Dominik Weishaupt

Combined Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy Imaging in the Diagnosis of Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXTnMagnetic resonance imaging (MRI) combined with magnetic resonance spectroscopy imaging (MRSI) emerged as a promising test in the diagnosis of prostate cancer and showed encouraging results.nnnOBJECTIVEnThe aim of this systematic review is to meta-analyse the diagnostic accuracy of combined MRI/MRSI in prostate cancer and to explore risk profiles with highest benefit.nnnEVIDENCE ACQUISITIONnThe authors searched the MEDLINE and EMBASE databases and the Cochrane Library, and the authors screened reference lists and contacted experts. There were no language restrictions. The last search was performed in August 2008.nnnEVIDENCE SYNTHESISnWe identified 31 test-accuracy studies (1765 patients); 16 studies (17 populations) with a total of 581 patients were suitable for meta-analysis. Nine combined MRI/MRSI studies (10 populations) examining men with pathologically confirmed prostate cancer (297 patients; 1518 specimens) had a pooled sensitivity and specificity on prostate subpart level of 68% (95% CI, 56-78%) and 85% (95% CI, 78-90%), respectively. Compared with patients at high risk for clinically relevant cancer (six studies), sensitivity was lower in low-risk patients (four studies) (58% [46-69%] vs 74% [58-85%]; p>0.05) but higher for specificity (91% [86-94%] vs 78% [70-84%]; p<0.01). Seven studies examining patients with suspected prostate cancer at combined MRI/MRSI (284 patients) had an overall pooled sensitivity and specificity on patients level of 82% (59-94%) and 88% (80-95%). In the low-risk group (five studies) these values were 75% (39-93%) and 91% (77-97%), respectively.nnnCONCLUSIONSnA limited number of small studies suggest that MRI combined with MRSI could be a rule-in test for low-risk patients. This finding needs further confirmation in larger studies and cost-effectiveness needs to be established.

Primary anterior shoulder dislocation and rotator cuff tears

In a prospective controlled study 167 patients with 167 primary traumatic anterior shoulder dislocations underwent early ultrasonograpic evaluation for rotator cuff tears. We found 53 (31.7%) full-thickness cuff tears in this group. Compared with a group of 93 healthy volunteers, we found with statistical significance more cuff tears in the patients aged < 60 years. Women ruptured the cuff more often than men. If the patient is not able to elevate the affected arm more than 90 degrees in the scapular plane 2 weeks after the dislocation, there should be a high suspicion of rotator cuff tear (76.7%). For early detection of relevant rotator cuff lesions, we recommend shoulder ultrasonographic examination and measurement of active elevation after each traumatic shoulder dislocation in the above mentioned age group.

Diagnostic accuracy of whole-body MRI/DWI image fusion for detection of malignant tumours: a comparison with PET/CT.

ObjectiveTo prospectively evaluate the diagnostic accuracy of whole-body T2-weighted (wbT2), whole-body diffusion-weighted imaging (wbDWI) and wbT2/wbDWI image fusion for malignant tumour detection compared with PET/CT.MethodsSixty-eight patients (44 men; 60u2009±u200914xa0years) underwent PET/CT for staging of malignancy and were consecutively examined by 1.5-Tesla MRI including wbT2 and wbDWI. Two radiologists independently assessed wbDWI, wbT2, wbT2 + wbDWI (side-by-side) and wbT2 + wbDWI + wbT2/wbDWI image fusion for the presence of malignancy. PET/CT served as a reference standard.ResultsPET/CT revealed 374 malignant lesions in 48/64 (75%) patients. Detection rates and positive predictive value (PPV) of wbT2 and wbDWI alone were 64% and 84%, and 57% and 93%, respectively. Detection rates and PPV of wbT2 and wbDWI for side-by-side analysis without and with fused images were 72% and 89%, and 74% and 91%, respectively. The detection rate was significantly higher with side-by-side analysis and fused image analysis compared with wbT2 and wbDWI alone (pu2009=u2009.0159; pu2009<u2009.0001). There was no significant difference between fused image interpretation and side-by-side analysis.ConclusionsWbDWI allows detection of malignant lesions with a similar detection rate to wbT2. Side-by-side analysis of wbT2 and wbDWI significantly improves the overall detection rate and fused image data provides no added value.

Accuracy and confidence of Gd-EOB-DTPA enhanced MRI and diffusion-weighted imaging alone and in combination for the diagnosis of liver metastases

PURPOSEnTo evaluate the accuracy and confidence in diagnosing liver metastases using combined gadolinium-EOB-DTPA (Gd-EOB-DTPA) enhanced magnetic resonance imaging (MRI)/diffusion-weighted imaging (DWI) in comparison to Gd-EOB-DTPA enhanced MRI and DWI alone.nnnMATERIALS AND METHODSnForty-three patients (age, 58 ± 13 years) with 89 liver lesions (28 benign, 61 malignant) underwent liver MRI for suspected liver metastases. Three image sets (DWI, Gd-EOB-DTPA and combined Gd-EOB-DTPA/DWI) in combination with unenhanced T1- and T2-weighted images were reviewed by three readers. Detection rates of focal liver lesions were assessed and diagnostic accuracy was evaluated by calculating the areas under the receiver-operating-characteristics curve (AUC). Confidence in diagnosis was evaluated on a 3-point scale. Histopathology and imaging follow-up served as the standard of reference.nnnRESULTSnDetection of liver lesions and confidence in final diagnosis for all readers were significantly higher for the combined Gd-EOB-DTPA/DWI dataset than for DWI. The combination of DWI and Gd-EOB-DTPA rendered a significantly higher confidence in final diagnosis (2.44 vs. 2.50) than Gd-EOB-DTPA alone for one reader. For two readers, accuracy in diagnosis of liver metastases was significantly higher for Gd-EOB-DTPA/DWI (AUCs of 0.84 and 0.83) than for DWI datasets (AUCs of 0.73 and 0.72). Adding DWI to Gd-EOB-DTPA did not significantly increase diagnostic accuracy as compared to Gd-EOB-DTPA imaging alone.nnnCONCLUSIONnAddition of DWI sequences to Gd-EOB-DTPA enhanced MRI did not significantly increase diagnostic accuracy as compared to Gd-EOB-DTPA enhanced MRI alone in the diagnosis of liver metastases. However, the increase in diagnostic confidence might justify acquisition of DWI sequences in a dedicated MRI protocol.

Dynamic pelvic floor imaging: MRI techniques and imaging parameters.

Magnetic resonance imaging (MRI) is an excellent tool to understand the complex anatomy of the pelvic floor and to assess pelvic floor disorders. MRI enables static and dynamic imaging of the pelvic floor. Using static T2-weighted sequences the morphology of the pelvic floor can be visualized in great detail. A rapid half-Fourier T2-weighted, balanced steady state free precession, or gradient-recalled echo sequence are used to obtain sagittal images while the patient is at rest, during pelvic squeeze, during pelvic strain and to document the evacuation process. On these images the radiologist identifies the pubococcygeal line (PCL) (which represents the level of the pelvic floor). In normal findings, the base of the anterior and the middle compartment are above the PCL at rest, and the pelvic floor elevates during contraction. During straining the pelvic floor muscles should relax and the pelvic floor descends normally less than 3xa0cm below the PCL. Pelvic floor MRI based on the static and dynamic MRI sequences allows for the detection and characterization of a vast array of morphologic and functional pelvic floor disorders. In this review, we focus on technical aspects of static and dynamic pelvic floor MRI.

MR imaging-guided percutaneous sclerotherapy of peripheral venous malformations with a clinical 1.5-T unit: a pilot study.

PURPOSEnTo evaluate the feasibility of magnetic resonance (MR) imaging-guided percutaneous sclerotherapy of venous malformations (VMs) by using a clinical 1.5-T MR unit and the safety and therapeutic outcome of the performed procedures.nnnMATERIALS AND METHODSnThis is a prospective pilot study with ethical approval and written informed patient consent. Ten MR imaging-guided percutaneous sclerotherapy treatments were performed in 10 patients (one male and nine female patients; age range, 16-47 years; mean age, 30.3 years) with a VM in the foot and/or ankle (n = 5), calf (n = 2), thigh and/or knee (n = 2), and elbow (n = 1). MR imaging was used for needle insertion guidance and real-time monitoring of the injection process by using three-dimensional fast spoiled gradient-echo MR sequences (repetition time msec/echo time msec = 3.7-5.2/1.1-1.6, flip angle = 35 degrees) and meglumine gadoterate/ethanol solutions as the sclerosing agent. The technical success (ie, absence of technical problems, number of needle position corrections) was systematically evaluated along with safety aspects (ie, absence of complications) and the therapeutic outcome (eg, VM volume decrease, relief of symptoms) during a 1-year follow-up period.nnnRESULTSnMR imaging-guided sclerotherapy was technically successful in all patients. A mean of 2.5 +/- 1.85 (range, 1-6) needle position corrections were needed for correct needle placement. The distribution of the sclerosing agent (mean amount, 10.5 mL; range, 0.8-33.0 mL) was clearly visible with real-time MR monitoring. One patient developed a compartment syndrome, which was managed with surgery. No other complications were observed. VM volumes significantly decreased by 53% (range, 24%-86%; P = .02) 12 weeks after therapy. Nine of the 10 patients (90%) noted an improvement of symptoms.nnnCONCLUSIONSnIn this limited preliminary series, 1.5-T MR imaging-guided percutaneous sclerotherapy for the treatment of VMs was feasible with a high degree of technical success, was relatively safe, and had a good therapeutic outcome after 1 year.

Accuracy of multidetector-row CT for restaging after neoadjuvant treatment in patients with oesophageal cancer

ObjectivesTo assess the diagnostic accuracy of 64-multidetector CT (MDCT) for restaging of patients with oesophageal cancer undergoing neoadjuvant therapy.MethodsResults of pathological staging were correlated with those from 64-MDCT before and after neoadjuvant treatment in 35 patients using the American Joint Committee on Cancer/TNM classification (7th edition). CT response was determined using the Response Evaluation Criteria in Solid Tumours (RECIST) method, modified for one-dimensional tumour diameter measurement.Results64-MDCT predicted T stage correctly in 34xa0% (12/35), overstaged in 49xa0% (17/35) and understaged in 17xa0% (6/35). Sensitivity/specificity values were as follows: T0, 20xa0%/92xa0%; T1–T2, 31xa0%/59xa0%; T3, 60xa0%/64xa0%; T4, 100xa0%/4xa0%. Negative predictive values for T3/T4 were 80xa0%/100xa0%. MDCT accurately predicted complete histopathological response in 20xa0% (accuracy 74xa0%) and overstaged in 80xa0%. Tumour regression grade was predicted correctly in only 8xa0% (2/25) and underestimated in 68xa0% (17/25). Accurate N stage was noted in 69xa0% (24/35).ConclusionAlthough MDCT tends to be able to exclude advanced tumour stages (T3, T4) with a higher likelihood, the diagnostic accuracy of high resolution MDCT for restaging oesophageal cancer and assessing the response to neoadjuvant therapy has not improved in comparison to older-generation CT. Therefore, the future assessment of oesophageal tumour response should focus on combined morphologic and metabolic imaging.Key Points• Multidetector CT (MDCT) has been beneficial for the evaluation of many tumours.• However diagnostic accuracy for restaging oesophageal cancer has not improved with MDCT.• MDCT tends to be able to exclude advanced tumour stages (T3/T4).• MDCT has a low accuracy for determining lymph node metastasis.• Oesophageal tumour response should be assessed by combined morphological and metabolic imaging.

Magnetic resonance imaging of pelvic floor dysfunction - joint recommendations of the ESUR and ESGAR Pelvic Floor Working Group

ObjectiveTo develop recommendations that can be used as guidance for standardized approach regarding indications, patient preparation, sequences acquisition, interpretation and reporting of magnetic resonance imaging (MRI) for diagnosis and grading of pelvic floor dysfunction (PFD).MethodsThe technique included critical literature between 1993 and 2013 and expert consensus about MRI protocols by the pelvic floor-imaging working group of the European Society of Urogenital Radiology (ESUR) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) from one Egyptian and seven European institutions. Data collection and analysis were achieved in 5 consecutive steps. Eighty-two items were scored to be eligible for further analysis and scaling. Agreement of at least 80xa0% was defined as consensus finding.ResultsConsensus was reached for 88xa0% of 82 items. Recommended reporting template should include two main sections for measurements and grading. The pubococcygeal line (PCL) is recommended as the reference line to measure pelvic organ prolapse. The recommended grading scheme is the “Rule of three” for Pelvic Organ Prolapse (POP), while a rectocele and ARJ descent each has its specific grading system.ConclusionThis literature review and expert consensus recommendations can be used as guidance for MR imaging and reporting of PFD.Key points• These recommendations highlight the most important prerequisites to obtain a diagnostic PFD-MRI.• Static, dynamic and evacuation sequences should be generally performed for PFD evaluation.• The recommendations were constructed through consensus among 13 radiologists from 8 institutions.

Molecular Imaging of Malignant Tumor Metabolism: Whole-Body Image Fusion of DWI/CT vs. PET/CT

PURPOSEnTo prospectively investigate the technical feasibility and performance of image fusion for whole-body diffusion-weighted imaging (wbDWI) and computed tomography (CT) to detect metastases using hybrid positron emission tomography/computed tomography (PET/CT) as reference standard.nnnMATERIAL AND METHODSnFifty-two patients (60 ± 14 years; 18 women) with different malignant tumor disease examined by PET/CT for clinical reasons consented to undergo additional wbDWI at 1.5 Tesla. WbDWI was performed using a diffusion-weighted single-shot echo-planar imaging during free breathing. Images at b = 0 s/mm(2) and b = 700 s/mm(2) were acquired and apparent diffusion coefficient (ADC) maps were generated. Image fusion of wbDWI and CT (from PET/CT scan) was performed yielding for wbDWI/CT fused image data. One radiologist rated the success of image fusion and diagnostic image quality. The presence or absence of metastases on wbDWI/CT fused images was evaluated together with the separate wbDWI and CT images by two different, independent radiologists blinded to results from PET/CT. Detection rate and positive predictive values for diagnosing metastases was calculated. PET/CT examinations were used as reference standard.nnnRESULTSnPET/CT identified 305 malignant lesions in 39 of 52 (75%) patients. WbDWI/CT image fusion was technically successful and yielded diagnostic image quality in 73% and 92% of patients, respectively. Interobserver agreement for the evaluation of wbDWI/CT images was κ = 0.78. WbDWI/CT identified 270 metastases in 43 of 52 (83%) patients. Overall detection rate and positive predictive value of wbDWI/CT was 89% (95% CI, 0.85-0.92) and 94% (95% CI, 0.92-0.97), respectively.nnnCONCLUSIONnWbDWI/CT image fusion is technically feasible in a clinical setting and allows the diagnostic assessment of metastatic tumor disease detecting nine of 10 lesions as compared with PET/CT.

How accurate is unenhanced multidetector-row CT (MDCT) for localization of renal calculi?

PURPOSEnTo investigate the correlation between unenhanced MDCT and intraoperative findings with regard to the exact anatomical location of renal calculi.nnnDESIGN, SETTING, AND PARTICIPANTSnFifty-nine patients who underwent unenhanced MDCT for suspected urinary stone disease, and who underwent subsequent flexible ureterorenoscopy (URS) as treatment of nephrolithiasis were included in this retrospective study. All MDCT data sets were independently reviewed by three observers with different degrees of experience in reading CT. Each observer was asked to indicate presence and exact anatomical location of any calcification within pyelocaliceal system, renal papilla or renal cortex. Results were compared to intraoperative findings which have been defined as standard of reference. Calculi not described at surgery, but present on MDCT data were counted as renal cortex calcifications.nnnRESULTSnOverall 166 calculi in 59 kidneys have been detected on MDCT, 100 (60.2%) were located in the pyelocaliceal system and 66 (39.8%) in the renal parenchyma. Of the 100 pyelocaliceal calculi, 84 (84%) were correctly located on CT data sets by observer 1, 62 (62%) by observer 2, and 71 (71%) by observer 3. Sensitivity/specificity was 90-94% and 50-100% if only pyelocaliceal calculi measuring >4 mm in size were considered. For pyelocaliceal calculi≤4 mm in size diagnostic performance of MDCT was inferior.nnnCONCLUSIONnCompared to flexible URS, unenhanced MDCT is accurate for distinction between pyelocaliceal calculi and renal parenchyma calcifications if renal calculi are >4 mm in size. For smaller renal calculi, unenhanced MDCT is less accurate and distinction between a pyelocaliceal calculus and renal parenchyma calcification is difficult.