Sumit Roy

Intra-operative MRI facilitates tumour resection during trans-sphenoidal surgery for pituitary adenomas

BackgroundDuring trans-sphenoidal microsurgical resection of pituitary adenomas, the extent of resection may be difficult to assess, especially when extensive suprasellar and parasellar growth has occurred. In this prospective study, we investigated whether intra-operative magnetic resonance imaging (iMRI) can facilitate tumour resection.MethodsTwenty patients with macroadenomas, (16 non-functioning, three growth-hormone secreting and one pharmaco-resistant prolactinoma) were selected for surgery in the iMRI. The mean tumour diameter was 27 mm (range 11–41). The mean parasellar grade, according to the Knosp classification, was 2.3. Pre-operative coronal and sagittal T1-weighted and T2-weighted images were obtained. The trans-sphenoidal tumour resection was performed at the edge of the tunnel of a Signa SP 0.5-Tesla MRI. The surgeon aimed at a radical tumour resection that was followed by a peri-operative MRI scan. When a residual tumour was visualised and deemed resectable, an extended resection was performed, followed by another MRI scan. This procedure was repeated until the imaging results were satisfactory. In all patients, we were able to obtain images to assess the extent of resection and to classify the resection as either total or subtotal.ResultsAfter primary resection, eight out of 20 cases were classified as total resections. A second resection was performed in 11 of 12 cases classified as subtotal resections, and in four of these, total resection was achieved. A third resection was performed in three of the remaining seven cases with subtotal resections, but we did not achieve total resection in any of these cases. Therefore, the use of iMRI increased the number of patients with total resection from 8/20 (40%) to 12/20 (60%). The only observed complication was a transient spinal fluid leakage.ConclusionIntra-operative MRI during trans-sphenoidal microsurgery is useful in selected patients for a safe and more complete resection.

Typical atypical findings on dynamic MRI of the breast

Dynamic contrast enhanced magnetic resonance imaging (DCE MRI) of the breast has become an important tool to detect and characterize breast disease. The American College of Radiology Breast Imaging Reporting and Data System (BI-RADS(®)) provides a standardized vocabulary for describing the morphologic features and contrast kinetics of breast lesions. However, some lesions may show morphologic and dynamic MR features not consistent with their histologic nature resulting in incorrect categorization as malignant or benign. Another cause of diagnostic problems is artifacts. Thus correct interpretation of dynamic MRI of the breast demands knowledge of the most common pitfalls encountered in clinical practice. A pictorial overview of these is presented, with particular reference to the differentiation of malignant tumors from benign lesions.

MRI features of intraductal papilloma of the breast: sheep in wolf's clothing?

Background Intraductal papillomas often present as small, smooth masses, dilated ducts or microcalcifications at mammography and as smooth, hypoechoic masses at sonography. At magnetic resonance imaging (MRI), intraductal papillomas often present as small smooth masses, however, often with strong enhancement with type 2 or 3 time intensity curves. The result of the MR analysis is therefore not infrequently inconclusive in order to characterize the mass as benign or malignant. Purpose To characterize the appearance of intraductal papillomas of the breast at MRI, and determine whether the application of diagnostic rules described in literature could contribute to correctly classifying the lesions as benign. Material and Methods Twenty patients with histologically proven intraductal papillomas were included. Two radiologists independently reviewed the MR images of the breast. The BI-RADS® nomenclature was used to describe morphology and contrast-enhancement kinetics. Interobserver agreement in the interpretation of the MR images by the two investigators was performed. Kappa coefficient was calculated as index for the level of agreement. Subsequently, three sets of diagnostic rules, including the Göttinger score described by Fischer and the interpretation flowcharts according to Kinkel and to Tozaki were applied to characterize whether a biopsy should be recommended or not. Results All papillomas presented as masses on dynamic contrast-enhanced MRI. Only five papillomas showed a round, oval, or lobulated shape combined with smooth margins and continuous rise of the time intensity curve. Using the Göttingen score, biopsy would be recommended in 16 patients. Based on the interpretation flowcharts of Kinkel and of Tozaki, an additional 13 and 10 papillomas, respectively, were correctly classified as benign. Dilated ducts were visible in 10 patients. The interobserver agreement was good or excellent for all included variables. Conclusion Including systematic analysis of breast MRI to the diagnostic protocol and interpreting the images according to predetermined diagnostic rules, most solitary intraductal papillomas of the breast may be correctly characterized as benign.

Evaluation of the recombinant tissue plasminogen activator pretreatment in acute stroke patients with large vessel occlusions treated with the direct bridging approach. Is it worth the effort

The direct bridging concept in acute stroke treatment combines intravenous thrombolysis (IVT) and endovascular treatment (EVT). The frequency and extent of reperfusion obtained already due to IVT were evaluated. Additionally undesired events and the clinical outcome were analysed.

Transcarotid Endovascular Thrombectomy for Acute Ischemic Stroke

Endovascular thrombectomy (EVT) via a transfemoral approach can be extremely time-consuming or even impossible. This brief review presents 7 transcarotid EVT procedures in which reperfusion graded as 2b or 3 on the Thrombolysis In Cerebral Infarction scale was achieved. Neck hematoma in need of treatment occurred in 1 patient. Two patients died. In the remaining patients, clinical outcome was graded as a modified Rankin scale score of 3 or less. The results suggest that transcarotid access may be a realistic option for EVT when transfemoral catheterization of the internal carotid artery is not feasible.

Percutaneous closure of catheter enterotomy: feasibility determination in vivo.

Abstract Aim: To determine whether a catheter enterotomy can be percutaneously sealed with a commercially available vascular closure implant. Material and methods: The study was performed using a porcine model of small intestinal obstruction. Preliminary experiments were performed to allow an informed choice between two of the most promising commercially available alternatives: A multipronged metal clip (StarClose®) and a resorbable anchored polymer plate (FemoSeal®). Thereafter closure of seven enterotomies was attempted with the most suitable implant. The deployment procedure was subjectively analyzed. The sealed enterotomies were visually evaluated and hydrostatically tested. Results: StarClose was rejected for formal assessment because it was both difficult to deploy and could not ensure a watertight seal. The conventional method for deploying FemoSeal was found to be inappropriate for percutaneously closing enterotomies. However an improvised accessory allowed all seven enterotomies to be successfully sealed with the implant using a modified procedure that involved only one additional step. After closure, six of the seven enterotomies tolerated intraluminal pressure up to 65 mm Hg. Conclusion:FemoSeal has the potential to serve as an implant for percutaneous closure of catheter enterotomies if the deployment tool can be appropriately modified.