A stable, highly concentrated fluorous nanoemulsion formulation for in vivo cancer imaging via 19F-MRI.

Magnetic resonance imaging (MRI) is a routine diagnostic modality in oncology that produces excellent imaging resolution and tumor contrast without the use of ionizing radiation. However, improved contrast agents are still needed to further increase detection sensitivity and avoid toxicity/allergic reactions associated with paramagnetic metal contrast agents, which may be seen in a small percentage of the human population. Fluorine-19 (19F)-MRI is at the forefront of the developing MRI methodologies due to near-zero background signal, high natural abundance of 100%, and unambiguous signal specificity. In this study, we have developed a colloidal nanoemulsion (NE) formulation that can encapsulate high volumes of the fluorous MRI tracer, perfluoro-[15-crown-5]-ether (PFCE) (35% v/v). These nanoparticles exhibit long-term (at least 100 days) stability and high PFCE loading capacity in formulation with our semifluorinated triblock copolymer, M2F8H18. With sizes of approximately 200 nm, these NEs enable in vivo delivery and passive targeting to tumors. Our diagnostic formulation, M2F8H18/PFCE NE, yielded in vivo 19F-MR images with a high signal-to-noise ratio up to 100 in a tumor-bearing mouse model at clinically relevant scan times. M2F8H18/PFCE NE circulated stably in the vasculature, accumulated in high concentration of an estimated 4-9 × 1017 19F spins/voxel at the tumor site, and cleared from most organs over the span of 2 weeks. Uptake by the mononuclear phagocyte system to the liver and spleen was also observed, most likely due to particle size. These promising results suggest that M2F8H18/PFCE NE is a favorable 19F-MR diagnostic tracer for further development in oncological studies and potential clinical translation.

First in vivo fluorine-19 magnetic resonance imaging of the multiple sclerosis drug siponimod.

Theranostic imaging methods could greatly enhance our understanding of the distribution of CNS-acting drugs in individual patients. Fluorine-19 magnetic resonance imaging (19F MRI) offers the opportunity to localize and quantify fluorinated drugs non-invasively, without modifications and without the application of ionizing or other harmful radiation. Here we investigated siponimod, a sphingosine 1-phosphate (S1P) receptor antagonist indicated for secondary progressive multiple sclerosis (SPMS), to determine the feasibility of in vivo 19F MR imaging of a disease modifying drug. Methods: The 19F MR properties of siponimod were characterized using spectroscopic techniques. Four MRI methods were investigated to determine which was the most sensitive for 19F MR imaging of siponimod under biological conditions. We subsequently administered siponimod orally to 6 mice and acquired 19F MR spectra and images in vivo directly after administration, and in ex vivo tissues. Results: The 19F transverse relaxation time of siponimod was 381 ms when dissolved in dimethyl sulfoxide, and substantially reduced to 5 ms when combined with serum, and to 20 ms in ex vivo liver tissue. Ultrashort echo time (UTE) imaging was determined to be the most sensitive MRI technique for imaging siponimod in a biological context and was used to map the drug in vivo in the stomach and liver. Ex vivo images in the liver and brain showed an inhomogeneous distribution of siponimod in both organs. In the brain, siponimod accumulated predominantly in the cerebrum but not the cerebellum. No secondary 19F signals were detected from metabolites. From a translational perspective, we found that acquisitions done on a 3.0 T clinical MR scanner were 2.75 times more sensitive than acquisitions performed on a preclinical 9.4 T MR setup when taking changes in brain size across species into consideration and using equivalent relative spatial resolution. Conclusion: Siponimod can be imaged non-invasively using 19F UTE MRI in the form administered to MS patients, without modification. This study lays the groundwork for more extensive preclinical and clinical investigations. With the necessary technical development, 19F MRI has the potential to become a powerful theranostic tool for studying the time-course and distribution of CNS-acting drugs within the brain, especially during pathology.

Water-Soluble Chemically Precise Fluorinated Molecular Clusters for Interference-Free Multiplex 19F MRI in Living Mice.

Fluorine-19 magnetic resonance imaging (19F MRI) is gaining widespread interest from the fields of biomolecule detection, cell tracking, and diagnosis, benefiting from its negligible background, deep tissue penetration, and multispectral capacity. However, a wide range of 19F MRI probes are in great demand for the development of multispectral 19F MRI due to the limited number of high-performance 19F MRI probes. Herein, we report a type of water-soluble molecular 19F MRI nanoprobe by conjugating fluorine-containing moieties with a polyhedral oligomeric silsesquioxane (POSS) cluster for multispectral color-coded 19F MRI. These chemically precise fluorinated molecular clusters are of excellent aqueous solubility with relatively high 19F contents and of single 19F resonance frequency with suitable longitudinal and transverse relaxation times for high-performance 19F MRI. We construct three POSS-based molecular nanoprobes with distinct 19F chemical shifts at -71.91, -123.23, and -60.18 ppm and achieve interference-free multispectral color-coded 19F MRI of labeled cells in vitro and in vivo. Moreover, in vivo 19F MRI reveals that these molecular nanoprobes could selectively accumulate in tumors and undergo rapid renal clearance afterward, illustrating their favorable in vivo behavior for biomedical applications. This study provides an efficient strategy to expand the 19F probe libraries for multispectral 19F MRI in biomedical research.

Papel actual de las técnicas de imagen en la amiloidosis cardíaca / Current role of imaging techniques in cardiac amyloidosis

La amiloidosis cardíaca (AC) es una enfermedad infradiagnosticada, y si no se trata es rápidamente fatal. Los nuevos tratamientos disponibles aumentan la necesidad de desarrollar métodos diagnósticos no invasivos para su detección precoz y para la monitorización de la respuesta terapéutica. Los hallazgos típicos de la AC en ecocardiografía y resonancia magnética, no son suficientemente específicos para distinguir la AC de cadenas ligeras (AL) de la amiloidosis por transtiretina (ATTR). La captación de un radiofármaco óseo por el miocardio es altamente específica para la AC-ATTR cuando se ha excluido la discrasia de células plasmáticas. Ahora, este método diagnóstico está reemplazando la necesidad de biopsia en muchos pacientes. La detección precoz de la AC, la cuantificación de su carga y la evaluación de la respuesta al tratamiento son los siguientes pasos importantes para que las imágenes avancen en la evaluación y el tratamiento de la AC. (AU)

Cardiac amyloidosis (CA) is an underdiagnosed disease and, if left untreated, rapidly fatal. Emerging therapies for CA increase the urgency of developing non-invasive diagnostic methods for its early detection and for monitoring therapeutic response. Classic imaging features on echocardiography and cardiac magnetic resonance, although typical for cardiac amyloidosis, are not specific enough to distinguish light chain amyloidosis from transthyretin. Myocardial bone-avid radiotracer uptake is highly specific for transthyretin cardiac amyloidosis when plasma cell dyscrasia has been excluded; it is now replacing the need for biopsy in many patients. Detection of early cardiac amyloidosis, quantitation of its burden, and assessment of response to therapy are important next steps for imaging to advance the evaluation and management of cardiac amyloidosis. (AU)

Flexible and Zwitterionic Fluorinated Hydrogel Scaffold with High Fluorine Content for Noninvasive 19 F Magnetic Resonance Imaging under Ultrahigh Scanning Resolution.

The imaging of hydrogel scaffolds by 19 F magnetic resonance imaging (MRI) represents an attractive tool for straightforward and noninvasive monitoring of their morphology and in vivo fate. However, their further applications are significantly limited by a dilemma of insufficient signal resolution with low 19 F content, and/or hydrophobic aggregation of fluorine moieties-induced signal attenuation with high 19 F content. Herein, a novel label-free fluorinated hydrogel (PFCB) is fabricated with high fluorine content to realize noninvasive monitoring through 19 F MRI under ultrahigh scanning resolution (1 mm of scanning thickness). The integration of a zwitterionic unit into each fluorine moiety completely overcame the hydrophobic aggregation-induced signal attenuation, manifesting as high 19 F content and imaging performance. Importantly, 3D reconstruction of the PFCB hydrogel in vivo can be facilely and accurately performed with background free signals, providing detailed biological information of the implanted hydrogel. Additionally, PFCB hydrogel showed adjustable and high mechanical performance, and exhibited minimum foreign body reaction after implantation. As a proof of concept, PFCB hydrogel could be further applied as gel electrodes and wireless flexible sensors for healthcare monitoring. Overall, such label-free fluorinated PFCB hydrogel is an ideal flexible scaffold for eventual clinical applications integrating 19 F MRI-guided unequivocally 3D reconstruction and healthcare monitoring.

Lista de verificación de tomografía computarizada de hueso temporal y base de cráneo lateral / Checklist of the temporal bone and lateral skull base CT- scan

La tomografía computarizada del hueso temporal es una prueba de imagen fundamental para el diagnóstico y tratamiento de diversas entidades que afectan a esta compleja estructura. La tomografía computarizada permite una representación más detallada de las estructuras óseas que la resonancia magnética, lo que determina que sea la prueba de elección para la planificación de la cirugía otológica.El objetivo de este trabajo es el de elaborar una lista de verificación o checklist que permita al otorrinolaringólogo estudiar y valorar de forma sistemática y organizada las principales estructuras de referencia, variantes anatómicas y cambios posquirúrgicos más frecuentes antes de una cirugía segura.Esta revisión ha sido promovida por la Sociedad Española de Otorrinolaringología y redactada en un formato de lista de verificación dividida en las diferentes regiones del hueso temporal y base de cráneo lateral. (AU)

Computed tomography scan of the temporal bone is a fundamental imaging modality for both the diagnosis and treatment of a wide range of pathologies affecting this complex structure. Temporal bone computed tomography scan provides a more detailed depiction of bone structures, compared with magnetic resonance imaging and, for this reason computed tomography scan is the imaging modality of choice in the planning of otological surgery.The aim of this article is to present a checklist to allow the otolaryngologist to assess systematically and in an organized manner the main anatomical landmarks, anatomical variants, as well as the most common postoperative surgical changes, which can be identified before any safe otological surgery.This revision was promoted by the Spanish Society of Otolaryngology and elaborated in a checklist template divided into the different areas of the temporal bone and the lateral skull base. (AU)

Quantifying Micromolar Crystallinity in Pharmaceutical Materials Utilizing 19F Solid-State NMR.

Quantifying low-level components in solid-state analysis presents a significant challenge for most thermal, diffractometric, vibrational, and spectroscopic techniques. In pharmaceutical analysis, identifying and quantifying the physical form of the drug substance in solid dosages is a critical task to ensure the quality of drug products. For example, recrystallization of active pharmaceutical ingredients in amorphous solid dispersions can compromise the stability and bioavailability of drug products. Herein, we have developed and demonstrated fluorine-19 solid-state nuclear magnetic resonance (19F ssNMR) methods and pushed the boundary to quantify minor crystalline contents in amorphous pharmaceuticals. Calibration curves suggest that 19F direct polarization and 1H-19F cross-polarization ssNMR can readily quantify 0.1% w/w crystalline compound I, a commercial fluorinated drug molecule developed by Merck & Co., Inc., Rahway, NJ, U.S.A., in its amorphous formulation. 1H-19F multiple cross-polarization (MultiCP) has been implemented, for the first time, and compared with conventional cross-polarization methods. Most importantly, a relaxation-filtered 19F ssNMR method was utilized to unambiguously identify and quantify as low as 0.04% w/w crystalline components, that is, 6 µmol in a 100 mg tablet at 25% drug loading, by suppressing the signal from the amorphous counterpart. Such a low level of detection offers high confidence and sensitivity to quantify trace amounts of phase change in pharmaceutical amorphous materials in the solid state, which can facilitate formulation development as well as quality control.

Partially fluorinated nanoemulsions for 19F MRI-fluorescence dual imaging cell tracking.

Fluorine-19 magnetic resonance imaging (19F MRI) has been a technology of choice for in vivo cell tracking, in which perfluorocarbons (PFCs) nanoemulsions are the most used 19F MRI agents. However, the peculiar physicochemical properties of PFCs may lead to poor cell uptake and misleading cell tracking results. Herein, we employed partially fluorinated aromatic agents to formulate paramagnetic nanoemulsions as novel 19F MRI-fluorescence (FL) dual imaging agents for cell tracking. With the intramolecular π-π interaction, low density and fluorine content, the partially fluorinated agents enable considerable solubilities of functional agents and short relaxation times, which facilitates convenient preparation of stable, biocompatible, and multifunctional nanoemulsions with high 19F MRI sensitivity. Replacing PFCs in 19F MRI nanoemulsions with readily available partially fluorinated aromatic agents may address many issues associated with PFCs and provide a novel strategy for high-performance 19F MRI agents of broad biomedical applications.

Enhanced detection of paramagnetic fluorine-19 magnetic resonance imaging agents using zero echo time sequence and compressed sensing.

Fluorine-19 (19 F) magnetic resonance imaging (MRI) is an emerging technique offering specific detection of labeled cells in vivo. Lengthy acquisition times and modest signal-to-noise ratio (SNR) makes three-dimensional spin-density-weighted 19 F imaging challenging. Recent advances in tracer paramagnetic metallo-perfluorocarbon (MPFC) nanoemulsion probes have shown multifold SNR improvements due to an accelerated 19 F T1 relaxation rate and a commensurate gain in imaging speed and averages. However, 19 F T2 -reduction and increased linewidth limit the amount of metal additive in MPFC probes, thus constraining the ultimate SNR. To overcome these barriers, we describe a compressed sampling (CS) scheme, implemented using a "zero" echo time (ZTE) sequence, with data reconstructed via a sparsity-promoting algorithm. Our CS-ZTE scheme acquires k-space data using an undersampled spherical radial pattern and signal averaging. Image reconstruction employs off-the-shelf sparse solvers to solve a joint total variation and l1 -norm regularized least square problem. To evaluate CS-ZTE, we performed simulations and acquired 19 F MRI data at 11.7 T in phantoms and mice receiving MPFC-labeled dendritic cells. For MPFC-labeled cells in vivo, we show SNR gains of ~6.3 × with 8-fold undersampling. We show that this enhancement is due to three mechanisms including undersampling and commensurate increase in signal averaging in a fixed scan time, denoising attributes from the CS algorithm, and paramagnetic reduction of T1 . Importantly, 19 F image intensity analyses yield accurate estimates of absolute quantification of 19 F spins. Overall, the CS-ZTE method using MPFC probes achieves ultrafast imaging, a substantial boost in detection sensitivity, accurate 19 F spin quantification, and minimal image artifacts.

(R)-α-Trifluoromethylalanine as a 19 F NMR Probe for the Monitoring of Protease Digestion of Peptides.

Fluorinated non-natural amino acids are useful tools for improving the bioavailability of peptides but can also serve as fluorinated probes in 19 F NMR-based enzymatic assays. We report herein that the use of the non-natural α-quaternarized (R)-α-trifluoromethylalanine ((R)-α-TfmAla) provides convenient and accurate monitoring of trypsin proteolytic activity and increases resistance towards pepsin degradation.

The sensitivity of magnetic particle imaging and fluorine-19 magnetic resonance imaging for cell tracking.

Magnetic particle imaging (MPI) and fluorine-19 (19F) MRI produce images which allow for quantification of labeled cells. MPI is an emerging instrument for cell tracking, which is expected to have superior sensitivity compared to 19F MRI. Our objective is to assess the cellular sensitivity of MPI and 19F MRI for detection of mesenchymal stem cells (MSC) and breast cancer cells. Cells were labeled with ferucarbotran or perfluoropolyether, for imaging on a preclinical MPI system or 3 Tesla clinical MRI, respectively. Using the same imaging time, as few as 4000 MSC (76 ng iron) and 8000 breast cancer cells (74 ng iron) were reliably detected with MPI, and 256,000 MSC (9.01 × 1016 19F atoms) were detected with 19F MRI, with SNR > 5. MPI has the potential to be more sensitive than 19F MRI for cell tracking. In vivo sensitivity with MPI and 19F MRI was evaluated by imaging MSC that were administered by different routes. In vivo imaging revealed reduced sensitivity compared to ex vivo cell pellets of the same cell number. We attribute reduced MPI and 19F MRI cell detection in vivo to the effect of cell dispersion among other factors, which are described.

Deep-tissue real-time imaging of drug-induced liver injury with peroxynitrite-responsive 19F MRI nanoprobes.

Peroxynitrite is an important biomarker for assessing drug-induced liver injury (DILI), which is critical for the development and use of drugs. Herein, we report the development of peroxynitrite-responsive self-assembled 19F MRI nanoprobes, which enable the sensitive imaging of peroxynitrite in L02 cells subjected to oxidative stress and living mice with DILI.

NOTA CLÍNICA: Enfermedad deMarchiafava-Bignami en un paciente con esquizofrenia y trastorno por uso de alcohol / CLINICAL NOTE: Marchiafava-Bignami disease in a patient with schizophrenia and alcohol use disorder

Introducción: Los trastornos por abuso de sustancias sonla comorbilidad más frecuente en la esquizofrenia, siendo elalcohol, concretamente, la sustancia más frecuentementeconsumida tras el tabaco. Los pacientes con esquizofreniaque presentan esta comorbilidad presentan una peor evolución clínica y pueden desarrollar graves complicaciones neuropsiquiátricas. Una de ellas, la enfermedad de Marchiafava-Bignami (EMB), puede ser erróneamente diagnosticadacomo una descompensación del trastorno mental, conllevando graves consecuencias.Método. Se presenta el caso de un varón de 51 años,diagnosticado de esquizofrenia y trastorno por consumode alcohol. Experimentó síntomas neuropsiquiátricos agudos por los que se sospechó una descompensación de suesquizofrenia. Dada la presentación clínica atípica y susantecedentes médicos, se sospechó una patología orgánicay se realizó una prueba de imagen cerebral en la que sediagnosticó una EMB.Conclusiones. La EMB es una entidad clínica infrecuenteque debe formar parte del diagnóstico diferencial en pacientes con trastorno por consumo de alcohol que experimenten síntomas neuropsiquiátricos atípicos. (AU)

Introduction: Substance-related disorders are the mostfrequent comorbidity in schizophrenia. Concretely, alcohol isthe most commonly consumed substance after tobacco. Patients with schizophrenia with this comorbidity have a worseclinical course and can develop serious neuropsychiatriccomplications. One of them, Marchiafava-Bignami disease(MBD) can be incorrectly diagnosed as a decompensation oftheir mental disorder.Methods. A case of a 51-year-old man, diagnosed withschizophrenia and alcohol use disorder is presented. He experienced acute neuropsychiatric symptoms for which schizophrenia decompensation was suspected. Based on his atypical symptoms and medical history, a brain imaging test wasperformed and MBD was diagnosed.Conclusions. MBD is an infrequent clinical entity thatshould be part of differential diagnosis in patients with alcohol abuse disorder experiencing atypical neuropsychiatricsymptoms. (AU)

Fluorine NMR Spectroscopy Enables to Quantify the Affinity Between DNA and Proteins in Cell Lysate.

The determination of the binding affinity quantifying the interaction between proteins and nucleic acids is of crucial interest in biological and chemical research. Here, we have made use of site-specific fluorine labeling of the cold shock protein from Bacillus subtilis, BsCspB, enabling to directly monitor the interaction with single stranded DNA molecules in cell lysate. High-resolution 19 F NMR spectroscopy has been applied to exclusively report on resonance signals arising from the protein under study. We have found that this experimental approach advances the reliable determination of the binding affinity between single stranded DNA molecules and its target protein in this complex biological environment by intertwining analyses based on NMR chemical shifts, signal heights, line shapes and simulations. We propose that the developed experimental platform offers a potent approach for the identification of binding affinities characterizing intermolecular interactions in native surroundings covering the nano-to-micromolar range that can be even expanded to in cell applications in future studies.

Valor actual de los hallazgos histológicos de biopsias de próstata negativas en la predicción del riesgo futuro de cáncer de próstata clínicamente significativo / The current value of histological findings in negative prostate biopsies to predict the future risk of clinically significant prostate cancer

Introducción: Se recomienda realizar una biopsia prostática (PBx) de repetición ante una sospecha persistente de cáncer de próstata (PCa) o cuando se identifica proliferación acinar atípica (ASAP), neoplasia intraepitelial de alto grado (HGPIN) extensa (≥3 zonas de biopsia) o HGPIN con células atípicas sospechosas de adenocarcinoma (PIN-ATYP). Actualmente se recomienda realizar una resonancia magnética multiparamétrica (mpMRI) y PBx guiada por mpMRI (MRI-TBx) en una PBx de repetición. Nuestro objetivo fue analizar el valor actual para predecir el riesgo de PCa clínicamente significativo (csPCa) del hallazgo de ASAP, mHGPIN, PIN-ATYP y otros hallazgos histológicos.MétodosSe realizó un análisis retrospectivo de 377 PBx de repetición. Se realizó MRI-TBx cuando la puntuación PI-RADS fue≥3 y PBX sistemáticas de 12 cilindros guiadas por ecografía transrectal (TRUS) cuando fue≤2. ASAP, HGPIN, HGPIN multifocal (mHGPIN), PIN-ATYP y otros 8 hallazgos histológicos fueron reportados prospectivamente en las PBx negativas. El csPCa fue definido como grado ISUP≥2.ResultadosLa incidencia de ASAP, mHGPIN y PIN-ATYP fue 4,2%, 39,7% y 3,7% respectivamente, y la tasa de csPCa fue estadísticamente similar en los pacientes con estos hallazgos histológicos. Sin embargo, las tasas de csPCa con atrofia proliferativa inflamatoria (PIA) presente y ausente fueron 22,2% y 36,1%, respectivamente. La PIA fue el único hallazgo histológico que predijo un menor riesgo de csPCa, con OR de 0,54 (IC 95%: 0,308-0,945, p=0,031). La PIA fue, también, un factor predictor independiente en un modelo combinando variables clínicas y mpMRI, que obtuvo un área bajo la curva de 0,86 (95% IC: 0,83-0,90).ConclusionesLa PIA resultó ser el único hallazgo histológico predictor del riesgo de csPCa, y puede contribuir en un modelo predictivo; mHGPIN no fue predictor de riesgo de csPCa. La baja incidencia de ASAP (4,2%) y PIN-ATYP (3,7%) impidió que pudiéramos obtener conclusiones sobre estas lesiones. (AU)

Introduction: Repeat prostate biopsy (PBx) is recommended under persistent suspicion of prostate cancer (PCa) or in the face of the following findings: atypical small acinar proliferation (ASAP), extense (≥3 biopsy sites) high-grade prostatic intraepithelial neoplasia (HGPIN), or HGPIN with atypical glands, suspicious for adenocarcinoma (PIN-ATYP). Nowadays, multiparametric magnetic resonance imaging (mpMRI) and mpMRI targeted PBx (MRI-TBx) are recommended in repeat PBx. Our objective was to analyze the current value of ASAP, mHGPIN, PIN-ATYP and other histological findings to predict clinically significant PCa (csPCa) risk.MethodsRetrospective analysis of 377 repeat PBxs. MRI-TBx was performed when Prostate Imaging-Reporting and Data System (PI-RADS) score>3 and 12-core transrectal ultrasound (TRUS) systematic PBx when≤2. ASAP, HGPIN, mHGPIN, PIN-ATYP, and 8 other histological findings were prospectively reported in negative PBx. CsPCa was defined as ISUP group grade>2.ResultsIncidence of ASAP, multifocal HGPIN (mHGPIN) and PINATYP was 4.2%, 39.7% and 3.7% respectively, and csPCa rate was statistically similar among men with these histological findings. However, the rate of csPCa was 22.2% when proliferative inflammatory atrophy (PIA) was present, and 36.1% when it was not. PIA was the only histological finding which predicted lower risk of csPCa, with an OR of .54 (95% CI: .308-.945, P=.031). In addition, PIA was an independent predictor of a model combining clinical variables and mpMRI which reached area under de ROC curve of .86 (95% CI: .83-.90).ConclusionsPIA emerged as the only predictive histological finding of csPCa risk and can contribute to a predictive model. mHGPIN failed to predict csPCa risk. The low incidence of ASAP (4.2%) and PIN-ATYP (3.7%) prevented us from drawing conclusions. (AU)

Perfluoro-tert-butanol: a cornerstone for high performance fluorine-19 magnetic resonance imaging.

As a versatile quantification and tracking technology, 19F magnetic resonance imaging (19F MRI) provides quantitative "hot-spot" images without ionizing radiation, tissue depth limit, and background interference. However, the lack of suitable imaging agents severely hampers its clinical application. First, because the 19F signals are solely originated from imaging agents, the relatively low sensitivity of MRI technology requires high local 19F concentrations to generate images, which are often beyond the reach of many 19F MRI agents. Second, the peculiar physicochemical properties of many fluorinated compounds usually lead to low 19F signal intensity, tedious formulation, severe organ retention, etc. Therefore, the development of 19F MRI agents with high sensitivity and with suitable physicochemical and biological properties is of great importance. To this end, perfluoro-tert-butanol (PFTB), containing nine equivalent 19F and a modifiable hydroxyl group, has outperformed most perfluorocarbons as a valuable building block for high performance 19F MRI agents. Herein, we summarize the development and application of PFTB-based 19F MRI agents and analyze the strategies to improve their sensitivity and physicochemical and biological properties. In the context of PFC-based 19F MRI agents, we also discuss the challenges and prospects of PFTB-based 19F MRI agents.