Adjuvant chemotherapy in stage 1 colon cancer: Patient characteristics and survival analysis from the national cancer database.

BACKGROUND: A subset of patients in ACS-NCDB with stage-1 colon cancer received adjuvant chemotherapy (AC), in contrast to national guidelines. This study aimed to define this population and evaluate associations between AC and survival. METHODS: Patients with T1-2N0 colon cancer from 2004 to 2016 were separated into AC and non-AC groups. Adverse pathological features (APF) included T2, poor differentiation, lymphovascular invasion, positive margin, and inadequate lymph nodes (<12). Cox proportional hazard models were used to estimate prognostic factors for overall survival (OS). RESULTS: A total of 1745 of 139,857 patients (1.2 %) received AC. Receiving AC was associated with male sex (p = 0.02), uninsured (p < 0.01), low income (p = 0.02), or having ≥2 APFs (p < 0.001). In the total cohort, AC was associated with increased mortality (HR 1.14 [1.04-1.24] P < 0.01). On subset analysis, AC was associated with improved OS for patients with ≥2 APFs (log-rank P=<0.001), and decreased mortality when adjusted for covariates (HR 0.81 [0.69-0.95] P=<0.01). The most significant predictor of mortality was old age (HR 3.78 [3.67, 3.89] p ≤ 0.01), followed by higher Charlson Comorbidity Index (HR 1.73 [1.69, 1.76] (p ≤ 0.01), and higher APF score (HR 1.46 [1.42, 15.2] p ≤ 0.01). CONCLUSION: AC was associated with decreased survival in the total cohort of stage 1 colon cancer patients, but was associated with improved survival for patients with multiple APFs.

Gender and Racial Diversity Among Colon and Rectal Surgery Trainees and Leaders.

BACKGROUND: Despite recent changes in women and underrepresented minorities in medicine, there still exists large gender and racial gaps in surgical training and leadership. OBJECTIVE: We hypothesize that gender and racial representation have improved among general and colorectal surgical trainees and leadership over the past 20 years. DESIGN: This cross-sectional study examines gender and racial representation of general and colorectal surgery residents, colorectal faculty members, and the American Society of Colon and Rectal Surgeons Executive Council. SETTINGS: We extracted data from the Journal of the American Medical Association Graduate Medical Education yearly reports for information on surgical residents. We used the American Society of Colon and Rectal Surgeons website and publicly available practice websites to obtain information regarding colon and rectal surgery residents, faculty members, and the American Society of Colon and Rectal Surgeons Executive Council. MAIN OUTCOME MEASURES: We primarily focused on the gender and underrepresented minority breakdowns of general surgery residents, colorectal surgery residents, and the American Society of Colon and Rectal Surgeons Executive Council. RESULTS: We found that between 2001 and 2021, the number of women and people identifying as underrepresented minorities increased within general surgery programs. In addition, there has been a similar increase in underrepresented minorities and women entering colorectal surgery residency programs. Finally, there has been a steady, significant increase in women representation in the American Society of Colon and Rectal Surgeons Executive Council, with a slower increase in underrepresented minorities on the council. LIMITATIONS: The study is limited by using previously collected data and relying on publicly available profiles for gender and race information. CONCLUSIONS: General and colon and rectal surgery have significantly increased gender and racial diversity at the training and leadership levels. DIVERSIDAD RACIAL Y DE GNERO ENTRE LOS APRENDICES Y LDERES DE CIRUGA DE COLON Y RECTO: ANTECEDENTES: A pesar de los cambios recientes en las mujeres y las minorías subrepresentadas en la medicina, todavía existen grandes brechas de género y raza en la capacitación y el liderazgo quirúrgico.OBJETIVO: Presumimos que la representación racial y de género ha mejorado entre los pasantes y el liderazgo en cirugía general y colorrectal en los últimos 20 años.DISEÑO: Este es un estudio transversal que examina la representación racial y de género de los residentes de cirugía general y colorrectal, miembros de la facultad colorrectal y el Consejo Ejecutivo de la Sociedad Estadounidense de Cirujanos de Colon y Recto.CONFIGURACIÓN: Extrajimos datos de los informes anuales de Educación Médica para Graduados del Journal of the American Medical Association para obtener información sobre los residentes quirúrgicos. Utilizamos el sitio web de la Sociedad Estadounidense de Cirujanos de Colon y Recto, así como los sitios web de práctica disponibles públicamente para obtener información sobre los residentes de cirugía de colon y recto, miembros de la facultad y el Consejo Ejecutivo de la Sociedad Estadounidense de Cirujanos de Colon y Recto.MEDIDAS PRINCIPALES DE RESULTADO: Nos enfocamos principalmente en los desgloses de género y minorías subrepresentadas de residentes de cirugía general, residentes de cirugía colorrectal y el Consejo Ejecutivo de la Sociedad Estadounidense de Cirujanos de Colon y Recto.RESULTADOS: Encontramos que entre 2001 y 2021, la cantidad de mujeres y personas que se identificaron como minorías subrepresentadas aumentó dentro de los programas de cirugía general. Además, ha habido un aumento similar en minorías subrepresentadas y mujeres que ingresan a programas de residencia en cirugía colorrectal. Finalmente, ha habido un aumento constante y significativo en la representación de mujeres en el Consejo Ejecutivo de la Sociedad Estadounidense de Cirujanos de Colon y Recto con un aumento más lento en las minorías subrepresentadas en el consejo.LIMITACIONES: El estudio está limitado por el uso de datos recopilados previamente y por confiar en perfiles disponibles públicamente para la información de género y raza.CONCLUSIONES: La cirugía general y de colon y recto han hecho algunos avances significativos en el aumento de la diversidad racial y de género en los niveles de formación y liderazgo. (Traducción-Yesenia.Rojas-Khalil ).

Understanding the Well-Being of General Surgery Residents.

BACKGROUND: In 2017, the Accreditation Council for Graduate Medical Education program guidelines changed to include a section that requires programs to optimize resident and faculty member well-being. There is still a poor understanding of general surgery resident wellness, and there are few well-established wellness programs. METHODS: We created a novel 50-question anonymous survey to assess burnout, depression, and wellness that was distributed to the general surgery residents as part of a pilot study. Univariate analysis was performed to assess wellness and wellness changes. Bivariate analysis was performed to determine the association between wellness variables and gender, age, and postgraduate year (PGY) level. RESULTS: Thirty-five of 55 residents participated in the survey. Over half of the residents (54%) reported gaining weight during residency. Nearly 70% reported working while having an ongoing family issue, and 77% worked at least once while ill. Fourteen residents (40%) reported that their wellness worsened over the previous academic year, while 7 (20%) reported that it remained the same, and 11 (31%) reported that it improved. These changes varied significantly by the PGY level (P < .01). Age (younger vs older than 30) and sex were found to be effective measure modifiers of the association between wellness change and PGY level. DISCUSSION: The overall wellness of the general surgery residents at our institution varies greatly. Poor wellness may lead to inferior patient care, burnout and depression, and negative resident morale. Residency programs need to implement programming to address wellness deficiencies.

Femoral Neck Shortening After Hip Fracture Fixation Is Associated With Inferior Hip Function: Results From the FAITH Trial.

OBJECTIVE: To describe the distribution of femoral neck shortening after internal fixation and to determine whether shortening is associated with inferior hip function at 24 months after a hip fracture in patients 50 years of age or older. DESIGN: Retrospective cohort study. SETTING: A secondary analysis of data from 81 clinical centers included in the Fixation using Alternative Implants for the Treatment of Hip Fractures (FAITH) trial. PARTICIPANTS: Three hundred fifty patients, 50 years of age or older, who had an isolated femoral neck fracture and underwent timely operative fixation of the fracture. INTERVENTION: Femoral neck shortening was measured as a categorical variable and classified into one of the following groups, as determined by the Central Adjudication Committee: no shortening, mild shortening (≤5 mm), moderate shortening (6-10 mm), or severe shortening (>10 mm). MAIN OUTCOME MEASUREMENT: The primary outcome for the current analysis was hip function, as measured by the Western Ontario & McMaster Universities Osteoarthritis Index questionnaire, at 24 months after injury. RESULTS: Two-thirds of patients had no or mild shortening (≤5 mm), whereas one-third of patients had moderate or severe shortening (>5 mm). After adjusting for surgical treatment, a greater amount of femoral neck shortening was found to be associated with poorer hip function (P < 0.01). CONCLUSIONS: We found that increasing femoral neck shortening was associated with inferior hip function. Although internal fixation often results in successful union, patients who heal in a shortened position report poorer functional outcomes. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Postoperative bleeding after laparoscopic Roux en Y gastric bypass: predictors and consequences.

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (LRYGB) is a common, safe and effective bariatric procedure. Bleeding is a significant source of postoperative morbidity. We aimed to determine the incidence, outcomes, and predictors of postoperative bleeding after LRYGB. METHODS: LRYGB patients included in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) 2015 dataset were identified. Preoperative and intraoperative factors were tested for associations with bleeding using univariable and multivariable logistic regression analysis. Outcomes of length of stay, in-hospital mortality, 30-day mortality, discharge disposition, and 30-day complications among patients with and without clinically significant postoperative bleeding were compared using multivariable regression. RESULTS: In the 43,280 LRYGB patients included in this analysis, postoperative bleeding occurred in 652 (1.51%) patients. Of these, 165 (25.3%) underwent a re-operation and 97 (14.9%) underwent an unplanned endoscopy for 'bleeding'. Postoperative bleeding was associated with a longer median postoperative length of stay (4 vs. 2 days), higher in-hospital mortality (1.23 vs. 0.04%), higher 30-day mortality (1.38 vs. 0.15%), discharge to an extended-care facility (3.88 vs. 0.6%), and higher rates of major complications (all P < 0.05). Independent predictors of postoperative bleeding included; a history of renal insufficiency (OR 2.55, 95% CI 1.43-4.52), preoperative therapeutic anticoagulation (OR 2.44, 95% CI 1.69-3.53), and revisional surgery (OR 1.45, 95% CI 1.06-1.97). Intraoperative associated factors included conversions (OR 3.37, 95% CI 1.42-7.97), and drain placement (OR 1.40, 95% CI 1.18-1.67). Robotic approaches resulted in independently lower postoperative bleeding rates (OR 0.50, 95% CI 0.32-0.77). CONCLUSIONS: Postoperative bleeding occurs in 1.5% of patients undergoing a LRYGB and is associated with significantly increased morbidity and mortality. We have identified patient and operative factors that are independently associated with postoperative bleeding.

A 19F magnetic resonance imaging-based diagnostic test for bile acid diarrhea.

In up to 50% of people diagnosed with a common ailment, diarrhea-predominant irritable bowel syndrome, diarrhea results from excess spillage of bile acids into the colon-data emerging over the past decade identified deficient release of a gut hormone, fibroblast growth factor 19 (FGF19), and a consequent lack of feedback suppression of bile acid synthesis as the most common cause. 75Selenium homotaurocholic acid (SeHCAT) testing, considered the most sensitive and specific means of identifying individuals with bile acid diarrhea, is unavailable in many countries, including the United States. Other than SeHCAT, tests to diagnose bile acid diarrhea are cumbersome, non-specific, or insufficiently validated; clinicians commonly rely on a therapeutic trial of bile acid binders. Here, we review bile acid synthesis and transport, the pathogenesis of bile acid diarrhea, the reasons clinicians frequently overlook this disorder, including the limitations of currently available tests, and our efforts to develop a novel 19F magnetic resonance imaging (MRI)-based diagnostic approach. We created 19F-labeled bile acid analogues whose in vitro and in vivo transport mimics that of naturally occurring bile acids. Using dual 1H/19F MRI of the gallbladders of live mice fed 19F-labeled bile acid analogues, we were able to differentiate wild-type mice from strains deficient in intestinal expression of a key bile acid transporter, the apical sodium-dependent bile acid transporter (ASBT), or FGF15, the mouse homologue of FGF19. In addition to reviewing our development of 19F-labeled bile acid analogue-MRI to diagnose bile acid diarrhea, we discuss challenges to its clinical implementation. A major limitation is the paucity of clinical MRI facilities equipped with the appropriate coil and software needed to detect 19F signals.

Attenuated Accumulation of Novel Fluorine (19F)-Labeled Bile Acid Analogues in Gallbladders of Fibroblast Growth Factor-15 (FGF15)-Deficient Mice.

Our work has focused on defining the utility of fluorine (19F)-labeled bile acid analogues and magnetic resonance imaging (MRI) to identify altered bile acid transport in vivo. In the current study, we explored the ability of this approach to differentiate fibroblast growth factor-15 (FGF15)-deficient from wild-type (WT) mice, a potential diagnostic test for bile acid diarrhea, a commonly misdiagnosed disorder. FGF15 is the murine homologue of human FGF19, an intestinal hormone whose deficiency is an underappreciated cause of bile acid diarrhea. In a pilot and three subsequent pharmacokinetic studies, we treated mice with two 19F-labeled bile acid analogues, CA-lys-TFA and CA-sar-TFMA. After oral dosing, we quantified 19F-labeled bile acid analogue levels in the gallbladder, liver, small and large intestine, and plasma using liquid chromatography mass spectrometry (LC-MS/MS). Both 19F bile acid analogues concentrated in the gallbladders of FGF15-deficient and WT mice, attaining peak concentrations at approximately 8.5 h after oral dosing. However, analogue levels in gallbladders of FGF15-deficient mice were several-fold less compared to those in WT mice. Live-animal 19F MRI provided agreement with our LC-MS/MS-based measures; we detected robust CA-lys-TFA 19F signals in gallbladders of WT mice but no signals in FGF15-deficient mice. Our finding that 19F MRI differentiates FGF15-deficient from WT mice provides additional proof-of-concept for the development of 19F bile acid analogues and 19F MRI as a clinical test to diagnose bile acid diarrhea due to FGF19 deficiency and other disorders.

Diminished gallbladder filling, increased fecal bile acids, and promotion of colon epithelial cell proliferation and neoplasia in fibroblast growth factor 15-deficient mice.

Fibroblast growth factor-19 (human FGF19; murine FGF15) suppresses bile acid synthesis. In FGF19 deficiency, diarrhea resulting from bile acid spillage into the colon mimics irritable bowel syndrome. To seek other consequences of FGF19/15 deficiency, we used Fgf15-/- and wild-type (WT) mice to assess gallbladder filling, the bile acid pool, fecal bile acid levels, and colon neoplasia. We fasted mice for six hours before assessing gallbladder size by magnetic resonance imaging (MRI). We measured bile acid levels in different compartments by enzymatic assay, and induced colon neoplasia with azoxymethane (AOM)/dextran sodium sulfate (DSS) and quantified epithelial Ki67 immunostaining and colon tumors 20 weeks later. In vivo MRI confirmed the gross finding of tubular gallbladders in FGF15-deficient compared to WT mice, but fasting gallbladder volumes overlapped. After gavage with a bile acid analogue, ex vivo MRI revealed diminished gallbladder filling in FGF15-deficient mice (P = 0.0399). In FGF15-deficient mice, the total bile acid pool was expanded 45% (P <0.05) and fecal bile acid levels were increased 2.26-fold (P <0.001). After AOM/DSS treatment, colons from FGF15-deficient mice had more epithelial cell Ki67 staining and tumors (7.33 ± 1.32 vs. 4.57 ± 0.72 tumors/mouse; P = 0.003 compared to WT mice); carcinomas were more common in FGF15-deficient mice (P = 0.01). These findings confirm FGF15, the murine homolog of FGF19, plays a key role in modulating gallbladder filling and bile acid homeostasis. In a well-characterized animal model of colon cancer, increased fecal bile acid levels in FGF15-deficient mice promoted epithelial proliferation and advanced neoplasia.

Targeting M3 Muscarinic Receptors for Colon Cancer Therapy.

BACKGROUND: Expression and activation of subtype-3 muscarinic receptors (M3R) plays an important role in the progression of colorectal neoplasia. METHOD: Herein, we describe the role of muscarinic receptors in colon cancer, focusing specifically on M3R, illustrate how M3R over-expression and activation of post-receptor signaling pathways potentiates tumor progression, and explore the efficacy and safety of a variety of therapeutic approaches that can target the molecules involved. RESULTS: Colon cancers overexpress M3R mRNA (CHRM3) and protein, and post-M3R signaling stimulates cell proliferation. Post-M3R signal transduction is complex, involving interplay between epidermal growth factor receptors (EGFR)/ERK and protein kinase C (PKC)/p38 mitogen-activated protein (MAP) kinase signaling pathways. In particular, the development of an invasive and metastatic phenotype requires that these signaling interactions augment cellular release of a key collagenase, matrix metalloproteinase-1 (MMP1). Blocking either M3R activation or post-M3R signaling attenuates MMP1 release and colon cancer invasiveness. CONCLUSION: Parsing the complexities of these signaling interactions is important, not only to understand these mechanisms of cancer initiation and progression, but also to develop novel treatment modalities. Since the vast majority of persons with colon cancer die from disseminated disease, preventing or reversing metastatic spread of cancer cells by targeting M3R, post-M3R signaling, or MMP1 has therapeutic potential.

Pelvic floor disorders in women with gynecologic malignancies: a systematic review.

INTRODUCTION AND HYPOTHESIS: Pelvic floor disorders (PFDs) negatively affect quality of life in the general population, and their prevalence in gynecologic cancer survivors has not been systematically described. This study aimed to determine the prevalence of PFDs in cancer survivors. We hypothesized that the prevalence of PFDs in the gynecologic cancer population would be higher than in the general female population. METHODS: We searched PubMed (1809 to present), EMBASE (1974 to present), and the Cochrane Central Register of Controlled Trials (CENTRAL) through May 2017. The search combined subject headings, title, and abstract words for gynecologic cancer, PFDs, and prevalence. Any studies evaluating the prevalence of PFDs in gynecologic malignancies were included. RESULTS: A total of 550 articles met the designated search criteria and 31 articles were included in this review. In cervical cancer survivors, before treatment the prevalences of stress urinary incontinence (SUI), urgency urinary incontinence (UUI) and fecal incontinence (FI) were 24-29%, 8-18% and 6%, respectively, and after treatment the prevalences of SUI, UUI, urinary retention, FI, fecal urge, dyspareunia and vaginal dryness were 4-76%, 4-59%, 0.4-39%, 2-34%, 3-49%, 12-58% and 15-47%, respectively. In uterine cancer survivors, before treatment the prevalences of SUI, UUI and FI were 29-36%, 15-25% and 3%, respectively, and after treatment the prevalences of urinary incontinence (UI) and dyspareunia were 2-44% and 7-39%, respectively. In vulvar cancer survivors, after treatment the prevalences of UI, SUI and FI were 4-32%, 6-20% and 1-20%, respectively. In ovarian cancer survivors, the prevalences of SUI, UUI, prolapse and sexual dysfunction were 32-42%, 15-39%, 17% and 62-75%, respectively. CONCLUSIONS: PFDs are prevalent in gynecologic cancer survivors and this is an important area of clinical concern and future research.

Staple Line Treatment and Bleeding After Laparoscopic Sleeve Gastrectomy.

BACKGROUND AND OBJECTIVES: Staple line treatment during laparoscopic sleeve gastrectomy (LSG) remains a controversial issue among bariatric surgeons. The objective of this study was to compare rates of postoperative bleeding (POB) among various methods of staple line reinforcement. METHODS: The Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program 2015 dataset was queried for patients undergoing an LSG. Patients were stratified by staple line treatment groups-no treatment (NT), suture oversewing (OVERSEW), buttressing by a commercial product (BUTTRESS), and both buttress and oversew (COMBINATION). The primary outcome was POB. Multivariable logistic regression was used to compare POB rates among the treatment groups. RESULTS: In the 98,142 LSG patients meeting selection criteria, 623 (0.63%) patients had POB and 181 (0.18%) required reoperation. POB occurred in 0.80% for the NT group, 0.68% for the OVERSEW group, 0.57% for the BUTTRESS group, and 0.55% for the COMBINATION group. On multivariable analyses, all treatment groups were less likely to have POB compared with the NT group-OVERSEW (odds ratio [OR] 0.73, 95% confidence interval [CI] 0.54-0.98), BUTTRESS (OR 0.70, 95% CI 0.57-0.84), and COMBINATION (OR 0.66, 95% CI 0.50-0.89) (all P < .01). Subset analysis revealed no difference between BUTTRESS and OVERSEW (OR 0.95, 95% CI 0.71-1.26, P = .71). CONCLUSIONS: Relative to an NT staple line, the use of OVERSEW or BUTTRESS can decrease the rates of POB by up to 30%. The use of these techniques should be strongly considered by the bariatric surgeon.

Two sides to colon cancer: mice mimic human anatomical region disparity in colon cancer development and progression.

AIM: Strong evidence reveals important differences between cancers in the proximal vs. distal colon. Animal models of metastatic colon cancer are available but with varying degrees of reproducibility and several important limitations. We explored whether there were regional differences in the location of murine colon cancers and assessed the utility of murine models to explore the biological basis for such differences. METHODS: We re-analyzed data from our previous studies to assess the regional distribution of murine colon cancer. In survival surgery experiments, we injected HT-29 human colon cancer cells into the wall of the cecum or distal colon of Nu(NCr)-Foxn1nu or NOD.Cg-PrkdcscidIl2rgTim1Wji/SzJ mice and compared the development of primary tumors and metastases. RESULTS: Within 7-17 weeks after intramural cecal injection of HT-29 cells, eight mice failed to develop solid primary tumors or metastases. In contrast, within four weeks after cell injection into the distal colon, 13 mice developed metastases - 12 mice developed subcutaneous metastases; of these, four developed liver metastases and one developed both liver and lung metastases. One mouse developed liver metastases only. Histological examination confirmed these lesions were adenocarcinomas. CONCLUSION: Our findings reveal the preferential growth of murine colon neoplasia and invasive human orthotopic xenografts in the distal mouse colon. The new approach of injecting cells into the distal colon wall results in a pattern of colon cancer development that closely mimics the progression of metastatic colon cancer in humans. This novel model of colon neoplasia has great potential for exploring anatomical differences in colon cancer and testing novel therapeutics.

Exponential decay modeling can define parameters of weight loss trajectory after laparoscopic Roux-en-Y gastric bypass.

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass (LRYGB) produces durable and clinically significant weight loss. We aim to characterize the trajectory of weight loss, and demonstrate the predictive ability of three-month performance on final weight loss. METHODS: Retrospective analysis of 1097 consecutive LRYGB patients allowed for assessment of conformity of various weight loss trajectory models. Establishing exponential decay as the optimal fit, initial, three-month and final BMI values were used to determine empiric rate constants (λ3). Empirically derived weight loss curves and associated rate constants (λ) were generated. RESULTS: Exponential decay optimally characterizes post-LRYGB weight loss trajectory. Final weight loss can be characterized by λ3, as well as by the demographics black race (P = 0.008) and initial BMI (P < 0.001). Stratification by three-month weight loss allowed derivation of weight loss trajectory curves to predict weight at any point until and including plateau. CONCLUSIONS: Weight loss after LRYGB conforms well to exponential decay, and postoperative trajectory can thus be predicted early. This allows the clinician early identification and intervention upon patients at risk of poor performance.

Using Multi-fluorinated Bile Acids and In Vivo Magnetic Resonance Imaging to Measure Bile Acid Transport.

Along with their traditional role as detergents that facilitate fat absorption, emerging literature indicates that bile acids are potent signaling molecules that affect multiple organs; they modulate gut motility and hormone production, and alter vascular tone, glucose metabolism, lipid metabolism, and energy utilization. Changes in fecal bile acids may alter the gut microbiome and promote colon pathology including cholerrheic diarrhea and colon cancer. Key regulators of fecal bile acid composition are the small intestinal Apical Sodium-dependent Bile Acid Transporter (ASBT) and fibroblast growth factor-19 (FGF19). Reduced expression and function of ASBT decreases intestinal bile acid up-take. Moreover, in vitro data suggest that some FDA-approved drugs inhibit ASBT function. Deficient FGF19 release increases hepatic bile acid synthesis and release into the intestines to levels that overwhelm ASBT. Either ASBT dysfunction or FGF19 deficiency increases fecal bile acids and may cause chronic diarrhea and promote colon neoplasia. Regrettably, tools to measure bile acid malabsorption and the actions of drugs on bile acid transport in vivo are limited. To understand the complex actions of bile acids, techniques are required that permit simultaneous monitoring of bile acids in the gut and metabolic tissues. This led us to conceive an innovative method to measure bile acid transport in live animals using a combination of proton (1H) and fluorine (19F) magnetic resonance imaging (MRI). Novel tracers for fluorine (19F)-based live animal MRI were created and tested, both in vitro and in vivo. Strengths of this approach include the lack of exposure to ionizing radiation and translational potential for clinical research and practice.