Automated Intervertebral Disc Detection from Low Resolution, Sparse MRI Images for the Planning of Scan Geometries

Robust and accurate identification of intervertebral discs from low resolution, sparse MRI scans is essential for the automated scan planning of the MRI spine scan. This paper presents a graphical model based solution for the detection of both the positions and orientations of intervertebral discs from low resolution, sparse MRI scans. Compared with the existing graphical model based methods, the proposed method does not need a training process using training data and it also has the capability to automatically determine the number of vertebrae visible in the image. Experiments on 25 low resolution, sparse spine MRI data sets verified its performance.

MRI of hip osteoarthritis and implications for surgery

Osteoarthritis of the hip joint is caused by a combination of intrinsic factors and extrinsic factors. Different surgical techniques are being performed to delay or halt osteoarthritis. Success of salvage procedures of the hip depends on the existing cartilage and joint damage before surgery; the likelihood of therapy failure rises with advanced osteoarthritis. For imaging of intra-articular hip pathology, MR imaging represents the best technique because of its ability to directly visualize cartilage, superior soft tissue contrast, and the prospect of multidimensional imaging. This article gives an overview on the standard MR imaging techniques used for diagnosis of hip osteoarthritis and their implications for surgery.

MRI morphometry, cartilage damage and impaired function in the follow-up after slipped capital femoral epiphysis

To assess rotation deficits, asphericity of the femoral head and localisation of cartilage damage in the follow-up after slipped capital femoral epiphysis (SCFE).

T2 and T2* mapping in patients after matrix-associated autologous chondrocyte transplantation: initial results on clinical use with 3.0-Tesla MRI

To use T2 and T2* mapping in patients after matrix-associated autologous chondrocyte transplantation (MACT) of the knee, and to compare and correlate both methodologies.

Delayed gadolinium-enhanced MRI of cartilage in the ankle at 3 T: feasibility and preliminary results after matrix-associated autologous chondrocyte implantation

To demonstrate the feasibility of delayed gadolinium-enhanced magnetic resonance imaging (MRI) of cartilage (dGEMRIC) in the ankle at 3 T and to obtain preliminary data on matrix associated autologous chondrocyte (MACI) repair tissue.

Diagnostic performance and accuracy of 3-D spoiled gradient-dual-echo MRI with water- and fat-signal separation in liver-fat quantification: comparison to liver biopsy

To prospectively evaluate a 3-dimensional spoiled gradient-dual-echo (3D SPGR-DE) magnetic resonance imaging (MRI) sequence for the qualitative and quantitative analysis of liver fat content (LFC) in patients with the suspicion of fatty liver disease using histopathology as the standard of reference.

Can MRI of the neck compete with clinical findings in assessing danger to life for survivors of manual strangulation? A statistical analysis

The aim of the study was to examine the clinical forensic findings of strangulation according to their ability to differentiate between life-threatening and non-life-threatening strangulation, compare clinical and MRI findings of the neck and discuss a simple score for life-threatening strangulation (SLS).

DW-MRI of the urogenital tract: applications in oncology

Diffusion-weighted magnetic resonance imaging (DW-MRI) appears to hold promise as a non-invasive imaging modality in the detection of early microstructural and functional changes of different organs. DW-MRI is an imaging technique with a high sensitivity for the detection of a large variety of diseases in the urogenital tract. In kidneys, DW-MRI has shown promise for the characterization of solid lesions. Also in focal T1 hyperintense lesions DW-MRI was able to differentiate hemorrhagic cysts from tumours according to the lower apparent diffusion coefficient (ADC) values reported for renal cell carcinomas. Promising results were also published for the detection of prostate cancer. DW-MRI applied in addition to conventional T2-weighted imaging has been found to improve tumour detection. On a 3 T magnetic resonance unit ADC values were reported to be lower for tumours compared with the normal-appearing peripheral zone. The combined approach of T2-weighted imaging and DW-MRI also showed promising results for the detection of recurrent tumour in patients after radiation therapy. DW-MRI may improve the performance of conventional T2-weighted and contrast-enhanced MRI in the preoperative work-up of bladder cancer, as it may help in distinguishing superficial from muscle invasive bladder cancer, which is critical for patient management. Another challenging application of DW-MRI in the urogenital tract is the detection of pelvic lymph node metastases. As the ADC is generally reduced in malignant tumours and increased under inflammatory conditions, reduced ADC values were expected in patients with lymph node metastases.

Diffusion-weighted MRI in head and neck radiology: applications in oncology

Extracranial application of diffusion-weighted magnetic resonance imaging (MRI) has gained increasing importance in recent years. As a result of technical advances, this new non-invasive functional technique has also been applied in head and neck radiology for several clinical indications. In cancer imaging, diffusion-weighted MRI can be performed for tumour detection and characterization, monitoring of treatment response as well as the differentiation of recurrence and post-therapeutic changes after radiotherapy. Even for lymph node staging promising results have been reported recently. This review article provides overview of potential applications of diffusion-weighted MRI in head and neck with the main focus on its applications in oncology.

Feasibility of small bowel flow rate measurement with MRI

To evaluate whether it is feasible to measure the segmental flux of small bowel content using MR phase-contrast (PC) pulse sequences.

MRI-based breast volumetry-evaluation of three different software solutions

As lipofilling of the female breast is becoming more popular in plastic surgery, the use of MRI to assess breast volume has been employed to control postoperative results. Therefore, we sought to evaluate the accuracy of magnetic resonance imaging (MRI)-based breast volumetry software tools by comparing the measurements of silicone implant augmented breasts with the actual implant volume specified by the manufacturer. MRI-based volume analysis was performed in eight bilaterally augmented patients (46 ± 9 years) with three different software programs (Brainlab© I plan 2.6 neuronavigation software; mass analysis, version 5.3, Medis©; and OsiriX© v.3.0.2. 32-bit). The implant volumes analysed by the BrainLab© software had a mean deviation of 2.2 ± 1.7% (r?=?0.99) relative to the implanted prosthesis. OsiriX© software analysis resulted in a mean deviation of 2.8 ± 3.0% (r?=?0.99) and the Medis© software had a mean deviation of 3.1 ± 3.0% (r?=?0.99). Overall, the volumes of all analysed breast implants correlated very well with the real implant volumes. Processing time was 10 min per breast with each system and 30 s (OsiriX©) to 5 min (BrainLab© and Medis©) per silicone implant. MRI-based volumetry is a powerful tool to calculate both native breast and silicone implant volume in situ. All software solutions performed well and the measurements were close to the actual implant sizes. The use of MRI breast volumetry may be helpful in: (1) planning reconstructive and aesthetic surgery of asymmetric breasts, (2) calculating implant size in patients with missing documentation of a previously implanted device and (3) assessing post-operative results objectively.

[Cost analysis of contrast-enhanced cranial MRI at a German university hospital]

Detailed evaluation and cost analysis of a cranial contrast-enhanced MRI (c-ceMRI) in outpatients, inpatients, patients in an intensive care unit and children under anesthesia.

Arterial spin-labeling MRI perfusion in tuberous sclerosis: correlation with PET

Neuroimaging using magnetic resonance imaging (MRI) is required for the investigation of surgically intractable epilepsy. In addition to the standard MRI techniques, perfusion sequences can be added to improve visualization of the underlying pathological changes. Also, as arterial spin-labeling (ASL) MRI perfusion does not require contrast administration, it may even be advantageous in these patients. We report here on three patients with epilepsy and tuberous sclerosis who underwent brain MRI with ASL and positron emission tomography (PET), both of which were found to correlate with each other and with electrophysiological data.

Combined use of pulsed arterial spin-labeling and susceptibility-weighted imaging in stroke at 3T

Background and Purpose: In acute stroke it is no longer sufficient to detect simply ischemia, but also to try to evaluate reperfusion/recanalization status and predict eventual hemorrhagic transformation. Arterial spin labeling (ASL) perfusion may have advantages over contrast-enhanced perfusion-weighted imaging (cePWI), and susceptibility weighted imaging (SWI) has an intrinsic sensitivity to paramagnetic effects in addition to its ability to detect small areas of bleeding and hemorrhage. We want to determine here if their combined use in acute stroke and stroke follow-up at 3T could bring new insight into the diagnosis and prognosis of stroke leading to eventual improved patient management. Methods: We prospectively examined 41 patients admitted for acute stroke (NIHSS >1). Early imaging was performed between 1 h and 2 weeks. The imaging protocol included ASL, cePWI, SWI, T2 and diffusion tensor imaging (DTI), in addition to standard stroke protocol. Results: We saw four kinds of imaging patterns based on ASL and SWI: patients with either hypoperfusion and hyperperfusion on ASL with or without changes on SWI. Hyperperfusion was observed on ASL in 12/41 cases, with hyperperfusion status that was not evident on conventional cePWI images. Signs of hemorrhage or blood-brain barrier breakdown were visible on SWI in 15/41 cases, not always resulting in poor outcome (2/15 were scored mRS = 0–6). Early SWI changes, together with hypoperfusion, were associated with the occurrence of hemorrhage. Hyperperfusion on ASL, even when associated with hemorrhage detected on SWI, resulted in good outcome. Hyperperfusion predicted a better outcome than hypoperfusion (p = 0.0148). Conclusions: ASL is able to detect acute-stage hyperperfusion corresponding to luxury perfusion previously reported by PET studies. The presence of hyperperfusion on ASL-type perfusion seems indicative of reperfusion/collateral flow that is protective of hemorrhagic transformation and a marker of favorable tissue outcome. The combination of hypoperfusion and changes on SWI seems on the other hand to predict hemorrhage and/or poor outcome.