Magnetic Resonance Imaging patterns in central nervous system lymphomas: A pictorial review.

Five distinctive Magnetic Resonance Imaging (MRI) patterns of Central Nervous System Lymphomas (CNSL) are introduced in this pictorial essay - in an attempt to differentiate lymphoma from other abnormalities with similar MRI appearance, - namely a. solitary supratentorial, b. multiple supratentorial, c. infratentorial, d. intravascular, and e. extraparencymal. Recognition of a specific imaging pattern on brain MR imaging, may facilitate the early diagnosis and prompt treatment initiation, thus improving prognosis of brain lymphoma.

A technical note on intra-arterial cone-beam computed tomography for the evaluation of flow-diverter stents: Image quality differences between diluted and non-diluted contrast medium.

BACKGROUND: Design of flow-diverter stents for flexibility, tractability, and low profile limits their radiopacity on conventional digital subtraction angiography. Cone-beam computed tomography (CBCT) offers higher spatial resolution for the evaluation of flow-diverter stents. However, CBCT requires optimal dilution and timing of contrast medium for simultaneous visualization of the stent, arterial lumen, and vessel wall. There are only limited data on the effects of different contrast dilutions on CBCT image quality in neurointerventional applications. MATERIALS AND METHODS: In our institution, intra-arterial CBCTs were acquired during stent deployment and at follow-ups with 10% diluted contrast. We had recently started acquiring intra-arterial CBCTs with non-diluted contrast. Retrospective analysis of our flow-diverter data identified eight cases with different aneurysm locations who had intra-arterial CBCT with 10% diluted contrast immediately after flow-diverter stent deployment and with non-diluted contrast technique during follow-ups. For each case, the image quality between diluted and non-diluted contrast techniques was compared qualitatively by assessing stent visualization and quantitatively by plotting gray-scale intensity values along the vessel lumen. RESULTS: In two sets of CBCT images per each case, there was no substantial difference between diluted and non-diluted CBTC techniques for the evaluation of stent architecture and lumen opacification. Gray-scale intensity values perpendicular to the lumen revealed similar intensity values along the neighboring parenchyma, vessel wall, and lumen for the two different contrast techniques. CONCLUSION: Intra-arterial CBCT angiography can be performed without contrast dilution and still achieve adequate image quality in certain cerebral aneurysms treated with flow diverter. The non-diluted contrast technique avoids the time loss during preparation of diluted contrast and installation of diluted contrast to the injector in angiography suites with a single power injector.

Vacuum for straightening the microcatheter after intra-aneurysmal looping: The "Lagman vacuum" technique.

In many cases, an intra-arterial microcatheter loop is necessary to bypass the neck of wide-necked giant aneurysms for the placement of a stent across it. The removal of this loop is usually challenging, and many techniques have been described to achieve it. We describe a simple novel technique for straightening the microcatheter across the aneurysm's neck, without the need for additional products/devices or complex exchanging techniques. The method has been successfully applied in two cases. We named this novel maneuver the "Lagman vacuum" technique.

Stroke Incidence and Outcomes in Northeastern Greece: The Evros Stroke Registry.

BACKGROUND AND PURPOSE: Data are scarce on both stroke incidence rates and outcomes in Greece and in rural areas in particular. We performed a prospective population-based study evaluating the incidence of first-ever stroke in the Evros prefecture, a region of a total 147 947 residents located in North Eastern Greece. METHODS: Adult patients with first-ever stroke were registered during a 24-month period (2010-2012) and followed up for 12 months. To compare our stroke incidence with that observed in other studies, we standardized our incidence rate data according to the European Standard Population, World Health Organization, and Segi population. We also applied criteria of data quality proposed by the Monitoring Trends and Determinants in Cardiovascular Disease project. Stroke diagnosis and classification were performed using World Health Organization criteria on the basis of neuroimaging and autopsy data. RESULTS: We prospectively documented 703 stroke cases (mean age: 75±12 years; 52.8% men; ischemic stroke: 80.8%; intracerebral hemorrhage: 11.8%; subarachnoid hemorrhage: 4.4%; undefined: 3.0%) with a total follow-up time of 119 805 person-years. The unadjusted and European Standard Population-adjusted incidences of all strokes were 586.8 (95% confidence interval [CI], 543.4-630.2) and 534.1 (95% CI, 494.6-573.6) per 100 000 person-years, respectively. The unadjusted incidence rates for ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage were 474.1 (95% CI, 435-513), 69.3 (95% CI, 54-84), and 25.9 (95% CI, 17-35) per 100 000 person-years, respectively. The corresponding European Standard Population-adjusted incidence rates per 100 000 person-years were 425.9 (95% CI, 390.9-460.9), 63.3 (95% CI, 49.7-76.9), and 25.8 (95% CI, 16.7-34.9) for ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage, respectively. The overall 28-day case fatality rate was 21.3% (95% CI, 18.3%-24.4%) for all strokes and was higher in hemorrhagic strokes than ischemic stroke (40.4%, 95% CI, 31.3%-49.4% versus 16.2%, 95% CI, 13.2%-19.2%). CONCLUSIONS: This is the largest to date population-based study in Greece documenting one of the highest stroke incidences ever reported in South Europe, highlighting the need for efficient stroke prevention and treatment strategies in Northeastern Greece.

Abdominal adipose tissue distribution on MRI and diabetes.

RATIONALE AND OBJECTIVES: To introduce a simple magnetic resonance imaging (MRI) protocol for quantitative assessment of intraperitoneal, retroperitoneal, and subcutaneous adipose tissue (AT) and to compare AT distribution between diabetic and nondiabetic individuals. MATERIALS AND METHODS: Thirty-eight consecutive male diabetic patients (group A) and 38 males (who matched for body mass index [BMI]) without metabolic syndrome (group B) underwent abdominal MRI with a three-dimensional spoiled gradient echo T1-weighted sequence. The amounts of intraperitoneal, retroperitoneal, and subcutaneous AT were calculated on a workstation, after manual anatomic segmentation and were correlated with 10 anthropometric measurements. Pearson product-moment correlation coefficients were used for correlation of AT volumes with anthropometric measurements, Wilcoxon test to compare AT measurements between automatic and manual technique used, and unpaired t test to compare volumes of AT compartments between group A and B. RESULTS: Diabetic patients exhibited larger amount of intraperitoneal and retroperitoneal AT than normal individuals at all levels (t = 2.02,P < .05). Among anthropometric measurements, the waist circumference, BMI, and body fat percentage exhibited the best correlations with intraperitoneal and retroperitoneal AT (group A (r) = 0.88/0.78/0.0.69 and group B (r) = 0.91/0.87/0.81). The L2-L5 set of images was found to be the most representative of the amount of AT volumes. CONCLUSIONS: Amount and distribution of AT can be accurately and easily assessed on MRI. Quantification of intraabdominal AT may promote the role of imaging in the study of metabolic syndrome.

Peripheral nerve sheath tumors. Benign or malignant? The role of MRI and ultrasonography in a case report.

A 31-year-old male patient admitted to another hospital for investigation of a localized painful hump in the medial surface of his left leg. The clinical examination revealed a painful palpable lump in the medial surface of left thigh that was initially thought to be a hematoma due to a history of recent trauma. However, an ultrasound was requested to exclude deep venous thrombosis (DVT). The US examination revealed a heterogeneous, fusiform lesion with elongated proximal and distal projections in close proximity to superficial femoral artery and vein and could not definitely exclude the DVT hypothesis. In a second ultrasound examination performed in our department, a neurogenic origin of the lesion was proposed. A consequent MRI examination confirmed the presence of a fusiform tumor in the anatomic path of the saphenous nerve. This was further confirmed intraoperatively, and pathologically was diagnosed as a malignant peripheral nerve sheath tumor (MPNST). In this present study the role of ultrasonography, the correlation between MRI and ultrasonographic findings are discussed and a review of the literature is presented.

Bilateral claw hand: an uncommon presentation of regional Guillain-Barré syndrome.

We present an uncommon case of a 38-year-old man presented with bilateral subacute weakness of intrinsic hand muscles, manifesting as bilateral claw-hand, without sensory deficits and absent tendon reflexes in upper arms. Nerve conduction studies showed findings consistent with demyelinating GBS. During the fourth day of hospitalization the patient presented symmetrical distal leg weakness and was treated with intravenous immunoglobulin.

Successful endovascular treatment of a ruptured gigantic pseudoaneurysm of the common iliac artery secondarily complicated by infection.

We report our experience with a case of emergent endovascular treatment of a large ruptured pseudoaneurysm of the common iliac artery. A 65-year-old male was admitted to the surgical department in hypovolemic shock, due to active retroperitoneal bleeding. A computerized tomography scan with intravenous contrast revealed a ruptured gigantic pseudoaneurysm of the right common iliac artery, with a maximal diameter of 7 cm and retroperitoneal hematoma. An intraoperative angiogram revealed active extravasation through the neck of the pseudoaneurysm, which was successfully sealed with the placement of a stent graft (Medtronic Endurant(®))limb component. Infection of the pseudoaneurysm sac after one month was successfully treated with catheter drainage. No shortterm relapse occurred. Endovascular management should be part of the basic surgical armamentarium on emergent basis, since it provides a fast and safe solution, especially when a patient's co-morbitities preclude open management and hemodynamic and anatomical status allows endovascular treatment.

An uncommon clinical presentation of acute limb ischemia: underscoring the role of perigenicular collaterals.

We present a case of atypical acute limb ischemia in a non-diabetic patient, with ankle-brachial pressure index of 0.6 and rest pain localized exclusively over the gastrocnemius muscle, sparing the foot. This uncommon presentation was attributed to an impaired perigenicular collateral network. Thrombolysis restored adequate perfusion only temporarily and was followed by thromboembolectomy. The ischemia presentation in our case underscores the importance of the adequacy of the perigeniculate collateral network for the perfusion of the tibial muscles and, especially, the gastrocnemius muscle.

The use of CT or MRI for the one-stage placement of stents in biliary obstructions.

PURPOSE: This study describes and evaluates a simple method of percutaneous intervention planning in order to treat obstructed biliary systems using computed tomography (CT) or magnetic resonance imaging (MRI). MATERIALS AND METHODS: CT (n=18) and MRI (n=31) examinations, which were performed during the imaging work-up of 31 patients with malignant biliary obstruction, were used to plan transhepatic percutaneous biliary intervention. The appropriate intrahepatic duct, the entry point on the skin, and the puncture direction and depth were determined on axial CT or MR images. Under fluoroscopic guidance, a 21-G needle was used for puncture, and the puncture was followed by a percutaneous transhepatic cholangiography, the placement of a stent, and the placement of an external drainage catheter. RESULTS: The biliary system was successfully accessed on the first attempt in 16 patients (51.6%). Second or third attempts were required in eight (25.8%) and two (6.4%) patients, respectively, whereas more than three attempts were necessary for the remaining five (16.3%) patients. One-stage percutaneous transhepatic biliary stent placement was performed in 29 patients (93.5%). Two (n=1) and three (n=1) interventional sessions were required in order to successfully complete stent placement in the remaining two cases. The mean fluoroscopy time for one-stage biliary stent placement was 12.6 min +/- 2.6 min, and no major complications were noted. CONCLUSION: Thorough CT/MRI-based planning is suggested prior to the interventional treatment of malignant biliary obstruction so as to reduce the number of needle passes, the duration of the procedure, the fluoroscopy time, and the number of complications.

Bilio-cutaneous fistula formation after percutaneous liver mass biopsy: embolization of the tract with a gelatin matrix.

We report an unusual complication of ultrasound-guided percutaneous liver biopsy, in the form of a persisting iatrogenic bilio-cutaneous fistula. A patient with liver hilar tumor and malignant obstructive jaundice was initially treated by successful placement of bilateral metallic stents and did well until mass biopsy was decided. The fistula created decreased patient's quality of life, and because the patient refused further interventions, fistula catheterization for embolization was proposed. We injected a gelatin matrix into the extrahepatic portion of the fistula and embolized the tract successfully.