A Retrospective Application of the Arbon and Hartman Models to the Union Cycliste International Mountain Bike World Cup

INTRODUCTION

Outdoor activities have accelerated in the past several years. The authors were tasked with providing medical care for the Union Cycliste International (UCI) mountain biking World Cup in Snowshoe, West Virginia (USA) in September 2021. The Hartman and Arbon models were designed to predict patient presentation and hospital transport rates as well as needed medical resources at urban mass-gathering events. However, there is a lack of standardized methods to predict injury, illness, and insult severity at rural mass gatherings.

STUDY OBJECTIVE

This study aimed to determine whether the Arbon model would predict, within 10%, the number of patient presentations to be expected and to determine if the event classification provided by the Hartman model would adequately predict resources needed during the event.

METHODS

Race data were collected from UCI event officials and injury data were collected from participants at time of presentation for medical care. Predicted presentation and transport rates were calculated using the Arbon model, which was then compared to the actual observed presentation rates. Furthermore, the event classification provided by the Hartman model was compared to the resources utilized during the event.

RESULTS

During the event, 34 patients presented for medical care and eight patients required some level of transport to a medical facility. The Arbon predictive model for the 2021 event yielded 30.3 expected patient presentations. There were 34 total patient presentations during the 2021 race, approximately 11% more than predicted. The Hartman model yielded a score of four. Based on this score, this race would be classified as an "intermediate" event, requiring multiple Advanced Life Support (ALS) and Basic Life Support (BLS) personnel and transport units.

CONCLUSION

The Arbon model provided a predicted patient presentation rate within reasonable error to allow for effective pre-event planning and resource allocation with only a four patient presentation difference from the actual data. While the Arbon model under-predicted patient presentations, the Hartman model under-estimated resources needed due to the high-risk nature of downhill cycling. The events staffed required physician skills and air medical services to safely care for patients. Further evaluation of rural events will be needed to determine if there is a generalized need for physician presence at smaller events with inherently risky activities, or if this recurring cycling event is an outlier.

Stay and play or load and go? The association of on-scene advanced life support interventions with return of spontaneous circulation following traumatic cardiac arrest

INTRODUCTION

Traumatic out-of-hospital cardiac arrest (tOHCA) has a mortality rate over 95%. Many current protocols dictate rapid intra-arrest transport of these patients. We hypothesized that on-scene advanced life support (ALS) would increase the odds of arriving at the emergency department with ROSC (ROSC at ED) in comparison to performance of no ALS or ALS en route.

METHODS

We utilized the 2018-2021 ESO Research Collaborative public use datasets for this study, which contain patient care records from ~2000 EMS agencies across the US. All OHCA patients with an etiology of "trauma" or "exsanguination" were screened (n=15,691). The time of advanced airway management, vascular access, and chest decompression was determined for each patient. Logistic regression modeling was used to evaluate the association of ALS intervention timing with ROSC at ED.

RESULTS

4942 patients met inclusion criteria. 14.6% of patients had ROSC at ED. In comparison to no vascular access, on-scene (aOR: 2.14 [1.31, 3.49]) but not en route vascular access was associated with increased odds of having ROSC at ED arrival. In comparison to no chest decompression, neither en route nor on-scene chest decompression were associated with ROSC at ED arrival. Similarly, in comparison to no advanced airway management, neither en route nor on-scene advanced airway management were associated with ROSC at ED arrival. The odds of ROSC at ED decreased by 3% (aOR: 0.97 [0.94, 0.99]) for every 1-minute increase in time to vascular access and decreased by 5% (aOR: 0.95 [0.94, 0.99]) for every 1-minute increase in time to epinephrine.

CONCLUSION

On-scene ALS interventions were associated with increased ROSC at ED in our study. These data suggest that initiating ALS prior to rapid transport to definitive care in the setting of tOHCA may increase the number of patients with a palpable pulse at ED arrival.

The Association of Combined Prehospital Hypotension and Hypoxia with Outcomes following Out-of-Hospital Cardiac Arrest Resuscitation

BACKGROUND

Prehospital post-resuscitation hypotension and hypoxia have been associated with adverse outcomes in the context of out-of-hospital cardiac arrest (OHCA). We aimed to investigate the association between clinical outcomes and post-resuscitation hypoxia alone, hypotension alone, and combined hypoxia and hypotension.

METHODS

We used the 2018-2021 ESO annual datasets to conduct this study. All EMS-treated non-traumatic OHCA patients who had a documented prehospital return of spontaneous circulation (ROSC) and two or more SpO2 readings and systolic blood pressures recorded were evaluated for inclusion. Patients who were less than 18 years of age, pregnant, had a do-not-resuscitate order or similar, achieved ROSC after bystander CPR only, or had an EMS-witnessed cardiac arrest were excluded. Multivariable logistic regression adjusted for standard Utstein factors and highest prehospital Glasgow Coma Scale (GCS) score was used to investigate the association between hypoxia, hypotension, and outcomes.

RESULTS

We analyzed data for 17,943 patients, of whom 3,979 had hospital disposition data. Hypotension and hypoxia were not documented in 1,343 (33.8%) patients, 1,144 (28.8%) had only hypoxia documented, 507 (12.7%) had only hypotension documented, and 985 (24.8%) had both hypoxia and hypotension documented. In comparison to patients who did not have documented hypotension or hypoxia, patients who had documented hypoxia (aOR: 1.76 [1.38, 2.24]), documented hypotension (aOR: 3.00 [2.15, 4.18]), and documented hypoxia and hypotension combined (aOR: 4.87 [3.63, 6.53]) had significantly increased mortality. The relationship between mortality and vital sign abnormalities (hypoxia and hypotension > hypotension > hypoxia) was observed in every evaluated subgroup.

CONCLUSIONS

In this large dataset, hypotension and hypoxia were independently associated with mortality both alone and in combination. Compared to patients without documented hypotension and hypoxia, patients with documented hypotension and hypoxia had nearly five-fold greater odds of mortality.

A retrospective comparison of the King Laryngeal Tube and iGel supraglottic airway devices: a study for the CARES surveillance group

OBJECTIVE

Supraglottic airway devices are increasingly used during the resuscitation of out-of-hospital cardiac arrest (OHCA) patients in the United States and worldwide. In this study, we aimed to compare the neurologic outcomes of OHCA patients managed with the King Laryngeal Tube (King LT) to the neurologic outcomes of patients managed with the iGel.

METHODS

We used the Cardiac Arrest Registry to Enhance Survival (CARES) public use research dataset for our analysis. Non-traumatic OHCA cases with attempted EMS resuscitation enrolled from 2013-2021 were included. We used two-level mixed effects multivariable logistic regression analyses with treating EMS agency as the random effect to determine the association between supraglottic airway device and outcome. The primary outcome was survival with a Cerebral Performance Category (CPC) score of 1 or 2 at discharge. Secondary outcomes included survival to hospital admission and survival to hospital discharge. Age, sex, calendar year of OHCA, initial ECG rhythm, witnessed status (unwitnessed, bystander witnessed, 9-1-1 responder witnessed), bystander CPR, response interval, and OHCA location (private/home, public, institutional) were used as covariables.

RESULTS

In comparison to use of the King LT, use of the iGel was associated with greater neurologically favorable survival (aOR: 1.45 [1.33, 1.58]). In addition, use of the iGel was associated with greater survival to hospital admission (1.07 [1.02, 1.12]) and survival to hospital discharge (1.35 [1.26, 1.46]).

CONCLUSIONS

This study adds to the body of literature suggesting that use of the iGel during OHCA resuscitation is associated with better outcomes than use of the King LT.

A Retrospective Nationwide Comparison of the iGel and King Laryngeal Tube Supraglottic Airways for Out-of-Hospital Cardiac Arrest Resuscitation

INTRODUCTION

While various supraglottic airway devices are available for use during out-of-hospital cardiac arrest (OHCA) resuscitation, comparisons of patient outcomes by device are limited. In this study, we aimed to compare outcomes of OHCA patients who had airway management by emergency medical services (EMS) with the iGel or King-LT.

METHODS

We used the 2018-2021 ESO Data Collaborative public use research datasets for this retrospective study. All patients with non-traumatic OHCA who had iGels or King-LTs inserted by EMS were included. Our primary outcome was survival to discharge to home, and secondary outcomes included first-pass success, return of spontaneous circulation (ROSC), and prehospital rearrest. We examined the association between airway device and each outcome using two-level mixed effects logistic regression with EMS agency as the random effect, adjusted for standard Utstein variables and failed intubation prior to supraglottic airway insertion. Average treatment effects were calculated through propensity score matching.

RESULTS

A total of 286,192 OHCA patients were screened, resulting in 93,866 patients eligible for inclusion in this analysis. A total of 9,456 transported patients (59.8% iGel) had associated hospital disposition data. Use of the iGel was associated with greater survival to discharge to home (aOR:1.36 [1.06, 1.76]; ATE: 2.2%[+0.5, +3.8]; n = 7,576), first pass airway success (aOR:1.94 [1.79, 2.09]; n = 73,658), and ROSC (aOR:1.19 [1.13, 1.26]; n = 73,207) in comparison to airway management with the King-LT. iGel use was associated with lower odds of experiencing a rearrest (aOR:0.73 [0.67, 0.79]; n = 20,776). Among patients who received a supraglottic device as a primary airway, use of the iGel was not associated with significantly greater survival to discharge to home (aOR:1.26 [0.95, 1.68]). Among patients who received a supraglottic device as a rescue airway following failed intubation, use of the iGel was associated with greater odds of survival to discharge to home (aOR:2.16 [1.15, 4.04]).

CONCLUSION

In this dataset, use of the iGel during adult OHCA resuscitation was associated overall with better outcomes compared to use of the King-LT. Subgroup analyses suggested that use of the iGel was associated with greater odds of achieving the primary outcome than the King-LT when used as a rescue device but not when used as the primary airway management device.

Mechanisms of intracellular calcium homeostasis in developing and mature bovine corpora lutea

Although calcium (Ca(2+)) is accepted as an intracellular mediator of prostaglandin F2 alpha (PGF2alpha) actions on luteal cells, studies defining mechanisms of Ca(2+) homeostasis in bovine corpora lutea (CL) are lacking. The increase in intracellular Ca(2+) concentration ([Ca(2+)]i) induced by PGF2alpha in steroidogenic cells from mature CL is greater than in those isolated from developing CL. Our hypothesis is that differences in signal transduction associated with developing and mature CL contribute to the increased efficacy of PGF2alpha to induce a Ca(2+) signal capable of inducing regression in mature CL. To test this hypothesis, major genes participating in Ca(2+) homeostasis in the bovine CL were identified, and expression of mRNA, protein, or activity, in the case of phospholipase Cbeta (PLCbeta), in developing and mature bovine CL was compared. In addition, we examined the contribution of external and internal Ca(2+) to the PGF2alpha stimulated rise in [Ca(2+)]i in LLCs isolated from developing and mature bovine CL. Three differences were identified in mechanisms of calcium homeostasis between developing and mature CL, which could account for the lesser increase in [Ca(2+)]i in response to PGF2alpha in developing than in mature CL. First, there were lower concentrations of inositol 1,4,5-trisphosphate (IP3) after similar PGF2alpha challenge, indicating reduced phospholipase C beta (PLCbeta) activity, in developing than mature CL. Second, there was an increased expression of sorcin (SRI) in developing than in mature CL. This cytoplasmic Ca(2+) binding protein modulates the endoplasmic reticulum (ER) Ca(2+) release channel, ryanodine receptor (RyR), to be in the closed configuration. Third, there was greater expression of ATP2A2 or SERCA, which causes calcium reuptake into the ER, in developing than in mature CL. Developmental differences in expression detected in whole CL were confirmed by Western blots using protein samples from steroidogenic cells isolated from developing and mature CL. Localization of these genes in steroidogenic luteal cells was confirmed by immunohistochemistry. Therefore, it is concluded that the cellular mechanisms that allow PGF2alpha to induce a calcium signal of greater magnitude in mature than in developing CL involve 1) greater PLCbeta activity with enhanced generation of IP3, 2) an enhanced Ca(2+) release from the ER via unrestrained RYR2 due to a decrease in SRI expression, and 3) a reduction in calcium reuptake to the ER due to lower expression of ATP2A2. Accordingly, the increase in [Ca(2+)]i induced by PGF2alpha in mature large steroidogenic cells had less dependency from extracellular calcium than in those isolated from immature CL.

Diagnosis of prostate cancer in patients with persistently elevated PSA and tumor-negative biopsy in ambulatory care: performance of MR imaging in a multi-reader environment

PURPOSE

False-negative results are obtained in approx. 20 % of prostate cancer (PCa) patients (pts) at initial systematic transrectal biopsy (Bx), in particular when digital rectal examination (DRE) or transrectal ultrasound (TRUS) is negative. The aim of this study was to assess whether MR endorectal imaging of the prostate in a multi-reader ambulatory care setting may assist in patient selection for re-biopsy.

MATERIALS AND METHODS

115 consecutive pts with persistent PSA elevation, negative Bx, DRE and TRUS were examined using T2w axial and coronal and T1w axial sequences for tumor diagnosis. MR images were prospectively read as tumor-suspicious or tumor-negative by the MR radiologist on duty. Additionally, a retrospective readout of a prostate MR expert and an abdominal imaging fellowship-trained radiologist was performed to evaluate the effect of the reader's experience on tumor detection. Imaging findings were compared to the results of the repeat Bx (61 pts) or the clinical course of at least two years.

RESULTS

For the prospective reading, the sensitivity of MRI was 83 %, the specificity was 69 %, the PPV was 33 % and the NPV was 96 %. ROC analysis revealed a significantly better performance of the prostate MR imaging expert compared to the abdominal imaging radiologist (area under ROC 0.88 vs. 0.66, p < 0.001). Based on the prospective reading, a pre-test probability for PCa of 17.4 % as in our study can be reduced to 5 % when obtaining a tumor-negative result in MRI.

CONCLUSION

MR imaging in a multi-reader ambulatory care setting assists in patient selection for re-biopsy. Reducing the post-test probability for PCa to 5 % allows for further follow-up instead of re-biopsy in MR tumor-negative patients. Specific training and experience improve tumor detection in prostate MR imaging.

[Herniation pits and their renaissance in association with femoroacetabular impingement]

Hernitation pits (HPs) of the femoral neck were first described in 1982. The purpose of this paper is to summarize the information concerning HPs published since then and to show their association with the diagnosis of femoroacetabular impingement (FAI) which has occurred within the last years. HPs are predominantly located at the anterior-superior femoral neck with a typical radiological appearance, which makes it possible to differentiate them from the numerous differential diagnoses mentioned. In the early publications HPs were described as a separate entity, while recent studies increasingly assign them to intra-osseous ganglia. In contrast to the early publications depicting HPs as an incidental finding, they are currently mainly mentioned in association with FAI and at the same time are partly considered to be a radiological indicator of FAI. In summary, HPs should always be recognized and documented because they may contribute to the diagnosis of FAI which is essential for preventing or delaying osteoarthritis of the hip joint in the early stage.

Combined MRI and MRS in prostate cancer: improvement of spectral quality by susceptibility matching

PURPOSE

Local magnetic field inhomogeneity caused by susceptibility artifacts due to air in the endorectal coil substantially degrades the quality of 3D MR spectroscopic imaging (3D-MRSI). Perflubron (PFB) has magnetic susceptibility similar to that of human tissue. We prospectively assessed the effect of susceptibility matching using PFB on in vivo prostate (1)H-3D-MRSI.

MATERIALS AND METHODS

Ninety-one consecutive patients referred for 3D-MRSI were examined using air and PFB as the filling agent for endorectal coils at 1.5T with an identically placed PRESS box and sat bands. Solely auto-shim without additional manual shimming was used. The full width at half maximum (FWHM) of the water peak was statistically compared with a paired t-test. The spectral quality was visually evaluated for the definition of metabolite peaks and for the citrate peak split (duplet). The MR image quality was rated on a five-point scale.

RESULTS

FWHM was significantly less (p < 0.001) using PFB (mean 9.0 +/- 3.3, range 3 - 20) than air (mean 14.9 +/- 4.2, range 6 - 26) in 85/91 patients (93%). The spectral quality markedly improved using PFB and frequently the duplet of the citrate peak was able to be identified. Image quality ratings were similar (mean rating PFB 4.2, air 4.3 points). Omitting manual shimming led to a time savings of 4 min. per study.

CONCLUSION

3D-MRSI using PFB for susceptibility matching benefits from significantly better local field homogeneity, thus providing improved spectra quality. Combined with a substantial time savings in data acquisition, this may increase the clinical utilization of 3D-MRSI in patients with prostate cancer.

Meniskus- und Bandläsionen

The knee is one of the major weight-bearing joints and is relatively exposed to trauma. Capsuloligamentous structures are essential to provide joint stability and -- in turn -- persistent instability bears a risk for osteoarthritis that needs timely and comprehensive diagnosis. Using MRI it may be beneficial to routinely apply (T)SE sequences in all three major planes as a basic protocol and to add additional sequences according to the clinical information available and imaging findings in the basic protocol. Especially fat-suppressed sequences (STIR, T2w/PDw FS TSE) are very useful because they sensitively depict bone marrow edema pattern (BMEP)-like changes. This finding often alerts the reader to -- sometimes only discrete -- underlying pathologies and may -- if found in typical locations -- give information about the mechanism of injury and thus lead the radiologist to look for specific concomitant capsuloligamentous, cartilage, and/or meniscal injury. BMEP is quite prominent in contusion injury, whereas often it is but discrete in avulsion lesions. There is extensive literature about the signs, possible pitfalls, and the accuracy of MRI for the diagnosis of specific pathologies such as meniscal tears or cruciate or collateral ligament ruptures. However, combined injuries of more than one structure are frequent and affect the therapeutic approach. Thus, the primary goal of the radiologist is to go beyond the description of any isolated lesion and to give a comprehensive description of (or to reliably exclude) any injury to other structures. A necessary prerequisite to accomplish this is a thorough knowledge of the -- in some locations -- complex anatomic relationships, pitfalls, and locations where lesions typically occur and where they may be overlooked.

Staging of rectal cancer: diagnostic potential of multiplanar reconstructions with MDCT

OBJECTIVE

The purpose of this study was to evaluate whether multiplanar reconstructions (MPRs) of MDCT could improve local staging of rectal cancer.

CONCLUSION

Adding MPRs, on the basis of the MDCT data sets, provides definite improvements in the accurate local staging of rectal cancer compared with standard axial reconstructions alone.

[MR imaging of prostate cancer]

PURPOSE

Accurate diagnosis and staging of prostate cancer (PC) is developing into an important health care issue in light of the high incidence of PC and the improvements in stage-adapted therapy. The purpose of this paper is to provide an overview on the current role of MR imaging and MR spectroscopy in the diagnosis and staging of PC.

MATERIAL AND METHODS

Pertinent literature was searched and evaluated to collect information on current clinical indications, study techniques, diagnostic value, and limitations of magnetic resonance imaging and spectroscopy.

RESULTS

Major indications for MR imaging of patients with suspected PC are to define tumor location before biopsy when clinical or TRUS findings are inconclusive, and to provide accurate staging of histologically proven PC to ascertain effective therapy. Current MR imaging techniques for the evaluation of PC include multiplanar high-resolution T2-weighted FSE and T1-weighted SE sequences using combined endorectal and phased-array coils. Using these techniques, the reported accuracy of MR imaging for the diagnosis of extracapsular tumor extension ranges between 82 and 88% with sensitivities between 80 and 95%, and specificities between 82 and 93%. Typical MR findings of PC in different stages of disease, as well as diagnostic problems, such as chronic prostatitis, biopsy-related hemorrhage and therapy-related changes of prostatic tissue are discussed. In addition, the current perspectives and limitations of MR spectroscopy in PC are summarized.

CONCLUSIONS

Current MR imaging techniques provide important diagnostic information in the pretherapeutic workup of PC including a high staging accuracy, and is superior to TRUS.

Moving-table MR angiography of the peripheral runoff vessels: comparison of body coil and dedicated phased array coil systems

OBJECTIVE

The aim of our study was to compare the signal-to-noise ratio and the diagnostic accuracy of moving-table MR angiography of the peripheral arteries with body coil and dedicated phased array coil systems.

SUBJECTS AND METHODS

Forty patients were examined with digital subtraction angiography and moving-table MR angiography with a 1.5-T MR imaging system either with a body coil (n = 20) or with a dedicated phased array coil (n = 20). The timing of contrast material was performed with real-time MR fluoroscopy.

RESULTS

For the iliac artery, upper leg, and lower leg, the mean values for signal-to-noise ratios were 56, 51, and 17, respectively, for the body coil, and 54, 74, and 64, respectively, for the dedicated phased array coil. For the body coil, sensitivity and specificity in identifying stenosis greater than 50% and occlusions were 100% and 96%, respectively, for the iliac arteries, and 100% and 96%, respectively, for the upper leg. For the dedicated phased array coil, sensitivity and specificity for stenosis greater than 50% and occlusions were 100% and 96%, respectively, for the iliac arteries, and 100% and 98%, respectively, for the upper leg. Sensitivity and specificity were inferior for the body coil (88% and 85%) compared with the dedicated phased array coil (100% and 96%) in the lower leg. A significant difference of the mean values of contrast-to-noise ratio was found before and after subtraction for the dedicated phased array coil and body-coil techniques (Student's t test, p < 0.01).

CONCLUSION

In comparison with the body coil, the dedicated peripheral phased array surface coil system improves signal-to-noise ratio for the upper and lower leg and diagnostic accuracy in the lower leg.

Clinical evaluation of further-developed MRCP sequences in comparison with standard MRCP sequences

The purpose of this study was the comparison of technically improved single-shot magnetic resonance cholangiopancreatography (MRCP) sequences with standard single-shot rapid acquisition with relaxation enhancement (RARE) and half-Fourier acquired single-shot turbo spin-echo (HASTE) sequences in evaluating the normal and abnormal biliary duct system. The bile duct system of 45 patients was prospectively investigated on a 1.5-T MRI system. The investigation was performed with RARE and HASTE MR cholangiography sequences with standard and high spatial resolutions, and with a delayed-echo half-Fourier RARE (HASTE) sequence. Findings of the improved MRCP sequences were compared with the standard MRCP sequences. The level of confidence in assessing the diagnosis was divided into five groups. The Wilcoxon signed-rank test at a level of p<0.05 was applied. In 15 patients no pathology was found. The MRCP showed stenoses of the bile duct system in 10 patients and choledocholithiasis and cholecystolithiasis in 16 patients. In 12 patients a dilatation of the bile duct system was found. Comparison of the low- and high spatial resolution sequences and the short and long TE times of the half-Fourier RARE (HASTE) sequence revealed no statistically significant differences regarding accuracy of the examination. The diagnostic confidence level in assessing normal or pathological findings for the high-resolution RARE and half-Fourier RARE (HASTE) was significantly better than for the standard sequences. For the delayed-echo half-Fourier RARE (HASTE) sequence no statistically significant difference was seen. The high-resolution RARE and half-Fourier RARE (HASTE) sequences had a higher confidence level, but there was no significant difference in diagnosis in terms of detection and assessment of pathological changes in the biliary duct system compared with standard sequences.

Contrast-enhanced MR angiography in patients after kidney transplantation

The aim of this study was to investigate the value of a contrast-enhanced 3D MR angiography in detecting postoperative vascular complications after kidney transplantation in comparison with digital subtraction angiography (DSA). Forty-one patients who underwent a kidney transplantation were examined with MR angiography and DSA. Contrast-enhanced MR angiography was performed as a dynamic measurement with one precontrast and three postcontrast measurements. Maximum intensity projection reconstructions were performed for all postcontrast data sets after DSA. The results were evaluated by two independent observers who were unaware of the DSA results. Twenty-three hemodynamically significant arterial stenoses were identified with DSA in the iliac arteries ( n=7), the renal allograft arteries ( n=12), and in their first branches ( n=4). For a patient-based analysis the sensitivity and specificity, respectively, for observer 1 were 100 and 97%, and for observer 2, 100 and 93%. Respective data were 100 and 100% after a consensus evaluation by two observers. Complications involving the renal veins were detected in 2 cases and perfusion defects of the kidney parenchyma were detected in 4 cases. Contrast-enhanced MR angiography is a reliable method in identifying postoperative arterial stenoses after kidney transplantation. In addition, dynamic MR angiography can be helpful in detecting venous complications and perfusion defects in kidney allografts.

Shared patient analysis: a method to assess the clinical benefits of patient referrals

BACKGROUND

Referral to specialized physicians or institutions often is deemed necessary in clinical medicine, but no method exists to assess the clinical benefit of such referrals.

OBJECTIVES

To describe a method, which is shared patient analysis, to measure the expected improvement in clinical management associated with referrals and to apply that method in the field of abdominal and pelvic oncological radiology.

SUBJECTS

All patients referred, during a 4-year period, to surgical oncologists at four academic centers (the referral providers, or RPs) with radiographs performed before referral at a community site (the initial providers, or IPs). Patients (n = 396) for whom both the IP interpretation and a final diagnosis was available were eligible. All IP and RP readings were placed in random order and presented to surgical oncologists, who then recommended a treatment course.

MEASUREMENTS

Diagnostic accuracy of the IP and RP readings and the proportion of patients who were assigned to an appropriate treatment by the oncologist were determined.

RESULTS

When the indication for imaging was primary diagnosis or staging, the kappa for presence of cancer was 0.70. When the indication was cancer follow-up, the kappa for presence of recurrent/progressing cancer was 0.66. There were disagreements between the IP and RP radiologists over the interpretation of 162 films, with the RP radiologists being correct in 153 (94%). Had the patients been treated using IP readings, there would have been 19 more inappropriate surgeries and 19 more admissions (both P <0.05) than if the oncologists had based their recommendations on RP readings.

CONCLUSIONS

The technique of shared patient analysis permits assessment of the clinical benefits associated with referrals.

Localized prostate cancer: effect of hormone deprivation therapy measured by using combined three-dimensional 1H MR spectroscopy and MR imaging: clinicopathologic case-controlled study

PURPOSE

To determine the accuracy of combined magnetic resonance (MR) imaging and three-dimensional (3D) proton MR spectroscopic imaging in localizing prostate cancer to a sextant of the gland in patients receiving hormone deprivation therapy.

MATERIALS AND METHODS

Combined MR imaging/3D MR spectroscopic imaging examinations were performed in 16 hormone-treated patients and 48 nontreated matched control patients before radical prostatectomy and step-section histopathologic analysis. At MR imaging, cancer presence within the peripheral zone was assessed on a per sextant basis by two readers. At 3D MR spectroscopic imaging, cancer was identified by using (choline plus creatine)-to-citrate ratios at cutoff values of 2 and 3 SDs above mean normal peripheral zone values. Data were compared by using receiver operating characteristic analysis.

RESULTS

There was no significant difference in the ability of combined MR imaging/3D MR spectroscopic imaging to localize prostate cancer in treated versus control patients. For MR imaging alone, the sensitivity and specificity were 91% and 48% (reader 1) and 75% and 60% (reader 2) in treated patients versus 79% and 60% (reader 1) and 84% and 43% (reader 2) in control patients. For 3D MR spectroscopic imaging alone (>3 SDs cutoff), higher specificity (treated, 80%; controls, 73%) but lower sensitivity (treated, 56%; controls, 53%) was attained. In treated patients, high sensitivity or specificity (up to 92%) was achieved when either or both modalities indicated cancer.

CONCLUSION

When performed within 4 months after initiating hormone deprivation therapy, combined MR imaging/3D MR spectroscopic imaging had the same accuracy in localizing prostate cancer as in nontreated patients.

[Paravaginal abscess in pregnancy]

Paravaginal abscess in pregnancy. We report the diagnosis and treatment of an infected Gartner's duct cyst during pregnancy. The patient presented with lower abdominal pain, fever (38.5 degrees C) and an elevated C-reactive Protein level. Pelvic examination revealed a painful paravaginal mass. Sonography was not able to detect the cranial border of the tumor. Magnetic resonance imaging (MRI) revealed fluid accumulation laterodorsal to the vagina without evidence of a connection with the retroperitoneal space. An infected Gartner's duct cyst with consecutive abscess formation along the mesonephric duct system, was diagnosed. Following transvaginal drainage, the remainder of the pregnancy was uneventful and the patient was delivered vaginally at 40 + 5 weeks without complications. - The rare clinical finding of a paravaginal abscess in pregnancy was treated without termination of the pregnancy. Preoperative planning of the surgical approach using MRI can be easier for pelvic processes extending out of the pelvis than using ultrasound and is less painful for the patient.

[Diagnostic value of different rectal contrast media in the detection of colorectal diseases by multi-slice CT]

PURPOSE

Assessment of 3 different rectal contrast agents (water, methylcellulose, ultrasound gel) for their suitability for colorectal imaging in multislice CT (MS-CT).

METHODS

115 patients with colorectal diseases underwent MS-CT with varying, rectal contrast agents in a prospective study. Images were assessed by 2 independent CT-experienced radiologists. 6 criterias were evaluated, using a 5-point scale.

RESULTS

Methylcellulose (MC) proved to be significantly superior to ultrasound gel (US). Especially, differentiation of healthy and diseased bowel and bowel wall and lumen were aided, which was proven by quantitative analysis of attenuation values. Rectal distension is greater using MC or US than for water. More proximal parts of the colon could be better distended with water. The interobserver correlation was good (kappa 0.76).

CONCLUSIONS

Rectal filling with MC significantly improves diagnostic confidence in colorectal examinations. Ease of administration and lack of problems suggest its use as a clinical routine tool.

Navigator Echo-Based Respiratory Gating for Three-Dimensional MR Coronary Angiography: Reduction of Scan Time Using a Slice Interpolation Technique

PURPOSE

The aim of the study was to compare a conventional respiratory-gated 3D MR coronary angiographic technique (conventional MRCA) with a respiratory-gated 3D MR coronary angiographic technique that includes a slice interpolation technique (slice interpolation MRCA). Both MRCA techniques were compared based on the quality of visualization of the coronary arteries and the diagnostic accuracy in identifying hemodynamically significant coronary artery stenoses.

METHOD

Forty patients with known proximal coronary artery stenosis after conventional CA were examined on a 1.5 T scanner, that is, 20 patients with each sequence. A 6 point grading system (0 = worst quality, 5 = best quality) was used to evaluate and compare the image quality. The length and proximal diameter of the depicted coronary arteries were measured. Detection of coronary artery stenoses was compared with that obtained by conventional CA by two blinded readers.

RESULTS

With the slice interpolation technique, the average scan time of the entire heart was reduced by approximately 40%. With use of conventional MRCA, 69% of all proximal and middle coronary artery segments were visualized with a sufficient image quality; with the slice interpolation technique, 79% of these segments were depicted adequately. For the assessment of stenoses, sensitivity was 71% and specificity was 53% for conventional MRCA and 72 and 60% for slice interpolation MRCA, respectively. These differences in sensitivity and specificity were statistically not significant.

CONCLUSION

The application of a slice interpolation technique reduces the scan time, maintains a comparable sensitivity and specificity for the assessment of coronary artery stenoses, and increases the number of completely identified coronary artery segments compared with the conventional technique.

Carpal tunnel syndrome: assessment by turbo spin echo, spin echo, and magnetization transfer imaging applied in a low-field MR system

PURPOSE

The purpose of this work was to evaluate patients with carpal tunnel syndrome (CTS) using a low-field extremity MR system (E-MRI: 0.2 T).

METHOD

Twenty-two patients with typical findings of CTS and 30 control persons were imaged on an E-MRI. Axial T2-weighted turbo SE (TSE), T1-weighted SE sequences, and 2D GRE magnetization transfer (MTC) sequences were compared. SE and MTC sequences were obtained before and after contrast agent administration (0.1 mmol/kg body wt of Gd-DTPA). Two readers evaluated typical MR findings of CTS independently.

RESULTS

Patients with CTS demonstrated palmar bowing of the flexor retinaculum significantly more often. The normal or edematous median nerve was best identified on TSE and MTC scans (kappa = 0.59 and 0.8). The MTC sequences showed perineural enhancement significantly better than respective T1-weighted SE sequences but were rated second in comparison with T2-weighted TSE scans.

CONCLUSION

At low-field strength, median nerve edema is best depicted on T2-weighted TSE sequences, whereas MTC sequences are most sensitive to perineural contrast enhancement.

[MR angiography of the supraaortic vessels]

PURPOSE

To compare high resolution contrast-enhanced MR angiography (MRA) and digital subtraction angiography (DSA) in the assessment of supraaortic vessel stenosis.

METHODS

14 patients with suspicion of cerebrovascular disease or upper limb ischemia underwent selective DSA and high resolution contrast enhanced MRA employing a new Panoramic-Array coil. Stenosis assessment in comparison to DSA followed NASCET criteria. Additionally signal-/noise ratios (SNR) were evaluated to assess contrast enhancement.

RESULTS

Diagnostic image quality was achieved in all patients. Sensitivity and specificity for assessing high-grade stenosis of the supraaortic vessels were 100% and 96% respectively. In the assessment of high-grade common or internal carotid artery stenosis sensitivity and specificity was 100%.

CONCLUSION

High resolution contrast enhanced supraaortic MRA combined with new coil systems allow for a reliable assessment of stenoses along the whole vessel course including the aortic arch. Previous stent procedures limit its use in postinterventional follow-up.

MRI of the female and male pelvis: current and future applications of contrast enhancement

Magnetic resonance imaging (MRI) of the pelvis has proven to be a most valuable diagnostic tool to examine pathologies of various organ systems in the pelvis. For most conditions MRI was found to be superior to other imaging modalities, like ultrasound and computed tomography. Controversy still exists on the value of intraluminal and intravenous contrast enhancement. This article gives an overview on currently available intraluminal and intravenous contrast agents. The techniques and results for contrast-enhanced MRI in the female and male pelvis are discussed based on a review of the literature. New developments and upcoming techniques, such as lymph node specific contrast agents and breathhold volumetric MRI, are described and initial results are presented.

Optimization and evaluation of the signal intensity change in multisection oxygen-enhanced MR lung imaging

The behavior of the signal intensity in MRI of human lungs was investigated during inhalation of pure oxygen. Nine volunteers were examined, five using a breath-hold and four using a non-breath-hold technique. Four coronal slices were acquired in each volunteer using an inversion recovery turbo spin-echo sequence. The inversion time of the sequence was optimized for maximum contrast. Breathing of pure oxygen and room air was alternated in the volunteers. Breath-hold and non-breath-hold cases were compared. Breathing pure oxygen lead to a statistically significant signal intensity increase (up to 18%) compared to breathing room air. In addition, T(1) maps were acquired during breathing 100% oxygen and room air. Inhalation of pure oxygen reduced the mean T(1) time of the lungs from 1280 (+/-85) msec to 1224 (+/-139) msec without breath-hold and from 1219 (+/-176) to 1074 (+/-92) msec with breath-hold. Therefore, an optimized sequence and measurement protocol provided significant signal intensity changes utilizing 100% oxygen. Magn Reson Med 43:860-866, 2000.

[Effects of biphasic spiral CT, conventional and iron oxide enhanced MRI on therapy and therapy costs in patients with focal liver lesions]

PURPOSE

Evaluation of the diagnostic efficacy and cost-benefit of contrast enhanced CT (CT) and MRI pre- and post-SPIO-particles in focal hepatic disease with consideration of therapeutic outcome.

METHODS

In 52 patients with the suspicion of primary or secondary hepatic malignancy, biphasic spiral CT and breath-hold gradient-echo T1- and fast spin-echo T2-weighted MRI pre- and post-iron oxide administration (1.5 T, body-phased-array coil) were compared. The number of hepatic lesions and the related diagnoses resulting from each imaging modality were recorded and statistically correlated to the final diagnoses established by biopsy/OP (34/52), long term follow-up of 12 months (18/52), and a consensus reading of all imaging modalities considering all clinical imaging information. The most likely induced therapy resulting from each imaging test was correlated to the final therapy. Based on data from the hospitals accountants, the therapy-related costs were estimated without hospitalization costs.

RESULTS

In 34/52 (65.4%) of the cases the correct diagnosis was primarily stated by CT (sensitivity [se.] 85.2%, specificity [sp.] 44.0%). In additional 10/52 of the cases unenhanced MRI (se. 91.4%, sp. 75.0%) enabled correct diagnoses, and in another 6 cases the diagnosis was established only by SPIO-MRI (se. 100%, sp. 86.7%). Considering the possible therapeutic recommendation arising from each modality, CT would have induced needles therapy costs of 191,042 DM, unenhanced MRI of 171,035 DM, and SPIO-MRI of 7,311 DM. In comparison to the real therapy costs of 221,873 DM, this would have corresponded to an unnecessary increase of therapy costs of 86.1%, 77.1%, and 3.3%, respectively. In two cases (1 hemangioma, 1 regenerative nodule) all modalities failed, causing unnecessary surgery in one patient.

DISCUSSION

In this problem-oriented scenario unenhanced and SPIO-enhanced MRI proved to be superior to CT regarding diagnostic efficacy. The cost-benefit resulted mainly due to preserving patients from unnecessary surgical procedures.

[Myocardial perfusion at rest and during stress. MR signal characteristics of persistent and reversible myocardial ischemia]

AIM

Performance of combined rest/stress MR perfusion studies and the analysis of qualitative signal intensity parameters in comparison with 99mTc-SestaMIBI SPECT in patients with known coronary artery disease (CAD).

METHODS

Sixteen patients with CAD underwent MR myocardial perfusion assessment at rest and after dipyridamole-induced hyperemia. Qualitative parameters (SI increase, SI upslope) of the SI time-curves were evaluated and characteristics of normal, reversible and persistent hypoperfused myocardium as assessed by 99mTc-SestaMIBI SPECT were compared.

RESULTS

Compared with the rest values, normal myocardium showed a significant increase of the SI upslope during hyperemia (P < 0.001), whereas persistent (P = 0.07) and reversible (P = 0.15) hypo-perfusions showed only minor changes. SI increase over baseline also showed a significant increase only in normal myocardium (P < 0.001). At rest, reversible ischemic areas showed no significant differences from normal myocardium, whereas during hyperemia SI increase was significantly lower (P = 0.02).

CONCLUSIONS

Qualitative SI parameters of a combined rest/stress MR myocardial perfusion study allow to differentiate normal from reversibly or persistently hypoperfused myocardium.

Prostate cancer: localization with three-dimensional proton MR spectroscopic imaging--clinicopathologic study

PURPOSE

To assess the efficacy of combined magnetic resonance (MR) imaging and three-dimensional (3D) proton MR spectroscopic imaging in the detection and localization of prostate cancer.

MATERIALS AND METHODS

MR imaging and 3D MR spectroscopic imaging examinations were performed in 53 patients with biopsy-proved prostate cancer and subsequent radical prostatectomy with step-section histopathologic examination. The prostate was divided into sextants. At MR imaging, the presence or absence of cancer in the peripheral zone of each sextant was assessed independently by two readers (readers 1 and 2) unaware of the findings at 3D MR spectroscopic imaging and histopathologic examination. At 3D MR spectroscopic imaging, cancer was diagnosed as possible if the ratio of choline plus creatine to citrate exceeded 2 SD above population norms or as definite if that ratio exceeded 3 SDs above the norm.

RESULTS

On the basis of sextants, sensitivity and specificity, respectively, for MR imaging were 77% and 61% (reader 1) and 81% and 46% (reader 2) with moderate interreader agreement (kappa = 0.43). The 3D MR spectroscopic imaging diagnosis of definite cancer had significantly higher specificity (75%, P < .05) but lower sensitivity (63%, P < .05). Receiver operating characteristic analysis showed significantly (P < .001) improved tumor localization for both readers when 3D MR spectroscopic imaging was added to MR imaging. High specificity (up to 91%) was obtained when combined MR imaging and 3D MR spectroscopic imaging indicated cancer, whereas high sensitivity (up to 95%) was obtained when either test alone indicated a positive result.

CONCLUSION

The addition of 3D MR spectroscopic imaging to MR imaging provides better detection and localization of prostate cancer in a sextant of the prostate than does use of MR imaging alone.

Prostate cancer: prediction of extracapsular extension with endorectal MR imaging and three-dimensional proton MR spectroscopic imaging

PURPOSE

To determine if the addition of three-dimensional (3D) proton magnetic resonance (MR) spectroscopic imaging to endorectal MR imaging helps diagnose extracapsular extension (ECE) of prostate cancer.

MATERIALS AND METHODS

Endorectal MR imaging and 3D MR spectroscopic imaging were performed in 53 patients with prostate cancer before radical prostatectomy. MR imaging studies were evaluated by two independent readers unaware of histopathologic findings. The presence of ECE was graded on a five-point scale. At 3D MR spectroscopic imaging, cancer was diagnosed if the ratio of choline plus creatine to citrate was 2 or more SDs above normal. The accuracy of MR imaging alone was compared with that of combined MR imaging and 3D MR spectroscopic imaging, with use of the step-section histopathologic results as the standard of reference.

RESULTS

For the less experienced reader, the addition of 3D MR spectroscopic imaging to MR imaging significantly improved accuracy (area under the receiver operating characteristic curve [Az] = 0.75 vs Az = 0.62, P < .05). For the more experienced reader, the addition improved accuracy but not significantly (Az = 0.86 vs Az = 0.78). The addition also reduced interobserver variability (Az = 0.86 vs Az = 0.75).

CONCLUSION

The addition of 3D MR spectroscopic imaging to MR imaging improves accuracy for less experienced readers and reduces interobserver variability in the diagnosis of ECE of prostate cancer.

Echo-planar magnetic resonance imaging (EPI) with high-resolution matrix in intra-axial brain tumors

The aim of this study was to assess the potential of high-speed interleaved echo-planar imaging (EPI) to achieve diagnostic image quality comparable to T2-weighted imaging in patients with brain tumors. Seventeen patients with intra-axial, supratentorial tumors (10 untreated gliomas, 7 radiated gliomas) were investigated on a 1. 5-T scanner. The conventional scan (SE, TR/TE = 2200/80 ms, 18 slices) was acquired in 8 min, 4 s, and EPI (TR/TE = 3000/80 ms, 18 slices) was completed in 25 s. The films were compared in a blinded trail by three radiologists. On the general impression and anatomic display, both sequences were rated to be of similar quality. Artifacts were slightly more pronounced at the skull base and around surgical clips using EPI. Tumor delineation was nearly equivalent using EPI, compared with the T2-weighted sequence. Echo-planar imaging reached diagnostic quality in all patients. Interleaved high-resolution EPI yielded sufficient quality to depict intra-axial, supratentorial brain tumors. Since EPI can be obtained in a small fraction of the time needed for conventional spin echo, in addition to other indications it could be considered to study patients unable to cooperate.

[New techniques and pulse sequences in MRI of the liver]

PURPOSE

The MRI techniques which have contributed to increasing utilization of MRI for abdominal imaging are described and recent advances addressed.

METHODS

For breath-hold examinations of the abdomen, two basic techniques are required: array coil technology and fast and ultrafast pulse sequences providing T1 and T2 contrast.

RESULTS

Circular polarized array coils render high signal-to-noise ratios (SNR) within large imaging volumes. With fast gradient-echo sequences the liver can be scanned with or without fat saturation within one breath-hold. When adequate parameters are selected, T2-weighted fast (turbo) spin-echo sequences allow high contrast between normal liver tissue and focal liver lesions, even if breath-hold acquisition is applied. Moreover, good soft tissue contrast can also be achieved with ultrafast single-shot sequences. Based on this sequence type, MRCP with a 512 matrix could be performed. The "TRUE FISP" allows for high resolution visualisation of vessels without contrast media. Three-dimensional T1-weighted sequences allow for scanning the upper abdomen with a slice thickness of 3 mm within one breath-hold. Diffusion-weighted sequences contribute to the characterisation of focal liver lesions.

DISCUSSION

Modern MRI technology including phase-array coils and high-performance gradient systems made it possible to perform all examinations in breath-hold techniques, reducing motion artifacts.

[MRI of plantar fasciitis]

PURPOSE

The purpose of this study was to determine the type and frequency of characteristic bone and soft tissue changes on MRI of patients with a clinical diagnosis of plantar fasciitis.

MATERIALS AND METHODS

28 patients with a clinical diagnosis of plantar fasciitis underwent MR imaging. Besides T1- and T2-weighted sequences, short-tau-inversion-recovery sequences were used routinely. In 27 patients T1-weighted images after intravenous contrast injection were acquired additionally. As a control group the images of 15 patients without clinical signs for plantar fasciitis were evaluated.

RESULTS

In 25 of 28 cases (89%) the clinical diagnosis of plantar fasciitis was established by MR imaging. The most common finding was a peritendinous edema at the calcaneal insertion site which was found in all 25 patients. In 19 of 25 cases (76%) a bone marrow edema of the calcaneus was present. In 14 of 25 cases (56%) an intratendinous signal intensity increase of the plantar fascia could be observed which showed contrast enhancement in 12 cases. Compared to the control group (mean thickness 3.3 mm) the plantar fascia showed significant thickening in the 25 MR positive patients (mean thickness 6.72 mm).

DISCUSSION

Besides thickening of the plantar fascia and intratendinous signal intensity increase with contrast enhancement to some extent, bone marrow edema of the calcaneus and peritendinous edema close to the plantar fascia are characteristic signs of plantar fasciitis on MRI. Both signs can reliably be seen on STIR sequences only.

Endovaginal ultrasound to exclude endometrial cancer and other endometrial abnormalities

CONTEXT

Postmenopausal vaginal bleeding is a common clinical problem. Endovaginal ultrasound (EVUS) is a noninvasive diagnostic test that may help determine which women should undergo endometrial biopsy.

OBJECTIVE

To determine the accuracy of EVUS in detecting endometrial disease in postmenopausal women with vaginal bleeding according to hormone replacement use.

DATA SOURCES

Literature search of English-language and non-English-language articles published from 1966 through November 1996 using MEDLINE and by a manual search of bibliographies of published articles.

STUDY SELECTION

Studies were included if they prospectively collected EVUS measurements of endometrial thickness prior to obtaining endometrial tissue for histologic evaluation in postmenopausal women with vaginal bleeding. Of 85 studies that included data on EVUS and endometrial histology, 35 were included in the meta-analysis and included 5892 women.

DATA EXTRACTION

Articles were reviewed and independently selected and abstracted by 2 reviewers. Disagreement was resolved by consensus.

DATA SYNTHESIS

The overall summary mean weighted estimates of sensitivity and specificity were calculated for thresholds of endometrial thickness from 3 to 10 mm. Using a 5-mm threshold to define abnormal endometrial thickening, 96% (95% confidence interval [CI], 94%-98%) of women with cancer had an abnormal EVUS result, whereas 92% (95% CI, 90%-93%) of women with endometrial disease (cancer, polyp, or atypical hyperplasia) had an abnormal result. This did not vary by hormone replacement use. However, the number of women with normal histology who had an abnormal EVUS result did vary by hormone replacement use. In women who were not using hormone replacement therapy, 593 (8%) with normal histological findings had an abnormal EVUS result (specificity, 92%; 95% CI, 90%-94%), whereas 1544 (23%) using hormone replacement therapy had an abnormal EVUS result (specificity, 77%; 95% CI, 75%-79%). For a postmenopausal woman with vaginal bleeding with a 10% pretest probability of endometrial cancer, her probability of cancer is 1% following a normal EVUS result.

CONCLUSION

Endovaginal ultrasound has a high sensitivity for detecting endometrial cancer and other endometrial disease and can reliably identify postmenopausal women with vaginal bleeding who are highly unlikely to have significant endometrial disease so that endometrial sampling may be unnecessary.

[Virtual colonoscopy using CT and MRI]

PURPOSE

To evaluate experimentally and in patients the sensitivity and effective dose of virtual electron-beam tomography (EBT) colonoscopy for detecting small colon tumors and to compare the methods and results with virtual colonoscopy using spiral CT and MR imaging in a review of the literature.

MATERIALS AND METHODS

Six polyps with diameters between 3 and 12 mm were created and randomly placed in resected pig colon. After distension with air, the pig colon was scanned with continuous volume scanning (CVS, 3 mm collimation) and a pitch of 0.4, 0.8 and 1.5. Twenty patients positive for the fecal blood test were examined after rectal CO2 insufflation and i.v. administration of 1 mg glucagon. A 13 s CVS scan was used to cover the entire colon within one breath-hold. 3D volume-rendered fly-throughs were evaluated by two independent radiologists. Effective dose equivalent was estimated using an Alderson phantom equipped with thermoluminescence dosimeters.

RESULTS

In the tumor model, all polyps were detectable at a pitch of 1.5. A further reduction of the pitch ratio did not improve the conspicuity of the polyps. In patient studies, all tumors (n = 4) and polyps (n = 3) were correctly identified on 3D fly-throughs. Two false positive results were obtained. Effective dose equivalent was calculated at 3.2 mSv per scan.

CONCLUSIONS

Our preliminary results indicate that virtual EBT colonoscopy holds promise for fast screening for colon polyps. The best technique for virtual colonoscopy (Spiral CT, EBT, MRI) has not yet been determined and the future role of virtual colonoscopy must still be defined.

Parametrial invasion in cervical carcinoma: evaluation of detection at MR imaging with fat suppression

PURPOSE

To evaluate detection of parametrial invasion at magnetic resonance (MR) imaging with fat suppression.

MATERIALS AND METHODS

In 35 patients with cancer of the cervix, MR imaging was performed with the following sequences: T2-weighted turbo spin echo (SE), turbo short inversion time inversion recovery (STIR), and unenhanced or gadolinium-enhanced T1-weighted SE with and without excitation-spoiling fat suppression. Images obtained with each sequence were evaluated for parametrial invasion by two blinded radiologists separately, who scored their level of diagnostic confidence from 0 to 10 (no confidence to high confidence). Then, all images were evaluated together and findings were correlated with histopathologic findings.

RESULTS

No statistically significant differences were found between staging with T2-weighted turbo SE, turbo STIR, and T1-weighted fat-suppressed gadolinium-enhanced SE images. Staging with T1-weighted SE, T1-weighted gadolinium-enhanced SE, and T1-weighted fat-suppressed SE images was significantly worse (P < .05). Diagnostic confidence was lower (P < .001) with T1-weighted gadolinium-enhanced SE and T1-weighted fat-suppressed gadolinium-enhanced SE images (5.5 and 6.2 points, respectively) compared to staging with T2-weighted turbo SE and turbo STIR images (8.2 and 7.6 points, respectively). No statistically significant improvement in staging accuracy was found when all images were evaluated together.

CONCLUSION

In MR diagnosis of parametrial invasion, the addition of fat-suppressed or gadolinium-enhanced MR images did not improve the accuracy with T2-weighted turbo SE images alone.

MRI of pelvic masses: efficacy of the rectal superparamagnetic contrast agent Ferumoxsil

The purpose of this study was to determine the potential value of rectally administered Ferumoxsil for pelvic MRI. Twenty patients with suspected rectosigmoid and ovarian tumors were prospectively examined before and after rectal administration of 300 to 600 ml of the superparamagnetic contrast agent Ferumoxsil. Imaging parameters (1.5-T system, phased-array coil, transverse T1-weighted spin echo (SE) and T2-weighted turbo-SE sequences, 6-mm slice thickness, 350-mm field of view [FOV], 512 x 512 matrix) were kept constant. Images were evaluated for tumor presence, lymphadenopathy, bowel involvement, and peritoneal implants. Precontrast and postcontrast studies were rated for bowel delineation, lesion/organ-to-bowel differentiation, presence of artifacts, and confidence of diagnosis. Delineation of rectum and sigmoid colon (P < .001) as well as separation of bowel and vagina, uterus/adnexa, dome of the urinary bladder, lymph nodes, and vessels improved significantly (P < .01) on both T1-weighted and T2-weighted postcontrast sequences. The rectal contrast agent did not increase the level of artifacts. Changes in diagnosis in 7 of 20 patients were mainly due to identification of colorectal tumors or bowel involvement on postcontrast images. The readers' diagnostic confidence was significantly higher on contrast-enhanced than on unenhanced studies (93 +/- 6.4% vs 68 +/- 25.2%). Rectal application of Ferumoxsil improves lesion/organ-to-bowel delineation and overall diagnostic confidence in pelvic MRI.

Radiological evaluation of lymph node metastases in patients with cervical cancer. A meta-analysis

OBJECTIVE

To apply meta-analysis to compare the utility of lymphangiography (LAG), computed tomography (CT), and magnetic resonance (MR) imaging for the diagnosis of lymph node metastasis in patients with cervical cancer.

DATA SOURCES

MEDLINE literature search and manual reviews of article bibliographies.

STUDY SELECTION

Studies selected included at least 20 patients with imaging-histologic correlation, described diagnostic criteria for lymph node metastasis, and presented data to allow calculation of contingency tables.

DATA EXTRACTION

Independently by 2 investigators, stratified for stage of disease (early vs late) and for lymph node location (pelvic vs para-aortic).

DATA SYNTHESIS

Seventeen studies met the inclusion criteria for LAG, 17 for CT, and 10 for MR imaging. Summary receiver operator characteristic analysis showed no significant differences in the overall performance of LAG, CT, and MR imaging. There was, however, a trend toward better performance for MR imaging than for LAG or CT, both globally and when stratified for stage of disease or for lymph node location. Bayesian analysis of clinical utility showed only moderate increases in positive posttest probability of lymph node metastasis for all methods. Negative test results had a greater impact and, depending on the clinical setting, decreased the probability of lymph node metastasis from 15% to 44% (pretest) to 3% to 18% (posttest).

CONCLUSIONS

The LAG, CT, and MR imaging perform similarly in the detection of lymph node metastasis from cervical cancer. As CT and MR imaging are less invasive than LAG and also assess local tumor extent, they should be considered the preferred adjuncts to clinical evaluation of invasive cervical cancer.

MRI gadolinium enhancement of bone marrow: age-related changes in normals and in diffuse neoplastic infiltration

OBJECTIVE

To quantify gadolinium-related enhancement in the bone marrow of the spine in normals and in patients with homogeneous diffuse malignant bone marrow infiltration.

DESIGN AND PATIENTS

The patients consisted of two groups: group 1 comprised 94 healthy adults (18-86 years) without bone marrow disease and group 2 comprised 30 patients with homogeneous diffuse malignant bone marrow infiltration due to myeloma (n = 20) or breast carcinoma (n = 10). All patients received intravenous gadopentetate dimeglumine (Gd-DTPA), 0.1 mmol/kg body weight. Pre- and postcontrast signal intensity (SI) on T1-weighted spin-echo (SE) images (TR/TE: 572 ms/15 ms) was measured over a region of interest (ROI) and the percentage SI increase was calculated. The results were confirmed by bone marrow biopsy (n = 20) and clinical parameters (n = 10). Dynamic contrast-enhanced studies using a spoiled gradient-recalled-echo (GRE) sequence (TR/TE/alpha: 68 ms/6 ms 75 degrees) were performed in 10 controls with normal bone marrow.

RESULTS AND CONCLUSION

Contrast material enhancement in healthy persons can vary greatly (range 3-59%, mean 21%, SD 11%). With increasing age there is a significant decrease in contrast enhancement (Pearson's correlation, P < 0.01). The percentage SI increase in patients with intermediate-grade (biopsy 20-50 vol%) and high-grade (biopsy > 50 vol%) diffuse malignant bone marrow infiltration was significantly higher than in normals (mean 67%, SD 34%, P < 0.001). Low-grade (biopsy < 20 vol%) diffuse malignant bone marrow infiltration can not be assessed by non-enhanced T1-weighted SE images or Gd-DTPA application. In conclusion, contrast material enhancement in healthy persons can vary greatly and is dependent on age, while intermediate-grade and high-grade diffuse malignant bone marrow infiltration can be objectively assessed with SI measurements.

[Parametrial infiltration of cervix carcinoma: diagnostic value of contrast-enhanced fat-suppressed T1-weighted SE sequences at 1.5 tesla]

PURPOSE

To determine whether contrast-enhanced and fat-suppressed sequences contribute to the MR imaging diagnosis of parametrial invasion.

METHODS

21 patients with carcinoma of the cervix were prospectively examined with a phased-array coil and a 1.5T MR-scanner using the following sequences: transverse T2-weighted turbo spin echo (T2-TSE), T1-weighted spin echo (T1-SE) and fat suppressed T1-weighted SE sequences before and after Gd-DTPA. The sequences were evaluated separately for the presence of parametrial invasion. Image quality and diagnostic confidence were classified on a scale of 0-10 (nondiagnostic-excellent). Findings were compared to the results of the pathohistological examination.

RESULTS

Sensitivity, specificity and diagnostic accuracy were highest for T2-TSE sequences (100%, 79% and 86%, respectively). Contrast-enhanced T1-SE sequences with fat-suppression (71%, 79%, and 76%) showed no improvement compared to T2-TSE. Unenhanced fat-suppressed T1-SE (100%, 30%, and 56%) and unenhanced T1-SE (100%, 7%, and 38%) as well as contrast-enhanced T1-SE (86%, 20%, and 47%) were significantly worse than T2-TSE. With similar image quality (p < 0.05) diagnostic confidence was higher on T2-TSE than on any of the other sequences (p < 0.001).

CONCLUSION

Considering the cost-effectiveness of the examination, for the MR diagnosis of parametrial invasion the use of fat-suppressed contrast-enhanced sequences can be abandoned in favour of T2-weighted TSE sequences.

[Lymph node staging in cervix carcinomas: the results of high-resolution magnetic resonance tomography (MRT) with a phased-array body coil]

PURPOSE

To determine the diagnostic value of high resolution MR imaging with a circularly polarised (c.p.) body phased-array coil for the staging of pelvic lymph nodes in cervical carcinoma.

MATERIAL AND METHODS

42 patients with histologically proven carcinoma of the cervix were studied on a 1.5 T scanner by using a c.p. body phased-array coil. The imaging protocol included T2-weighted turbo-spin-echo (TSE) and T1-weighted spin-echo sequences pre and post i.v. application of Gd-DTPA; slice thickness was 5-7 mm and pixel size 0.53 mm2. Lymph nodes with a diameter of > or = 8 mm were considered to have metastatic involvement. MR imaging results were compared with histopathologic findings.

RESULTS

MR imaging showed enlarged lymph nodes (> or = 8 mm) in 16 of 18 patients with histologic proof of lymph node metastases (sensitivity 89%). In 22 of 24 cases MR findings were true negative (specificity 92%). Diagnostic accuracy was 91%.

CONCLUSION

High-resolution MR imaging with a c.p. body phased-array coil provides high sensitivity, specificity, and diagnostic accuracy for pelvic lymph node staging in cervical carcinoma.

Magnetic resonance imaging of the female pelvis. New circularly polarized body array coil versus standard body coil

RATIONALE AND OBJECTIVES

The authors compare the value of a new circularly polarized body array coil (BAC) system with a standard body coil (BC) for high-resolution magnetic resonance imaging of the female pelvis.

METHODS

Twenty patients with cervical cancer were examined with a BC and BAC. Imaging parameters were kept constant (sagittal T2-weighted turbo spin-echo: repetition time = 4000 mseconds; effective echo time = 99 mseconds; 160 x 160 mm field of view; 256 x 256 matrix; 0.63 x 0.63 mm pixel size; 4-mm slice thickness). Images were scored for lesion-to-organ delineation and overall image quality/ artifacts using a scale from 5 to 1 (excellent to poor). Signal-to-noise (S/N) ratios for different tissues (tumor, uterus, vagina, rectum, muscle, and fat) as well as contrast-to-noise (C/N) ratios between tumor and (1) uterus, (2) vagina, and (3) rectum were calculated. Magnetic resonance tumor staging was performed according to the International Federation of Gynecology and Obstetrics (FIGO) classification.

RESULTS

Using the BAC, S/N and C/N ratios increased significantly compared with the BC (S/N: 2.7-3.4-fold increase for all organs evaluated, P < 0.001: C/N: tumor versus uterus 2.4-fold, P < 0.01; tumor versus vagina 6.1-fold, P < 0.001; tumor versus rectum 3.1-fold, P < 0.01). This resulted in an improved overall image quality (average ratings: BAC-4.3 points; BC-2.6 points; P < 0.001). Lesion-to-organ delineation (average ratings: BAC 4.3-4.1 points, BC 3.5-2.7 points for all organs evaluated; P < 0.001) was increased noticeably on BAC images. No significant difference was found for staging accuracy.

CONCLUSIONS

Circularly polarized BAC provide superior S/N and C/N ratios and improve lesion conspicuity compared with standard BC.

CT and MRI findings with pathological correlation of an intracerebral malignant fibrous histiocytoma (MFH): a case report

The CT and MRI findings in a case of an intracranial malignant fibrous histiocytoma are reported. Pathological correlation was demonstrated and tumour vascularization was best seen at angiography. Despite its low incidence in brain, MFH is of special interest because of its ubiquitous location and poor prognosis.