Positive Predictive Value Of MRI Research Articles

Comparing Methods to Determine Complete Response to Chemoradiation in Patients with Locally Advanced Cervical Cancer.

There is no consensus on the most reliable procedure to determine remission of cervical cancer after chemoradiotherapy (CRT). Therefore, this study aims to assess the diagnostic performance of two different imaging techniques, MRI and 18F[FDG]-PET/CT, in determining the presence of locoregional residual disease after CRT in patients with locally advanced cervical cancer. Patients diagnosed with locally advanced cervical cancer (FIGO 2009) treated with CRT were retrospectively identified from a regional cohort. The accuracy of MRI and 18F[FDG]-PET/CT in detecting locoregional residual disease was assessed with histology as the reference standard. The negative predictive value (NPV) and positive predictive value (PPV) for locoregional residual disease detection of MRI and 18F[FDG]-PET/CT combined were 84.2% (95% CI 73.2-92.1), and 70.4% (95% CI 51.8-85.2), respectively. The NPV and PPV of MRI alone were 80.2% (95% CI 71.2-87.5) and 47.7% (95% CI 35.8-59.7), respectively, and values of 81.1% (95% CI 72.2-88.3) and 55.8 (95% CI 42.2-68.7), respectively, were obtained for 18F[FDG]-PET/CT alone. In this study, the reliability of MRI and 18F[FDG]-PET/CT in detecting locoregional residual disease was limited. Combining MRI and 18F[FDG]-PET/CT did not improve predictive values. Routine use of both MRI and 18F[FDG]-PET/CT in the follow-up after CRT should be avoided. MRI during follow-up is the advised imaging technique. Pathology confirmation of the presence of locoregional residual disease before performing salvage surgery is warranted.

PD39-08 INTER-CENTER VARIABILITY IN POSITIVE PREDICTIVE VALUES OF PIRADS SCORE IN PATIENTS UNDERGOING PROSTATE BIOPSY: RESULTS FROM THE PROMOD STUDY GROUP

PD39-08 INTER-CENTER VARIABILITY IN POSITIVE PREDICTIVE VALUES OF PIRADS SCORE IN PATIENTS UNDERGOING PROSTATE BIOPSY: RESULTS FROM THE PROMOD STUDY GROUP

The Value of MRI in Early Cervical Cancer Staging with Vaginal Filling of Ultrasound Gel

To investigate the value of MRI after ultrasonic gel vagina filling in the staging of early-stage cervical cancer. A total of 158 patients with cervical cancer who underwent MRI examination after their cervical cancer diagnosis was confirmed by cervical biopsy were prospectively enrolled. Routine MRI examination was performed first, followed by another MRI examination after vaginal filling with ultrasound gel. Two physicians used a double-blind method to determine the staging of cervical cancer based on the MRI images before and after vaginal filling of ultrasound gel. Results of the postoperative pathology analysis were used as the golden standard. The positive predictive value and negative predictive value for stage Ⅱa cases of the two examinations of the same patient were compared, and the sensitivity, specificity and accuracy in identifying stage Ⅱa cervical cancer were compared. Two physicians used the double blind method to determine the staging of cervical cancer based on conventional MRI images, achieving moderate consistency ( κ=0.680). However, for the staging of cervical cancer with MRI images after vaginal filling of ultrasound gel, the two physicians achieved highly consistent results ( κ=0.932). Regarding identifying stage Ⅱa cervical cancer, the positive predictive value of conventional MRI was 66.67%, the negative predictive value was 76.74%, and the sensitivity, specificity and accuracy were 70.59%, 73.33% and 72.15%, respectively. The positive predictive value of MRI after vaginal filling of ultrasound gel was 90.91%, the negative predictive value was 91.3%, and the sensitivity, specificity and accuracy were 88.24%, 93.33% and 91.14%, respectively. The sensitivity, specificity and accuracy of the two methods were compared and the difference was statistical significant ( P<0.05). MRI examination after ultrasound gel vaginal filling has better diagnostic value for identifying stage Ⅱa cervical cancer. The method is simple and easy to do, and can be used in routine MRI examination of cervical cancer.

Clinical Impact of Preoperative Magnetic Resonance Imaging in the Evaluation of Myometrial Infiltration and Lymph-Node Metastases in Stage I Endometrial Cancer.

: Purpose: In the developed world, endometrial cancer is one of the most common malignant gynecological cancer types. Due to the highly available diagnostic modalities and patient education, the early detection of the tumor leads to high overall survival. Methods: In this study we analyzed the reliability of preoperative MRI findings in the staging of early stage endometrial cancer, as well as the clinical characteristics of patients underwent radical hysterectomy and the histopathologic evaluation of their tumor, with the retrospective data of radical hysterectomies performed in our hospital between 2010 and 2019. Results: The accuracy, sensitivity, specificity, negative- and positive predictive value of MRI regarding stage were 94.7, 63.3, 94.8, 83.8, and 83.8%, respectively. The accuracy, sensitivity, specificity, negative- and positive predictive value of MRI for the detection of the myometrial invasion were 69.8, 80.0, 60.8, 64.3, and 77.5%, respectively. The accuracy, sensitivity, specificity, negative- and positive predictive value of MRI for the detection of lymph node metastases were 78.1, 28.6, 82, 11.1, and 93.6%, respectively. Conclusions: Based on our results, MRI is the method of choice in terms of evaluating overall staging, as well as myometrial invasion, as its specificity and negative predictive value are relatively high. However, systematic lymphadenectomy showed improved cancer-related survival and recurrence-free survival. Our studies showed that the diagnosis of lymph node metastases is difficult with MRI modality since hyperplastic and metastatic nodes cannot easily differentiate, leading to a high percentage of false-positive results. Therefore, other imaging modalities may be used for more accurate evaluation. New findings of our study were that the role of the radiologist’s expertise in the evaluation of MR imaging plays an essential role in lowering false-negative and false-positive results. Therefore, findings evaluated by a radiologist with high-level expertise in gynecological imaging can complement the clinical findings and help substantially define the needed treatment.

Positive Predictive Value of MRI in the Diagnosis of Intra-Abdominal Undescended Testes Taking Laparoscopic Findings as Gold Standard

Background: Cryptorchidism also known as undescended testis, is a birth defect in male babies with higher frequency in preterm infants, leading infertility and other genital problems. In its treatment, diagnosis has a vital role. Objective: The objective of this study was to determine the positive predictive value of MRI in the diagnosis of intra-abdominal undescended testes taking laparoscopic findings as gold standard. Study Design: It was a cross-sectional survey. Settings: Research was conducted at Department of Diagnostic Radiology, Children Hospital &amp; Institute of Child Health Lahore Pakistan. Duration: Six months from June 23, 2018 to December 22, 2018. Methodology: This study involved 68 boys aged between 2 to 15 years presenting with undescended testes. Intra-abdominal undescended testes were diagnosed on MRI and was later confirmed on laparoscopic findings which were taken as gold standard and diagnosis of MRI was judged accordingly as true positive or false positive. A written informed consent was obtained from parents of every patient. Results: The age of the children ranged from 2 years to 15 years with a mean of 8.1±3.5 years. Majority (n=53, 77.9%) of the children had right while 15 (22.1%) children had left undescended testes. Diagnosis of intra-abdominal testes was confirmed in 64 (94.1%) patients on laparoscopy. Thus, there were 64 true positive and 4 false positive cases. It yielded a positive predictive value of 94.1% for MRI in predicting intra-abdominal undescended testes taking laparoscopy as gold standard. Similar positive predictive value was noted across various age and anatomical side groups. Conclusion: The positive predictive value of MRI was found to be 94.1% in predicting intra-abdominal undescended testes taking laparoscopic findings as gold standard regardless of patient’s age and anatomical side which along with its non-invasive and radiation free nature advocates its preferred use in future practice.

Positive Predictive Value of Magnetic Resonance Imaging in Intradural Spinal Tumors Taking Histopathology as Gold Standard

Objective: To observe the positive predictive value of MRI, taking histopathology as gold standard in detecting spinal intradural tumors.Materials and Methods: Total 180 cases were included through non-probability purposive sampling, at Ganga Ram Hospital, Radiology department, Lahore. The radiological diagnosis obtained through MRI, was observed. The cases fit in inclusion criteria were underwent surgery and their histopathological findings were observed. Comparison between the outcomes of MRI and histopathology were undertaken, keeping histopathology as gold standard. Positive predictive value of MRI in the diagnosis of intradural spinal tumor was calculated andpresented in the form of percentages and frequency.Results: There were total 180 patients presenting in OPD with the mean age of 45.71 ± 13.57 years. There were 112 (62%) male. Male to female ratio was 1.6:1. There were 134 (74.4%) cases who were positive for malignant spinal intradural tumor on histopathology showing the PPV of MRI as 74.4%.Conclusion: Magnetic Resonance Imaging is very beneficial imaging tool for early diagnosis of spinal cord tumors.

Predictive Validity of Lumbar X-ray Images and MRIs for Chronic Low Back Pain Subtypes

Purpose: The aim of this observational study alongside our inter-rater reliability trial (ISRCTN 43417727) is to investigate the accuracy of lumbar X-ray images and MRIs as diagnostic tools of low back pain (LBP) subtypes (sacroiliac joint, disc and facet joint).Patients and methods: Included were patients aged 18 or more with medical history and physical examination suggestive of a chronic LBP subtype, followed by a diagnostic test block. Numbers of spinal imaging tests, and whether or not pathology was present was evaluated in patients with positive- as well as negative diagnostic test blocks. The sensitivity, specificity, positive and negative predictive value of the lumbar X-ray images and MRIs discriminating between the three LBP subtypes are presented.Results: One hundred patients were included. Facet joint pain was a general working diagnosis in 40 patients, disc pain in 8 patients and SI joint pain in 35 patients. The positive predictive value of X-ray was 82.6% for facet joint pain, 66.7% for disc pain and 60% for SI joint pain; the negative predictive value of X-ray was 50% for facet joint pain, 66.7% for disc pain and 7.7% for SI joint pain. The positive predictive value of MRI was 81.8% for facet joint pain, 50% for disc pain and 0% for SI joint pain; the negative predictive value of MRI was 55.6% for facet joint pain, 0% for disc pain and 13% for SI joint pain.Conclusion: The predictive validity of lumbar X-ray images and MRIs to distinguish between low back pain subtypes in patients with chronic LBP is questionable.

Role of EEG background activity, seizure burden and MRI in predicting neurodevelopmental outcome in full-term infants with hypoxic-ischaemic encephalopathy in the era of therapeutic hypothermia.

To investigate the role of EEG background activity, electrographic seizure burden, and MRI in predicting neurodevelopmental outcome in infants with hypoxic-ischaemic encephalopathy (HIE) in the era of therapeutic hypothermia. Twenty-six full-term infants with HIE (September 2011-September 2012), who had video-EEG monitoring during the first 72h, an MRI performed within the first two weeks and neurodevelopmental assessment at two years were evaluated. EEG background activity at age 24, 36 and 48h, seizure burden, and severity of brain injury on MRI, were compared and related to neurodevelopmental outcome. EEG background activity was significantly associated with neurodevelopmental outcome at 36h (p=0.009) and 48h after birth (p=0.029) and with severity of brain injury on MRI at 36h (p=0.002) and 48h (p=0.018). All infants with a high seizure burden and moderate-severe injury on MRI had an abnormal outcome. The positive predictive value (PPV) of EEG for abnormal outcome was 100% at 36h and 48h and the negative predictive value (NPV) was 75% at 36h and 69% at 48h. The PPV of MRI was 100% and the NPV 85%. The PPV of seizure burden was 78% and the NPV 71%. Severely abnormal EEG background activity at 36h and 48h after birth was associated with severe injury on MRI and abnormal neurodevelopmental outcome. High seizure burden was only associated with abnormal outcome in combination with moderate-severe injury on MRI.

Additional diagnostic value of MRI in patients with suspicious breast lesions based on ultrasound.

Biopsy has long been the standard approach in Breast Imaging Reporting and Data System® (BI-RADS) 4 or BI-RADS 5 (American College of Radiology, Reston, VA) lesions despite a wide variation in reported incidence of malignancy in BI-RADS 4 lesions. This study examined the diagnostic value of breast MRI as well as its ability to decrease unnecessary biopsies in patients with solid breast lesions who had an indication for biopsy. In this retrospective study, 277 breast lesions with a documented histological diagnosis as established by ultrasound-guided biopsy were included. All patients were female, and biopsy was performed owing to a BI-RADS score of 4 or 5 on ultrasonography. In addition, all patients had undergone MRI before biopsy. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of MRI in predicting malignancy were calculated. When all lesions were analysed, sensitivity, specificity, NPV and PPV of MRI in detecting malignancy were 94.2%, 56.1%, 90.7% and 68.1%, respectively. When only ultrasonographic BI-RADS 4 lesions are considered, the corresponding figures were as follows: 90.9%, 56.7%, 93.8% and 46.4%, respectively. False-negative rate of MRI for the latter group of lesions was 2.6%. 42% of unnecessary biopsies were avoided in sonographic BI-RADS 4 lesions. Despite promising results obtained in this study, dynamic MRI currently does not seem to be effective in ruling out the need for biopsy in the assessment of sonographic BI-RADS 4 lesions. However, advanced MRI techniques may assist in improving possible benefits of MRI in this patient group.

Auditing a Breast MRI Practice: Performance Measures for Screening and Diagnostic Breast MRI

Breast MRI is increasingly used for both screening and diagnostic purposes. Although performance benchmarks for screening and diagnostic mammography have been published, performance benchmarks for breast MRI have yet to be established. The purpose of this study was to comprehensively evaluate breast MRI performance measures, stratified by screening and diagnostic indications, from a single academic institution. Institutional review board approval was acquired for this HIPAA-compliant study. Informed consent was not required. Retrospective review of the institutional database identified all breast MRI examinations performed from April 1, 2007, to March 31, 2008. After application of exclusion criteria, the following performance measures for screening and diagnostic indications were calculated: cancer detection rate, positive predictive value (PPV), and abnormal interpretation rates. The study included 2,444 examinations, 1,313 for screening and 1,131 for diagnostic indications. The cancer detection rates were 14 per 1,000 screening breast MRI examinations and 47 per 1,000 diagnostic examinations (P < .00001). The abnormal interpretation rate was 12% (152 of 1,313) for screening and 17%(194 of 1,131) for diagnostic indications (P= .00008). The PPVs of MRI were lower for screening [PPV1(abnormal findings) = 12%, PPV2(biopsy recommended) = 24%, PPV3(biopsy performed) = 27%] compared with diagnostic indications (PPV1(abnormal findings) = 28%, PPV2(biopsy recommended) =36%, PPV3(biopsy performed) = 38%]. Breast MRI performance measures differ significantly between screening and diagnostic MRI indications. Medical audits for breast MRI should calculate performance measures for screening and diagnostic breast MRI separately, as recommended for mammography.

Cystic apocrine hyperplasia is the most common finding in MRI detected breast lesions

MRI of the breast is an increasingly employed modality for breast imaging due to its relatively high sensitivity for the detection of breast carcinoma. Cumulative data indicate that MRI of...

Chronic Anal and Perianal Pain Resolved With MRI

The purpose of this study was to assess the diagnostic value of anorectal MRI in the care of patients with chronic anal and perianal pain but without findings of abnormalities in the clinical workup. Patients referred from a tertiary department of colorectal surgery to the MRI unit with clinically occult chronic anal and perianal pain were included. MRI of the anorectum was performed with an endoanal or pelvic phased-array coil. The images from all examinations were read by two radiologists. MRI findings were correlated with clinical follow-up data. The study group (103 patients) was stratified into patients with no history of anorectal disease (n = 60) and those who had a history of surgery for anorectal disease (n = 43). MRI findings suggested the final diagnoses in 40 patients (39%). These diagnoses were 28 cases of suppurative lesions (27%), 11 cases of painful scarring of the anus (11%), and one case of metastasis to the sacrum (1%). Suppurative lesions were surgically proved with marked relief of pain after surgery. In the other patients the final diagnoses were 37 cases of levator ani syndrome (36%) and 26 cases of unspecified functional anorectal pain (25%). No MRI abnormalities were found in 33 of the patients with levator ani syndrome and 26 of the patients with unspecified anorectal pain. The two readers had very good agreement (κ = 0.92). The patients with a history of anorectal disease had significantly more MRI findings of abnormalities (60%) than did patients without a history of anorectal disease (23%). The positive predictive value of MRI was 91%, and the negative predictive value was 100%. In 39% of patients, MRI showed abnormalities that were clinically confirmed as the final diagnosis. Surgical treatment will especially benefit patients with suppurative lesions, resulting in relief of pain.

3T MRI of the prostate correlation to 3D reconstruction of transperineal mapping biopsies.

e15176 Background: MRI is new tool in the diagnosis and surveillance of localized prostate cancer. Studies have examined the sensitivity and specificity of MRI for detecting and localizing prostate cancer as compared to radical prostatectomy specimens. We have previously demonstrated excellent correlation between 3-dimensional transperineal mapping biopsies (3DMB) to radical prostatectomy specimens. We hypothesize that MRI does not perform as well detecting smaller lesions of the prostate as larger ones. In this study, we retrospectively compare the correlation of 3DMB to 3T MRI-positive lesions. Methods: Between 2010 and 2011, 34 men with histologically-proven prostate cancer underwent 3T endorectal coil MRI and subsequent template-guided (5-mm grid) 3DMB. Three-dimensional computer models of the mapping biopsies were created using Proview software to identify clusters of positive biopsies likely belonging to a single lesion. MRIs were read by two trained radiologists blinded to 3DMB results. Disagreement between radiologists was settled by consensus. MRI and 3DMB were then compared in a retrospective fashion. Results: Median age and PSA were 65 years (49-76) and 4.3 ng/mL (0.7-15.0). Median prostate volume was 40 cm3 (21-105 cm3). Median total biopsy cores on 3DMB was 60 (26-151), and mean positive cores was 3 (0-13). 3D reconstruction of patient biopsy sets resulted in 58 distinct foci of cancer. MRI identified 64 individual lesions suspicious for cancer. Of these, 66% (n=42) could be correlated to a positive area on 3DMB consisting of one or more positive biopsies, and 34% (n=22) corresponded to negative regions on 3DMB. When two or more biopsies represented a positive lesion on 3DMB, the positive-predictive value of MRI was 100% (n=24). Conversely, only 72% (n=42) of positive 3DMB areas could be correlated to a lesion on MRI, and 28% (n=16) were not seen on MRI.. Conclusions: MRI has vast potential as a less-invasive method in the detection and surveillance of prostate cancer. While MRI does appear to have excellent positive predictive value, the number of false negatives and relevance to clinically-significant lesions require further illumination.

Comparative Effectiveness of Positron Emission Mammography and MRI in the Contralateral Breast of Women With Newly Diagnosed Breast Cancer

The objective of our study was to compare the performance of positron emission mammography (PEM) with that of MRI in the evaluation of the contralateral breast of women with newly diagnosed cancer. Four hundred seventy-two women with newly diagnosed breast cancer offered breast-conserving surgery from September 2006 through November 2008 consented to participate in a multicenter protocol. Participants underwent contrast-enhanced breast MRI and 18F-FDG PEM in randomized order, and the examinations were interpreted independently. The performance characteristics of the imaging modalities were compared using the McNemar test and generalized estimating equations. A retrospective blinded review of PEM images was performed by four experienced observers to understand the reasons for false-negatives. Three hundred sixty-seven women (median age, 58 years; age range, 26-93 years) eligible for analysis completed the appropriate follow-up for study inclusion. Fifteen women (4.1%) were found to have contralateral cancer (11 invasive [mean tumor size, 12 mm; median, 10 mm; range, 1-22 mm] and four ductal carcinoma in situ). Of the 15 cases, both PEM and MRI showed three (20%), only MRI showed 11 (73%), and one (6.7%) was found at prophylactic mastectomy. MRI sensitivity at 14 of 15 (93%; 95% CI, 66-94) was higher than PEM at three of 15 (20%; 95% CI, 5.3-46) (p<0.001). On PEM, three additional cancers were seen prospectively but were considered probably benign and two other cancers were visible in retrospect at the site. Of 352 contralateral breasts without cancer, findings were negative or benign on PEM for 335 (95.2%; 95% CI, 92.2-97.0), which is more than MRI at 315 (89.5%; 95% CI, 85.7-92.4; p=0.002). The positive predictive value (PPV) of PEM-prompted biopsies (3/14 [21%]) was not significantly different from the PPV of MRI (15/54 [28%], p=0.58). On blinded retrospective PEM review of the 15 contralateral cancers, PEM findings for 11 (73%) were considered suspicious. Contralateral cancer was found in 15 of 367 women (4.1%), with MRI showing 14 (93%). Eleven contralateral cancers (73%) were visible on PEM, but only three (20%) were recognized prospectively as suspicious. Lesions that are visible on PEM should be viewed as suspicious unless known to be benign by prior breast imaging or biopsy.

Assessment of the suspected fracture of the scaphoid

A suspected fracture of the scaphoid remains difficult to manage despite advances in knowledge and imaging methods. Immobilisation and restriction of activities in a young and active patient must be balanced against the risks of nonunion associated with an undiagnosed and undertreated fracture of the scaphoid. The assessment of diagnostic tests for a suspected fracture of the scaphoid must take into account two important factors. First, the prevalence of true fractures among suspected fractures is low, which greatly reduces the probability that a positive test will correspond with a true fracture, as false positives are nearly as common as true positives. This situation is accounted for by Bayesian statistics. Secondly, there is no agreed reference standard for a true fracture, which necessitates the need for an alternative method of calculating diagnostic performance characteristics, based upon a statistical method which identifies clinical factors tending to associate (latent classes) in patients with a high probability of fracture. The most successful diagnostic test to date is MRI, but in low-prevalence situations the positive predictive value of MRI is only 88%, and new data have documented the potential for false positive scans. The best strategy for improving the diagnosis of true fractures among suspected fractures of the scaphoid may well be to develop a clinical prediction rule incorporating a set of demographic and clinical factors which together increase the pre-test probability of a fracture of the scaphoid, in addition to developing increasingly sophisticated radiological tests.

Perforations de la coiffe des rotateurs : intérêt de l’IRM 3,0T

To demonstrate the value of 3.0T MR imaging for the detection of rotator cuff tendon tears and surgical planning by correlating imaging findings to surgical findings. Materials and methods. Prospective follow-up of patients who underwent 3.0T MR imaging of the shoulder in our department between November 2005 and June 2007. Surgical findings were correlated to imaging findings for 48 patients who underwent surgery: detection, size, partial thickness or complete, and tendon edges. In this patient group, the positive predictive value of MRI for detecting surgical tears was 100% (100% of complete tears and 92% of partial thickness tears). No change in surgical management was recorded when arthroscopy was performed based on MRI findings (size of tear). 3.0 T MRI is valuable for the detection of small tears, especially for partial thickness tears due to increased spatial resolution. The identification of surgical candidates and surgical planning are improved due to more accurate measurements of tear size and quality of the tendon edges.

Preoperative Evaluation of Potential Living Related Kidney Donors with High-Spatial-Resolution Magnetic Resonance (MR) Angiography at 3 Tesla

The purpose of this prospective study was to determine the feasibility and accuracy of high-spatial-resolution MR imaging at 3 Tesla (T) in the preoperative evaluation of potential living related kidney donors. Eighteen potential donors (8 men, 10 women; mean age, 50.1 +/- 14.2 years) for renal transplantation were evaluated with 3 T MR imaging. A high-spatial-resolution 3-dimensional (3D) gradient-echo MR angiography (repetition time/echo time, 3.0/1.14 ms; flip, 19-23 degrees; matrix, 512; slice thickness, 1.0 mm) using parallel acquisition technique (GRAPPA) with an acceleration factor of 3 was performed on a whole body scanner. Images were evaluated in a prospective and blinded fashion by 2 MR radiologists. The number of renal arteries, presence of early branches (defined as a branch arising within 2 cm of the main renal ostium), and renal artery stenosis were analyzed. The renal parenchyma, collecting system and ureters, were evaluated on the MR urograms. Interpretation of MR images were compared with surgical findings. Based on MR angiography data sets, a total of 36 main and 9 accessory renal arteries was found. There were 5 renal arteries presenting an early branching (<or=2 cm). The correct venous anatomy was identified in 13 of 14 patients (93%), including a single left renal vein anterior to the aorta (n = 3), retroaortic left renal vein (n = 2), and single right renal vein (n = 9). A single collecting system in all harvested kidneys was identified correctly with MR imaging. Overall, the sensitivity and positive predictive value of MRI in correctly determining the vascular and parenchymal anatomy in the harvested kidney was 85% and 93%, respectively. High-spatial-resolution contrast-enhanced MR angiography at 3 T can predict successful donor nephrectomy in potential living related kidney donors.

Positive predictive value of MRI for the diagnosis of mucinous cystic lesions of the pancreas

Positive predictive value of MRI for the diagnosis of mucinous cystic lesions of the pancreas

Preoperative local MRI-staging of patients with a suspected pancreatic mass.

The aim of this study was to define the value of MRI of the pancreas for preoperative local staging of patients with a suspected pancreatic mass. Ninety-four patients (41 women, 53 men; age range 32-87 years) with a suspected pancreatic tumor underwent preoperative staging with MRI on a 1.5-T system. The MRI protocol included breath-hold MR cholangiopancreatography in turbo spin-echo technique, biphasic contrast-enhanced 3D MR angiography, and MRI of the upper abdomen with breath-hold T2-weighted half-Fourier acquired single-shot turbo spin-echo and T1-weighted fast-low-angle-shot (pre- and postcontrast) sequences. Data were collected prospectively and analyzed by two radiologists in agreement modality. Evaluation criteria were vascular involvement, resectability, and a characterization benign vs malignant. Results were compared to histopathology in 78 patients. Sixteen patients were followed-up. In 74 of 94 patients a solid tumor or an inflammation of the pancreas ( n=62) or the papilla ( n=12) was detected. In this group, MRI had a sensitivity of 98%, a specificity of 92%, and an accuracy of 96% in the characterization of malignant tumors. Regarding only the solid tumors, the positive predictive value of MRI was 87% with respect to resectability. Other pathologic findings included adenoma or inflammation of the duodenum ( n=5), carcinoma or benign stenosis of the choledochus duct ( n=7) and carcinoma of the gall bladder ( n=2). In 6 patients MRI did not depict any pathologic findings, and follow-up confirmed this interpretation. Magnetic resonance imaging allows a local preoperative staging in patients with suspected pancreatic tumor. Limitations, however, concern to the diagnostics of peritoneal and/or liver metastases.

Prospective Evaluation of Magnetic Resonance Imaging in the Management of Acute Diabetic Foot Infections

Infectious complications of the foot are a major cause of morbidity and mortality in diabetic patients. This prospective study evaluated the ability of MRI to adequately direct the medical and surgical management of 41 diabetic patients with acute foot infections. Forty-seven MRI scans of the foot in question were performed and classified as consistent with osteomyelitis, abscess, cellulitis or diffuse soft tissue infection, or any combination of these. Twenty-seven scans were negative or showed ill-defined soft tissue infection, or superficial cellulitis. Nineteen of these infections were treated nonoperatively and 17 resolved without surgical intervention. MRI was unsuccessful in directing management in one patient in whom an abscess spontaneously drained but was not seen on an MRI scan 4 days earlier. Eight scans revealed focal osteomyelitis and all eight of these patients were successfully managed with one operation. MRI showed a focal abscess in 12 patients, and adequate drainage was achieved without excessive disruption of uninvolved tissue planes in 11 of these patients. The remaining patient required a major amputation from the outset. Based on clinical outcome during the acute hospitalization period, operative findings, and/or pathologic confirmation, the positive predictive value of MRI in defining infectious pathology in the foot was 100% in this series of 20 positive scans. The negative predictive value of MRI was 96%. On the basis of this experience, we conclude that MRI is a diagnostic modality particularly well suited to evaluate acute diabetic foot infections and reliably aids in the management of acute infection to avoid exploration and debridement of uninvolved tissue.(ABSTRACT TRUNCATED AT 250 WORDS)