Diagnóstico clínico, radiográfico e histológico de un caso de fibrosis periapical posendodóntica / Clinical, radiographic, and histologic diagnosis of a postendodontic periapical fibrosis case

Objetivo: La fibrosis periapical posendodóntica es un proceso reparativo asintomático, radiolúcido y no progresivo que se interpreta con frecuencia como una lesión patológica persistente. El diagnóstico de esta entidad suele ser dudoso y sólo puede definirse mediante la correlación de las obser- vaciones clínicas, radiográficas e histológicas. El objetivo de este informe es describir el caso de un paciente que presenta un área radiolúcida periapical persistente y asintomática en un incisivo lateral superior. Caso clínico: Luego de cuatro años y dos meses de ha- ber recibido un tratamiento endodóntico el paciente concurre a la consulta para un examen de rutina. El examen radiográfico del diente revela un área radiolúcida persistente y bien defini- da. A causa de una fractura radicular irreparable, se indicó la extracción de la pieza dentaria. Esto permitió realizar el estu- dio histológico del tejido blando que permanecía adherido en el ápice de la raíz, lo que confirmó y completó el diagnóstico de fibrosis periapical posendodóntica.(AU)

Aim: The postendodontic periapical fibrosis is an asymp- tomatic radiolucent and non-progressive healing process that is often interpreted as a persistent pathological lesion. The diagnosis of this entity is usually uncertain, and it is only de- fined by the correlation of clinical, radiographic and histo- logical observations.The aim of this report is to describe the case of a patient with a long-term persisting asymptomatic and radiolucent area in a upper lateral incisor. Clinical case: Four years and two months after receiv- ing an endodontic treatment the patient comes to our office for a routine control. Radiographic examination revealed the presence of a persistent well defined radiolucent area. Sur- gical tooth extraction was required due to the presence of a complicated root fracture.This allowed to perform a histolog- ical study of the soft tissue attached to the apex of the ex- tracted root, which confirmed and completed the diagnosis of postendodontic periapical fibrosis (AU)

Late gadolinium enhancement-MRI determines definite lesion formation most accurately at 3 months post ablation compared to later time points.

AIMS: Neither the long-term development of ablation lesions nor the capability of late gadolinium enhancement (LGE)-MRI to detect ablation-induced fibrosis at late stages of scar formation have been defined. We sought to assess the development of atrial ablation lesions over time using LGE-MRI and invasive electroanatomical mapping (EAM). METHODS AND RESULTS: Ablation lesions and total atrial fibrosis were assessed in serial LGE-MRI scans 3 months and >12 months post pulmonary vein (PV) isolation. High-density EAM performed in subsequent repeat ablation procedures served as a reference. Serial LGE-MRI of 22 patients were analyzed retrospectively. The PV encircling ablation lines displayed an average LGE, indicative of ablation-induced fibrosis, of 91.7% ± 7.0% of the circumference at 3 months, but only 62.8% ± 25.0% at a median of 28 months post ablation (p < 0.0001). EAM performed in 18 patients undergoing a subsequent repeat procedure revealed that the consistent decrease in LGE over time was owed to a reduced detectability of ablation-induced fibrosis by LGE-MRI at time-points > 12 months post ablation. Accordingly, the agreement with EAM regarding detection of ablation-induced fibrosis and functional gaps was good for the LGE-MRI at 3 months (κ .74; p < .0001), but only weak for the LGE-MRI at 28 months post-ablation (κ .29; p < .0001). CONCLUSION: While non-invasive lesion assessment with LGE-MRI 3 months post ablation provides accurate guidance for future redo-procedures, detectability of atrial ablation lesions appears to decrease over time. Thus, it should be considered to perform LGE-MRI 3 months post-ablation rather than at later time-points > 12 months post ablation, like for example, prior to a planned redo-ablation procedure.

Left atrial imaging and registration of fibrosis with conduction voltages using LGE-MRI and electroanatomical mapping.

BACKGROUND AND PURPOSE: Abnormal electrical conduction and excitability associated with fibrosis in the left atrium (LA) may serve as a substrate for atrial fibrillation (AF). Electroanatomical voltage mapping systems (EAMs) have become a dominant facilitator to treat AF with catheter ablation assisted by additional diagnostic imaging modalities. Importantly, AF has been associated with structural changes to the extracellular matrix of the myocardium, including increased collagen deposition-a process known as fibrosis. Late gadolinium enhancement-magnetic resonance imaging (LGE-MRI) may aid in guiding AF cardiac ablation therapy by determination of location of fibrosis in the LA. To locate fibrosis for cardiac ablation, however, accurate registration between EAMs and LGE-MRI data is crucial. The purpose of this work was to develop a method for registering EAMs with late gadolinium enhancement-magnetic resonance (LGE-MR) images of fibrosis. METHODS: Twenty patients with persistent AF, who underwent magnetic resonance imaging scanning and EAMs prior to first-time catheter ablation, participated in the study. In our registration pipeline, LGE-MR images were registered to the left atrial surface on EAMs using manual alignment followed by iterative closest point (ICP), and non-rigid ICP (NICP) algorithm. RESULTS AND CONCLUSIONS: The results demonstrate that NICP provided a substantial reduction in registration error when compared to the use of affine ICP alone. Regions of fibrosis on LGE-MR images identified using the signal threshold to reference mean threshold demonstrated the most regional overlap with low bipolar voltage points on EAMs. Successful co-registration of LGE-MR images to EAMs may assist electro-physiologists in selecting candidate targets for ablation and ultimately, reduce the rate of AF recurrence for patients.

Can Contrast-Enhanced Sonography Detect Bowel Wall Fibrosis in Mixed Inflammatory and Fibrotic Crohn Disease Lesions in an Animal Model?

OBJECTIVES: To determine whether contrast-enhanced sonographic quantitative perfusion parameters can detect bowel wall fibrosis in the setting of mixed inflammatory and fibrotic lesions in a Crohn disease animal model. METHODS: This study was approved by the institutional Committee on the Use and Care of Animals. Multiple (range, 1-5) 2,4,6-trinitrobenzenesulfonic acid-ethanol enemas were used to create intestinal inflammatory lesions with variable fibrosis in female Lewis rats. Low-mechanical index contrast-enhanced sonography was performed 3 days after the final enema using a 0.2-mL bolus of sulfur hexafluoride microbubbles injected through a tail vein. Contrast-enhanced sonographic data were analyzed with software that converts video data into echo-power (linearized) data. Colorectal lesions were scored for histopathologic inflammation and fibrosis; bowel wall collagen was quantified by Western blotting. The Spearman correlation was used to assess associations between contrast-enhanced sonographic quantitative parameters and bowel wall collagen; the Kruskal-Wallis test was used to compare continuous results between histopathologic groups. RESULTS: Thirty-one animals were included in our analysis. Animals were placed into 3 histopathologic cohorts: (1) severe bowel wall inflammation/minimal or no fibrosis (n = 11); (2) severe bowel wall inflammation/moderate fibrosis (n = 9); and (3) severe bowel wall inflammation/severe fibrosis (n = 11). Western blotting showed a significant difference in bowel wall collagen between histopathologic cohorts (P = .0001). There was no correlation between any contrast-enhanced sonographic quantitative parameter and bowel wall collagen (P > .05). There was no difference between histopathologic cohorts for any contrast-enhanced sonographic quantitative parameter (P > .05). CONCLUSIONS: Contrast-enhanced sonographic quantitative perfusion parameters failed to effectively detect bowel wall fibrosis in the setting of superimposed inflammation in a Crohn disease animal model.

Phlebosclerotic colitis: case report and literature review focused on the radiologic findings in relation to the intake period of toxic material.

Phlebosclerotic colitis (PC) is a rare disease entity of intestinal ischemia characterized by calcification at the right hemicolon and is predominant in Asian populations. We present a 57-year-old Korean patient who was an Oriental medicine practitioner himself and had been taking herbal medicine for decades. We reviewed previous literature on similar cases and analyzed radiologic features of PC in relation to the intake period of toxic material and extent of disease.

Synthesis and preclinical evaluation of 68Ga-labeled collagelin analogs for imaging and quantification of fibrosis.

OBJECTIVES: Fibrosis affecting functionality of vital organs such as liver, lung, heart, and kidney, is involved in many chronic diseases. Positron emission tomography (PET) would not only provide precise localization and extent of the affected tissue but also allow the accurate quantification of the fibrotic process for the subsequent prognosis. METHODS: A cyclic peptide c[CPGRVMHGLHLGDDEGPC] conjugated either to 2-(4,7-bis(2-(tert-butoxy)-2-oxoethyl)-1,4,7-triazonan-1-yl)acetic acid (NOTA(tBu)2) or 4-(4,7-bis(2-(tert-butoxy)-2-oxoethyl)-1,4,7-triazacyclononan-1-yl)-5-(tert-butoxy)-5-oxopentanoic acid (NODAGA(tBu)3) via polyethylene glycol link (PEG2) was synthesized and labeled with (68)Ga. Non-specific organ distribution, blood clearance, and excretion were investigated ex vivo in healthy rats. The binding specificity of the radioligands was assessed in vitro using autoradiography on cryosections of dog fibrotic heart tissue. RESULTS: The yield of NOTA-PEG2-c[CPGRVMHGLHLGDDEGPC] and NODAGA-PEG2-c[CPGRVMHGLHLGDDEGPC] was 56% and 41%, respectively. Non-decay-corrected radiochemical yield was 80 ± 5% with radiochemical purity of 95 ± 4%. Pharmacokinetic studies in healthy male Sprague-Dawley rats showed fast blood clearance and renal excretion. Lower uptake in liver, spleen, and kidney was found for [[(68)Ga]Ga-NOTA](+1)-PEG2-c[CPGRVMHGLHLGDDEGPC] as compared to [[(68)Ga]Ga-NODAGA](0)-PEG2-c[CPGRVMHGLHLGDDEGPC]. Histologic evaluation of the left ventricle (LV) myocardium from a dog with severe mitral regurgitation (MR), revealed mild to moderate perivascular and subendocardial, and mild diffuse interstitial fibrosis. The tracer binding to the cryosections of the tissue was specific with the equilibrium Kd of 2.3 ± 0.8 µM and 2.1 ± 0.9 µM, respectively for [(68)Ga]Ga-NO2A-Col and [(68)Ga]Ga-NODAGA-Col. CONCLUSIONS: Two novel peptide based agents for the imaging of fibrosis by PET were developed. Moderation of the biodistribution could be achieved by variation of the charge on the complex moiety of the agents. The combination of the fast clearance from non-target organs as well as organs of interest such as lung, heart, and liver and binding specificity to the target tissue suggests the potential of the analogs for the imaging of fibrosis.

US elastography-derived shear wave velocity helps distinguish acutely inflamed from fibrotic bowel in a Crohn disease animal model.

PURPOSE: To determine if acoustic radiation force impulse elastography-derived bowel wall shear wave velocity (SWV) allows distinction of acutely inflamed from fibrotic intestine in a Crohn disease animal model. MATERIALS AND METHODS: University Committee on the Use and Care of Animals approval was obtained. An acute inflammation Crohn disease model was produced by treating eight Lewis rats with a single administration of trinitrobenzenesulfonic acid (TNBS) enema, with imaging performed 2 days later in the surviving six rats. Colonic fibrosis in an additional eight Lewis rats was achieved by administering repeated TNBS enemas during 4 weeks, with imaging performed in the surviving seven rats 7 days later to allow acute inflammation resolution. Nine transcutaneous bowel wall SWV measurements were obtained from the colon in all rats without and with applied strain. Mean SWVs without and with applied strain were compared between animal cohorts by using the Student t test, and receiver operating characteristic (ROC) curves were created to assess diagnostic performance. RESULTS: Mean bowel wall SWVs were significantly higher for fibrotic versus acute inflammation cohort of rats at 0% (3.4 ± 1.1 vs 2.3 ± 0.5 m/sec; P = .047) and 30% (6.3 ± 2.2 vs 3.6 ± 0.9 m/sec; P = .02) applied strain. Both acute inflammation and fibrotic cohort of rats demonstrated linear increases in mean SWV with increasing applied strain, with significantly different mean slopes (P = .02) and y-intercepts (P = .02). The area under the ROC curve of the SWV ratio (mean SWV/applied strain) for differentiating histopathologically confirmed fibrotic from inflamed bowel was 0.971. CONCLUSION: Bowel wall SWV helps distinguish acutely inflamed from fibrotic intestine in a Crohn disease animal model.