Boronated starburst dendrimer-monoclonal antibody immunoconjugates: evaluation as a potential delivery system for neutron capture therapy

Boron neutron capture therapy (BNCT) is based on the nuclear capture reaction that occurs when boron-10, a stable isotope, is irradiated with low-energy or thermal neutrons (< or = 0.025 eV) to yield high LET alpha particles and recoiling 7Li nuclei [10B + nth-->[11B]-->4He(alpha) + 7Li + 2.39 MeV]. Approximately 10(9) boron-10 atoms must be delivered to each target cell in order to sustain a lethal 10B(n,alpha)7Li reaction. If MoAbs are to be used for targeting boron-10, then it is essential that they recognize a surface membrane epitope that is highly expressed on tumor cells and that a large number of boron-10 atoms be attached to each antibody molecule. In order to heavily boronate MoAbs, we have utilized starburst dendrimers (SD), which are precise, spherical macromolecules composed of repetitive poly(amidoamino) groups. Second- and fourth-generation dendrimers, having 12 and 48 reactive terminal amino groups and molecular weights of 2414 and 10,632 Da, respectively, were boronated using an isocyanato polyhedral borane, Na(CH3)3NB10H8NCO. The boronated starburst dendrimers (BSD), in turn, were derivatized with m-maleimidobenzoyl N-hydroxysulfosuccinimide ester (sulfo-MBS). The MoAbIB16-6, which is directed against the murine B16 melanoma, was derivatized with N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP). The MBS-derivatized BSD and SPDP-derivatized MoAb were reacted to yield stable immunoconjugates.(ABSTRACT TRUNCATED AT 250 WORDS)

Boron neutron capture therapy: linkage of a boronated macromolecule to monoclonal antibodies directed against tumor-associated antigens

Two new protein-binding polyhedral boron derivatives, isocyanatoundecahydro-closo-dodecaborate(2-) (1) and isocyanato(trimethylamino)octahydro-closo-decaborate(1 -) (2), were synthesized. These anionic isocyanates have long hydrolysis half-lives at pH 7 and react readily with primary or secondary aliphatic amines resulting in spontaneous urea linkage. Utilizing 1, 1100 boron atoms (7.3% boron by weight) were incorporated per molecule of a polyclonal antibody directed against human thymocytes (anti-thymocyte globulin) without denaturation. However, immunoreactivity of the conjugates was lost. Reaction of 1 and 2 with polylysine yielded boronated macromolecules containing 21-28% boron by weight (up to 2000 boron atoms per molecule). Polylysine boronated with 2 was successfully linked to antibody molecules employing the heterobifunctional linking molecules N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP) and m-maleimidobenzoyl sulfosuccinimide ester (sulfo-MBS). Separation of the conjugated antibody from the free boronated macromolecules and unconjugated antibody molecules has been achieved by gel filtration on a Sephacryl S-300 column. By linking boronated polylysine to antibodies, greater than 10(3) boron atoms were incorporated with the attachment of this species to one or more sites on the antibody molecule. The resulting immunoconjugates contained greater than 10(3) boron atoms per molecule, retained their immunoreactivity, and potentially might be useful for the selective delivery of large numbers of boron atoms to tumor cells.

Determination of boron in tissues and cells using direct-current plasma atomic emission spectroscopy

We have developed a safe, simple, and efficient method for boron determination by means of direct-current plasma atomic emission spectroscopy. Tissues were solubilized by using concentrated sulfuric acid and 70% hydrogen peroxide to digest the samples without the need of high temperatures and pressures. Boron cluster compounds could be measured with sensitivity, precision, and accuracy similar to those of boric acid standards. Results obtained with [(C2H5)3NH]2B12H12, Cs2B12H11SH.H2O, and C15H32B10O6 show that this analytical method is applicable to a variety of compounds with different chemical structures. A sensitivity of 0.1 ppm has been obtained with known standards alone and in a variety of tissue matrices including tumor, blood, liver, skin, and cell suspensions. The measurement of total boron by direct-current plasma atomic emission spectroscopy (DCP-AES) has been achieved with as little as 50 mg of tissue or as few as 5 x 10(7) cells. The procedure is applicable to the analysis of boron in the ppm range with a high degree of precision and accuracy.

Oral drug delivery systems using chemical conjugates or physical complexes

Oral delivery of therapeutics is extremely challenging. The digestive system is designed in a way that naturally allows the degradation of proteins or peptides into small molecules prior to absorption. For systemic absorption, the intact drug molecules must traverse the impending harsh gastrointestinal environment. Technologies, such as enteric coating, with oral dosage formulation strategies have successfully provided the protection of non-peptide based therapeutics against the harsh, acidic condition of the stomach. However, these technologies showed limited success on the protection of therapeutic proteins and peptides. Importantly, inherent permeability coefficient of the therapeutics is still a major problem that has remained unresolved for decades. Addressing this issue in the context, we summarize the strategies that are developed in enhancing the intestinal permeability of a drug molecule either by modifying the intestinal epithelium or by modifying the drug itself. These modifications have been pursued by using a group of molecules that can be conjugated to the drug molecule to alter the cell permeability of the drug or mixed with the drug molecule to alter the epithelial barrier function, in order to achieve the effective drug permeation. This article will address the current trends and future perspectives of the oral delivery strategies.

MR imaging of inflammatory joint diseases of the foot and ankle

Pain affecting the foot and ankle is a common complaint frequently attributable to inflammatory joint diseases. Although conventional radiography is regarded as the initial step in the diagnostic investigation, MR imaging may contribute to further evaluation of these patients due to the direct visualization of the inflammatory soft tissue formed in the disease and its effects on bone, cartilage and para-articular structures. The high spatial resolution of MR imaging combined with tissue characterization often allows initial detection of inflammatory joint abnormalities at a stage that precedes radiographic evaluation. The typical MR appearance of certain inflammatory joint disorders may be helpful in narrowing the wide differential diagnosis. Furthermore, MR imaging can be used for an exact assessment of the extent of the disorder as well as its complications. Accurate diagnostic information can guide the clinician in further diagnostic tests and implementation of proper therapeutic treatment.

Electron spectroscopic imaging for high-resolution immunocytochemistry: use of boronated protein A

In the present study we adapted electron spectroscopic imaging (ESI) for high-resolution immunocytochemistry. To accomplish this, we applied boronated protein A (B-pA) for indirect detection of specific antigenic sites using pre-embedding and post-embedding protocols. Isolated acinar cells were exposed to wheat germ agglutinin (WGA) and anti-WGA, followed by B-pA, to reveal WGA binding sites at the level of the plasma membrane. The cells were then embedded in Epon and unstained ultra-thin sections were examined by electron microscopy using the ESI mode. For post-embedding, ultra-thin sections of glutaraldehyde-fixed, Lowicryl-embedded pancreatic tissue were exposed to specific antibodies (anti-insulin or anti-amylase), followed by B-pA. The unstained sections were examined using the ESI mode. In both cases, boron was detected with high resolution either at the level of the plasma membrane of acinar cells, demonstrating WGA binding sites, or over secretory granules in pancreatic insulin-secreting cells or acinar cells, demonstrating insulin and amylase, respectively. These findings were compared to those obtained with the protein A-gold technique, and have demonstrated the analogy of both types of labeling. In addition, several control experiments assessed this novel approach. They have demonstrated the specificity of labeling and the high reactivity of B-pA, as well as its antibody-binding properties. Finally, electron energy loss spectral analysis confirmed the presence of boron in the tissue sections at sites where immunolabeling was detected. These results demonstrate that ESI is an appropriate approach for cytochemistry. Since the technique is based on detection of elements, spatial resolution is considered to be in the magnitude of 0.5 nm, which represents a major improvement in resolution over actual electron microscopic cytochemical techniques.

Mangafodipir trisodium: effects on T2- and T1-weighted MR cholangiography

The purpose of this study was to determine the effects of mangafodipir trisodium on heavily T2-weighted magnetic resonance cholangiography (MRC) images and on functional T1-weighted MRC. Pre- and post-mangafodipir trisodium heavily T2-weighted MRC and fat-suppressed T1-weighted three-dimensional (3D) gradient-echo MRC images were obtained in a patient with a prior cholecystectomy and a long cystic duct remnant that had apparent biliary stasis. Multiplanar reconstructed images were created. The precontrast T2-weighted MRC showed a long cystic duct remnant and a normal common bile duct (CBD). The postcontrast T2-weighted MRC showed loss of CBD signal, but persistent signal in the cystic duct remnant due to biliary stasis. Post-mangafodipir T1-weighted 3D gradient-echo images showed the main right and left hepatic ducts, but the cystic duct was not depicted. Conventional T2-weighted MRC sequences should not be obtained after administering mangafodipir trisodium because this contrast agent decreases the T2 and therefore the signal intensity of bile within normally functioning bile ducts. Functional MRC images can be acquired by using a post-mangafodipir T1-weighted technique.

Oligomeric bile acid-mediated oral delivery of low molecular weight heparin

Intestinal transporters are limited to the transport of small molecular substrates. Here, we describe the development of apical sodium-dependent bile acid transporter (ASBT)-targeted high-affinity oligomeric bile acid substrates that mediate the transmembrane transport of low molecular weight heparin (LMWH). Several oligomers of deoxycholic acid (oligoDOCA) were synthesized to investigate the substrate specificity of ASBT. To see the binding of oligoDOCA on the substrate-binding pocket of ASBT, molecular docking was used and the dissociation rate constants (KD) were measured using surface plasmon resonance. The KD for tetrameric DOCA (tetraDOCA) was 50-fold lower than that for monomeric DOCA, because tetraDOCA interacted with several hydrophobic grooves in the substrate-binding pocket of ASBT. The synthesized oligoDOCA compounds were subsequently chemically conjugated to macromolecular LMWH. In vitro, tetraDOCA-conjugated LMWH (LHe-tetraD) had highest selectivity for ASBT during its transport. Orally administered LHe-tetraD showed remarkable systemic anticoagulation activity and high oral bioavailability of 33.5±3.2% and 19.9±2.5% in rats and monkeys, respectively. Notably, LHe-tetraD successfully prevented thrombosis in a rat model of deep vein thrombosis. These results represent a major advancement in ASBT-mediated LMWH delivery and may facilitate administration of many important therapeutic macromolecules through a non-invasive oral route.

A feasibility study: evaluation of radiofrequency ablation therapy to hepatocellular carcinoma using image registration of preoperative and postoperative CT

RATIONALE AND OBJECTIVES

The therapeutic response to radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) often is evaluated by comparing pre- and post-RFA computed tomography (CT). However, judgment about whether an ablative margin, ie, 5-10 mm of normal hepatic tissue, is ensured sometimes is difficult. The aim of this study is to assess the feasibility of fusion images of pre- and post-RFA CT.

MATERIALS AND METHODS

HCCs (n = 20) sized 13 +/- 5 mm (range, 4-23 mm) were included. For pre-RFA CT, the arterial phase of intravenous dynamic CT (n = 17), CT arterioportography (n = 2), and CT hepatic arteriography (n = 1) was used. Using automatic image registration software (n = 20) and a manual segmentation technique (n = 4), fusion images were created in combination with post-RFA CT (equilibrium phase of intravenous CT).

RESULTS

Automatic image registration and manual segmentation technique took approximately 2-3 and 5 minutes, respectively. Total time required for the creation of fusion images was less than 10 minutes in all cases. Fusion images enabled easier understanding of the relationship between the tumor and ablation zone, helping judge whether an ablative margin was ensured.

CONCLUSION

Fusion of pre- and post-RFA CT images is considered a feasible tool in the evaluation of RFA therapy for HCC.

Oral mucosal lichen planus in children

Although lichen planus is a relatively common mucocutaneous disorder in adults, it has only rarely been described in children. Moreover, even less data has been published regarding mucosal lesions in children. Six case reports of childhood oral lichen planus are presented and the available literature reviewed. It is believed that this paper documents the largest series of cases of childhood oral mucosal lichen planus to be reported in the literature to date. Lichen planus should be considered in the differential diagnosis of oral mucosal white patches in children, particularly those of Asian origin.

Dicesium N-succinimidyl 3-(undecahydro-closo-dodecaboranyldithio)propionate, a novel heterobifunctional boronating agent

The synthesis of a novel heterobifunctional agent, dicesium N-succinimidyl 3-(undecahydro-closo-dodecaboranyldithio)propionate, is described. This structure contains an active ester component known to react rapidly under very mild conditions with amino groups of proteins, resulting in covalent linkage. With use of this boronating agent, approximately 480 boron atoms have been incorporated per molecule of a polyclonal antibody directed against human thymocytes and 1300 boron atoms per molecule were incorporated into a monoclonal antibody, 17-1A, directed against human colorectal carcinoma cells. Binding of the boronated antibodies to the corresponding target cells was demonstrated by means of membrane immunofluorescence. There was some loss in reactivity, as determined by fluorescent end point titers, but specificity remained unchanged. The data suggest that boronated antibodies potentially could be used to selectively deliver boron-10 to tumor cells in order to achieve their destruction by neutron capture.

Oral delivery of a potent anti-angiogenic heparin conjugate by chemical conjugation and physical complexation using deoxycholic acid

Angiogenesis, the formation of new blood vessels, plays a pivotal role in tumor progression and for this reason angiogenesis inhibitors are an important class of therapeutics for cancer treatment. Heparin-based angiogenesis inhibitors have been newly developed as one of such classes of therapeutics and possess a great promise in the clinical context. Taurocholate conjugated low molecular weight heparin derivative (LHT7) has been proven to be a potent, multi-targeting angiogenesis inhibitor against broad-spectrum angiogenic tumors. However, major limitations of LHT7 are its poor oral bioavailability, short half-life, and frequent parenteral dosing schedule. Addressing these issues, we have developed an oral formulation of LHT7 by chemically conjugating LHT7 with a tetrameric deoxycholic acid named LHTD4, and then physically complexing it with deoxycholylethylamine (DCK). The resulting LHTD4/DCK complex showed significantly enhanced oral bioavailability (34.3 ± 2.89%) and prolonged the mean residence time (7.5 ± 0.5 h). The LHTD4/DCK complex was mostly absorbed in the intestine by transcellular pathway via its interaction with apical sodium bile acid transporter. In vitro, the VEGF-induced sprouting of endothelial spheroids was significantly blocked by LHTD4. LHTD4/DCK complex significantly regressed the total vessel fractions of tumor (77.2 ± 3.9%), as analyzed by X-ray microCT angiography, thereby inhibiting tumor growth in vivo. Using the oral route of administration, we showed that LHTD4/DCK complex could be effective and chronically administered as angiogenesis inhibitor.

Primary syphilis remains a cause of oral ulceration

After many years the incidence of infective syphilis (infection with Treponema pallidum) is increasing in the United Kingdom. This may reflect changes in sexual attitudes and behaviour, altering trends in HIV disease, and increased foreign travel. Oral disease as a consequence of primary syphilis is rare. The present report details two patients presenting to an oral medicine clinic in London, within a 6-month period in 1999, with oral ulceration as their only clinical manifestation of undiagnosed primary syphilis. The oral aspects of early syphilis and the need for dentists to be aware of changing epidemiological trends in relevant infectious diseases are highlighted.

Offering HCV treatment to prisoners is an important opportunity: key principles based on policy and practice assessment in Europe

Background

Prisoners have a high prevalence of hepatitis C virus (HCV) infection but may find it difficult to access healthcare services. This may be related to risk behaviour including history of injecting drugs and marginalisation related to problem drug use/ opioid use disorder (OUD). Direct-acting antiviral products with superior efficacy and safety compared to interferon-based regimens offer HCV cure. Many citizens in Europe have been treated, although few received therapy in prisons.

Methods

Analysis of prisoner HCV treatment need and policy determinants of clinical practice was completed for 5 EU countries. Evidence was collected from national statistical sources and peer-reviewed publications to describe prison populations and HCV prevalence, to map national prison/ HCV health policy or guidance. A consensus of important principles for prisoner HCV care was developed.

Results

Data from published sources describing prisoner HCV prevalence is limited. Prisoner population requiring HCV treatment is not known; estimated numbers based on analysis of evidence: England and Wales, 9000, France, 8000, Spain, 6000, Italy, 6000, Germany, 6000. Treatment access: national law defines right to equivalent care in all countries implying access to HCV therapy in prison similar to community; useful prisoner HCV guidance facilitating treatment decisions present in: 4 of 5 national/ regional HCV policy documents, 4 of 5 national prison healthcare policies. Four of five had practical prison HCV clinical guidelines. Despite existence of policy, implementation of guidance, and so HCV treatment, is suboptimal in many locations.

Conclusions

Prison is an important location to detect, address and treat HCV infection in people who may be underserved for healthcare and find it difficult to navigate community treatment pathways. This is often related to problems with OUD and resulting social inequity. HCV management in prisons must be improved. Policy and clinical practice guidance must be set to promote treatment, and practical steps to make treatment easy should be followed including education to promote engagement, set-up of optimal screening and work up processes with modern tools to reduce time needed/ achieve efficiency; programs to make it easier to get specialists’ input include remote working and nurse-led services.

Dexamethasone-induced tumor lysis syndrome in high-grade non-Hodgkin's lymphoma

Tumor lysis syndrome is a catastrophic complication of the treatment of certain neoplasms. It most commonly occurs in association with hematologic malignancies and manifests a few hours to a few days after initiation of specific chemotherapy. It has rarely been encountered as a complication of steroid therapy only. Tumor lysis syndrome is a potentially fatal condition if it is not recognized promptly and managed aggressively. We report on a patient with high-grade non-Hodgkin's lymphoma who developed severe metabolic acidosis, hyperkalemia, hyperphosphatemia, and hypocalcemia within 2 days of starting corticosteroid therapy. He was managed with intravenous fluids, bicarbonate infusion, calcium gluconate, and 25% dextrose with insulin. He did not respond to these measures and died within a few hours of the diagnosis of tumor lysis syndrome. Increasing awareness of this complication and proper prophylactic measures are necessary to improve the outcome.

Evidence for a link between locus R-R sequence type and outcome of infection with Entamoeba histolytica

The results of Entamoeba histolytica infections range from asymptomatic colonization to variable disease outcomes. However, markers that may predict infection outcomes are not known. Here, we investigated sequence types of a non-coding tRNA-linked locus R-R to identify surrogate markers that may show association with infection outcomes. Among 112 clinical samples--21 asymptomatic, 20 diarrhoea/dysentery and 71 liver abscesses--we identified 11 sequence types. Sequence type 5RR was mostly associated with asymptomatic samples, and sequence type 10RR was predominantly associated with the symptomatic (diarrhoea/dysentery and liver abscess) samples. This is the first report that identifies markers that may predict disease outcomes in E. histolytica infection.

Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Background

Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice.

Methods

COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien–Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement.

Results

Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001).

Conclusion

Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk.

Targeting prion-like protein doppel selectively suppresses tumor angiogenesis

Controlled and site-specific regulation of growth factor signaling remains a major challenge for current antiangiogenic therapies, as these antiangiogenic agents target normal vasculature as well tumor vasculature. In this article, we identified the prion-like protein doppel as a potential therapeutic target for tumor angiogenesis. We investigated the interactions between doppel and VEGFR2 and evaluated whether blocking the doppel/VEGFR2 axis suppresses the process of angiogenesis. We discovered that tumor endothelial cells (TECs), but not normal ECs, express doppel; tumors from patients and mouse xenografts expressed doppel in their vasculatures. Induced doppel overexpression in ECs enhanced vascularization, whereas doppel constitutively colocalized and complexed with VEGFR2 in TECs. Doppel inhibition depleted VEGFR2 from the cell membrane, subsequently inducing the internalization and degradation of VEGFR2 and thereby attenuating VEGFR2 signaling. We also synthesized an orally active glycosaminoglycan (LHbisD4) that specifically binds with doppel. We determined that LHbisD4 concentrates over the tumor site and that genetic loss of doppel in TECs decreases LHbisD4 binding and targeting both in vitro and in vivo. Moreover, LHbisD4 eliminated VEGFR2 from the cell membrane, prevented VEGF binding in TECs, and suppressed tumor growth. Together, our results demonstrate that blocking doppel can control VEGF signaling in TECs and selectively inhibit tumor angiogenesis.

Overview of substance use disorders and incarceration of african american males

Incarceration affects the lives of many African American men and often leads to poverty, ill health, violence, and a decreased quality of life. There has been an unprecedented increase in incarceration among African American males since 1970. In 2009, the incarceration rate among black males was 6.7 times that of white males and 2.6 times of Hispanic males. Substance abuse in African American males leads to higher mortality rates, high rates of alcohol-related problems, more likely to be victims of crimes, and HIV/AIDS. African Americans comprised only 14% of the U.S. population but comprised 38% of the jail population. The cost of incarcerating persons involved in substance related crimes has increased considerably over the past two decades in the U.S. A reduction in the incarceration rate for non-violent offences would save an estimated $17 billion per year. Substance use disorder makes the individual more prone to polysubstance use and leads to impulse control problems, selling drugs, and other crimes. The high rate of incarceration in U.S. may adversely affect health care, the economy of the country, and will become a burden on society. Implementation of good mental health care, treatment of addiction during and after incarceration will help to decrease the chances of reoffending. Therapeutic community programs with prison-based and specialized treatment facilities, cognitive behavioral therapy treatment for 91-180 days, and 12-step orientation with staff specialized in substance abuse can be helpful. It is essential for health care professionals to increase public awareness of substance abuse and find ways to decrease the high rates of incarceration.

The impact of motion artifacts on the reproducibility of repeated coronary artery calcium measurements

The purpose of this study is, using a 16-section multidetector-row helical computed tomography (MDCT) scanner with retrospective reconstruction, to compare variability in repeated coronary calcium scoring and qualitative scores of the motion artifacts. One hundred forty-four patients underwent two subsequent scans using MDCT. According to Agatston and volume algorithms, the coronary calcium scores during mid-diastole (the center corresponding to 70% of the R-R cycle) were calculated and the inter-scan variability was obtained. Motion artifacts from coronary artery calcium were subjectively evaluated and classified using a 5-point scale: 1, excellent; no motion artifacts; 2, fine, minor motion artifacts; 3, moderate, mild motion artifacts; 4, bad, severe motion artifacts; 5, poor, doubling or discontinuity. Each reading was done by vessels (left main, left descending, left circumflex and right coronary arteries) and the motion artifact score (mean of the scales) was determined per patient. The variability in the low (1.2+/-0.2) and high (2.4+/-0.6) motion artifact score groups was 7+/-6 (median, 6)% and 19+/-15 (16)% on the Agatston score (P<0.01) and 7+/-7 (6)% and 16+/-13 (14)% on the volume score (P<0.01), respectively. In conclusion, motion has a significant impact on the reproducibility of coronary calcium scoring.

Frequency and spectrum of abnormalities in the bone marrow of the wrist: MR imaging findings

OBJECTIVE

To describe the frequency of marrow abnormalities on wrist MR imaging and the MR findings of these various abnormalities.

DESIGN AND PATIENTS

Five hundred and nineteen patients were studied at 1.5 T. Two observers recorded the presence and location of avascular necrosis, occult fractures and arthritic edema [focal osteoarthritis, ulnolunate abutment, rheumatoid arthritis, septic arthritis, gouty arthritis and scapholunate advanced collapse (SLAC)].

RESULTS AND CONCLUSION

One hundred and eighty-seven (36%) patients demonstrated marrow abnormalities in the wrist, of which 101 were diagnosed as arthritis [64 (34%) as focal osteoarthritis, 17 (9%) as ulnolunate abutment, 15 (8%) as rheumatoid arthritis, 2 as septic arthritis, 2 as SLAC, and 1 as gouty arthritis]. Seventy-two patients had occult fractures and in 27 patients avascular necrosis was seen. MR imaging can reveal various abnormalities in bone marrow of the wrist when findings on radiography are normal or equivocal.