Diffusion tensor imaging and fiber tractography of the median nerve at 1.5T: optimization of <Emphasis Type="Italic">b</Emphasis> value

Objective  The objective of this study was to systematically assess the optimal b value for diffusion tensor imaging and fiber tractography of the median nerve at 1.5 T. Materials and methods  This is a prospective study which was carried out with institutional review board approval and written informed consent from the study subjects. Fifteen healthy volunteers (seven men, eight women; mean age, 31.2 years) underwent diffusion tensor imaging of the wrist. A single-shot spin-echo-based echo-planar imaging sequence (TR/TE, 7000/103 ms) was performed in each subject at eight different b values ranging from 325 to 1,550 s/mm². Number and length of reconstructed fiber tracts, fiber density index (FDi), fractional anisotropy (FA), and apparent diffusion coefficient (ADC) were calculated for the median nerve. Signal-to-noise ratio (SNR) was also calculated for each acquisition. The overall image quality was assessed by two readers in consensus by ranking representative fiber tract images for each subject using a scale range from 1 to 8 (1 = best to 8 = worst image quality). Results  Longest fibers were observed for b values between 675 and 1,025 s/mm². Maximum FDi was found at b values of 1,025 s/mm². FA was between 0.5 and 0.6 for all b values. ADC gradually decreased from 1.44 × 10⁻³ to 0.92 × 10⁻³ mm²/s with increasing b values. Maximum SNR ± standard deviation (175.4 ± 72.6) was observed at the lowest b value and decreased with increasing b values. SNR at b values of 1,025 s/mm² was 48.5% of the maximum SNR. Optimal fiber tract image quality was found for b values of 1,025 s/mm². Conclusions  The optimal b value for diffusion tensor imaging and fiber tractography of the median nerve at 1.5 T was 1,025 s/mm².     

Breast tumor characteristics of <Emphasis Type="Italic">BRCA1</Emphasis> and <Emphasis Type="Italic">BRCA2</Emphasis> gene mutation carriers on MRI

The appearance of malignant lesions in BRCA1 and BRCA2 mutation carriers (BRCA-MCs) on mammography and magnetic resonance imaging (MRI) was evaluated. Thus, 29 BRCA-MCs with breast cancer were retrospectively evaluated and the results compared with an age, tumor size and tumor type matched control group of 29 sporadic breast cancer cases. Detection rates on both modalities were evaluated. Tumors were analyzed on morphology, density (mammography), enhancement pattern and kinetics (MRI). Overall detection was significantly better with MRI than with mammography (55/58 vs 44/57, P = 0.021). On mammography, lesions in the BRCA-MC group were significantly more described as rounded (12//19 vs 3/13, P = 0.036) and with sharp margins (9/19 vs 1/13, P = 0.024). On MRI lesions in the BRCA-MC group were significantly more described as rounded (16/27 vs 7/28, P = 0.010), with sharp margins (20/27 vs 7/28, P < 0.001) and with rim enhancement (7/27 vs 1/28, P = 0.025). No significant difference was found for enhancement kinetics (P = 0.667). Malignant lesions in BRCA-MC frequently have morphological characteristics commonly seen in benign lesions, like a rounded shape or sharp margins. This applies for both mammography and MRI. However the possibility of MRI to evaluate the enhancement pattern and kinetics enables the detection of characteristics suggestive for a malignancy.     

Fulminant endogenous <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis> endophthalmitis: imaging findings

Endogenous endophthalmitis is a rare but serious complication of Klebsiella pneumoniae infection that has been predominantly reported to occur in diabetic patients of East Asian origin with K. pneumoniae liver abscesses. The clinical symptoms and signs of endogenous endophthalmitis are nonspecific and may mimic other causes of an acute non-traumatic eye. Permanent visual loss and blindness are common sequelae because of delayed diagnosis and treatment. Computed tomography and magnetic resonance imaging can help to differentiate endophthalmitis from other causes of acute non-traumatic eye when the clinical findings are equivocal. Fluid attenuated inversion recovery and diffusion-weighted imaging with apparent diffusion coefficient map are superior to T2-weighted and gadolinium-enhanced T1-weighted sequences in demonstrating intra-ocular abscesses.     

CT imaging of acute <Emphasis Type="Italic">E. Coli</Emphasis>-related colitis

Patients with abdominal pain and bloody diarrhea often present in the acute setting to the emergency department for evaluation. After the appropriate clinical assessment, cross-sectional imaging is often utilized to evaluate for the severity of the disease. Although a wide spectrum of findings may be seen, diffuse colonic mural thickening, consistent with pancolitis, is most common. We report an Escherichia coli 0157:H7-related pancolitis in a patient with spinach intake linked to the recent outbreak.     

<Emphasis Type="Italic">Muscina prolapsa</Emphasis> (Harris 1780)

Background

Reference data for the growth of forensically important insects mainly focus on blowflies, which essentially ignores the relevance of other insect taxa. In the present study the biology and ecology of Muscina prolapsa (Diptera: Muscidae), the larvae of which are often found on buried bodies, were analyzed under constant and varying temperature conditions in the field as well as in the laboratory.

Objective

The seasonal activity patterns and the temperature dependent development of the forensically relevant true fly M. prolapsa were analyzed to provide the basis for case relevant calculations of the post-mortem interval.

Material and methods

Using baited traps the flying activity of M. prolapsa was studied over a period of 2 years. Rat cadavers were buried (approximately 10 cm deep). Samples were taken at 2-week intervals up to 42 days and the degree of larval infestation was determined. The development was studied in the laboratory at constant temperatures at 17?℃, 20?℃ and 25?℃ as well as under varying field conditions.

Results

M. prolapsa was on the wing from March to November. All buried carcasses were heavily infested by its larvae. With increasing temperature an accelerated development was observed. Pupation occurred between 8 and 12.6 days, hatching occurred 16.7 days after oviposition but lasted up to 30 days at the lowest temperature. For the overall period of development, the lower temperature threshold was 6.7?℃.

Conclusion

The genus Muscina represents the dominant insect fauna on scantily buried cadavers and shows flying activity for most of the year. The development is temperature dependent and is, therefore, useful for calculate the post-mortem interval.

     

Population differences of two coding SNPs in pigmentation-related genes <Emphasis Type="Italic">SLC24A5</Emphasis> and <Emphasis Type="Italic">SLC45A2</Emphasis>

The two genes SLC24A5 and SLC45A2 were recently identified as major determinants of pigmentation in humans and in other vertebrates. The allele p.A111T in the former gene and the allele p.L374F in the latter gene are both nearly fixed in light-skinned Europeans, and can therefore be considered ancestry informative marker (AIMs). AIMs are becoming useful for forensic identification of the phenotype from a DNA profile sampled, for example, from a crime scene. Here, we generate new allelic data for these two genes from samples of Chinese, Uygurs, Ghanaians, South African Xhosa, South African Europeans, and Sri Lankans (Tamils and Sinhalese). Our data confirm the earlier results and furthermore demonstrate that the SLC45A2 allele is a more specific AIM than the SLC24A5 allele because the former clearly distinguishes the Sri Lankans from the Europeans.     

The anterior glenohumeral joint capsule: macroscopic and MRI anatomy of the <Emphasis Type="Italic">fasciculus obliquus</Emphasis> or so-called <Emphasis Type="Italic">ligamentum glenohumerale spirale</Emphasis>

The purpose of this study was to demonstrate the macroscopic and MRI anatomy of the fasciculus obliquus, otherwise known as the ligamentum glenohumerale spirale or spiral GHL of the anterior shoulder joint capsule. Conventional and MR arthrography (1.5-T device Somatom Symphony, Siemens with shoulder coil) images in standard planes were compared with gross anatomic dissection findings in six fresh shoulder specimens from three cadavers. The MR imaging protocol included T1, PD and DESS 3D WI sequences. The macroscopically recognisable band—the spiral GHL—was identified by anatomic dissection and MRI in all the specimens. It was best visualised by MR arthrography on axial and oblique sagittal planes (T1; PD WI) and appeared as a low signal intensity stripe within the superficial layer of the anterior joint capsule. The absence of the variable middle glenohumeral ligament did not influence the anatomic properties and the MR imaging of the spiral GHL. Diagnostic visualisation of the normal anatomic structures is a prerequisite to distinguish between normal and pathologic conditions. Anatomy of the spiral GHL can be used by radiologists for more detailed interpretation of the anterior shoulder joint capsule ligaments on MR images.     

<Emphasis Type="Italic">Candida albicans</Emphasis> osteomyelitis of the cervical spine

Fungal osteomyelitis is a rare infection that usually develops in immunocompromised patients. Additionally, involvement of the cervical spine by Candida albicans is extremely rare; only three previous cases of Candida vertebral osteomyelitis have been reported in the literature. The diagnosis may be delayed due to nonspecific radiologic findings and a slow progression. We report the CT, MRI, bone scan, and PET-CT findings in a patient who developed Candida osteomyelitis, which was initially misdiagnosed as metastasis, at the atlas and axis following treatment for nasopharyngeal cancer.     

Quantitative <Emphasis Type="Italic">T</Emphasis><Subscript>1</Subscript> and <Emphasis Type="Italic">T</Emphasis><Subscript>2</Subscript>* carotid atherosclerotic plaque imaging using a three-dimensional multi-echo phase-sensitive inversion recovery sequence: a feasibility study

Magnetic resonance imaging (MRI) is widely used to detect carotid atherosclerotic plaques. Although it is important to evaluate vulnerable carotid plaques containing lipids and intra-plaque hemorrhages (IPHs) using T₁-weighted images, the image contrast changes depending on the imaging settings. Moreover, to distinguish between a thrombus and a hemorrhage, it is useful to evaluate the iron content of the plaque using both T₁-weighted and T₂*-weighted images. Therefore, a quantitative evaluation of carotid atherosclerotic plaques using T₁ and T₂* values may be necessary for the accurate evaluation of plaque components. The purpose of this study was to determine whether the multi-echo phase-sensitive inversion recovery (mPSIR) sequence can improve T₁ contrast while simultaneously providing accurate T₁ and T₂* values of an IPH. T₁ and T₂* values measured using mPSIR were compared to values from conventional methods in phantom and in vivo studies. In the phantom study, the T₁ and T₂* values estimated using mPSIR were linearly correlated with those of conventional methods. In the in vivo study, mPSIR demonstrated higher T₁ contrast between the IPH phantom and sternocleidomastoid muscle than the conventional method. Moreover, the T₁ and T₂* values of the blood vessel wall and sternocleidomastoid muscle estimated using mPSIR were correlated with values measured by conventional methods and with values reported previously. The mPSIR sequence improved T₁ contrast while simultaneously providing accurate T₁ and T₂* values of the neck region. Although further study is required to evaluate the clinical utility, mPSIR may improve carotid atherosclerotic plaque detection and provide detailed information about plaque components.     

Organizing pneumonia associated with <Emphasis Type="Italic">Mycoplasma pneumoniae</Emphasis> infection

Mycoplasma pneumoniae infection is known to produce infiltrative and/or nodular opacities that are often localized. A patient presented to us with diffuse centrilobular, peribronchovascular, and perilobular opacities after documented Mycoplasma pneumoniae infection. A surgical biopsy proved the lung disease to be organizing pneumonia, which dramatically resolved in response to treatment with corticosteroid. This case represents an unusual radiological manifestation associated with M. pneumoniae infection, thereby stressing the importance of this disease in the differential diagnosis for patients with diffuse opacities of the lungs.     

Indication,surgical technique and results of endoscopic <Emphasis Type="Italic">fascial</Emphasis> release in plantar fasciitis (E<Emphasis Type="Italic">F</Emphasis>RPF)

The purpose of the present study is to present the surgical technique for, and review our indications and results after, endoscopic fascial release in patients with plantar fasciitis. In five thiel-embalmed human specimens, a biportal technique for endoscopic release of the plantar fascia was established. The aim was here to evaluate the relation between the plantar fascia and the heel spur and to perform a release that would not exceed 50–70% of the diameter of the calcaneoplantar fascia. The endoscopic technique was performed within the last 5 years in ten male and seven female patients. All patients with the clinical entity of plantar fasciitis underwent conservative treatment for at least 6 months. The average age at surgery was 35 years (24–56 years). In the first five patients, surgery was performed under c-arm control. In all patients the operation could be finished endoscopically. The endoscopic portals healed without complications. The time for surgery during the learning curve ranged between 21 and 74 min (average 41 min) and was still longer compared to the open technique. The clinical follow-up ranged between 4 and 48 months (average 18.5 months). Out of 17 patients, 13 improved clinically, and they would choose the treatment option again. In the Ogilvie-Harris score, seven patients showed good and six excellent results. In two patients, the initial results were not satisfactory, because of a bony stress reaction of the calcaneus. This complication was treated by 6 weeks of partial weight bearing, without any further problems. Two other patients developed secondary pain in the lateral column. In spite of the minimal invasive approach it seems to be important to be careful in increasing the weight bearing in early rehabilitation. The technique of the endoscopic plantar fascia release (EFRPF) can be performed in a standardised and reproducible procedure. The follow-up examination showed good midterm results, but a loss of stability of the plantar arch has to be strictly avoided.     

The blowfly <Emphasis Type="Italic">Chrysomya albiceps</Emphasis> (Wiedemann) (Diptera: <Emphasis Type="Italic">Calliphoridae</Emphasis>) as a new forensic indicator in Central Europe

During the summer months of the year 2001, six forensic cases (one is reported in the present paper), a pig carrion study in the city of Vienna (latitude 48 degrees 12'N, longitude 16 degrees 22'E) and several liver-baited traps north of Vienna, yielded large numbers of maggots of the blowfly Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae). Apart from some records from France, reports of C. albiceps from the palearctic region north of the Alps (i.e. north of a latitude of 48 degrees N) have been scarce. Our findings provided an opportunity to derive developmental schedules for C. albiceps at five different constant temperatures (15, 20, 25, 30, 35 degrees C). The minimal duration of development from oviposition to adult was inversely related to temperature, ranging from 8.3 +/- 0.5 days at 35 degrees C to 19.2 +/- 0.92 days at 20 degrees C. Although eggs hatched after 1.9 +/- 0.16 days at 15 degrees C, larvae did not complete development and frequently died during the first instar stage. We also found a high mortality rate (up to 99%) of native L. sericata larvae caused by predation of C. albiceps larvae under laboratory conditions, indicating a high susceptibility of L. sericata to attack by C. albiceps. Apart from this, the current and possible future distribution of C. albicepsin Europe is discussed. The northward expansion of its range beyond southern Europe obviously decreases the value of C. albiceps in estimating the site of death, in that it is no longer exclusive to southern European regions. Moreover, the aggressive feeding behaviour of second and third instar larve of C. albiceps could reset the post-mortem insect clock by clearing a corpse of all earlier arrivers.     

<Emphasis Type="Italic">Salmonella</Emphasis>-Mediated Cancer Therapy: Roles and Potential

The use of bacteria for cancer therapy, which was proposed many years ago, was not recognized as a potential therapeutic strategy until recently. Technological advances and updated knowledge have enabled the genetic engineering of bacteria for their safe and effective application in the treatment of cancer. The efficacy of radiotherapy depends mainly on tissue oxygen levels, and low oxygen concentrations in necrotic and hypoxic regions are a common cause of treatment failure. In addition, the distribution of a drug is important for the therapeutic effect of chemotherapy, and the poor vasculature in tumors impairs drug delivery, limiting the efficacy of a drug, especially in necrotic and hypoxic regions. Bacteria-mediated cancer therapy (BMCT) relies on facultative anaerobes that can survive in well or poorly oxygenated regions, and it therefore improves the therapeutic efficacy drug distribution throughout the tumor mass. Since the mid-1990s, the number of published bacterial therapy papers has increased rapidly, with a doubling time of 2.5 years in which the use of Salmonella increased significantly. BMCT is being reevaluated to overcome some of the drawbacks of conventional therapies. This review focuses on Salmonella-mediated cancer therapy as the most widely used type of BMCT.2.     

Influence of Gd-EOB-DTPA on <Emphasis Type="Italic">T</Emphasis>1 dependence of the proton density fat fraction using magnetic resonance spectroscopy

This phantom study assessed the effect of Gd-EOB-DTPA on T1 bias (difference in T1 between water and fat) of the proton density fat fraction when using magnetic resonance spectroscopy. Phantoms containing varying fat percentages, without and with Gd-EOB-DTPA (precontrast and postcontrast, respectively), were scanned with repetition times ranging from 1000 to 5000 ms. The relationship between the proton density fat fraction at a reference repetition time of 5000 ms and that using different repetition times, was evaluated in the precontrast and postcontrast phantoms using linear regression and Bland–Altman analyses. In the precontrast phantom, as the repetition time increased, the slope tended to approach one. In the postcontrast phantom, the slope and intercept were near one and zero, respectively. The mean difference was smaller in the postcontrast phantom (range ??0.24 to ??0.01%) than in the precontrast phantom (range 0.12 to 3.52%). We conclude that I1 bias is minimized by Gd-EOB-DTPA.     

Incremental diagnostic value of targeted biopsy using mpMRI-TRUS fusion <Emphasis Type="Italic">versus</Emphasis> 14-fragments prostatic biopsy: a prospective controlled study

Objectives

To compare the incremental diagnostic value of targeted biopsy using real-time multiparametric magnetic resonance imaging and transrectal ultrasound (mpMRI-TRUS) fusion to conventional 14-cores biopsy.

Patients and Methods

Uni-institutional, institutional review board (IRB) approved prospective blinded study comparing TRUS-guided random and targeted biopsy using mpMRI-TRUS fusion, in 100 consecutive men. We included men with clinical-laboratorial suspicious for prostate cancer and Likert score ≥ 3 mp-MRI. Patients previously diagnosed with prostate cancer were excluded. All patients were submitted to 14-cores TRUS-guided biopsy (mpMRI data operator-blinded), followed by targeted biopsy using mpMRI-TRUS fusion.

Results

There was an overall increase in cancer detection rate, from 56% with random technique to 62% combining targeted biopsy using mpMRI-TRUS fusion; incremental diagnosis was even more relevant for clinically significant lesions (Gleason ≥ 7), diagnosing 10% more clinically significant lesions with fusion biopsy technique. Diagnosis upgrade occurred in 5 patients that would have negative results in random biopsies and had clinically significant tumours with the combined technique, and in 5 patients who had the diagnosis of significant tumours after fusion biopsy and clinically insignificant tumours in random biopsies(p=0.0010).

Conclusions

Targeted biopsy using mpMRI-TRUS fusion has incremental diagnostic value in comparison to conventional random biopsy, better detecting clinically significant prostate cancers.

Key Points

? mpMRI-TRUS targeted biopsy increases overall cancer detection rate, but not statistically significant.? mpMRI-TRUS targeted biopsy actually improves the diagnosis of clinically significant PCa.? There was no evidence to acquire the mpMRI-TRUS fusion cores alone.