20 research outputs found
Role of imaging in the diagnosis and management of complete androgen insensitivity syndrome in adults
Complete androgen insensitivity syndrome is an X-linked recessive androgen receptor disorder characterized by a female phenotype with an XY karyotype. Individuals affected by this syndrome have normal female external genitalia but agenesis of the Müllerian duct derivatives, that is, absence of the Fallopian tubes, uterus, cervix, and the proximal part of the vagina, with presence of endoabdominal, labial, or inguinal testes. The estimated prevalence is between 1 and 5 in 100,000 genetic males. Complete androgen insensitivity syndrome can be diagnosed as a result of mismatch between the prenatal sex prediction and the phenotype at birth, can be detected by chance, or remain undetected until investigations for primary amenorrhea. Imaging can be important both to diagnose the pathology and to localize gonads prior to surgical treatment. In this paper, we present three cases of complete androgen insensitivity syndrome in adult women of 34, 22, and 38 years old
Acquisition Parameters Influence Diffusion Metrics Effectiveness in Probing Prostate Tumor and Age-Related Microstructure
: This study aimed to investigate the Diffusion-Tensor-Imaging (DTI) potential in the detection of microstructural changes in prostate cancer (PCa) in relation to the diffusion weight (b-value) and the associated diffusion length lD. Thirty-two patients (age range = 50-87 years) with biopsy-proven PCa underwent Diffusion-Weighted-Imaging (DWI) at 3T, using single non-zero b-value or groups of b-values up to b = 2500 s/mm2. The DTI maps (mean-diffusivity, MD; fractional-anisotropy, FA; axial and radial diffusivity, D// and D┴), visual quality, and the association between DTI-metrics and Gleason Score (GS) and DTI-metrics and age were discussed in relation to diffusion compartments probed by water molecules at different b-values. DTI-metrics differentiated benign from PCa tissue (p ≤ 0.0005), with the best discriminative power versus GS at b-values ≥ 1500 s/mm2, and for b-values range 0-2000 s/mm2, when the lD is comparable to the size of the epithelial compartment. The strongest linear correlations between MD, D//, D┴, and GS were found at b = 2000 s/mm2 and for the range 0-2000 s/mm2. A positive correlation between DTI parameters and age was found in benign tissue. In conclusion, the use of the b-value range 0-2000 s/mm2 and b-value = 2000 s/mm2 improves the contrast and discriminative power of DTI with respect to PCa. The sensitivity of DTI parameters to age-related microstructural changes is worth consideration
Imaging of Renal Medullary Carcinoma
Renal medullary carcinoma (RMC) is a rare, highly aggressive tumor recognized as an independent pathological entity. African-descent adolescents and young adults with sickle cell hemoglobinopathy are the most affected groups. This rare subtype of renal cell carcinoma has its own morphogenetic and pathological characteristics. The major clinical manifestations include gross hematuria, abdominal or flank pain, and weight loss. The prognosis is very poor, with 95% of cases diagnosed at an advanced stage of the disease. In this review, we summarize the morphologic and dynamic characteristics of RMC under various imaging modalities such as ultrasound, computed tomography, and magnetic resonance. Differential diagnosis and management strategies are also discussed
transperineal laser ablation (TPLA) with ultrasound/MRI fusion guidance in the treatment of localized radiotherapy-resistant prostate cancer
objective: the objective of this study was to assess the technical feasibility, safety, and efficacy of transperineal laser ablation (TPLA) guided by ultrasound/magnetic resonance (MR) fusion as a salvage treatment for refractory focal prostate cancer. methods: a total of five patients who had undergone radiation therapy (RT) for prostate carcinoma and biochemical recurrence, confirmed by both prostate-specific antigen (PSA) levels and MRI (3T mpMRI), were enrolled in this study. focal ablation was performed using a 1064 nm diode laser. Post-ablation follow-up was conducted for a duration of 18 months, which included regular PSA sampling, 3T mpMRI, and ultrasound/MR fusion-guided biopsies systematic and targeted at the site of the focal treatment. results: the focal ablation procedure was carried out in an outpatient setting regimen with optimal clinical and biochemical outcomes. no recurrence was detected throughout the follow-up period. conclusion: TPLA focal treatment effectively manages local recurrences of RT refractory prostate cancer without side-effects or complications. preservation of quality of life and functional outcomes, along with a >70% reduction in PSA, were achieved. advances in knowledge: our study investigated TPLA as a salvage treatment for low-risk recurrent prostate cancer after RT, demonstrating its tolerability, feasibility, and effectiveness
Imaging of Renal Medullary Carcinoma
Renal medullary carcinoma (RMC) is a rare, highly aggressive tumor recognized as an independent pathological entity. African-descent adolescents and young adults with sickle cell hemoglobinopathy are the most affected groups. This rare subtype of renal cell carcinoma has its own morphogenetic and pathological characteristics. The major clinical manifestations include gross hematuria, abdominal or flank pain, and weight loss. The prognosis is very poor, with 95% of cases diagnosed at an advanced stage of the disease. In this review, we summarize the morphologic and dynamic characteristics of RMC under various imaging modalities such as ultrasound, computed tomography, and magnetic resonance. Differential diagnosis and management strategies are also discussed.</p
Towards a definition of the biophysical bases of transient Anomalous Diffusion (TAD) parameters. Evaluation of tAD, DKI and DTI in normal and cancer prostate tissue with Magnetic Resonance micro-imaging at 9.4 Tesla
Synopsis
Since DKI and transient anomalous diffusion imaging (tADI) are based on statistical models, they can be performed without the need of a-priori hypothesis on tissue micro-structures. However, the relation between tissue micro-structure DKI and tADI derived parameters have not been clearly established yet. In this work, we evaluated DKI, tAD and DTI diffusion parameters in normal and high-grade cancer prostate, by MR microimaging at 9.4T with a 70μmx70μm in plane resolution. As prostate tissue is a complex tissue, composed by several micro-compartments that exhibit different diffusion behaviors, it is an ideal tissue to investigate the biophysical features of diffusion parameters.
Introduction
In this work Diffusion Kurtosis Imaging (DKI) and transient Anomalous Diffusion Imaging (tADI) were performed on ex-vivo prostate specimens, in addition to the conventional DTI. Kurtosis is the fourth-order term of the NMR signal cumulant expansion, it quantifies the signal deviation from the mono-exponential decay, providing a measure of tissue heterogeneity [1]. tADI derived from Continuous Time Random Walk model introduced by Metzler and Klafter [2], a generalization of the basic random walk theory, developed with the purpose to investigate heterogeneous and complex media. tADI allows to measure the γ-parameter that is sensitive to tissue susceptibility differences and multi-compartmentalization [3,4]. Since DKI and tADI are based on statistical models, they can be performed without needing a-priori hypothesis on tissue micro-structures. However, the relation between tissue micro-modifications and DKI- and tADI-derived parameters must be investigated and established. In this preliminary work, we evaluated DKI, tAD and DTI diffusion parameters in normal and high-grade PCa, by MR microimaging at 9.4T and with a resolution of 70x70μm2 in the plane. Prostate tissue is composed by several micro-compartments that exhibit different diffusion behaviors [5]. Therefore, as prostate is a complex tissue, consisting of structures with length scale from 100 μm to less than 1 μm, it is an ideal tissue to investigate the biophysical features of diffusion parameters.
Methods
Tissue samples were obtained from radical prostatectomy specimens and kept in 4% PBS formaldehyde at 4°C for conservation. An expert uropathologist selected one normal and one cancer sample from 3 patients with high-grade Pca (Gleason Score ≥ 4+4). Acquisition was performed on a Bruker AV400 spectrometer operating at 9.4 T with a micro-imaging probe and maximum gradient strength of 1200mT/m. XWINNMR® and ParaVision® 3.0 software were employed for data acquisition. DWIs were acquired with a Pulsed Gradient Stimulated Echo (TE/TR=14,8/4500 (ms); resolution=70x70x1000μm3; δ/Δ=3/40 (ms); NSA=8), by varing diffusion gradient strengths; 9 b-values from 0 to 5000 s/mm2 were applied along 6 non-collinear directions
DTI was performed by FSL 5.0 software, with the b-value range 0-1500 s/mm2; non-Gaussian parameters were calculated by a customized algorithm developed in Matlab R2012b. Mean Kurtosis (MK) and kurtosis-derived mean diffusivity (MDk) were calculated by fitting DWI signal for each diffusion encoding direction in the b-value range 0-2000 s/mm2. Moreover, proxy Kurtosis Fractional Anisotropy (KFA) was calculated as reported in [6].
tAD was performed, as described in [7], by fitting signal in the b-values range 0-5000s/mm2, according the approach of [3].
Region of Interests (ROI) were manually drawn on DW-images in tumoral and normal tissue.
Results
The glandular structure of prostate is visible in DWIs and diffusion parameters maps of normal samples, except for FA-map; MDk seems to better describe the tissue architecture (Fig. 1 and 2). MD, MDk and Mγ are lower in PCa, while FA, KFA and MK are higher; DTI-parameters show mean values comparable with other ex-vivo studies [5,8].
Discussion and Conclusions
Diffusion derived micro-images highlight tissue architecture and reflect structural modifications occurring with tumor. Histopathological evidences showed that Pca with Gleason Score (GS) ≥ 4+4 consists in a solid mass of undifferentiated cells (Fig.3), indeed no glandular structure is recognizable on DWIs or diffusion maps (Fig. 2). MD and MDk are lower in PCa, as a result of malignant cells proliferation that obstructs the almost-free diffusion compartments (acini, ducts), leading to an increase of tissue heterogeneity (K increases) and a reduction of tissue susceptibility differences (Mγ decreases). As a consequence of increasing cell density, FA and KFA are lower in cancer tissue.
In conclusion, MR micro-imaging in healthy and cancer prostate tissue allows to investigate diffusion proprieties of micro-structures approaching the cellular scale. As a consequence, micro-imaging technique could be employed to elucidate the biophysical underpinning of non–Gaussian diffusion parameters and in particular of the tAD parameters.
Acknowledgements
No acknowledgement found.
References
[1] Jensen J.H. and Helpern J.A., MRI quantification of Non-Gaussian water diffusion by Kurtosis Analysis. NMR Biomed, 2010.
[2] Metzler R. and Klafter J., The random walk’s guide to anomalous diffusion: a fractional dynamics approach. Physics Reports, 2000.
[3] Palombo M. et al., Spatio-temporal anomalous diffusion in heterogeneous media by nuclear magnetic resonance. J Chem Phys, 2011.
[4] Capuani S. et al., Spatio-temporal anomalous diffusion imaging: results in controlled phantoms and in excised human meningiomas. Magn Reson Imaging, 2013.
[5] Bourne R.M. et al., Microscopic diffusivity compartmentation in formalin-fixed prostate tissue.Magnetic Resonance in Medicine, 2012.
[6] Hansen B. and Jespersen S.N., Kurtosis fractional anisotropy, its contrast and estimation by proxy. Sci. Rep., 2016.
[7] Caporale A. et al.,The γ-parameter of Anomalous Diffusion quantified in human brain by MRI depends on local magnetic susceptibility differences, NeuroImage, 2016.
[8] Xu J.Q., et al.,. Magnetic resonance diffusion characteristics of histologically defined prostate cancer in humans. Magn Reson Med, 2009
Cone Beam CT use in the pre-prosthetic evaluation of endodontically treated of the rear maxilla
With our study we wanted to compare the diagnostic accuracy of conventional radiography (orthopanoramic and intraoral radiography) and Cone Beam CT (CBCT) for the diagnosis of periapical lesions on the posterior elements of the upper maxilla endodontically treated.
The images were analyzed by a radiologist and an endodontist whose interpretation of radiological examinations is unique. Were examined 34 molars (23 first molars and 13 second molars) with a total of 102 roots. The CBCT detected a significantly higher number of lesions (43%, p <0.001) compared to conventional radiography. Our results demonstrate that the CBCT can be inserted into the diagnostic routine for the evaluation of all pre-prosthetic posterior elements of the upper jaw endodontically treated in addition to the diagnostic techniques 2D, especially when in the treatment plan is provided the realization of an abutment. The CBCT, which has reduction of cost and absorption of radiation with respect to the conventional CT, is also very useful even when there is a need to perform a surgical treatment-endodontic (apicectomy) of a lesion diagnosed with 2D techniques
DWI of Prostate Cancer: Optimal b-Value in Clinical Practice
Aim. To compare the diagnostic performance of diffusion weighted imaging (DWI) using b-values of 1000 s/mm2 and 2000 s/mm2 at 3 Tesla (T) for the evaluation of clinically significant prostate cancer. Matherials and Methods. Seventy-eight prostate cancer patients underwent a 3T MRI scan followed by radical prostatectomy. DWI was performed using b-values of 0, 1000, and 2000 s/mm2 and qualitatively analysed by two radiologists. ADC maps were obtained at b-values of 1000 and 2000 s/mm2 and quantitatively analyzed in consensus. Results. For diagnosis of 78 prostate cancers the accuracy of DWI for the young reader was significantly greater at b = 2000 s/mm2 for the peripheral zone (PZ) but not for the transitional zone (TZ). For the experienced reader, DWI did not show significant differences in accuracy between b-values of 1000 and 2000 s/mm2. The quantitative analysis in the PZ and TZ was substantially superimposable between the two b-values, albeit with a higher accuracy with a b-value of 2000 s/mm2. Conclusions. With a b-value of 2000 s/mm2 at 3T both readers differentiated clinical significant cancer from benign tissue; higher b-values can be helpful for the less experienced readers
Early Magnetic Resonance Detection of Natalizumab-Related Progressive Multifocal Leukoencephalopathy in a Patient with Multiple Sclerosis
Diagnosis of progressive multifocal leukoencephalopathy is usually based on the clinical presentation, on the demonstration of the brain lesions at the magnetic resonance imaging examination, and on the detection of the JC virus DNA in the cerebrospinal fluid with high sensitive polymerase chain reaction. The role of magnetic resonance imaging specifically in natalizumab-associated progressive multifocal leukoencephalopathy is strengthening, and it is gaining importance not only as an irreplaceable diagnostic tool but also as a surveillance and risk stratifying tool in treated patients. While other imaging techniques such as computed tomography lack sensitivity and specificity, magnetic resonance performed with morphological and functional sequences offers clinicians the possibility to early identify the stage of the disease and the emergence of an immune reconstitution inflammatory syndrome after natalizumab blood removal plasmapheresis
Clinical Evaluation of Percutaneous Vertebroplasty in a Patient with Paraplegia and Immobilization Syndrome: A Case Report
We will discuss a potential role of percutaneous vertebroplasty (PVP) in the management of a patient with immobilization syndrome due to paraplegia and vertebral osteoporotic fractures. While PVP is commonly used for the treatment of osteoporotic thoracolumbar vertebral compression fractures, its role in vertebral stabilization in patient with immobilization syndrome has not been reported in the literature. A 73-year-old woman affected by immobilization syndrome due to paraplegia and vertebral osteoporotic fractures was treated with PVP of vertebrae D12, L1, and L4. After PVP, the patient did not need any antalgic therapy, and there was a significant improvement regarding mobilization, performance of physiological functions, daily management of personal care, and treatment of decubitus ulcers, increasing life quality and psychological well-being