Dynamic magnetic resonance imaging following native tissue vaginal reconstructive surgery; a prospective study.

INTRODUCTION AND HYPOTHESIS: To describe the impact of native tissue vaginal reconstruction on pelvic anatomy using dynamic magnetic resonance imaging. METHODS: This prospective single-cohort observational study involved women undergoing native tissue reconstruction with intraperitoneal vaginal vault suspension for pelvic organ prolapse. Concomitant procedures such as hysterectomy, midurethral sling, and anterior or posterior colporrhaphy were allowed. Enrolled participants underwent dynamic pelvic imaging pre- and postoperatively. Radiographic and anatomic measurements were compared. Secondary outcomes included validated patient questionnaires. RESULTS: Fourteen participants were included in the analysis. The mean age was 62 years; all participants were Caucasian. Most participants had stage III pelvic organ prolapse. Significant improvements were noted in several radiographic measurements. The average H-line (representing levator hiatus width) with straining maneuvers improved following surgery (7.2 cm preoperatively vs. 6.6 cm postoperatively, p = 0.015). The average M-line (representing levator muscular descent) improved significantly with both straining (4.0 cm preoperatively vs. 3.0 cm postoperatively, p < 0.001) and defecatory maneuvers (6.2 cm preoperatively vs. 5.2 cm postoperatively, p = 0.001). The average size of cystocele improved from 5.6 cm (moderate) preoperatively to 0.7 cm (absent descent) postoperatively (p < 0.001). The average descent of the vaginal apex with defecation preoperatively was 3.0 cm (moderate) and 0 cm (absent descent) postoperatively (p = 0.003). Posterior compartment descent with defecation did not change following surgical intervention (5.8 cm preoperatively vs. 5.2 cm postoperatively, p = 0.056). Pelvic Organ Prolapse Quantification measurements improved in all compartments, and Pelvic Floor Distress Inventory-20 scores improved significantly following surgery (102 preoperatively vs. 30 postoperatively, p < 0.001). CONCLUSIONS: Native tissue reconstruction with intraperitoneal vaginal vault suspension resulted in significant anatomic improvements, as defined by physical examination and dynamic magnetic resonance imaging.

MRI of ovarian torsion: Correlation of imaging features with the presence of perifollicular hemorrhage and ovarian viability.

PURPOSE: The purpose of our study is to test for: (a) correlation between the presence of a perifollicular T2-hypointense rim on MRI with the presence of perifollicular hemorrhage on histology; and (b) correlation between this finding and diminished ovarian viability after intra-operative detorsion. METHODS AND MATERIALS: Our IRB-approved, retrospective study evaluated 780 patients between August 2012 and February 2016 with ovarian torsion as a diagnostic consideration on the emergency department note. Patients were included if they had preoperative MRI and intraoperatively confirmed case of ovarian torsion. MRIs were retrospectively reviewed for presence of perifollicular T2 hypointense rim in the torsed ovary. Two arms of analysis were performed: (a) assessment of perifollicular hemorrhage on histological exam; and (b) assessment of ovarian viability after intra-operative detorsion. Sensitivity, specificity, positive predictive value, and negative predictive value of MRI for predicting ovarian viability in the setting of torsion was performed. κ test assessed level of agreement between readers. RESULTS: 24 patients included in one of the two arms; 20 in viability analysis and 12 in perifollicular hemorrhage analysis (8 in both). The presence of T2-hypointense rim on MRI demonstrated 88.9% sensitivity and 66.7% specificity for the diagnosis of perifollicular hemorrhage on histology, and 91.7% sensitivity and 100% specificity for predicting intraoperative viability. CONCLUSION: The presence of a perifollicular T2 hypointense rim on MRI in the setting of ovarian torsion correlates with perifollicular hemorrhage on histopathologic exam, and may also be a useful predictor of ovarian viability in patients presenting with ovarian torsion.

A Systematic Review and Meta-Analysis of Diagnostic Performance of MRI for Evaluation of Acute Appendicitis.

OBJECTIVE: A meta-analysis was performed to determine the accuracy of MRI in the diagnosis of acute appendicitis in the general population and in subsets of pregnant patients and children. MATERIALS AND METHODS: A systematic search of the PubMed and EMBASE databases for articles published through the end of October 2014 was performed to identify studies that used MRI to evaluate patients suspected of having acute appendicitis. Pooled data for sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: A total of 30 studies that comprised 2665 patients were reviewed. The sensitivity and specificity of MRI for the diagnosis of acute appendicitis are 96% (95% CI, 95-97%) and 96% (95% CI, 95-97%), respectively. In a subgroup of studies that focused solely on pregnant patients, the sensitivity and specificity of MRI were 94% (95% CI, 87-98%) and 97% (95% CI, 96-98%), respectively, whereas in studies that focused on children, sensitivity and specificity were found to be 96% (95% CI, 95-97%) and 96% (95% CI, 94-98%), respectively. CONCLUSION: MRI has a high accuracy for the diagnosis of acute appendicitis, for a wide range of patients, and may be acceptable for use as a first-line diagnostic test.

Accuracy of Unenhanced MR Imaging in the Detection of Acute Appendicitis: Single-Institution Clinical Performance Review.

PURPOSE: To determine the accuracy of unenhanced magnetic resonance (MR) imaging in the detection of acute appendicitis in patients younger than 50 years who present to the emergency department with right lower quadrant (RLQ) pain. MATERIALS AND METHODS: The institutional review board approved this retrospective study of 403 patients from August 1, 2012, to July 30, 2014, and waived the informed consent requirement. A cross-department strategy was instituted to use MR imaging as the primary diagnostic modality in patients aged 3-49 years who presented to the emergency department with RLQ pain. All MR examinations were performed with a 1.5- or 3.0-T system. Images were acquired without breath holding by using multiplanar half-Fourier single-shot T2-weighted imaging without and with spectral adiabatic inversion recovery fat suppression without oral or intravenous contrast material. MR imaging room time was measured for each patient. Prospective image interpretations from clinical records were reviewed to document acute appendicitis or other causes of abdominal pain. Final clinical outcomes were determined by using (a) surgical results (n = 77), (b) telephone follow-up combined with review of the patient's medical records (n = 291), or (c) consensus expert panel assessment if no follow-up data were available (n = 35). Logistic regression analysis was performed to evaluate the sensitivity and specificity of MR imaging in the detection of acute appendicitis, and corresponding 95% confidence intervals were determined. RESULTS: Of the 403 patients, 67 had MR imaging findings that were positive for acute appendicitis, and 336 had negative findings. MR imaging had a sensitivity of 97.0% (65 of 67) and a specificity of 99.4% (334 of 336). The mean total room time was 14 minutes (range, 8-62 minutes). An alternate diagnosis was offered in 173 (51.5%) of 336 patients. CONCLUSION: MR imaging is a highly sensitive and specific test in the evaluation of patients younger than 50 years with acute RLQ pain that uses a rapid imaging protocol performed without intravenous or oral contrast material.

Migrating bullet: A case of a bullet embolism to the pulmonary artery with secondary pulmonary infarction after gunshot wound to the left globe.

Bullet embolism is a rare phenomenon following gunshot injuries. We present a case of a 25-year-old male who sustained a gunshot wound to his left globe with the bullet initially lodged in his right transverse sinus. The bullet ultimately embolized to a left lower lobe pulmonary artery resulting in a pulmonary infarct. A discussion of select prior cases, pathophysiology, and management strategies follows.

Portal vein embolization: rationale, outcomes, controversies and future directions.

Portal vein embolization (PVE) is now considered the standard of care to improve safety for patients undergoing extensive hepatectomy with an anticipated small future liver remnant (FLR). PVE is used to induce contralateral liver hypertrophy in preparation for major liver resection. Optimal patient selection is essential to maximize the clinical benefits of PVE. Computed tomography volumetry is used to calculate a standardized FLR and determine the need for preoperative PVE. Percutaneous PVE can be performed via the transhepatic ipsilateral or contralateral approaches, depending on operator preference. Several different embolic agents are available to the interventional radiologist, all with similar effectiveness in inducing hypertrophy. When an extended hepatectomy is planned, right PVE should include segment 4, in order to maximize FLR hypertrophy. Multiple studies have demonstrated the beneficial outcomes of PVE in both patients with healthy livers and with underlying liver diseases. Novel improvements to PVE should expand its scope to patients who were previously not candidates for the procedure.

Agreement between competing imaging measures of response of hepatocellular carcinoma to yttrium-90 radioembolization.

PURPOSE: There are currently at least six major competing criteria used to determine response to yttrium-90 and other liver-directed therapies, including: (i) Response Evaluation Criteria in Solid Tumors (RECIST); (ii) World Health Organization (WHO), (iii) volumetric, (iv) two-dimensional (2D) European Association for the Study of the Liver (EASL), and (v) three-dimensional (3D) EASL criteria; and (vi) functional diffusion-weighted (DW) magnetic resonance (MR) imaging. This study evaluated agreement among these competing tumor response classification schemes based on quantitative measurements of tumor size, necrosis, and changes in water mobility. MATERIALS AND METHODS: In this retrospective study, 20 patients with hepatocellular carcinoma (HCC) underwent (90)Y radioembolization. The patients' tumor burden before and 3-6 months after treatment was assessed with MR imaging. The percent change in size of tumors was used to classify patients into response categories. kappa and agreement statistics were used to compare concordance among the different criteria. RESULTS: Conventional size criteria (RECIST, WHO, and volumetric) all had a substantial level of agreement (kappa = 0.76-0.78) when classifying patients into response categories. However, the conventional size criteria in relation to 2D or 3D EASL had only slight to moderate concurrence, with kappa statistics as low as 0.06. Two-dimensional EASL criteria and functional DW MR imaging resulted in the highest response rates, 55% (n = 11) and 75% (n = 15), respectively, whereas conventional size criteria produced lower response rates. CONCLUSIONS: Classification of HCC response to (90)Y radioembolization is related to which of the competing criteria are used. It is recommended that anatomic imaging criteria be used as the primary method to determine response and functional imaging criteria be used as a complementary secondary method.

Signalling during hypoxia in human T lymphocytes--critical role of the src protein tyrosine kinase p56Lck in the O2 sensitivity of Kv1.3 channels.

T lymphocytes encounter hypoxia when they migrate to pathological sites such as tumours and wounds. The inability of T cells to provide an efficient defence at these sites can in part be explained by the hypoxic environment. Kv 1.3 channels, important components of the T cell activation process are inhibited by hypoxia and their inhibition accounts for a hypoxia-induced decrease in T cell proliferation. Although Kv 1.3 channels play a key role in T cell O(2) sensing, the signalling mechanisms mediating their response to hypoxia are still not understood. In this study, we show that the src-protein tyrosine kinase p56Lck (Lck) is required for Kv 1.3 channel response to hypoxia. Pre-exposure to the src inhibitor PP2 abolished the hypoxia-induced inhibition of Kv 1.3 channels in primary human T lymphocytes. Moreover, Kv 1.3 channel sensitivity to hypoxia was lost in Lck-deficient Jurkat T cells. Further studies with recombinant Kv 1.3 channels showed that Kv 1.3 channels lack intrinsic O(2) sensitivity, but delivery of Lck into the cells and transfection of a constitutively active Lck (Y505FLck) restored their sensitivity to hypoxia. Although Lck is necessary for the Kv 1.3 channel response to hypoxia, it does not directly inhibit Kv 1.3 channels. Indeed, under normal oxygen tension, delivery of active Lck into L929 cells and overexpression of Y505FLck did not decrease recombinant Kv 1.3 currents. On the contrary, activation of endogenous src kinases increased wild-type Kv 1.3 currents in T lymphocytes. Our findings indicate that Lck is required for the acute response to hypoxia of human T lymphocytes as it is necessary to confer O(2) sensitivity on Kv 1.3 channels.