Underwent Magnetic Resonance Examination Research Articles

New trends in criteria indicative of neoadjuvant oncological therapy of lower and middle rectal cancers.

The indication for primary surgical resection or neoadjuvant therapy in lower and middle rectal cancers is often disputable. The aim of the study was to evaluate the occurrence of local recurrence of rectal cancer as for aperiod of at least 4 years after radical resection. The second aim was to evaluate and compare the results of preoperative magnetic resonance (MR) staging with definitive histology.From September 2013 to December 2017, we, at the 3rd Surgical Department Comenius University, Bratislava, prospectively evaluated patients with lower and middle rectal cancers with the distal tumor border being in a12-cm distance from the anal verge. All patients underwent MR examination at the same MRI department and were operated on at the 3rd Surgical Department, Comenius University, Bratislava. Inclusion criteria included parameters based on MRI examination, i.e., T-staging of T1-T3b, negative extramural vascular infiltration (EMVI), negative circumferential margin (CRM), no mesorectal fascia infiltration with a distance of more than 2 mm. We did not take lymph node staging into account in the indication for primary surgical resection. We performed a radical primary resection procedure (R0 resection) in all patients. The group consisted of 87 patients, of whom 49 were men and 38 were women. The mean age of the patients was 66 years (min. 36 - max. 86 years). Our study also shows significant differences in preoperative T and N staging as compared to definitive histology. The incidence of local recurrence during aperiod of at least 4 years after surgery was 6.76 %. Study also shows that the indication for preoperative radiotherapy for lower and middle rectal cancers based on N status is inaccurate and leads to unnecessary indications for preoperative radiotherapy which may decrease the patients´ quality of life and increase the post‑operative complications. We have also shown that leaving out the N-based radiotherapy from indications does not lead to an increase in the number of local recurrences in lower and middle rectal cancers (Tab. 1, Fig. 5, Ref. 22). Text in PDF www.elis.sk Keywords: rectal cancer, neoadjuvant therapy, local recurrence.

Correlation between apparent diffusion coefficient and Ki-67 in different pathological types of lung cancer.

BackgroundComputed tomography (CT) is common and valuable non-invasive method to evaluate proliferative activity in lung cancer; however, magnetic resonance (MR) is rarely used in lung cancer. To evaluate whether there were different expression levels of Ki-67 in different pathological types of lung cancer and the correlation between Ki-67 index and apparent diffusion coefficient (ADC) value.MethodsThe clinical and pathological data of 165 patients with lung cancer confirmed by needle biopsy or surgery were retrospectively evaluated, among whom 54 underwent MR examination. The level of Ki-67 was tested using the international standard IHC 2-step method. Kruskal-Wallis H test was used to compare the different expression level of Ki-67 index of adenocarcinoma, squamous cell carcinoma, and small cell carcinoma, and the least significant difference (LSD) method was used for pair-group comparison. Spearman correlation coefficient was used to analyze the correlation between Ki-67 index and ADC value. All statistical tests were bilateral, and P<0.05 was considered statistically significant.ResultsThe median of Ki-67 index in adenocarcinoma, squamous cell carcinoma, and small cell carcinoma were 20 (10, 30), 40 (40, 60), and 70 (60, 80), respectively. There was a statistical difference in the expression level of Ki-67 index in the 3 different pathological types of lung cancer (H=103.762, P=0.000). In 54 cases of lung cancer with MR examination, there was a significant negative correlation between average ADC value and expression level of Ki-67 index (r=−0.506, P=0.000), while there was no correlation between ADC value and Ki-67 index in distinguishing different pathological types of lung cancer.ConclusionsThe expression level of Ki-67 index was different among different pathological types of lung cancer. The ADC value is correlated with Ki-67 index in lung cancer, which can be used to evaluate the proliferative activity of lung cancer.

Can 3D Pseudo-Continuous Territorial Arterial Spin Labeling Effectively Diagnose Patients With Recanalization of Unilateral Middle Cerebral Artery Stenosis?

Unilateral middle cerebral artery (MCA) stenosis, as an independent risk factor for stroke, requires an intervention operation for vessel recanalization. Accurate perfusion measurement is thus essential after the operation. To explore the feasibility of three-dimensional (3D) pseudo-continuous territorial arterial-spin-labeling (tASL) in evaluating MCA recanalization. Prospective and longitudinal. Forty-seven patients with unilateral MCA stenosis or occlusion. A 3.0 T, 3D time-of-flight fast-field-echo magnetic resonance (MR) angiography sequence, spin-echo echo-planar diffusion-weighted imaging sequence, 3D fast-spin-echo pseudo-continuous ASL (pcASL) and tASL sequences. All patients underwent MR examination before and after MCA recanalization and scored using the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) at admission and discharge. An mRS score <2 was defined as a good prognosis. 3D-pcASL and tASL cerebral blood flow (CBF) maps were obtained, and the corresponding Alberta Stroke Program Early CT Score (ASPECTS)-based scores were evaluated. The Kolmogorov-Smirnov test, intra-class correlation coefficient, paired t-test, receiver operating characteristic (ROC) curve, and multivariable logistic regression analysis. After recanalization, tASL derived absolute CBFs between the affected and contralateral sides were significantly higher than before the operation (mean: 34.3 ± 8.5 mL/100 g/min vs. 40.6 ± 9.2 mL/100 g/min, 42.6 ± 9.8 mL/100 g/min vs. 43.5 ± 9.9 mL/100 g/min, both P < 0.05). In ROC analysis, tASL provided good prognosis (area under ROC curve [AUC]=0.829; 95% CI: 0.651-1.000, P < 0.05), while pcASL had lower prognostic value (AUC=0.760; 95% CI: 0.574-0.946, P < 0.05). The NIHSS score before recanalization, pcASL, and tASL-based ASPECTS scores were significantly associated with good clinical outcome (P < 0.05). Multivariable analysis revealed that ASPECTS-based scores of pcASL and tASL before and after surgery were independent predictors of good clinical outcome (all P < 0.05). DATA CONCLUSION: tASL can determine hypoperfusion in the responsible vascular perfusion area and predict clinical outcome. 4 TECHNICAL EFFICACY: Stage 2.

Magnetic Resonance Imaging Findings Differentiating Cutaneous Basal Cell Carcinoma from Squamous Cell Carcinoma in the Head and Neck Region.

ObjectiveThis study aimed to evaluate the efficacy of magnetic resonance (MR) imaging in differentiating between cutaneous basal cell carcinoma (cBCC) and cutaneous squamous cell carcinoma (cSCC) in the head and neck region.Materials and MethodsAmong patients with cutaneous head and neck cancers, 14 with primary cBCCs and 15 with primary cSCCs with a histologic tumor height of ≥ 4 mm underwent MR examinations; the findings were then examined for correlations.ResultscBCCs (71%) occurred more frequently on the nose than cSCCs (13%) (p < 0.01). The maximum diameter (23.5 ± 7.2 mm vs. 12.7 ± 4.5 mm; p < 0.01) and diameter-to-height ratio (2.8 ± 0.9 vs. 1.7 ± 0.4; p < 0.01) were significantly greater in cSCCs than in cBCCs. Superficial ulcer formation (67% vs. 21%; p < 0.05), protrusion into the subcutaneous tissue (60% vs. 21%; p < 0.05), ill-demarcated deep tumor margins (60% vs. 7%; p < 0.01), and peritumoral fat stranding (93% vs. 7%; p < 0.01) were more frequently observed in cSCCs than in cBCCs. Intratumoral T2-hyperintense foci (57% vs. 13%; p < 0.05) were more frequently observed in cBCCs than in cSCCs.ConclusioncBCCs predominantly occurred on the nose with intratumoral T2-hyperintense foci, whereas cSCCs predominantly exhibited a flattened configuration, superficial ulcer formation, protrusion into the subcutaneous tissue, ill-demarcated deep tumor margin, and peritumoral fat stranding.

Factors associated with the size of the adhesio interthalamica based on 3.0-T magnetic resonance images

Adhesio interthalamica (AI) is a small structure connecting bilateral thalami. To evaluate the effects of patient age, sex, and lateral diameter of the third ventricle on the long diameter of the AI using multivariate analyses based on magnetic resonance (MR) images obtained with 3.0-T scanners. This clinical retrospective study included images of 153 patients who underwent MR examination using 3.0-T scanners. The long diameter of the AI and lateral diameter of the third ventricle were measured on images in the mid-sagittal plane and axial plane at the anterior commissure, respectively. Univariate and multivariate analyses were performed. AI was observed in 138 patients (70 men, 68 women; mean age = 63.7 ± 13.7 years; mean AI size =5.34 ± 1.63 mm). By univariate analyses, patient age (r = -0.262, P = 0.002), sex ( P = 0.010), and lateral diameter of the third ventricle (r = -0.642, P < 0.001) were significantly associated with the long diameter of the AI. With multiple linear regression analyses with a stepwise selection of parameters, only the lateral diameter of the third ventricle (estimate = -0.432, P < 0.001) was significantly associated with the long diameter of the AI. The lateral diameter of the third ventricle was longer in patients without AI (15 patients) than in those with AI ( P = 0.006). The lateral diameter of the third ventricle was a major factor negatively associated with the long diameter of the AI.

Intravoxel incoherent motion magnetic resonance imaging in assessing histopathological features of gastric cancers: initial findings

Background: Intravoxel incoherent motion (IVIM) magnetic resonance (MR) imaging has been widely utilized in evaluating various tumors. The application of IVIM MR imaging in characterizing gastric cancer’s histopathological features has never been reported previously. Methods: A total of 62 patients with gastric cancers were prospectively enrolled in this study. All patients underwent MR examination before surgery. All MR images were reviewed by 2 radiologists using software IDL 6.3 and an oval region of interest (ROI) was manually drawn on the specific slice showing the largest area of tumor. Four parameters were calculated automatically: apparent diffusion coefficient (ADC), pure diffusion coefficient (D), perfusion related fraction (f) and pseudo diffusion coefficient (D*). One-way analysis of variance (normality) or Kruskal-Wallis test (non-normality), independent samples t-test (normality) or Mann-Whitney U test (non-normality), Spearman correlation test and receiver operating characteristic (ROC) curve analysis were used for statistical analyses. Results: Poorly/moderate-poorly differentiated gastric cancers showed significantly lower ADC and D values compared with moderately/well differentiated tumors (P=0.001, P 0.05). No significant differences were found for ADC, D, f or D* values among different status of vascular invasion and perineural invasion. Conclusions: The IVIM-derived ADC and D values showed significant differences among different histological differentiation, Lauren classification and TNM stage of gastric cancers. They showed potential in assessing gastric cancer’s histopathological features.

Brain morphometric analysis predicts decline of intelligence quotient in children with sickle cell disease: A preliminary study

PurposeFor children with sickle cell disease (SCD) and at low risk category of stroke, we aim to build a predictive model to differentiate those with decline of intelligence-quotient (IQ) from counterparts without decline, based on structural magnetic-resonance (MR) imaging volumetric analysis. Materials and methodsThis preliminary prospective cohort study included 25 children with SCD, homozygous for hemoglobin S, with no history of stroke and transcranial Doppler mean velocities below 170cm/s at baseline. We administered the Kaufman Brief Intelligence Test (K-BIT) to each child at yearly intervals for 2–4 years. Each child underwent MR examination within 30 days of the baseline K-BIT evaluation date. We calculated K-BIT change rates, and used rate of change in K-BIT to classify children into two groups: a decline group and a non-decline group. We then generated predictive models to predict K-BIT decline/non-decline based on regional gray-matter (GM) volumes computed from structural MR images. ResultsWe identified six structures (the left median cingulate gyrus, the right middle occipital gyrus, the left inferior occipital gyrus, the right fusiform gyrus, the right middle temporal gyrus, the right inferior temporal gyrus) that, when assessed for volume at baseline, are jointly predictive of whether a child would suffer subsequent K-BIT decline. Based on these six regional GM volumes and the baseline K-BIT, we built a prognostic model using the K* algorithm. The accuracy, sensitivity and specificity were 0.84, 0.78 and 0.86, respectively. ConclusionsGM volumetric analysis predicts subsequent IQ decline for children with SCD.

Role of magnetic resonance in evaluation of urinary bladder cancer

Objective The aim of this study was to prospectively evaluate the use of MRI as a noninvasive diagnostic tool for staging of bladder tumors using different magnetic resonance (MR) sequences: T2-weighted image (T2WI), diffusion-weighted image (DWI), and precontrast and postcontrast T1-weighted image. Background MRI with its superior resolution and supplemented with new emerging sequences is the optimal imaging modality for accurate local staging of bladder cancer, particularly for differentiation between the muscle-invasive and non-muscle-invasive urinary bladder tumors; it is a cornerstone in treatment decision making. Patients and methods The study protocol received institutional ethical committee approval, and informed consent was obtained. Between November 2014 and November 2015, 50 consecutive patients (44 men and 6 women; mean age: 64.3 years; range: 44–85 years) who presented with gross hematuria or suspected urinary bladder tumors were enrolled prospectively. All patients underwent MR examination followed by conventional cystoscopy. The patients were evaluated using T2-weighted high-spatial-resolution MRI of the urinary bladder, followed by diffusion-weighted-MRI. Precontrast T1 (with or without fat suppression) and immediate postgadolinium injection were performed if there were no contraindications. Results Of all 50 patients, four (8%) were at T1, 12 (24%) were at T2, 23 (46%) were at T3, and 11 (22%) were at T4. The most common symptom was gross hematuria (33 patients; 66%). The overall accuracy of T2WI, DWI, and postcontrast imaging sequences in differentiating stage Tis to T2 tumors from T3 to T4 tumors was 88, 98, and 94%, respectively. DWI has a higher overall accuracy compared with both T2WI and postcontrast T1-weighted image in T staging of bladder cancer. Conclusion MRI with new emerging sequences (diffusion-weighted and contrast-enhanced) is highly reliable for accurate local staging of urinary bladder cancer, which is similar to that of conventional cystoscopy. This noninvasive method could be efficiently used for evaluating patients with hematuria of lower urinary tract origin.

MR appearance of normal uterine endometrium considering menstrual cycle: differentiation with benign and malignant endometrial lesions.

Background The thickness and signal intensity (SI) of normal uterine endometrium on T2-weighted (T2W) imaging changes depend on the menstrual cycle phase. Cases of normal endometrium that appear similar to endometrial lesions sometimes occur, and may result in misdiagnosis. Purpose To investigate normal endometrial appearance in luteal phase (LP) compared to that in follicular phase (FP), and to differentiate these appearances with those of endometrial lesions. Material and Methods Thirty-two normal volunteers prospectively underwent magnetic resonance (MR) examinations during LP and FP. Patients with pathologically confirmed endometrial polyps ( n = 9), hyperplasia ( n = 7), and cancer ( n = 15), who underwent MR examinations, were evaluated for comparison. Endometrial appearance was categorized into the following five types on sagittal T2W imaging and compared between LP, FP, and endometrial lesions: type 1, homogeneous higher SI; type 2, homogeneous iso SI; type 3, a bright midline and a peripheral iso SI layer; type 4, a lower/iso SI central line; and type 5, heterogeneous lower/iso SI. Endometrial thickness and SI were measured and also compared. Results Endometrial lesions were more frequently categorized as type 5 than normal endometrium ( P < 0.05). Endometrial thickness in LP (mean, 1.0 cm) was significantly greater than that in FP (0.6 cm), but not significantly different from polyps (1.1 cm), hyperplasia (1.0 cm), and cancer (0.9 cm). SI in FP was significantly higher than that in LP and that of all endometrial lesions. Conclusion Differentiation between normal endometrium in LP and endometrial lesions may be difficult based on thickness alone. Heterogeneous low SI may help to differentiate normal endometrium from endometrial lesions. Performing MR imaging during FP may also help due to higher SI of normal endometrium.

An experimental study on the assessment of rabbit hepatic fibrosis by using magnetic resonance T1ρ imaging

ObjectiveTo explore the correlation between the T1ρ values of liver and liver fibrosis by using magnetic resonance (MR) T1ρ imaging. Materials and methodsThe study consisted of the control group and the hepatic fibrosis (HF) group. Carbon tetrachloride (CCl4) injection was performed once a week for 10weeks (week 1–10) in the HF group which was divided into 5 subgroups and underwent MR examinations at weeks 4, 5, 6, 10, and 15 respectively post the first CCl4 injection (week 1). According to Scheuer Classification, the stage of HF of all rabbits was classified as S0–S4. Mann–Whitney U test was performed to compare the T1ρ values, and p<0.05 was considered statistically significant. ResultsThe control group included 11 rabbits and the HF group included 46 rabbits. The T1ρ values in the HF group tended to increase with the increase of CCl4 injection duration or in higher HF stages. The T1ρ values were significantly lower (p=0.036) in the control group (or the stage S0 group) (23.5±4.0ms) compared to the whole HF group (or S1–S4 group) (26.1±3.7ms), and dropped at week 15 (p=0.043) after the CCl4 injection was stopped at week 10. ConclusionT1ρ imaging is closely associated with the severity of HF and may play an important role in the early diagnosis of HF.

Pseudolesions on Clinical imaging Caused by Sappey Veins

This study aimed to investigate the anatomy and mechanism of pseudolesions around falciform ligament, which appeared on dynamic contrast magnetic resonance (MR) imaging. A total of 30 cases were included in the normal control group (group 1), and 30 cases were enrolled into the liver cirrhosis group (group 2). All cases underwent MR examination including in-phase and out-phase T1-weighted image, T2-weighted fat-suppressed image, and dynamic MR imaging enhancement scanning. The MR images were analyzed to detect pseudolesions, and results from the 2 groups were compared. An ultrasound examination was also performed in all cases to assess the abdominal umbilical vein blood flow. In group 1, MR images detected pseudolesions in 13 cases, and signal reduction did not appear in out-phase MR images compared with in-phase MR images. In 5 of these cases, the umbilical vein was observed to be connected with the hepatic IV segment, and direction flow was toward hepatic during Doppler ultrasound examination. In the 30 patients with liver cirrhosis, pseudolesions were not detected in any of the cases, dilation of the vena epigastricas was observed in 12 cases, and flow direction was from liver. The difference in the incidence of falciform ligament pseudolesions between group 1 and group 2 was statistically significant (P > 0.01). Pseudolesions around the falciform ligament are associated with the Sappey vein, and there is no significant relationship with fatty infiltration.

An analysis on MRI diagnosis of knee injury in 38 patients

Objective To explore the diagnostic value of magnetic resonance ( MR ) for knee injury.Methods 38 patients who had signs of knee injury on clinical examination and underwent MR examinations during the period of 2011 to 2012 were included in this study.The findings of MR imaging were analyzed.Results MR clearly showed the injuries of the knees,including knee meniscus injury,ligament injuries,bone contusion,fractures,joint effusion,and soft tissue swelling,with characteristic appearance in imaging.It had a higher diagnostic reliability and accuracy rate,with a combination of history of knee injury.Conclusions MRI has greater values and clinical significance in the diagnosis of knee injury. Key words: Knee; Injury; Magnetic resonance

Assessment of response to chemoradiation therapy in rectal cancer using MR volumetry based on diffusion-weighted data sets: a preliminary report

This study evaluated the feasibility of magnetic resonance (MR) volumetry using a diffusion-weighted data set (V(DWI)) and compared it with conventional T2-weighted volumetry (V(C)) in patients affected by rectal cancer treated with chemoradiation therapy (CHRT). Fourteen patients with a biopsy diagnosis of rectal cancer underwent MR examination before and after CHRT. T2-weighted images were used to extrapolate V(C). A diffusion-weighted (DW) sequence was acquired [spin-echo diffusion-weighted echo-planar imaging (SE-DW-EPI)] with a b-value of 800 s/mm(2) and volume (V(DWI)) was calculated by semiautomatic segmentation of tumour hyperintensity. Two radiologists independently assessed volumes and analysed data in order to establish interobserver agreement and compare and correlate volumes to tumour regression grade (TRG), as evaluable at pathological examination of the surgical specimen. Interobserver agreement was 0.977 [(95% confidence interval (CI) 0.954-0.989) and 0.956 (95% CI 0.905-0.980) for V(C) and V(DWI) and 0.964 (95% CI 0.896-0.988) and 0.271 (95% CI-0.267 to 0.686) between V(C) and V(DWI) before and after CHRT. The correlation between TRG and V(C) and V(DWI) was, respectively, rho = 0.597 (p<0.05) and r(2)=0.156 (p=0.162) and rho=0.847 (p<0.001). V(DWI) seems to be a promising tool for assessing response to CHRT in rectal cancer. Further studies on large series of patients are needed to refine the technique and evaluate its potential predictive value.

MR Imaging of Uterine Adenosarcoma: Case Report and Literature Review

We report a case of uterine adenosarcoma demonstrated on magnetic resonance (MR) imaging. A 74-year-old woman with a large uterine mass underwent MR examination before total abdominal hysterectomy. Imaging revealed a markedly enlarged uterus with thin myometrium occupied by a large polypoid mass. The mass contained solid components with low intensity on T(1)-weighted images and high intensity on T(2)-weighted images compared to the myometrium and areas of small cysts.

MR imaging findings of elastofibroma dorsi in correlation with pathological features: our experience

This paper describes the role of magnetic resonance (MR) imaging for characterising elastofibroma dorsi in correlation with pathological findings. Over a period of 9 years, 1,233 MR examinations of the periscapular region assessed for the presence of elastofibroma dorsi with superconductive 1.5-T MR scanners at three different radiology institutes were retrospectively reviewed. Our study population included 15 patients (12 women, three men; mean age 58 years, range 28-82 years) presenting with 17 lesions. Two patients had bilateral elastofibroma dorsi. Thirteen of 15 patients underwent MR examination for clinical suspicion of a lesion located in the periscapular region, whereas in 2/15 cases it was an incidental finding during MR examination performed for other diseases. Diagnosis of elastofibroma dorsi was confirmed by histopathology in 11/17 cases. The remaining lesions were considered benign, as their size and morphology did not change over a mean follow-up period of 1.5 years. MR imaging with its multiplanar capabilities and high-contrast resolution has a high level of accuracy in characterising elastofibroma dorsi and may avoid the need for biopsy or surgical operation.

MR tomography of the bone marrow changes after high-dosage chemotherapy and autologous peripheral stem-cell transplantation

Evaluation of MR standard imaging and short time inversion recovery (STIR) imaging to assess changes in red bone marrow cellularity after high-dose chemotherapy (HDC) and peripheral blood stem cells transplantation (PBSCT). Sixty-one magnetic resonance (MR) studies were performed in 15 patients (8 female and 7 male, average age 45 years) who received HDC and PBSCT for therapy of either a solid tumor or multiple myeloma. All patients underwent MR examinations of the lumbar region and both femora with T1- and T2-weighted turbo spin-echo (TSE) and STIR sequences at predefined time intervals. Qualitative analysis of the signal intensity was performed by consensus reading of four radiologists. MR results were correlated with results of blood smears and marrow histology. STIR sequences demonstrated marked changes in signal intensity not only until the aplasia occurred but also during bone marrow repopulation. An increased signal intensity was observed after HDC in 13/15 patients (87%), followed by a decrease in signal intensity immediately after aplasia in 14/15 patients (93%). Signal intensity further changed parallel to marrow engraftment in 11/15 patients (73%). T2-TSE only showed clear changes during repopulation in 8/15 patients (53%). The individual course of the signal in T1-TSE was markedly inhomogeneous. STIR sequences show bone marrow edema during aplasia and marrow cellularity during reconstitution and are suitable for characterisation of red bone marrow after HDC and autologous PBSCT.

Diagnostic Performance of Myocardial Perfusion MR at 3 T in Patients with Coronary Artery Disease

To prospectively determine the diagnostic performance of myocardial perfusion magnetic resonance (MR) imaging at 3 T for helping depict clinically relevant coronary artery stenosis (> or =50% diameter) in patients with suspected or known coronary artery disease (CAD), with coronary angiography as the reference standard. The study was approved by the local ethics committee; written informed consent was obtained. Vasodilator stress perfusion imaging by using a turbo field-echo sequence was obtained in 101 patients (71 men, 30 women; mean age, 62 years +/- 7.7 [standard deviation]) scheduled for coronary angiography. Myocardial ischemia was defined as stress-inducible perfusion deficit in arterial territories without delayed enhancement (DE) or additional stress-inducible perfusion deficit in territories with nontransmural DE. Images were evaluated in consensus by two blinded readers. Diagnostic performance was determined on per-patient and per-coronary artery territory bases. The number of dark rim artifacts in patients without DE was determined in a second read. Interobserver variability was assessed in 40 randomly selected patients. One hundred one patients underwent MR examinations. Coronary angiography depicted relevant stenosis in 70 (69%) patients. Patient-based sensitivity and specificity were 90% and 71%, respectively. Sensitivity, specificity, and diagnostic accuracy for the detection of coronary stenosis in a specific territory were 76%, 89%, and 86%, respectively. In 24% of patients without DE, dark rim artifacts were detected, mostly in the left anterior descending artery territory (56%). In 40 randomly selected patients, there was agreement in the determination of myocardial perfusion deficits in 37 (93%, kappa = 0.79) patients. Myocardial perfusion MR imaging by using saturation-recovery spoiled gradient-echo imaging at 3 T has an accuracy of 84% for depicting hemodynamically relevant coronary artery stenosis in patients with suspected and known CAD.

Magnetic Resonance Imaging Parameters for Assessing Risk of Recurrent Hamstring Injuries in Elite Athletes

Background Magnetic resonance (MR) imaging has established its usefulness in diagnosing hamstring muscle strain and identifying features correlating with the duration of rehabilitation in athletes; however, data are currently lacking that may predict which imaging parameters may be predictive of a repeat strain. Purpose This study was conducted to identify whether any MR imaging-identifiable parameters are predictive of athletes at risk of sustaining a recurrent hamstring strain in the same playing season. Study Design Cohort study; Level of evidence, 3. Methods Forty-one players of the Australian Football League who sustained a hamstring injury underwent MR examination within 3 days of injury between February and August 2002. The imaging parameters measured were the length of injury, cross-sectional area, the specific muscle involved, and the location of the injury within the muscle-tendon unit. Players who suffered a repeat injury during the same season were reimaged, and baseline and repeat injury measurements were compared. Comparison was also made between this group and those who sustained a single strain. Results Forty-one players sustained hamstring strains that were positive on MR imaging, with 31 injured once and 10 suffering a second injury. The mean length of hamstring muscle injury for the isolated group was 83.4 mm, compared with 98.7 mm for the reinjury group (P = .35). In the reinjury group, the second strain was also of greater length than the original (mean, 107.5 mm; P = .07). Ninety percent of players sustaining a repeat injury demonstrated an injury length greater than 60 mm, compared with only 58% in the single strain group (P = .01). Only 7% of players (1 of 14) with a strain <60 mm suffered a repeat injury. Of the 27 players sustaining a hamstring strain >60 mm, 33% (9 of 27) suffered a repeat injury. Of all the parameters assessed, only a history of anterior cruciate ligament sprain was a statistically significant predictor for suffering a second strain during the same season of competition. Conclusion A history of anterior cruciate ligament injury was the only statistically significant risk factor for a recurrent hamstring strain in our study. Of the imaging parameters, the MR length of a strain had the strongest correlation association with a repeat hamstring strain and therefore may assist in identifying which athletes are more likely to suffer further reinjury.

Magnetic Resonance Screening Trial for Hepatic Metastasis in Patients with Locally Controlled Choroidal Melanoma

The aim of the present study was to evaluate the value of magnetic resonance (MR) screening for detection of hepatic metastasis in patients with locally controlled choroidal melanoma. MR examinations were performed after an initial diagnosis of choroidal melanoma in 159 patients (mean age 56 years: range, 10-86 years). The MR follow-up interval was 5.2 +/- 1.7 years (range, 1.2-6.6 years). A total of 363 MR studies were reviewed by two radiologists for predominant signal intensity characteristics. Hepatic metastasis was verified by histological examination: tumor resection and CT-guided needle biopsy specimens and/or on the basis of an obvious progression in number and/or size of the lesions on the follow-up MR examination. The majority of patients underwent MR examinations from one to three times (n = 126, 79%). During a mean follow-up period of 5.7 years, a focal abnormality in the liver was found in 20 patients (13%). Of these, 15 patients (9%) were diagnosed as having hepatic metastasis. The number of the metastatic lesions with a short T1 and short T2 pattern were one (n = 1, 9%), two (n = 2, 18%), three (n = 1, 9%) and multiple (n = 7, 63%). The focal abnormalities of MR examinations in five other patients consisted of vascular artifacts (n = 3, 15%) and cysts with hemorrhage (n = 2, 10%). The screening of MR examinations detected hepatic metastasis in 15 of 159 patients (9%) with locally controlled choroidal melanoma.

Pituitary Macroadenomas: Preoperative Evaluation of Consistency with Diffusion-weighted MR Imaging—Initial Experience

To prospectively evaluate use of diffusion-weighted (DW) magnetic resonance (MR) images and apparent diffusion coefficient (ADC) maps for determination of the consistency of macroadenomas. The study protocol was approved by the institutional ethics committee, and informed consent was obtained from all patients. Twenty-two patients with pituitary macroadenoma (10 men, 12 women; mean age, 54 years +/- 17.09 [standard deviation]; range, 21-75 years) were examined. All patients underwent MR examination, which included T1-weighted spin-echo and T2-weighted turbo spin-echo DW imaging with ADC mapping and contrast material-enhanced T1-weighted spin-echo imaging. Regions of interest (ROIs) were drawn in the macroadenomas and in normal white matter on DW images, ADC maps, and conventional MR images. Consistency of macroadenomas was evaluated at surgery and was classified as soft, intermediate, or hard. Histologic examination was performed on surgical specimens of macroadenomas. Mean ADC values, signal intensity (SI) ratios of tumor to white matter within ROIs on conventional and DW MR images, and degree of enhancement were compared with tumor consistency and with percentage of collagen content at histologic examination by using analysis of variance for linear trend. The mean value of ADC in the soft group was (0.663 +/- 0.109) x 10(-3) mm(2)/sec; in the intermediate group, (0.842 +/- 0.081) x 10(-3) mm(2)/sec; and in the hard group, (1.363 +/- 0.259) x 10(-3) mm(2)/sec. Statistical analysis revealed a significant correlation between tumor consistency and ADC values, DW image SI ratios, T2-weighted image SI ratios, and percentage of collagen content (P < .001, analysis of variance). No other statistically significant correlations were found. Findings in this study suggest that DW MR images with ADC maps can provide information about the consistency of macroadenomas.