Magnetic resonance imaging: current and emerging applications in the study of the central nervous system.

Neuroimaging is presently utilised in clinical practice for initial diagnosis and mapping of disease extent and distribution, noninvasive, preoperative grading of tumours, biopsy planning, surgery and radiation portal planning for tumors, judging response to therapy and finally, prognostication. Newer advances include magnetic resonance (MR) diffusion and diffusion tensor imaging with tractography, perfusion imaging, MR spectroscopy and functional imaging using the blood oxygen level-dependent contrast technique. Neuroimaging plays a pivotal role in various degenerative and neoplastic diseases, improving diagnostic accuracy, affecting patient care, monitoring dynamic changes within the brain during therapy, and establishing them as the arbiter of novel therapy that may one day prove cure of various brain diseases a reality.

Do cerebral blood volume and contrast transfer coefficient predict prognosis in human glioma?

INTRODUCTION: Noninvasive measurements of cerebral blood volume (CBV) and contrast transfer coefficient (K(trans)) have potential benefits in the diagnosis and therapeutic management of adult glioma. This study examines the relationship between CBV, K(trans), and overall survival. METHODS AND MATERIALS: Twenty-seven adult patients with glioma underwent T1-weighted dynamic contrast-enhanced MR imaging, and parametric maps of CBV and K(trans) were calculated. The relationship of histologic grade, CBV, K(trans), age, sex, surgical resection, and use of adjuvant therapy to survival were analyzed by using the logrank method and Cox regression analysis. The Kaplan-Meier method for displaying survival curves was used. The relationship of factors such as comorbidity, elevated intracranial pressure, size of nonenhancing tumor, and peritumoral edema were not considered. RESULTS: Both CBV (P < .01) and K(trans) (P < .01) show a significant relationship to histologic grade. CBV (P = .004), K(trans) (P = .008), and histologic grade (P < .001) all demonstrate a significant association with patient survival when analyzed individually. Cox regression analysis identified only histologic grade (P < .01) and K(trans) (P < .05) as independent significant prognostic indicators. Examination of survival data from high-grade (III and IV) tumors demonstrated a linear relationship between K(trans) and patient survival (P < .01). CONCLUSION: This study suggests a direct relationship between K(trans) and length of survival in high-grade gliomas, which could be of clinical importance. CBV relates directly to histologic grade but provides no independent prognostic information over and above that provided by grade. Further large prospective studies should be planned to test whether this observation holds true.

WEB in Partially Thrombosed Intracranial Aneurysms: A Word of Caution.

Despite the proved safety and efficacy of Woven EndoBridge (WEB) flow disruption in conventional intracranial saccular aneurysms, the literature on its use in partially thrombosed intracranial aneurysms is scarce. We report a series of 4 patients in whom partially thrombosed intracranial aneurysms were treated with the WEB. The 2 patients who received additional intraluminal treatment with conventional stents made a good clinical recovery. Meanwhile, those patients who were treated with the WEB alone had fatal rupture of the aneurysm at short- to medium-term follow-up. This small, select case series demonstrates that WEB placement with adjunctive stent placement may be an effective treatment in the management of partially thrombosed intracranial aneurysms, which merits further validation. However, exclusive intrasaccular flow disruption may have an adverse influence on the natural history of this disease.

Intrasaccular Flow Disruption in Acutely Ruptured Aneurysms: A Multicenter Retrospective Review of the Use of the WEB.

BACKGROUND AND PURPOSE: Use of the WEB intra-aneurysmal flow-disruption device in unruptured wide-neck bifurcation aneurysms has proven safety and efficacy. However, ruptured aneurysms are underrepresented in existing studies. This retrospective multicenter study describes the use of the WEB in patients with a ruptured intracranial aneurysm. MATERIALS AND METHODS: Ten centers contributed to this study. Clinical and procedural data of 47 patients with 52 aneurysms were analyzed retrospectively together with follow-up angiographies. RESULTS: There were 37 anterior and 15 posterior circulation aneurysms with a neck size of ≥4 mm in 49 of 52 (94%) aneurysms; 45 (87%) aneurysms were <10 mm, and 2 were partially thrombosed. Successful placement of the WEB was possible in every case. Adjunctive devices were used in 8 of 52 (15%) aneurysms. Thromboembolic events were observed in 4 of 52 (8%) patients. Adverse events occurred in 15 patients with 16 aneurysms, 9 of which were potentially related to the WEB procedure (3 thromboembolic events, 5 protrusions, and 1 perforations; 2 perforations were caused by the wire or catheter), but none had a clinical impact. Four patients were retreated. Short-term follow-up in 25 of 39 patients revealed complete occlusion in 15 of 25 (60%), 5 of 25 (20%) with residual neck, and 5 of 25 (20%) with residual aneurysm filling. Short- to midterm imaging in 9 of 25 patients revealed complete occlusion in 5 (55.6%), residual neck in 2 (22%), and residual aneurysm filling in 2 (22%). Of 47 patients, 23 (49%) had an mRS score of 0, 1, or 2; 13 (28%) had an mRS score of 3 or 4; and none had an mRS score of 5 at discharge. CONCLUSIONS: This retrospective series showed good procedural safety, feasibility, and stability of midterm occlusion in ruptured wide-neck bifurcation aneurysms.

Single-Layer WEBs: Intrasaccular Flow Disrupters for Aneurysm Treatment­Feasibility Results from a European Study.

BACKGROUND AND PURPOSE: The safety and efficiency of the dual-layer Woven EndoBridge (WEB) device has already been published. However, this international multicenter study sought to evaluate the safety of single-layer devices, which are the newest generation of the WEB intrasaccular flow-disrupter family. They have been designed to offer smaller-sized devices with a lower profile to optimize navigability and delivery, which may, in turn, broaden their range of use. MATERIALS AND METHODS: Data from all consecutive patients treated with a single-layer WEB device, in 10 European centers from June 2013 to May 2014 were included. Clinical presentations, technical details, intra- and perioperative complications, and outcomes at discharge were recorded. Clinical and angiographic data at last follow-up were also analyzed when available. RESULTS: Ninety patients with 98 WEB-treated aneurysms were included in this study. In 93 cases (95%), WEB placement was possible. Complete occlusion at the end of the procedure was obtained in 26 instances (26%). Additional treatment during the procedure (coiling and/or stent placement) was necessary in 12 cases (12.7%). Procedure-related complications occurred in 13 cases, leading to permanent neurologic deficits in 4 patients (4.4%). Early vascular imaging follow-up data were available for 44 patients (57%), with an average time interval of 3.3 months. Treatment-related morbidity and mortality rates at last follow-up were 2.2% and 1.1%, respectively. CONCLUSIONS: In this study, the feasibility and safety of the single-layer WEB device was comparable with that of the double-layer. However, further studies are needed to evaluate long-term efficacies.

Imaging findings in rabies encephalitis.

SUMMARY: Rabies encephalitis is perhaps one of the few infectious diseases that command attention and fear not only from the layman but also from physicians. The unique mode of transmission, the virtually exclusive neurotransmission shown by the agent, and the complete hopelessness of the established disease sets rabies apart from other zoonoses transmitted to man. Rabies encephalitis is a fatal disease and its diagnosis is usually based on the clinical presentations and findings. Hence, imaging in rabies is seldom done, and imaging findings in rabies encephalitis have rarely been described. We present the imaging findings in two confirmed cases of rabies encephalitis in which antemortem diagnosis was obtained by corneal impression smears showing the presence of viral antigens. The differential diagnosis of the imaging findings as well as the role and the relevance of imaging in the diagnosis of this disease are discussed. The current literature on the subject is also reviewed.

Cerebral cryptococcosis: atypical appearances on CT.

Cryptococcal infection is common in immunocompromised patients, often presenting with meningitis or meningoencephalitis. We report an unusual presentation of cryptococcal infection in an immunocompetent patient presenting with headache and hemiplegia. CT demonstrated a large ring-enhancing lesion in the parietal region with intralesional calcification.

Metanephric adenoma in a solitary kidney.

A case of metanephric adenoma occurring in a solitary kidney of a 31-year-old man is presented. Metanephric adenoma is extremely rare and its diagnosis should be considered in a patient with a well circumscribed renal tumour and concomitant paraneoplastic syndromes. Radiological features of the tumour are non-specific and histopathological examination is essential to establish a definitive diagnosis. Recognition of the tumour is of potential importance as conservative treatment with complete surgical enucleation will suffice in all cases.

Internal mammary artery pseudoaneurysms complicating chest wall infection in children: diagnosis and endovascular therapy.

Mycotic internal mammary artery (IMA) pseudoaneurysms are sparsely reported in medical literature. We report imaging findings of IMA pseudoaneurysms secondary to chest wall abscesses (staphylococcal and tuberculous) in two children. Both children were successfully treated by endovascular method thus obviating the need for surgery.

Imaging in pituitary tuberculosis.

Tuberculosis of the pituitary gland is extremely uncommon and may masquerade as a nonfunctional pituitary neoplasm. We describe imaging findings in three patients with pituitary tuberculosis and review the pattern of involvement and importance of imaging in its management. An accurate diagnosis was found to be important in these cases as antituberculous chemotherapy was curative.

Hypervascular nasal metastasis from hepatocellular carcinoma.

Metastases is an uncommon cause of tumors in the sinonasal region. We report a patient with hepatocellular carcinoma which metastasized to the nasal cavity.

Spontaneous isolated lesser sac hematoma in a patient with hemophilia.

In patients with hemophilia, hematomas in the mesentery and bowel wall have been described uncommonly. The lesser sac is a rare site of spontaneous hemorrhage even in patients with bleeding diathesis; only a single case of isolated lesser sac hemorrhage has been reported in a hemophiliac patient. We report a similar case with no history of trauma. He recovered with administration of factor VIII concentrate.

Helicobacter pylori gastritis masquerading as gastric lymphoma.

A 30-year-old man presented with acute acid-peptic symptoms. Endoscopy and radiological studies revealed generalized thickening of gastric folds with multiple superficial ulcerations and infiltration of the distal stomach simulating gastric neoplasm. Endoscopic biopsies revealed acute gastritis with foveolar hypertrophy with numerous Helicobacter pylori. The symptoms and endoscopy findings resolved completely with combination triple-drug therapy for H pylori.

Adult intrahepatic solitary choledochal cyst.

A 20-year-old woman presented with dull ache in the abdomen. Ultrasonography and CT scan showed a solitary liver cyst. Roux-en-Y cystojejunostomy was done since there was bile in the cyst. Histology of the cyst wall revealed it to be a choledochal cyst. Solitary intrahepatic choledochal cyst and presentation in adult life are rare.

Pancreatic lymphoma masquerading as adenocarcinoma.

Primary pancreatic lymphoma is rare. We report a young man with primary lymphoma in the pancreatic head who presented with obstructive jaundice.

Fistulization of hepatic hydatid cyst into duodenum.

Though rupture of hepatic hydatid cyst is not uncommon, fistulization into the gut following rupture is rare. We report a case in whom a hepatic hydatid cyst ruptured into the first part of the duodenum.

Encephalopathy in a patient with Addison disease.

Patients with adrenal insufficiency manifest a myriad of metabolic disorders which can inflict neurologic damage. Here we present an unusual clinical presentation and distinctive imaging features in a patient with Addison disease.

Isolated cerebral hydatid cysts: a comparative study of two different types of presentations.

OBJECTIVES: To demonstrate the existence of two imaging patterns of cerebral hydatidosis and discuss its clinical importance. MATERIAL AND METHODS: A retrospective review of six cases of cerebral hydatidosis using various imaging techniques including CT, MRI, angiography and cystogram. RESULTS: Clinically the most common findings included papilloedema, headache and vomiting. Two of the cases reported recurrence of symptoms and were reoperated. The first 4 cases presented the classical signs of unilocular well defined cysts while the last two cases had multilocular, often polygonal cysts with perifocal edema, calcification and membrane detachment. CONCLUSION: Two radiologically and pathologically distinct subtypes of hydatidosis exist. Division into groups may assist decision over treatment protocol.

Ileo-ileo-colic intussusception secondary to an ileal lipoma.

Adult intussusception is extremely uncommon and constitutes approximately 5-16% of all intussusceptions. We describe a case of ileo-ileo-colic intussusception secondary to an ileal lipoma occurring in a 22 year old man who in addition had autosomal dominant polycystic kidney disease. CT scan played a pivotal role in not only demonstrating the cause of intestinal obstruction (intussusception) but also showed that a lipoma was the lead point precipitating the intussusception.