Magnetic Resonance Imaging Appearance Research Articles

Subchondral insufficiency fractures: overview of MRI findings from hip to ankle joint.

Subchondral insufficiency fracture (SIF) represents a potentially severe condition that can advance to osteoarthritis, with collapse of the articular surface. SIF manifests as a fracture in bone weakened by non-tumorous disease, precipitated by repetitive physiological stress, without a clear history of major trauma. It is observed along the central weight-bearing region of the femoral condyle, with a higher incidence in the medial femoral condyle, but also in other large weight-bearing synovial joints, such as the femoral head, tibial plateau, or talus.A review of the literature from the past six years was performed by searching PubMed and ScienceDirect databases, using the keywords "subchondral insufficiency fracture" and "spontaneous osteonecrosis of the knee". The inclusion criteria were scientific papers presented in the English language that reported on the magnetic resonance imaging (MRI) aspects of SIF of the lower limb.Detecting SIF at the level of the hip, knee, and ankle may present challenges both clinically and radiologically. The MRI appearance is dominated by a bone marrow edema-like signal and subchondral bone changes that can sometimes be subtle. Subchondral abnormalities are more specific than the pattern of bone marrow edema-like signal and are best shown on T2-weighted and proton-density-weighted MR images. MRI plays an important role in accurately depicting even subtle subchondral fractures at the onset of the disease and proves valuable in follow-up, prognosis, and the differentiation of SIF from other conditions. · Subchondral insufficiency fractures may affect the hip, knee, and ankle.. · Subchondral insufficiency fractures may heal spontaneously or progress to collapse.. · MRI is important for the detection, follow-up, and prognosis of subchondral insufficiency fractures.. · Differential diagnosis may include transient osteoporosis and osteonecrosis of systemic origin.. · Buturoiu MM, Ghiea S, Weber M. Subchondral insufficiency fractures: overview of MRI findings from hip to ankle joint. Fortschr Röntgenstr 2024; DOI 10.1055/a-2344-5337.

Ureteral endometriosis: MR imaging appearance for predicting complex procedures

Ureteral endometriosis: MR imaging appearance for predicting complex procedures

Tibial-sided Anterolateral Ligament Injuries Are Associated With Poor Healing and Residual Pivot Shift Testing After Anterior Cruciate Ligament Reconstruction

Purpose; to investigate if tibial sided anterolateral ligament (ALL) injuries are associated with poor healing and residual pivot shift. Methods; Patients who underwent anterior cruciate ligament reconstructions within postinjury 6 weeks from January 2008 to March 2021 were included. They had concomitant ALL injury confirmed by preoperative magnetic resonance imaging (MRI) and were followed minimum 20 months. Preoperative ALL injury was graded by the Muramatsu classification and postoperative ALL healing were graded by a modification of the Lee classification (good, partial, and non-visualized). The patients were allocated to an improved group (IG) and an unimproved group (UG) based on a comparison of pre- and postoperative MRI. ALL tear site, postoperative knee stability, Lysholm score, and Tegner activity scale (PROs) were compared between the two groups. Results; 128 patients were enrolled. 94.5 % patients achieved the minimal clinically important difference (MCID) for PROs, respectively. The ALL was torn at the femoral side in 46.9% patients, at mid-substance in 31.2.%, and at tibial side in 21.9%, Preoperatively, 86 (67.2%) patients had a partial tear and 42 (32.8%) patients had a complete tear. Based on the postoperative MRI appearances, 38 (29.7%) and 90 (70.3%) patients were allocated to the IG and UG, respectively. The tibial side tears were significantly frequent in UG (p= .032). Pivot shift showed a significantly higher incidence in UG than IG (p=.004). Lachman test and PROs did not differ between the two groups. Conclusions; Tibial-sided ALL tears occurred in 18.7% of the UG compared to 3.2% of the IG, and 45.6% of the UG had a postoperative grade 1 or 2 pivot shift, compared to 15.8% of the IG. Percentages of patients with the MCID for PROs did not differ between the two groups. However, the clinical relevance is limited by a high transfer bias.

Comparing MRI and arthroscopic appearances of common knee pathologies: A pictorial review.

Knee pathology, including anterior cruciate ligament (ACL) tears, meniscal tears, articular cartilage lesions, and intra-articular masses or cysts are common clinical entities treated by orthopedic surgeons with arthroscopic surgery. Preoperatively, magnetic resonance imaging (MRI) is now standard in confirming knee pathology, particularly detecting pathology less evident with history and physical examination alone. The radiologist's MRI interpretation becomes essential in evaluating intra-articular knee structures. Typically, the radiologist that interprets the MRI does not have the opportunity to view the same pathology arthroscopically. Thus, the purpose of this article is to illustratively reconcile what the orthopedic surgeon sees arthroscopically with what the radiologist sees on magnetic resonance imaging when viewing the same pathology. Correlating virtual and actual images can help better understand pathology, resulting in more accurate MRI interpretations. In this article, we present and review a series of MR and correlating arthroscopic images of ACL tears, meniscal tears, chondral lesions, and intra-articular masses and cysts. Short teaching points are included to highlight the importance of radiological signs and pathological MRI appearance with significant clinical and arthroscopic findings.

Abstract PS05-03: MagSense® HER2, a Molecularly Targeted Magnetic Resonance Imaging Agent for the Detection of Axillary Nodal Metastasis in Subjects with Human Epidermal Growth Factor Receptor 2 Positive (HER2+) Breast Cancer

Abstract Background Precise nodal staging is critical in guiding systemic and regional treatments including surgery in the management of breast cancer. Regional nodal assessment includes axillary imaging (mostly by ultrasound) and lymph node sampling. Since imaging findings suggestive of nodal metastasis are based on size and morphologic changes and not specific to tumor type, pathologic confirmation through either biopsy or removal of sentinel lymph node (SLN) remains the gold standard. Imagion is developing the MagSense® HER2 Imaging Agent (MSH2IA), an anti-human epidermal growth factor receptor 2 (HER2) conjugated with iron oxide nanoparticles, for the detection of nodal metastasis in HER2+ breast cancer patients. MSH2IA is currently being investigated in a first-in-human phase 1 study (ACTRN12621000126819) in HER2+ breast cancer patients who are diagnosed to have suspicious nodes by conventional imaging. Methods The key objectives of the phase 1 study are safety and tolerability of MSH2IA and confirmation that MSH2IA drains to the axillary lymph nodes. The study also explores MSH2IA’s ability to detect metastatic nodes when used with magnetic resonance imaging (MRI), with tumor status assessed by standard tissue histopathology. All eligible subjects receive a 22.5 mg (iron equivalent) subareolar or peritumoral injection of MSH2IA. MRI of the axilla are obtained before and 24 to 72 hours after MSH2IA injection. Core biopsy or dissection of a node suspicious by ultrasound is obtained for histopathology assessments. After completing the first cohort of 6 subjects, the protocol was amended to include the insertion of an MRI compatible clip in a node suspicious by ultrasound to localize the suspicious node for core biopsy and postdose MRI scan. Review of MRI scans and histopathology are performed in respective central laboratories. Results Thirteen participants with HER2+ breast cancer have completed the study. MSH2IA appears safe and well tolerated. The imaging agent, as administered, is detectable by MRI and pathology, confirming that MSH2IA drains to the lymph nodes via the chosen route of administration. In postdose MRI scans, study central radiologists reported distinct and differentiable MRI appearance in morphologically normal and suspicious nodes. The presence of a distinct postdose MR image appearance was confirmed by a group of independent radiologists in a separate blinded review. While normal nodes appeared with homogeneous hypointensity, morphologically suspicious nodes showed partial irregular darkening and/or speckled heterogeneous hypointensity. In evaluable subjects, histopathology of the core biopsies obtained from the clipped nodes confirmed the presence of HER2+ nodal metastasis, providing preliminary evidence for node-level concordance between MRI vs pathology observations. Safety, imaging, and pathology results from all available subjects will be presented. This phase 1 study in Australia will be closing enrollment by July 31, 2023. A phase 2 study in the United States and elsewhere is being planned with the objectives of optimizing dose, schedule, and imaging parameters for best diagnostic performance for clinical utility. Conclusion Available data from the ongoing phase 1 study show that MSH2IA appears safe and drains to the axillary lymph nodes. MSH2IA displays a distinct and differentiable MRI appearance in nodes morphologically highly suspicious for tumor, which is confirmed to be HER2+ metastasis by histopathology by node level concordance. This data provides preliminary proof of principle for the mechanism of molecularly targeted MR imaging and suggests that MSH2IA has the potential to provide tumor-specific MR imaging not currently available in conventional axillary imaging. Citation Format: Jane Fox, Shanta Velaiutham, Natalie Yang, Eddie lau, Kowsi Murugappan, Beena Kumar, Alex Laslowski, Koushik Govindarajan, Steven Reich, Stephen Thomas, Nitika Neha, Marie Zhang, Isaac Bright. MagSense® HER2, a Molecularly Targeted Magnetic Resonance Imaging Agent for the Detection of Axillary Nodal Metastasis in Subjects with Human Epidermal Growth Factor Receptor 2 Positive (HER2+) Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS05-03.

Magnetic Resonance Imaging Features of the Sphenoid Sinus in Patients with Non-Functioning Pituitary Adenoma.

Background and Objectives: A magnetic resonance imaging (MRI) scan is part of the diagnostic protocol in pituitary adenoma patients. The goal of the present study is to present and analyse the MRI appearances of the sphenoid sinus (SS) in patients with non-functioning pituitary adenoma (NFPA). Materials and Methods: This is a retrospective case-control study conducted between January 2015 and December 2023 in a tertiary referral hospital. Forty NFPA patients were included in the study group, while the control group consisted of 30 age- and gender-matched cases. Results: The sellar type of SS pneumatization was the most frequently encountered pattern among both groups. The presence of the lateral recess of the SS, mucosal cysts, and sphenoethmoidal cells was similar in both patient groups. The proportion of patients with SS mucosal thickness greater than 3 mm was 42.5% in NFPA group and 3% in the control group, and this difference was statistically significant (p < 0.001). The space between the two optic nerves was significantly larger in the NFPA group as compared to the control group (p < 0.001). Conclusions: Our study was able to establish a statistically significant association between the presence of NFPA and both the thickening of the SS mucosa and increased space between optic nerves.

Hippocampal sclerosis and temporal lobe epilepsy following febrile status epilepticus: The FEBSTAT study.

This study was undertaken to determine whether hippocampal T2 hyperintensity predicts sequelae of febrile status epilepticus, including hippocampal atrophy, sclerosis, and mesial temporal lobe epilepsy. Acute magnetic resonance imaging (MRI) was obtained within a mean of 4.4 (SD = 5.5, median = 2.0) days after febrile status on >200 infants with follow-up MRI at approximately 1, 5, and 10 years. Hippocampal size, morphology, and T2 signal intensity were scored visually by neuroradiologists blinded to clinical details. Hippocampal volumetry provided quantitative measurement. Upon the occurrence of two or more unprovoked seizures, subjects were reassessed for epilepsy. Hippocampal volumes were normalized using total brain volumes. Fourteen of 22 subjects with acute hippocampal T2 hyperintensity returned for follow-up MRI, and 10 developed definite hippocampal sclerosis, which persisted through the 10-year follow-up. Hippocampi appearing normal initially remained normal on visual inspection. However, in subjects with normal-appearing hippocampi, volumetrics indicated that male, but not female, hippocampi were smaller than controls, but increasing hippocampal asymmetry was not seen following febrile status. Forty-four subjects developed epilepsy; six developed mesial temporal lobe epilepsy and, of the six, two had definite, two had equivocal, and two had no hippocampal sclerosis. Only one subject developed mesial temporal epilepsy without initial hyperintensity, and that subject had hippocampal malrotation. Ten-year cumulative incidence of all types of epilepsy, including mesial temporal epilepsy, was highest in subjects with initial T2 hyperintensity and lowest in those with normal signal and no other brain abnormalities. Hippocampal T2 hyperintensity following febrile status epilepticus predicted hippocampal sclerosis and significant likelihood of mesial temporal lobe epilepsy. Normal hippocampal appearance in the acute postictal MRI was followed by maintained normal appearance, symmetric growth, and lower risk of epilepsy. Volumetric measurement detected mildly decreased hippocampal volume in males with febrile status.

Local Tumor Progression Predictive Model Based on MRI for Colorectal Cancer Liver Metastases after Radiofrequency Ablation.

To investigate the post-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) characteristics in patients with liver metastases from colorectal cancer and to build a predictive model for local tumor progression based on these imaging markers. A cohort of 73 patients with 110 colorectal cancer liver metastases (CRCLM) who underwent RFA and MRI one month post-ablation was included in image signs analysis and predictive model training. Using a newly developed MRI appearance scoring criteria, MR Image Appearance Scoring at One Month after RFA (MRIAS 1MO), the semi-quantitative analysis of MRI findings within the ablation zone were conducted independently by two radiologists. The intraclass correlation coefficient (ICC) was calculated to evaluate measurement reliability. Differences in MRIAS 1MO scores were compared using Mann-Whitney U test, focusing on local tumor response outcomes. Using local tumor progression (LTP) as the primary end point, MRIAS 1MO scores and other lesion morphological and clinical characteristics were included to establish predictive model. Predication accuracy was subsequently evaluated using calibration curve, time-dependent concordance index (C index) curve, and LTP-free survival (LTPFS) curve. Another cohort comprising 60 patients with 76 CRCLMs provided additional MRIAS 1MO scores and clinical data associated with LTP. We evaluated the performance of the established predictive model using calibration curve, time-dependent C index curve, and LTPFS curve. The MRIAS 1MO criteria exhibited strong measurement reliability. The ICC values of T1S (scores from T1WI), T2S (scores form T2WI) and NCES (scores by adding T1S to T2S) MRIS (the overall scores) were 0.825, 0.779, 0.826 and 0.873, respectively. Lesions with LTP showed significantly higher median values for the overall MRIAS 1MO score (MRIS) compared to lesions without LTP (16 vs. 12, p < 0.001). MRIS and lesion diameter were independent prognostic factors of LTP and were included in predictive model (hazard ratio: MRIS over 13.5:4.275, lesion diameter larger than 30 mm: 2.056). The predictive model demonstrated an overall C index of 0.721 and risk stratification using the predictive model resulted in significantly different LPTFS times. In the validation cohort, the C index were 0.825, 0.794 and 0.764 at six, twelve and twenty-four months, respectively. Patients classified as high-risk in the validation cohort had a median LTPFS time of 10.0 months, while the median LTPFS time was not reached in the low-risk group. The semi-quantitative MRIAS 1MO criteria, used for post-RFA MRI appearance analysis, exhibited strong measurement reliability. Prediction models established based on overall MRIAS 1MO score (MRIS) and lesion diameter had good predictive performance for LTP in patients undergoing RFA for CRCLM treatment.

The Role of Radiation Therapy in the Management of Prostate Cancer and Posttreatment Imaging Appearances

AbstractProstate cancer remains a significant global health concern, necessitating continuous research and innovation in treatment modalities. This review explores the currently employed techniques in radiation dose planning and tumor irradiation in the context of prostate cancer management. In addition, we delve into the nuances of expected posttreatment magnetic resonance imaging (MRI) appearances within the gland or in the prostate bed, postradiation tumor recurrence, and its mimics.Radiation therapy (RT) has evolved as a cornerstone in prostate cancer treatment, offering both curative and palliative solutions. Recent developments have seen the emergence of advanced techniques such as intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT), allowing for precise targeting of cancer cells while minimizing damage to surrounding healthy tissue.The avoidance of normal tissue dose through more conformal dose distribution as in IMRT or proton therapy, improved imaging modalities as in multiparametric magnetic resonance imaging (mpMRI) and prostate positron emission tomography (PET), interventional separation of critical structures from the prostate target, and many other techniques can greatly reduce the side effects of RT. These advancements enhance treatment efficacy and reduce the risk of side effects, promoting improved patient outcomes.

Rotator cuff tear patterns: MRI appearance and its surgical relevance.

A new perspective on rotator cuff anatomy has allowed a better understanding of the patterns of the different rotator cuff tears. It is essential for radiologists to be aware of these different patterns of tears and to understand how they might influence treatment and surgical approach. Our objective is to review the arthroscopy correlated magnetic resonance imaging appearance of the different types of rotator cuff tears based on current anatomical concepts.Critical relevance statement Knowledge of the characteristics of rotator cuff tears improves our communication with the surgeon and can also make it easier for the radiologist to prepare a report that guides therapeutic conduct and serves as a prognosis for the patient.Key points• There is no universally accepted classification for RC tears.• New patterns such as delamination or myotendinous junction tears have been defined.• The most difficult feature to assess in full thickness tears on MRI is the pattern.• Fatty infiltration of the RC tendons is crucial in the prognosis and outcome.• The radiological report is an effective way of communication with the surgeon.

Brown adipose tissue – magnetic resonance imaging (MRI) appearance of these physiological fat deposits in a newborn

Brown adipose tissue (BAT) is responsible for thermogenesis in neonates and infants in response to cold environment. 18F-fluorodeoxyglucose positron emission tomography is the reference for imaging of BAT, but it is a functional imaging modality and hence lacks sensitivity due to varying patient and environmental factors. Magnetic resonance imaging (MRI) lacks the use of radioactivity and ionizing radiation and can prove to be an excellent imaging modality to study the distribution of BAT. We report a neonate with sepsis whose MRI study of the neck and upper chest done to look for infective focus revealed classical distribution and signal intensity of BAT.

Prevalence of middle ear effusion in French bulldogs without clinical signs of otic disease: A retrospective study of magnetic resonance imaging (2017-2022).

Canine middle ear effusion (MEE) is usually asymptomatic, being an incidental finding when computed tomography or magnetic resonance imaging (MRI) of the head is performed for other reasons unrelated to otic disease. The clinical relevance of the presence of material in the tympanic bulla (TB) remains uncertain, and more detail about its prevalence and appearance in MRI are required. To assess the prevalence of presence of material within the TB of French bulldogs (FB) with no clinical signs suggestive of otitis (externa, media or interna) that underwent high-field MRI for other medical reasons. Two hundred fifty-two TB of 126 FB were included in this study. Nonexperimental retrospective study in which MRI images were evaluated by a board-certified veterinary radiologist. Fifty-eight per cent of the dogs had material in the TB lumen (46% of the TB) and 59% were bilaterally affected. The signal intensity of this material related to the grey matter was variable on T1w and mainly hyperintense on T2w sequences. FB are predisposed to MEE. This is important when assessing imaging studies of TB of FB with chronic otitis externa, as high percentage of cases may have concurrent MEE. MRI findings in FB with MEE are characterised by a hyperintense signal to the grey matter on T2w in most cases and variable on T1w sequences.

Incidental Thalamic Lesions Identified on Brain MRI in Pediatric and Young Adult Patients: Imaging Features and Natural History.

Nonspecific, localized thalamic signal abnormalities of uncertain significance are occasionally found on pediatric brain MR imaging. The goal of this study is to describe the MR imaging appearance and natural history of these lesions in children and young adults. This retrospective study evaluated clinically acquired brain MR imaging examinations obtained from February 1995 to March 2022 at a large, tertiary care pediatric hospital. Examinations with non-mass-like and nonenhancing thalamic lesions were identified based on term search of MR imaging reports. A total of 221 patients formed the initial group for imaging assessment. Additional exclusions during imaging review resulted in 171 patients. Imaging appearance and size changes were assessed at baseline and at follow-up examinations. A total of 171 patients (102 male) at a median age of 11 years (range: 1-23 years), 568 MR imaging examinations, and 180 thalamic lesions were included. Median time from baseline to the last follow-up MR imaging was 542 days (range: 46-5730 days). No lesion enhanced at any time point. On imaging follow-up, 11% of lesions (18/161) became smaller, 10% (16/161) resolved, 73% (118/161) remained stable, and 6% (9/161) increased in size at some point during evaluation. Median time interval from baseline to enlargement was 430 days (range: 136-1074 days). Most incidental, non-mass-like thalamic signal abnormalities were stable, decreased in size, or resolved on follow-up imaging and are likely of no clinical significance. Surveillance strategies with longer follow-up intervals may be adequate in the management of such findings.

Lead Encephalopathy in a 73-year-old Man Manifesting as Acute Disturbance of Consciousness with a Unique Magnetic Resonance Imaging Appearance.

A 73-year-old man was admitted with Cheyne-Stokes respiration and progressive disturbance of consciousness over the course of a month. Cranial magnetic resonance imaging revealed signs suggestive of angioedema in the posterior limb of the internal capsule, external capsule, and subcortical white matter. Acute lead encephalopathy was diagnosed based on abnormally high plasma lead levels. After methylprednisolone pulse therapy followed by chelation therapy, the patient fully recovered. In this case, the angioedema with a distinctive magnetic resonance imaging appearance was attributed to the cytotoxic effects of lead on the nervous system, which responded well to methylprednisolone pulse therapy.

Radiogenomics Provides Insights into Gliomas Demonstrating Single-Arm 1p or 19q Deletion.

IDH-mutant gliomas are further divided on the basis of 1p/19q status: oligodendroglioma, IDH-mutant and 1p/19q-codeleted, and astrocytoma, IDH-mutant (without codeletion). Occasionally, testing may reveal single-arm 1p or 19q deletion (unideletion), which remains within the diagnosis of astrocytoma. Molecular assessment has some limitations, however, raising the possibility that some unideleted tumors could actually be codeleted. This study assessed whether unideleted tumors had MR imaging features and survival more consistent with astrocytomas or oligodendrogliomas. One hundred twenty-one IDH-mutant grade 2-3 gliomas with 1p/19q results were identified. Two neuroradiologists assessed the T2-FLAIR mismatch sign and calcifications, as differentiators of astrocytomas and oligodendrogliomas. MR imaging features and survival were compared among the unideleted tumors, codeleted tumors, and those without 1p or 19q deletion. The cohort comprised 65 tumors without 1p or 19q deletion, 12 unideleted tumors, and 44 codeleted. The proportion of unideleted tumors demonstrating the T2-FLAIR mismatch sign (33%) was similar to that in tumors without deletion (49%; P = .39), but significantly higher than codeleted tumors (0%; P = .001). Calcifications were less frequent in unideleted tumors (0%) than in codeleted tumors (25%), but this difference did not reach statistical significance (P = .097). The median survival of patients with unideleted tumors was 7.8 years, which was similar to that in tumors without deletion (8.5 years; P = .72) but significantly shorter than that in codeleted tumors (not reaching median survival after 12 years; P = .013). IDH-mutant gliomas with single-arm 1p or 19q deletion have MR imaging appearance and survival that are similar to those of astrocytomas without 1p or 19q deletion and significantly different from those of 1p/19q-codeleted oligodendrogliomas.

Magnetic Resonance Imaging of the Shoulder: Interpretation of Common Orthopaedic Injuries.

Magnetic resonance imaging (MRI) is frequently obtained to assess for pathology in the setting of shoulder pain and dysfunction. MRI of the shoulder provides diagnostic information that helps optimize patient management and surgical planning. Both general and subspecialized orthopaedic surgeons routinely order and review shoulder MRIs in practice. Therefore, familiarity with the MRI appearance of common shoulder pathologies is important. This document reviews the most common shoulder pathologies using a standardized MRI interpretative approach. Instructional videos demonstrating a musculoskeletal radiologist interpreting normal and abnormal shoulder MRIs are also provided.

Multiparametric MRI characteristics of prostatitis and atrophy in the peripheral zone in men without prostate cancer

PurposeTo analyse multiparametric magnetic resonance imaging (mpMRI) characteristics and appearance of histopathologically proven non-cancerous intraprostatic findings focussing on quantity of prostatitis and atrophy in the peripheral zone. MethodIn this retrospective analysis consecutive patients with mpMRI followed by MRI/TRUS-fusion biopsy comprising targeted (TB) and systematic biopsy (SB) cores without prostate cancer (PC) at histopathology were included. Subgroup analysis was performed in younger men (≤50 years). The proportions of prostatitis and atrophy were quantified for each biopsy core based on histopathology. MRI findings in the peripheral zone (PZ) and index lesions (IL, most suspicious/representative lesion) were characterized regarding changes in T2w, ADC value, and enhancement of dynamic contrast enhancement (DCE) and correlated with quantity of prostatitis and atrophy. ResultsSeventy-two patients were analysed. The median baseline characteristics were PSA 5.4 ng/ml (4.0–7.9), PI-RADS classification 3 (2–4), prostate volume 43 ml (33–57), and PSA density 0.13 ng/ml2 (0.10–0.19). Prostatitis was found in 44 % (n = 32) and atrophy in 65 % (n = 47) of cases. The quantity of atrophy demonstrated a significant correlation to T2w changes, ADC increase and DCE enhancement (p = 0.05, p = 0.05, p = 0.01), whereas quantity of prostatitis did not show any significant correlation to the MRI changes (p = 0.68, p = 0.58, p = 0.95). Quantity of prostatitis and atrophy increased with PI-RADS classification. Younger men had lower PSA (4.4 vs. 7.8 ml/ng; p < 0.001), smaller prostate volume (40 vs. 59 ml; p = 0.001), and lower PI-RADS classification (2–3 vs. 3–4; p = 0.005) and prostatitis and atrophy were less frequently observed (p ≤ 0.01, p = 0.03). ConclusionsQuantity of atrophy and prostatitis had different influence on MRI characteristics and increased within higher PI-RADS classification. Younger men had diffuse hypointense changes at T2w images, but less quantity of prostatitis and atrophy.

MR Imaging Appearance of Ruptured Rathke Cleft Cyst and Associated Bone Marrow Enhancement.

Rathke cleft cysts are common cystic pituitary lesions seen on MR imaging. A subset of Rathke cleft cysts can rupture within the sella and are uncommon. The imaging appearance of a ruptured Rathke cleft cyst has been previously described with nonspecific imaging findings. We present 7 cases of ruptured Rathke cleft cysts and basisphenoid bone marrow enhancement below the sella that could be used to potentially distinguish a ruptured Rathke cleft cyst from other cystic lesions.

“Leopard skin” sign: Magnetic resonance imaging appearance of Lhermitte-Duclos disease with histopathologic correlation

Dysplastic cerebellar gangliocytoma or Lhermitte-Duclos disease (LDD) is a rare hamartomatous malformation of cerebellum that can occur in isolation or as a component of Cowden syndrome. Although uncommon, the characteristic clinical symptoms and magnetic resonance imaging (MRI) features are highly suggestive of the condition and histopathological features confirm the diagnosis. We report a case of LDD, presenting with “Leopard skin” appearance of the lesion on MRI with a brief review of imaging, clinical, and histopathological features.

MRI in Evaluation of Rectal Cancer pre- and post-Chemo-Radiation Treatment.

Rectal cancer is associated with a high risk of metastases and local recurrence; local recurrence rates after surgical treatment being up to 32%. An accurate local staging at the time of initial diagnosis is therefore very important. Magnetic Resonance Imaging (MRI) is already established as an accurate tool for the preoperative staging of rectal cancer and has resulted in marked improvements in staging accuracy.&#x0D; Material and Methods: This study used MRI in comparing the morphologic features of rectal cancer before and after 8 weeks of chemo-radiation treatment (CRT) and to correlate the post treatment MRI appearances with the histological findings in resected tumors. 45 patients with histo-pathologically proven rectal adenocarcinoma received standardized 8 weeks chemo-radiation therapy and subjected to MRI before and after treatment for clinical staging. A correlation between pathological response and MRI findings was done.&#x0D; Results: The MRI diagnostic accuracy to diagnose T2 is 74.2% with relatively low specificity (64.7%). The diagnostic accuracy of MRI in evaluation of stage T3 and T4, the MRI sensitivity was 96.2% however of low specificity 26.3%. The diagnostic accuracy was 66.7%. Additionally, in evaluation of T2 stage, the sensitivity of MRI was very low 27.3% and specificity relatively high 94.7%. Diagnostic accuracy was 70%.&#x0D; Post RCT, based on downstaging after CRT, the sensitivity of MRI to show no tumor was very low 0% with diagnostic accuracy 88.9%. However, to evaluate stage T2, the sensitivity was 84.6% with low specificity 66.7% and the diagnostic accuracy was 74.2%.&#x0D; Conclusion: MRI had an accuracy average of 81.6% in T stage and 68.9% in N stage in re-staging rectal tumors after CRT. Over-staging results of majority of the inaccuracy. The statistical agreement between post-CRT MRI and the pathologic staging involving T and N stages was not satisfactory. In view of the above, Post CRT, restaging rectal cancer remains a challenge.