Enhanced Recovery After Surgery (ERAS) Spine Pathways and the Role of Perioperative Checklists.

Enhanced recovery after surgery (ERAS) proposes a multimodal, evidence-based approach to perioperative care. ERAS pathways have been shown to help reduce complications, hospital length of stay (LOS), 30-day readmission rates, pain scores, and ultimately surgical costs, while improving patient satisfaction scores and outcomes in multiple surgical subspecialties [1-6]. Numerous specialties have implemented ERAS programs across the globe, providing a foundation for spine surgeons to begin the process themselves. Over the last few years, a significant number of papers have been addressing ERAS pathways for spinal surgery [7-19]. The majority have addressed the lumbar spine [9, 20-26]. The number of cervical ERAS pathways has been limited [27-29]. Many spine programs have begun the implementation of ERAS pathways, incorporating principles and interventions to various spine surgical procedures. Although differences in implementation across programs exist, there are a few common elements that promote a successful enhanced recovery approach [11, 16, 23, 25, 30-33]. All spinal ERAS pathways have three major elements, which are preoperative, perioperative, and postoperative phases. Within these phases some common elements include preoperative and intraoperative surgical checklists. Intraoperative checklist in addition to the "surgical time out" has been integrated into the workflow of most hospitals doing surgeries and have become a standard of care. The surgical checklist is designed to help reduce surgical errors and prevent wrong site/patient surgeries. Several surgical checklists have been developed throughout the years. Despite these safety protocols wrong site/level and other surgical errors continue to occur. Many cases of wrong level spine surgery (WLSS) still occur even when intraoperative imaging is performed [34, 35]. One survey reported that about 50% of spine surgeons have performed at least one WLSS during their career [36, 37]. Another survey reported that 36% of spine surgeons had performed at least one WLSS that was not recognized intraoperatively [38]. On a similar account, about 30% of spine surgery fellows have experienced wrong-site surgery [39]. From raw incidence rates, WLSS may seem rare, but these surveys show that the experience of WLSS is rather common among spine surgeons. WLSS is not yet a "never event." This may be due to poor quality of the intraoperative images, hindering subsequent level identification [34, 35, 38, 40]. Errors in interpretation of the imaging may also occur, including inconsistency in numbering vertebrae, inconsistency in landmark usage for level counting, and problems with numbering vertebrae due to lumbosacral transitional vertebrae (LSTV) and other anatomical variants [34, 38, 41-43]. This chapter will describe a framework for the development and implementation of ERAS pathway for patients undergoing spine surgery. In addition, we will propose preoperative imaging guidelines and a comprehensive spine surgical checklist to incorporate into the perioperative phase to help reduce further surgical errors and WLSS.

Patients with Classic Hodgkin Lymphoma and Follicular Lymphoma Compared to Single Malignancy Controls.

Classic Hodgkin lymphoma (CHL) can arise in patients with low-grade B-cell lymphoma. The features of CHL arising in follicular lymphoma (FL) and its outcome are still unclear, mainly due to the very few cases reported. This study compares 17 patients with CHL and FL to 2 control groups: 1 of 26 patients with FL and a second of 60 patients older than 40 when diagnosed with CHL. Of the FL and CHL patients, 8 had simultaneous FL and CHL, while 9 had FL first, followed by CHL 4.7 years later on average. The age at the diagnosis of FL was 61 years for patients with synchronous FL and CHL and of 60 years for FL, followed by CHL at 65 years. Patients with FL only were, on average, 59 years old at presentation, while CHL patients were 61. FL was grade 1-2 in 75% of FL and CHL patients and 67% of FL first and CHL second patients, lower proportions than in the FL control group-92%. Epstein-Barr virus (EBV) was detected in a lower fraction (29%) of the FL and CHL group than in CHL-only controls (46%). BCL2 translocations were detected in 4 of the 7 cases with FL, but in positive cases, the rearrangement was also present in the CHL component, indicating a clonal relationship between FL and CHL. Patients with FL and CHL treated for CHL had an initial outcome more similar to FL than to CHL controls.

Fluoroscopic Guided Lumbar Erector Spinae (ESP) Field Blocks: A New Technique and Radiographic Analysis.

INTRODUCTION: Lumbar Erector Spinae (ESP) field blocks have become a common postoperative treatment for surgical pain. The use of long-acting medications like liposomal bupivacaine (Exparel) has become a major component of multimodal postsurgical pain control. Traditionally ESP injections have been performed using ultrasound (U/S) guidance by an anesthesiologist. Spine surgeons have begun to utilize these liposomal injections in their procedures for postoperative pain management. Our study describes a fluoroscopic guided ESP field block technique which provides reproducible muscular coverage and pain control for spine surgery. MATERIAL AND METHODS: Sixty patients undergoing single level lumbar fusion were treated preoperatively with bilateral fluoroscopically-guided lumbar erector spinae ESP field blocks with liposomal bupivacaine. We looked at 2 different injection locations involving the ESP or multifidus muscle fascial planes. The injections contained Iohexal, which was used to evaluate the coverage area of the injection. The levels of coverage were recorded, and postoperative pain control was measured immediately, postoperatively, and at 24 hours. RESULTS: Fluoroscopic field blocks at the L3-4 level were found to provide at least 4 levels of vertebral coverage rostral-caudally in both ESP and MF fascial planes. Pain was well controlled in both injection sites. CONCLUSIONS: Surgeon-administered fluoroscopic-guided ESP field blocks provided a reliable and consistent pattern of coverage with good postoperative pain control. This technique can be easily adopted by spine surgeons.

Cauda equina, conus medullaris and syndromes mimicking sciatic pain: WFNS spine committee recommendations.

Introduction: Cauda equina syndrome (CES), conus medullaris syndrome (CMS), and sciatica-like syndromes or "sciatica mimics" (SM) may present as diagnostic and/or therapeutic dilemmas for the practicing spine surgeon. There is considerable controversy regarding the appropriate definition and diagnosis of these entities, as well as indications for and timing of surgery. Our goal is to formulate the most current, evidence-based recommendations for the definition, diagnosis, and management of CES, CMS, and SM syndromes. Methods: We performed a systematic literature search in PubMed from 2012 to 2022 using the keywords "cauda equina syndrome", "conus medullaris syndrome", "sciatica", and "sciatica mimics". Standardized screening criteria yielded a total of 43 manuscripts, whose data was summarized and presented at two international consensus meetings of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. Utilizing the Delphi method, we generated seven final consensus statements. Results and conclusion: s: We provide standardized definitions of cauda equina, cauda equina syndrome, conus medullaris, and conus medullaris syndrome. We advocate for the use of the Lavy et al classification system to categorize different types of CES, and recommend urgent MRI in all patients with suspected CES (CESS), considering the low sensitivity of clinical examination in excluding CES. Surgical decompression for CES and CMS is recommended within 48 h, preferably within less than 24 h. There is no data regarding the role of steroids in acute CES or CMS. The treating physician should be cognizant of a variety of other pathologies that may mimic sciatica, including piriformis syndrome, and how to manage these.

Optimized quantitative mapping of cardiopulmonary oscillations using hyperpolarized 129 Xe gas exchange MRI: Digital phantoms and clinical evaluation in CTEPH.

PURPOSE: The interaction between 129 Xe atoms and pulmonary capillary red blood cells provides cardiogenic signal oscillations that display sensitivity to precapillary and postcapillary pulmonary hypertension. Recently, such oscillations have been spatially mapped, but little is known about optimal reconstruction or sensitivity to artifacts. In this study, we use digital phantom simulations to specifically optimize keyhole reconstruction for oscillation imaging. We then use this optimized method to re-establish healthy reference values and quantitatively evaluate microvascular flow changes in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after pulmonary thromboendarterectomy (PTE). METHODS: A six-zone digital lung phantom was designed to investigate the effects of radial views, key radius, and SNR. One-point Dixon 129 Xe gas exchange MRI images were acquired in a healthy cohort (n = 17) to generate a reference distribution and thresholds for mapping red blood cell oscillations. These thresholds were applied to 10 CTEPH participants, with 6 rescanned following PTE. RESULTS: For undersampled acquisitions, a key radius of 0.14 k max $$ 0.14{k}_{\mathrm{max}} $$ was found to optimally resolve oscillation defects while minimizing excessive heterogeneity. CTEPH participants at baseline showed higher oscillation defect + low (32 ± 14%) compared with healthy volunteers (18 ± 12%, p < 0.001). For those scanned both before and after PTE, oscillation defect + low decreased from 37 ± 13% to 23 ± 14% (p = 0.03). CONCLUSIONS: Digital phantom simulations have informed an optimized keyhole reconstruction technique for gas exchange images acquired with standard 1-point Dixon parameters. Our proposed methodology enables more robust quantitative mapping of cardiogenic oscillations, potentially facilitating effective regional quantification of microvascular flow impairment in patients with pulmonary vascular diseases such as CTEPH.

Complications of Anterior Cervical Discectomy and Fusion.

Anterior cervical discectomy and fusion (ACDF) is the most common surgery performed on the cervical spine, and the number of its cases has tripled over the last two decades. Although this intervention is typically safe and effective, it carries an inherent complication risk, which should not be underestimated. Improvements in surgical techniques and advances in interbody fusion devices and plating systems have certainly reduced the rate of postoperative morbidity, but despite such progress, surgeons need to beware consistently of the potential complications, inform the patient of their possibility, and have a management strategy as they develop. This review discusses postoperative morbidity encountered in recently reported large studies on ACDF and highlights the senior author's own single-surgeon experience with 2579 such procedures performed between 1998 and 2017. In his clinical series, which is the largest one reported to date, the overall complication rate was 7.0% (180 cases), and dysphagia (1.9% of cases), graft/hardware failures (1.3% of cases), and postoperative hematomas (0.9% of cases) were noted most frequently. Understanding of the risk and clinical impact of complications after ACDF is very important and every effort should be put on their possible avoidance and on appropriate management when they do occur.

Optimization of non-endorectal prostate MR image quality using PI-QUAL: A multidisciplinary team approach.

PURPOSE: To evaluate the utility of the PI-QUAL score in assessing protocol changes aimed to improve image quality from a non-endorectal coil prostate MR imaging protocol during a 9-month quality improvement (QI) project and to quantify the inter-reader agreement of PI-QUAL scores between radiologists, technologists, and physicists. METHODS: This retrospective study audited 1,012 multiparametric prostate MRI examinations as part of a national QI project according to the PI-QUAL standard. PI-QUAL scores were used to inform MR protocol changes. Following the project, 4 radiologists, 2 technologists, and 1 medical physicist collectively audited an additional set of 150 examinations to identify statistical improvements in image quality using the two-tailed Wilcoxon rank sum test. The improvements due to individual protocol changes were assessed among subsets of the 1,012 examinations which compared examinations occurring before and after the isolated protocol change. Inter-reader variability was assessed using the percent majority agreement and the average standard deviation of PI-QUAL scores between evaluators. RESULTS: During this QI project, PI-QUAL scores improved from 3.67 ± 0.75 to 4.16 ± 0.59 (p < 0.01) after implementing a series of protocol changes. Among a subset of 451 cases, we found that adopting R/L rather than A/P phase encoding reduced distortion in diffusion-weighted imaging (DW) from 21.6% (41/190 A/P phase encoded cases) to 11.5% (30/261 R/L phase encoded cases) (p < 0.01). Similarly, in the same 451 cases, adopting R/L phase encoding in T2WI reduced breathing motion artifacts from 34.6% (94/272 A/P phase encoding cases) to 12.8% (23/179 R/L phase encoding cases) (p < 0.01). DWI wraparound artifact was mitigated by employing a full-pelvis shim and enabling the abdomen shim option. The occurrence of low signal-to-noise ratio was reduced from 19.4% (19/98 cases without a weight-based threshold) to 6.3% (10/160) by instituting a weight-based threshold for using an endorectal coil (p < 0.01). The percent majority agreement was similar between radiologists, technologists and physicists, and all evaluators combined (72%, 77%, and 67%, respectively). CONCLUSIONS: PI-QUAL can evaluate image quality changes resulting from protocol optimizations at both the exam- and series-levels. With training, radiologists, technologists, and physicists can perform PI-QUAL scoring with similar performance. Broadening the scope of the quality improvement team can result in meaningful and lasting change.

Common statistical concepts in the supervised Machine Learning arena.

One of the core elements of Machine Learning (ML) is statistics and its embedded foundational rules and without its appropriate integration, ML as we know would not exist. Various aspects of ML platforms are based on statistical rules and most notably the end results of the ML model performance cannot be objectively assessed without appropriate statistical measurements. The scope of statistics within the ML realm is rather broad and cannot be adequately covered in a single review article. Therefore, here we will mainly focus on the common statistical concepts that pertain to supervised ML (i.e. classification and regression) along with their interdependencies and certain limitations.

A Hybrid Stainless-Steel SPME Microneedle Electrode Sensor for Dual Electrochemical and GC-MS Analysis.

A mechanically robust in-tube stainless steel microneedle solid phase microextraction (SPME) platform for dual electrochemical and chromatographic detection has been demonstrated. The SPME microneedle was fabricated by layer-by-layer (LbL) in-tube coating, consisting of carbon nanotube (CNT)/cellulose nanocrystal (CNC) film layered with an electrically conductive polyaniline (PANI) hydrogel layer (PANI@CNT/CNC SPME microneedle (MN)). The PANI@CNT/CNC SPME MN showed effective analysis of caffeine by GC-MS with an LOD of 26 mg/L and excellent precision across the dynamic range. Additionally, the PANI@CNT/CNC SPME MN demonstrated a 67% increase in sensitivity compared to a commercial SPME fiber, while being highly robust for repeated use without loss in performance. For electrochemical detection, the PANI@CNT/CNC SPME MN showed excellent performance for the detection of 3-caffeoylquinic acid (3-CQA). The dynamic range and limits of detection (LOD) for 3-CQA analysis were 75-448 mg/L and 11 mg/L, respectively. The PANI@CNT/CNC SPME MN was demonstrated to accurately determine the caffeine content and 3-CQA in tea samples and dark roast coffee, respectively. The PANI@CNT/CNC SPME MN was used for semiquantitative antioxidant determination and composition analysis in kiwi fruit using electrochemistry and SPME-coupled GC-MS, respectively.

View-sharing for 4D magnetic resonance imaging with randomized projection-encoding enables improvements of respiratory motion imaging for treatment planning in abdominothoracic radiotherapy.

Background and Purpose: The accuracy and precision of radiation therapy are dependent on the characterization of organ-at-risk and target motion. This work aims to demonstrate a 4D magnetic resonance imaging (MRI) method for improving spatial and temporal resolution in respiratory motion imaging for treatment planning in abdominothoracic radiotherapy. Materials and Methods: The spatial and temporal resolution of phase-resolved respiratory imaging is improved by considering a novel sampling function based on quasi-random projection-encoding and peripheral k-space view-sharing. The respiratory signal is determined directly from k-space, obviating the need for an external surrogate marker. The average breathing curve is used to optimize spatial resolution and temporal blurring by limiting the extent of data sharing in the Fourier domain. Improvements in image quality are characterized by evaluating changes in signal-to-noise ratio (SNR), resolution, target detection, and level of artifact. The method is validated in simulations, in a dynamic phantom, and in-vivo imaging. Results: Sharing of high-frequency k-space data, driven by the average breathing curve, improves spatial resolution and reduces artifacts. Although equal sharing of k-space data improves resolution and SNR in stationary features, phases with large temporal changes accumulate significant artifacts due to averaging of high frequency features. In the absence of view-sharing, no averaging and detection artifacts are observed while spatial resolution is degraded. Conclusions: The use of a quasi-random sampling function, with view-sharing driven by the average breathing curve, provides a feasible method for self-navigated 4D-MRI at improved spatial resolution.

Contrast-Enhanced In-Phase Dixon Sequence: Impact on Biopsy Clip Detection on Breast MRI.

BACKGROUND. Identification of breast biopsy clips using conventional MRI sequences may be challenging. A contrast-enhanced in-phase Dixon sequence may have greater conspicuity for areas of susceptibility compared with standard clinical sequences. OBJECTIVE. The purpose of this article is to compare detection of breast biopsy clips on MRI between the contrast-enhanced in-phase Dixon sequence and three routine clinical sequences. METHODS. This retrospective study included 164 patients (mean age, 50.3 years) with a total of 281 breast biopsy clips who underwent contrast-enhanced breast MRI between January 2, 2019, and April 16, 2020. Three radiologists, blinded to the clip location and sequence used, independently annotated biopsy clip locations on three clinical sequences (T1-weighted non-fat-suppressed [NFS], STIR, and first phase from dynamic contrast-enhanced T1-weighted fat-suppressed [FS]) and on a contrast-enhanced in-phase Dixon sequence and then recorded confidence scores (1-4 scale). A study coordinator used all available imaging and reports to localize clips on MRI, which served as the reference standard. A physicist measured clip CNR. Sequences were compared using the McNemar test and two-tailed Wilcoxon signed rank tests. RESULTS. Among the three readers, pooled sensitivity and PPV were 78.2% and 96.2% for T1-weighted NFS, 26.6% and 92.7% for STIR, 61.7% and 95.9% for contrast-enhanced T1-weighted FS, and 85.1% and 95.1% for contrast-enhanced in-phase Dixon sequence. Pooled sensitivity was higher for contrast-enhanced in-phase Dixon sequence than for the other sequences (all p < .05); pooled PPV was not significantly different between contrast-enhanced in-phase Dixon and the other sequences (all p > .05). Mean confidence scores (pooled across readers for true-positive assessments) and mean CNR were 3.0 ± 0.9 (SD) and 1.21 ± 0.61 for T1-weighted NFS, 1.7 ± 0.9 and 0.57 ± 0.69 for STIR, 2.5 ± 1.0 and 0.54 ± 0.61 for contrast-enhanced T1-weighted FS, and 3.5 ± 0.8 and 4.05 ± 2.6 for the contrast-enhanced in-phase Dixon sequence. Pooled mean confidence scores and CNR were higher for contrast-enhanced in-phase Dixon than for the other sequences (all p < .001). CONCLUSION. Compared with clinical sequences, the contrast-enhanced in-phase Dixon sequence had higher sensitivity for detecting breast biopsy clips on MRI and higher reader confidence and CNR, without change in PPV. CLINICAL IMPACT. The contrast-enhanced in-phase Dixon sequence may help address a current challenge in clinical breast MRI interpretation.

Molecularly Imprinted Polymer-Modified Microneedle Sensor for the Detection of Imidacloprid Pesticides in Food Samples.

A portable, molecularly imprinted polymer (MIP)-based microneedle (MN) sensor for the electrochemical detection of imidacloprid (IDP) has been demonstrated. The MN sensor was fabricated via layer-by-layer (LbL) in-tube coating using a carbon nanotube (CNT)/cellulose nanocrystal (CNC) composite, and an IDP-imprinted polyaniline layer co-polymerized with imidazole-functionalized CNCs (PANI-co-CNC-Im) as the biomimetic receptor film. The sensor, termed MIP@CNT/CNC MN, was analyzed using both cyclic voltammetry (CV) and differential pulse voltammetry (DPV) and showed excellent electrochemical performance for the detection of IDP. The CV detection range for IDP was 2.0-99 µM, with limits of detection (LOD) of 0.35 µM, while the DPV detection range was 0.20-92 µM with an LOD of 0.06 µM. Additionally, the MIP@CNT/CNC MN sensor showed excellent reusability and could be used up to nine times with a 1.4 % relative standard deviation (% RSD) between uses. Lastly, the MIP@CNT/CNC MN sensor successfully demonstrated the quantification of IDP in a honey sample.

Myeloid Sarcoma Involving the Testis in Adults: Clonal Evolution of Acute Myeloid Leukemia.

To describe the clinical, histologic, immunophenotypic, and genetic characteristics of myeloid sarcoma (MS) diagnosed in the testes of adults, 3 cases were identified, and information on their presentation, clinical features, treatment, and outcome was retrieved from the medical records. In addition, histologic, immunophenotypic, and molecular characteristics were reviewed. This showed that all patients had a previous history of acute myeloid leukemia (AML), in 2 cases diagnosed >10 years before the testicular lesions. In 1 case, there was bilateral involvement, while in 2, involvement was unilateral. The neoplastic cells showed evidence of cytogenetic/molecular clonal evolution in all cases, 1 of which also had significant immunophenotypic changes. A mutational profile including NPM1 p.Trp288Cysfs*12, IDH1 p.Arg132His NRAS p.Gly12Asp was seen in 2 of the 3 cases. Concurrent bone marrow involvement by a myeloid neoplasm was diagnosed in 2 patients, in 1, there was AML in the second 8% blasts. These patients progressed rapidly after MS and had a dismal outcome. The patient with no concurrent bone marrow disease had a favorable outcome. In conclusion, MS involving the testes of adults is a rare event, and it may represent the clonal evolution of AML.

A critical analysis of laparoscopic and open approaches to sporadic pancreatic insulinoma resection in the modern era.

BACKGROUND: A single center experience with sporadic pancreatic insulinoma was analyzed to develop an algorithm for modern surgical management. METHODS: Thirty-four patients undergoing surgery from 2001 to 2019 were reviewed. RESULTS: The majority underwent enucleation (10 laparoscopic, 15 open). Laparoscopy was performed in 22 patients with conversion to open in 11, mostly related to the proximity of the tumor to the pancreatic duct (n = 4). Tumors on the anterior and posterior surface of the pancreas in all anatomic locations were completed with laparoscopic enucleation. Overall, the clinically-relevant postoperative pancreatic fistula (CR-POPF) rate was 21%, with no difference between laparoscopic versus open enucleation (10% vs 20%, p = 0.50) or enucleation versus resection (16% vs 33%, p = 0.27). Laparoscopic enucleation had shorter median hospital length of stay (LOS) compared with open (4 vs 7 days, p = 0.02). CONCLUSIONS: Laparoscopic enucleation does not increase the CR-POPF risk and provides an advantage with a shorter hospital LOS in select patients. Tumor location and relationship to the pancreatic duct guide surgical decision-making. These findings highlight tumor-specific criteria that would benefit from a minimally invasive approach.

Compassion fatigue and the effectiveness of support structures for diagnostic radiographers in oncology.

INTRODUCTION: Diagnostic radiographers working in oncology will have frequent contact with the same patients over a prolonged period. This can be mentally exhausting for the radiographer. Compassion fatigue (CF) occurs after repeated exposure to stressful situations and it can become overwhelming, leading to irritability and decreased empathy. CF has been known to affect many healthcare professions, however few studies have examined diagnostic radiographers, nor if the current support systems are suitable. METHODS: An exploratory study was conducted as part of a local quality improvement project. An anonymised questionnaire was sent to all radiographers in a single oncology hospital within the UK to assess if the support provided met their needs. RESULTS: Sixty percent of those questioned responded. Almost half found their work affected their mental wellbeing, but they felt they could manage this stress at work. Almost all felt that some sort of support should be offered to the radiographers. The most popular options were already provided by the hospital, however many felt they were not accessible for a variety of reasons. When discussed further, it was found that the timings were prohibitive as most were held when they could not attend. CONCLUSION: Diagnostic radiographers working in oncology settings are at risk of CF. Although support structures are in place, they may not currently meet the needs of this staff group and at times are inaccessible. IMPLICATIONS FOR PRACTICE: Providing specific, accessible support for diagnostic radiographers will help reduce the potential effects of CF, reduce stress-related sickness and ultimately improve the service for patients.

Giardia Is Often Overlooked on Histopathologic Examination: A High-Volume, Single-Institution Experience.

AIMS. GIARDIA: is sometimes missed by the pathologist, and we sought to determine how often this occurs at our institution-a large tertiary care center with a subspecialty gastrointestinal pathology service and what certain clinical and histologic clues can be used to flag cases with a higher likelihood of infection, targeting them for greater scrutiny. METHODS AND RESULTS: We identified a set of patients who tested positive for Giardia with a stool-based test, and who also received a small bowel biopsy at a similar time-point. These biopsies were retrospectively reviewed for Giardia, finding 8 positive cases. The organism was prospectively detected in 4 cases (50%) but overlooked in the remaining 4 cases (50%). Three of the 4 cases missed cases showed only rare organisms. The detected cases tended to more frequently have prominent lymphoid aggregates (3 detected cases, 0 overlooked cases) and intraepithelial lymphocytosis (3 detected cases, 0 overlooked cases). Certain clinical and histologic clues can be used to flag cases with a higher likelihood of infection. Specifically, we found abnormalities of the mucosa (active inflammation, intraepithelial lymphocytosis, villous expansion, prominent lymphoid aggregates) in each case, and 4 of 8 cases were from immunocompromised patients. Finally, 2 of 8 cases were terminal ileum biopsies. CONCLUSIONS: Biopsies with a histologic abnormality or those from immunocompromised patients should receive greater attention. Routinely looking for Giardia at that terminal ileum is necessary.

Analysis of Spatial Dose-Volume Relationships and Decline in Sexual Function Following Permanent Brachytherapy for Prostate Cancer.

OBJECTIVE: To explore relationships between dose to periprostatic anatomic structures and erectile dysfunction (ED) outcomes in an institutional cohort treated with prostate brachytherapy. METHODS: The Sexual Health Inventory for Men (SHIM) instrument was administered for stage cT1-T2 prostate cancer patients treated with Pd-103 brachytherapy over a 10-year interval. Dose volume histograms for regional organs at risk and periprostatic regions were calculated with and without expansions to account for contouring uncertainty. Regression tree analysis clustered patients into ED risk groups. RESULTS: We identified 115 men treated with definitive prostate brachytherapy who had 2 years of complete follow-up. On univariate analysis, the subapical region (SAR) caudal to prostate was the only defined region with dose volume histograms parameters significant for potency outcomes. Regression tree analysis separated patients into low ED risk (mean 2-year SHIM 20.03), medium ED risk (15.02), and high ED risk (5.54) groups. Among patients with good baseline function (SHIM ≥ 17), a dose ≥72.75 Gy to 20% of the SAR with 1 cm expansion was most predictive for 2-year potency outcome. On multivariate analysis, regression tree risk group remained significant for predicting potency outcomes even after adjustment for baseline SHIM and age. CONCLUSION: Dose to the SAR immediately caudal to prostate was predictive for potency outcomes in patients with good baseline function. Minimization of dose to this region may improve potency outcomes following prostate brachytherapy.

An Update on the Role of Immunohistochemistry in the Evaluation of Gastrointestinal Tract Disorders.

As in other organ systems, immunohistochemistry (IHC) serves as an ancillary diagnostic tool for a wide variety of neoplastic and non-neoplastic disorders, including infections, work-up of inflammatory conditions, and subtyping neoplasms of the gastrointestinal (GI) tract. In addition, IHC is also used to detect a variety of prognostic and predictive molecular biomarkers for carcinomas of the GI tract. The purpose of this review is to highlight the use of IHC in common diagnostic scenarios throughout the tubular GI tract. The clinical indication and guidelines for performing IHC for detecting Helicobacter pylori is discussed along with role of gastrin and neuroendocrine markers in the diagnosis of autoimmune metaplastic atrophic gastritis. The major portion of this review discusses the use of IHC in the diagnostic workup of malignant neoplasms of the GI tract, such as adenocarcinoma versus squamous cell carcinoma, workup of poorly differentiated malignant neoplasms, and evaluation of uncommon gastric neoplasms (alpha-feto protein-producing carcinomas) and switch/sucrose-nonfermenting complex-deficient carcinomas. Lastly, localization of neuroendocrine tumors of unknown origin to aid clinical management, as well as HPV-driven anal neoplasia and IHC in the workup of basaloid anal neoplasms are also reviewed.

Mapping and correcting hyperpolarized magnetization decay with radial keyhole imaging.

PURPOSE: Hyperpolarized (HP) media enable biomedical imaging applications that cannot be achieved with conventional MRI contrast agents. Unfortunately, quantifying HP images is challenging, because relaxation and radio-frequency pulsing generate spatially varying signal decay during acquisition. We demonstrate that, by combining center-out k-space sampling with postacquisition keyhole reconstruction, voxel-by-voxel maps of regional HP magnetization decay can be generated with no additional data collection. THEORY AND METHODS: Digital phantom, HP 129 Xe phantom, and in vivo 129 Xe human (N = 4 healthy; N = 2 with cystic fibrosis) imaging was performed using radial sampling. Datasets were reconstructed using a postacquisition keyhole approach in which 2 temporally resolved images were created and used to generate maps of regional magnetization decay following a simple analytical model. RESULTS: Mean, keyhole-derived decay terms showed excellent agreement with the decay used in simulations (R2 = 0.996) and with global attenuation terms in HP 129 Xe phantom imaging (R2 > 0.97). Mean regional decay from in vivo imaging agreed well with global decay values and displayed spatial heterogeneity that matched expected variations in flip angle and oxygen partial pressure. Moreover, these maps could be used to correct variable signal decay across the image volume. CONCLUSIONS: We have demonstrated that center-out trajectories combined with keyhole reconstruction can be used to map regional HP signal decay and to quantitatively correct images. This approach may be used to improve the accuracy of quantitative measures obtained from hyperpolarized media. Although validated with gaseous HP 129 Xe in this work, this technique can be generalized to any hyperpolarized agent.