively. This case and review of the literature emphasizes the need for elective revascularization of renal artery aneurysms by primary repair or bypass graft, rather than performing an emergency nephrectomy.     

Evaluation of carotid endarterectomy with sequential MR perfusion imaging: a preliminary report

BACKGROUND AND PURPOSE: Current indications for carotid endarterectomy are determined by balancing the relative risks of surgery with the benefits of reduced risk of subsequent stroke. Our purpose was to use MR perfusion imaging to assess patients being considered for carotid endarterectomy and to monitor sequential changes in MR perfusion characteristics after surgery. In particular, we wished to determine whether this technique could be used to detect changes that might be related to post-carotid endarterectomy hyperemia. METHODS: We used a single-section gradient-recalled echo sequence to investigate 14 patients being examined before possible surgery for carotid artery disease. In the 12 patients in whom carotid endarterectomy was performed, sequential studies were performed 3 to 5 days after surgery and at 3 months. Analysis of bolus-arrival-time (BAT) images was performed. RESULTS: Significant delays in preoperative BAT images of 0.89 seconds (range, 0.05 to 3.22 seconds) were apparent between hemispheres. Excluding the two patients with contralateral internal carotid artery (ICA) occlusion, early arrival, possibly indicating postoperative hyperemia, was seen in five patients immediately after carotid endarterectomy but resolved within 3 to 5 months after surgery. CONCLUSION: MR perfusion imaging shows differences in BAT between hemispheres in patients with ICA stenosis. Changes in perfusion characteristics after carotid endarterectomy are complex, and early BAT on the operative side can occur soon after endarterectomy in over half those patients without an occluded contralateral vessel. The significance of these findings with regard to patient outcome and risk of postoperative hyperemia requires further investigation.     

Pancreatic adenocarcinoma: combination of MR imaging, MR angiography and MR cholangiopancreatography for the diagnosis and assessment of resectability

BACKGROUND: Enteropancreatic malignancy is an important cause of morbidity and mortality associated with multiple endocrine neoplasia type 1 (MEN 1). However, the risk factors and mechanisms of the tumorigenesis of this malignancy are poorly understood. METHODS: The authors conducted a retrospective study of factors associated with the development of malignant enteropancreatic tumor in 69 patients with MEN 1 belonging to a single family. RESULTS: Metastatic enteropancreatic tumor and gastrinoma were identified in 20% and 36% of patients, respectively. Compared with MEN 1 patients who did not have an immediate family history of enteropancreatic malignancy, MEN 1 patients with a first-degree relative affected by enteropancreatic malignancy had an increased risk of developing disseminated tumor (odds ratio, 3.7; P < 0.05). In addition, hypergastrinemia and advanced age were both associated with a significant increase in the risk of enteropancreatic malignancy. Elevated serum glycoprotein alpha subunit levels were associated with enterochromaffin-like cell hyperplasia, gastric carcinoid formation, and disseminated enteropancreatic tumor in hypergastrinemic patients (P < 0.05). CONCLUSIONS: Disease modifier factors act in concert with the MEN 1 gene to modulate the development of enteropancreatic neoplasia. It is possible to identify MEN 1 patients at high risk for developing aggressive enteropancreatic tumors. Heritable disease modifier factor(s) affecting enteropancreatic malignancy appear to reside at loci distinct from that of the MEN 1 gene.     

Hepatic artery aneurysm rupture: case report, imaging findings, and literature review

Hepatic artery aneurysm rupture is a rare condition that requires urgent diagnosis and treatment in order to avoid a potentially fatal outcome. The clinical presentation is often non-specific. The classic triad of abdominal pain, gastrointestinal hemorrhage, and obstructive jaundice occurs in less than one-third of cases. Physical examination is rarely helpful since bruits, masses or pulsations are infrequent. Radiologic imaging provides the best tool to early diagnosis. Angiography has historically been the gold standard of diagnosis and is needed prior to radiologic intervention. Computerized tomography, doppler ultrasound and even magnetic resonance imaging have all demonstrated visceral artery aneurysms with success. Conventional treatment has included surgical ligation and resection. More recently transcatheter embolization or even percutaneous transhepatic injection of thrombin has been successfully performed by the interventional radiologist. This article discusses the clinical presentation, imaging findings, and review of the literature of this elusive entity.     

Ruptured aortic arch aneurysm with hemorrhagic cardiac tamponade: report a case]

The ruptured thoracic aortic aneurysm has had severely high mortality. A 71-year-old male who suddenly fainted away was admitted to our hospital. He was in shock on arrival. Computed tomography and echo cardiogram demonstrated ruptured aortic arch aneurysm with hemorrhagic cardiac tamponade. Aortic arch replacement was performed using the selective cerebral perfusion under deep hypothermia. The recovery of his consciousness was delayed, and he had right hemiplegia postoperatively, but his state was improved gradually. Finally he complained only slight degree of aphasia, paralysis. An immediate and aggressive emergency operation is a only method to salvage the patient who has ruptured aneurysm of the thoracic aorta.     

Venous aneurysm of the cephalic vein: report of a case

We herein report the rare case of a 41-year-old Japanese woman in whom a venous aneurysm in the left cephalic vein was excised under local anesthesia. Histological examination revealed significant diminution in the number and size of muscle and elastic fibers in the aneurysm wall. Conceivably, a combination of endophlebohypertrophy and a congenital focal defect of the elastic and muscle fibers might have contributed to the development of this venous aneurysm.     

Three-dimensional spiral computed tomography angiography as an alternative imaging modality for a silent dissecting aortic aneurysm--a case report

The authors report a patient with silent dissecting aortic aneurysm in whom three-dimensional spiral computed tomography (CT) angiography (3D-CTA) provided important imaging data. Images obtained by 3D-CTA were compared with the results of both conventional angiography and CT. They conclude that 3D-CTA was a powerful diagnostic modality for this patient, in addition to conventional CT and angiography.     

Tuberculous aortitis: a rare cause of mycotic aneurysm of the aorta

A case of a true mycotic aneurysm of the aortic arch secondary to mediastinal lymph node tuberculosis is presented. This was promptly recognized by aortography, treated by surgery, diagnosed by pathology, and followed by antituberculous therapy. The early diagnosis is emphasized as a prerequisite to successful treatment.     

Congenital ganglioglioma: report of a case with an unusual imaging appearance

A newborn presented with a cerebral ganglioglioma. This is a rare diagnosis in a neonate. The imaging appearance (hyperdense on CT, hyperintense on T1-weighted and hypointense on T2-weighted MRI) is very unusual for this type of tumor.     

MR angiography of patients with peripheral arterial disease before and after transluminal angioplasty

The strength of the cytotoxic T lymphocyte (CTL) response is believed to influence the final outcome of hepatitis B virus (HBV) infection. Among the different CTL epitopes so far identified, the sequence 18-27 of the HBV nucleocapsid antigen is widely recognized by CTL of HLA-A2-positive patients with acute self-limited HBV infection, and represents the main component of a peptide-based therapeutic vaccine aimed at stimulating the antiviral CTL response in patients with chronic hepatitis B. In the present study, we further analyzed the features of this important HBV region by the following: 1) defining the contribution of individual residues of the epitope to the interaction with the T-cell receptor (TCR) and with the HLA-A0201 molecule; 2) assessing the antigenicity of this viral region in the context of the different HLA-A2 subtypes; and 3) testing whether this sequence can stimulate not only HLA-class I but also HLA class II restricted T-cell responses. A clear hierarchy was observed in the ability of individual residues to act as TCR or HLA binding sites. Furthermore, the sequence HBc18-27 was able to be recognized by specific CTL when presented in the context of different HLA-A2 subtypes. Finally, this HBV region was also found to stimulate HLA class II restricted T-cell responses. These data further increase the potential coverage and efficacy of therapeutic vaccines based on the HBc18-27 sequence.     

Time-of-flight MR angiography of the portal venous system: value compared with other imaging procedures

A simple method for determination of mimosine and 3,4-dihydroxypyridine (3,4-DHP) in plasma and milk was developed. Milk and plasma, with tyrosine as internal standard, were deproteinized using 9% trichloracetic acid and extracted with diethyl ether. Metabolites were separated by isocratic high-performance liquid chromatography, with 0.02 M orthophosphoric acid (pH 2.5) at 0.5 ml/min and a Hypersil ODS microbore column. Mimosine, 3,4-DHP and tyrosine were detected at 275 nm. The recovery of the mimosine added to the plasma samples was 101.6 +/- 2.3% and 103.3 +/- 1.0% for milk samples. 3,4-DHP recovery for plasma samples was 101.2 +/- 0.9% and for milk samples 100.8 +/- 1.4%. The reproducibility of the method was evaluated by analyzing six plasma samples and six goat milk samples. The analyses yielded relative standard deviations of 2.65 and 2.82%, respectively.     

Diffusion-weighted MR imaging in a case of dissociative amnesia

BACKGROUND: Management of thyroid cancer in pregnancy is controversial, as evidenced by disagreement in recommendations cited in leading obstetrics textbooks. Most thyroid carcinomas are well differentiated and pursue an indolent course. Many physicians recommend delay in surgical therapy until after delivery because of operative morbidity. CASE: A 27-year-old primigravida was found to have a solitary thyroid nodule at her initial obstetrics appointment. Fine needle aspiration was consistent with papillary carcinoma. Although detected at 8 weeks' estimated gestational age (EGA), the decision was made to defer surgical therapy until postpartum. The patient was referred to a tertiary care facility at 24 weeks' EGA secondary to rapid growth of the nodule. Surgery performed at that time revealed invasive disease. CONCLUSION: Review of the literature suggests that delay in definitive therapy stems from early reports of fetal loss related to surgery, but contemporary data suggest that the risk of fetal loss related to surgery is minimal.