Factors affecting the outcome of extraperitoneal laparoscopic radical prostatectomy: pelvic arch interference and depth of the pelvic cavity

Purpose

To determine the effect of pelvic arch interference and the depth of the pelvic cavity, as shown on preoperative magnetic resonance imaging (MRI), on the performance of extraperitoneal laparoscopic radical prostatectomy (ELRP).

Materials and Methods

In 115 patients, pelvic bone images were obtained at the time of prostate MRI before ELRP. In the reconstructed sagittal plane, we measured the true conjugate diameter, the obstetric conjugate diameter, the difference between the true and obstetric diameters, and the distance between the true conjugate and the prostate apex (pelvic depth). We analyzed which factors were associated with operative time (OT), estimated blood loss (EBL), and positive surgical margins (PSMs).

Results

The difference between the true and obstetric conjugate diameters was 12.7±3.7 mm, and the pelvic depth was 59.9±6.0 mm. The OT, EBL, and the rate of PSMs were 260.1±91.1 minutes, 633.3±524.7 ml, and 19% (22/115), respectively. According to multiple linear regression analysis, predictors of a higher EBL included pelvic depth (3.0% higher per 1 mm increase in diameter difference, p=0.01) and prostate volume (1.5% higher per 1 cc increase in prostate volume, p=0.002). Factors associated with a longer OT were pelvic depth (p=0.04), serum prostate-specific antigen (p=0.04), prostate volume (p=0.02), and Gleason score (p=0.001). For PSMs, only pT2 was an independent factor.

Conclusions

Our results suggest that the depth of the pelvic cavity and prostate volume may increase surgical difficulty in patients undergoing ELRP.

Current trends in staging rectal cancer

Management of rectal cancer has evolved over the years. In this condition preoperative investigations assist in deciding the optimal treatment. The relation of the tumor edge to the circumferential margin (CRM) is an important factor in deciding the need for neoadjuvant treatment and determines the prognosis. Those with threatened or involved margins are offered long course chemoradiation to enable R₀ surgical resection. Endoanal ultrasound (EUS) is useful for tumor (T) staging; hence EUS is a useful imaging modality for early rectal cancer. Magnetic resonance imaging (MRI) is useful for assessing the mesorectum and the mesorectal fascia which has useful prognostic significance and for early identification of local recurrence. Computerized tomography (CT) of the chest, abdomen and pelvis is used to rule out distant metastasis. Identification of the malignant nodes using EUS, CT and MRI is based on the size, morphology and internal characteristics but has drawbacks. Most of the common imaging techniques are suboptimal for imaging following chemoradiation as they struggle to differentiate fibrotic changes and tumor. In this situation, EUS and MRI may provide complementary information to decide further treatment. Functional imaging using positron emission tomography (PET) is useful, particularly PET/CT fusion scans to identify areas of the functionally hot spots. In the current state, imaging has enabled the multidisciplinary team of surgeons, oncologists, radiologists and pathologists to decide on the patient centered management of rectal cancer. In future, functional imaging may play an active role in identifying patients with lymph node metastasis and those with residual and recurrent disease following neoadjuvant chemoradiotherapy.

Primary clear cell carcinoma in the liver: CT and MRI findings

AIM: To retrospectively analyze the computed tomography (CT) and magnetic resonance imaging (MRI) appearances of primary clear cell carcinoma of the liver (PCCCL) and compare the imaging appearances of PCCCL and common type hepatocellular carcinoma (CHCC) to determine whether any differences exist between the two groups.

METHODS: Twenty cases with pathologically proven PCCCL and 127 cases with CHCC in the Second Affiliated Hospital of Sun Yat-sen University were included in this study. CT or MRI images from these patients were retrospectively analyzed. The following imaging findings were reviewed: the presence of liver cirrhosis, tumor size, the enhancement pattern on dynamic contrast scanning, the presence of pseudo capsules, tumor rupture, portal vein thrombosis and lymph node metastasis.

RESULTS: Both PCCCL and CHCC were prone to occur in patients with liver cirrhosis, the association rate of liver cirrhosis was 80.0% and 78.7%, respectively (P > 0.05). The mean sizes of PCCCL and CHCC tumors were (7.28 ± 4.25) cm and (6.96 ± 3.98) cm, respectively. Small HCCs were found in 25.0% (5/20) of PCCCL and 19.7% (25/127) of CHCC cases. No significant differences in mean size and ratio of small HCCs were found between the two groups (P = 0.658 and 0.803, respectively). Compared with CHCC patients, PCCCL patients were more prone to form pseudo capsules (49.6% vs 75.0%, P = 0.034). Tumor rupture, typical HCC enhancement patterns and portal vein tumor thrombosis were detected in 15.0% (3/20), 72.2% (13/18) and 20.0% (4/20) of patients with PCCCL and 3.1% (4/127), 83.6% (97/116) and 17.3% (22/127) of patients with CHCC, respectively. There were no significant differences between the two groups (all P > 0.05). No patients with PCCCL and 2.4% (3/127) of patients with CHCC showed signs of lymph node metastasis (P > 0.05).

CONCLUSION: The imaging characteristics of PCCCL are similar to those of CHCC and could be useful for differentiating these from other liver tumors (such as hemangioma and hepatic metastases). PCCCLs are more prone than CHCCs to form pseudo capsules.

Sprengel deformity: magnetic resonance imaging findings in two pediatric cases

The characteristics of Sprengel deformity, which is also called congenital high scapula, are malposition and dysplasia of the affected scapula, with possible omovertebral connection. The aim of the present study was mainly to present the magnetic resonance imaging (MRI) findings of two pediatric cases of Sprengel deformity. A 7-year-old girl and a 9-year-old boy with deformities in their right shoulder were studied. Plain radiographs were obtained. MRI was performed for both children. The fibrous omovertebral connection is depicted in its longest form in one plane. Omovertebral band is best screened in coronal and axial cross sections. We are introducing a new MRI sign which we named as "Ra's eye" to define the appearance of omovertebral band within the surrounding fat tissue.

Orbital plasmablastic lymphoma with remission following chemotherapy

We report the case of a middle-aged HIV-positive man who presented with proptosis and retro-ocular pain. On CT and MR imaging, a retro-orbital enhancing mass was seen, and PET/CT revealed this lesion as well as a similarly characterized mass in the nasopharynx to be hypermetabolic. Biopsy and subsequent pathological characterization revealed this mass to be plasmablastic lymphoma (PBL), a rare form of non-Hodgkin's lymphoma associated with HIV-infection. PBL is a diffuse B-cell lymphoma with characteristic cell marker patterns. The most common site of this malignancy is within the oral cavity. This case constitutes an unusual orbital manifestation of plasmablastic lymphoma as well as an unusual case in its response to chemotherapy. This case illustrates the importance of functional imaging with PET/CT in the diagnosis, management, and follow-up of plasmablastic lymphoma.

A patient with splenic marginal zone lymphoma presenting with spastic paraplegia as the initial symptom

In this report, we describe the case of a patient with splenic marginal zone lymphoma (SMZL) who presented with spastic paraplegia as the initial symptom. A 42-year-old male developed progressive spastic paraplegia over 4 months. His neurologic examination revealed paraplegia with pyramidal syndrome, hypoesthesia below the T1 level, and anal hypotonia. Magnetic resonance imaging (MRI) of the spinal cord revealed an extensive high-intensity signal in T2-weighted sequences and swelling involving the thoracic region and conus medullaris. A laboratory test revealed presence of the serum M component. Abdominal computed tomography images showed moderate splenomegaly. Abnormal lymphocytes of B-cell lineage markers (CD19+, CD20+, and CD25+; surface immunoglobulin κ expression; IgD+ and IgM+) were found in the peripheral blood, cerebrospinal fluid, bone marrow and spleen. Splenectomy confirmed the SMZL diagnosis. After the completion of chemotherapy, the patient was in complete remission, and spinal MRI findings were normal. Intramedullary spinal cord involvement in SMZL is extremely rare, and, to the best of our knowledge, this is the first case of SMZL with intramedullary spinal cord involvement associated with clinical and radiologic signs without the involvement of cerebral structures. Spastic paraplegia can be the initial presentation of SMZL.

Multiparametric MRI biomarkers for measuring vascular disrupting effect on cancer

Solid malignancies have to develop their own blood supply for their aggressive growth and metastasis; a process known as tumor angiogenesis. Angiogenesis is largely involved in tumor survival, progression and spread, which are known to be significantly attributed to treatment failures. Over the past decades, efforts have been made to understand the difference between normal and tumor vessels. It has been demonstrated that tumor vasculature is structurally immature with chaotic and leaky phenotypes, which provides opportunities for developing novel anticancer strategies. Targeting tumor vasculature is not only a unique therapeutic intervention to starve neoplastic cells, but also enhances the efficacy of conventional cancer treatments. Vascular disrupting agents (VDAs) have been developed to disrupt the already existing neovasculature in actively growing tumors, cause catastrophic vascular shutdown within short time, and induce secondary tumor necrosis. VDAs are cytostatic; they can only inhibit tumor growth, but not eradicate the tumor. This novel drug mechanism has urged us to develop multiparametric imaging biomarkers to monitor early hemodynamic alterations, cellular dysfunctions and metabolic impairments before tumor dimensional changes can be detected. In this article, we review the characteristics of tumor vessels, tubulin-destabilizing mechanisms of VDAs, and in vivo effects of the VDAs that have been mostly studied in preclinical studies and clinical trials. We also compare the different tumor models adopted in the preclinical studies on VDAs. Multiparametric imaging biomarkers, mainly diffusion-weighted imaging and dynamic contrast-enhanced imaging from magnetic resonance imaging, are evaluated for their potential as morphological and functional imaging biomarkers for monitoring therapeutic effects of VDAs.

Diffuse infiltrative lesion of the breast: clinical and radiologic features

The purpose of this paper is to show the clinical and radiologic features of a variety of diffuse, infiltrative breast lesions, as well to review the relevant literature. Radiologists must be familiar with the various conditions that can diffusely involve the breast, including normal physiologic changes, benign disease and malignant neoplasm.

A giant left atrium in rheumatic mitral stenosis

Enlargement of left atrium (LA) is not infrequently observed in patients with rheumatic mitral stenosis. We recently met a patient who had a giant LA associated with severe mitral stenosis. The right ventricle had almost collapsed due to compression by the LA. Mitral valve surgery was performed for mitral stenosis and the postoperative course was uneventful. Thus, we suggest that clinicians should not delay corrective surgery for severe mitral stenosis solely on account of a huge LA.

Imaging of gastroenteropancreatic neuroendocrine tumors

Imaging of gastroenteropancreatic neuroendocrine tumors can be broadly divided into anatomic and functional techniques. Anatomic imaging determines the local extent of the primary lesion, providing crucial information required for surgical planning. Functional imaging, not only determines the extent of metastatic disease spread, but also provides important information with regard to the biologic behavior of the tumor, allowing clinicians to decide on the most appropriate forms of treatment. We review the current literature on this subject, with emphasis on the strengths of each imaging modality.

High-field MRI for diagnosis of fatty liver and fat grading: recent research progress

The incidence of fatty liver has been increasing gradually. The development of magnetic resonance imaging (MRI) has increased the sensitivity and specificity for diagnosis of fatty liver. Currently, multiple MRI methods, including fat-suppression sequence, chemical shift, contrast-enhanced MRI and magnetic resonance spectroscopy (MRS), are available for detection and quantification of fatty liver. MR fat-suppression sequence, especially opposed-phase and in-phase chemical shift gradient-echo sequence, is particularly important for detection of fatty liver. MRS is used to quantify liver fat content at the molecular level. In this article, we review the recent progress in research of high-field MRI for diagnosis of fatty liver and fat grading.

Imaging in staging and management of pancreatic ductal adenocarcinoma

Pancreatic cancer is a relatively common malignancy of the gastrointestinal tract for which complete surgical excision remains the only curative option. Being infiltrative in nature and bearing a complex anatomical relationship with various organs, peritoneal ligaments and vascular structures, accurate anatomical staging is key in treatment of these patients. In this article, we will discuss and provide a brief overview of anatomy and use of imaging in staging pancreatic cancer.

Brain imaging studies in Leber's congenital amaurosis: new radiologic findings associated with the complex trait

Purpose

To report the incidence and new findings of abnormal brain imaging studies associated with patients initially diagnosed with Leber's congenital amaurosis (LCA) without definite systemic abnormalities and to determine the need for brain imaging studies in these patients.

Methods

A retrospective review of medical records was performed in 83 patients initially diagnosed as LCA and without definite systemic abnormalities before the age of 6 months in 2 tertiary referral centers. Brain magnetic resonance imaging was performed in 31 of 83 patients (37.3%).

Results

Six of 31 patients (19%) had radiologically documented brain abnormalities. Two patients had cerebellar vermis hypoplasia, 1 patient showed an absence of septum pellucidum, 2 subjects showed mild external hydrocephalus, and 1 patient was found to have a small cerebellum.

Conclusions

Approximately one fifth of the LCA patients in whom brain imaging was performed were associated with brain abnormalities, including the absence of septum pellucidum, which has not been documented in the literature. Brain imaging is mandatory in patients primarily diagnosed with LCA, even without definite neurologic or systemic abnormalities.

Retrorectal tumors in adults: Magnetic resonance imaging findings

AIM: To retrospectively evaluate the magnetic resonance imaging (MRI) features of adult retrorectal tumors and compare with histopathologic findings.

METHODS: MRI features of 21 patients with preoperative suspicion of retrorectal tumors were analyzed based on the histopathological and clinical data.

RESULTS: Fourteen benign cystic lesions appeared hypointense on T1-weighted images, and hyperintense on T2-weighted images with regular peripheral rim. Epidermoid or dermoid cysts were unilocular, and tailgut cysts were multilocular. Presence of intracystic intermediate signal intensity was observed in one case of tailgut cyst with a component of adenocarcinoma. Six solid tumors were malignant lesions and showed heterogeneous intensity on MRI. Mucinous adenocarcinomas showed high signal intensity on T2-weighted and mesh-like enhancing areas on fat-suppressed T2-weighted images. There was a fistula between the mass and anus with an internal opening in mucinous adenocarcinomas arising from anal fistula. Gastrointestinal stromal tumors displayed low signal intensity on T1-weighted images, and intermediate to high signal intensity on T2-weighted images. Central necrosis could be seen as a high signal on T2-weighted images.

CONCLUSION: MRI is a helpful technique to define the extent of the retrorectal tumor and its relationship to the surrounding structures, and also to demonstrate possible complications so as to choose the best surgical approach.

Spinal Cord Infarction following Abdominal Surgery and Postoperative Epidural Analgaesia

Ischemic infarction is a rare cause of acute myelopathy. We report the case of a young woman admitted to Sultan Qaboos University Hospital, Oman, who developed extensive spinal cord infarction in the setting of surgical evacuation and packing of liver haematoma and post-operative epidural analgesia. She had no vascular risk factors for stroke. The vascular mechanism underlying ischemic myelopathy and the relationship to abdominal surgery and epidural analgesia are discussed.

Rapid iron loading in heart and liver in a patient with transfusion dependent thalassaemia after brief poor compliance with iron chelation therapy

Iron loading in patients with transfusion dependent thalassaemia is considered to occur primarily in the liver and, once the liver becomes saturated, other organs begin loading. We report here a splenectomised male patient who was treated for hepatitis C virus infection. Prior to starting antiviral therapy, his serum ferritin was maintained below 500 ng/ml with deferiprone monotherapy; cardiac T2* by magnetic resonance imaging was 48.8ms and hepatic T2* was 19.5ms. After twelve months of antiviral treatment during which time he was very poorly compliant with his deferoxamine chelation therapy, his ferritin had risen to 3820 ng/ml and cardiac and hepatic T2* findings were 12.7 ms and 14.5 ms respectively, indicating increased iron loading in both organs, but particularly in the heart. Fifteen months after recommencing combination chelation, his ferritin was 95 ng/ml and cardiac and hepatic T2* were 27.5 and 28.4ms respectively, indicating complete clearance of iron load in both organs. This case demonstrates that iron overload can develop rapidly and in some cases there is relatively rapid iron loading in the heart as compared to the liver.

Manic episode associated with mega cisterna magna

Mega cisterna magna is a part of "Dandy-Walker Complex" and it is characterized by the enlargement of the cisterna magna, morphologically intact vermis and cerebellar hemispheres. We report a case of manic attack in a 23-year-old man with mega cisterna magna. The patient was treated with quetiapine 1,000 mg/day and sodium valproate 1,500 mg/day and the symptoms were ameliorated within 2.5 months. In this case, mega cisterna magna and manic symptoms may be found together coincidentally or any cerebellar dysfunction due to mega cisterna magna may cause or contribute to the appearance of affective symptoms. To our knowledge, this is the first case reporting manic attack with psychotic symptoms associated with mega cisterna magna. This report suggests that any lesion in the cerebellum might contribute to the occurrences of some affective and psychotic symptoms seen in bipolar disorder.

Fibrous dysplasia of the clivus

Fibrous dysplasia (FD) of craniofacial structures is well documented, however, its involvement of the clivus is seldom described. We report a case of clival FD in a young man who presented with headache localized to the occipital area. The radiological studies revealed a monostotic disease confined to the clivus, with typical findings of hypointensity on magnetic resonance images and ground-glass density on computed tomography. The diagnosis of FD was confirmed on pathological examination of specimens taken through transsphenoidal surgery. The patient showed reduction of symptoms and no change of residual lesion on follow-up imaging taken 2.5 years later after surgery. This study includes clinical aspect, radiographic appearance, differential diagnosis and treatment strategy of this rare skull base lesion.

Neuroradiologic and neurophysiologic findings of neuralgic amyotrophy

OBJECTIVE

Neuralgic amyotrophy (NA) is a distinct clinical syndrome that is characterized by the acute onset of shoulder and arm pain, weakness, and sensory loss. The purpose of this study was to assess the clinical characteristics of NA and to determine appropriate diagnostic modalities.

METHODS

We reviewed the medical and radiologic records of 10 patients diagnosed with NA retrospectively. Neurophysiologic studies were performed in all patients and magnetic resonance neurography was performed in the last three patients.

RESULTS

A total of 10 patients were enrolled in our study. All patients had clinical findings compatible with NA. The most common clinical presentation was severe shoulder pain and weakness in seven patients (70%). Neurophysiologic study results were abnormal in all patients. Brachial plexus magnetic resonance neurography showed that the affected brachial plexus showed a thickened and hyper-intense trunk. All patients were managed conservatively with analgesics and physical therapy. The pain and paralysis of all patients improved clinically within 6 months of the initiation of treatment.

CONCLUSION

NA is a rare disease but the symptoms of NA can mimic those of other diseases. Neurophysiologic studies and magnetic resonance neurography are extremely useful tools for the diagnosis of NA.

Linear endoscopic ultrasonography vs magnetic resonance imaging in ampullary tumors

AIM: To assess linear endoscopic ultrasound (L-EUS) and magnetic resonance imaging (MRI) in biliary tract dilation and suspect small ampullary tumor.

METHODS: L-EUS and MRI data were compared in 24 patients with small ampullary tumors; all with subsequent histological confirmation. Data were collected prospectively and the accuracy of detection, histological characterization and N staging were assessed retrospectively using the results of surgical or endoscopic treatment as a benchmark.

RESULTS: A suspicion of ampullary tumor was present in 75% of MRI and all L-EUS examinations, with 80% agreement between EUS and histological findings at endoscopy. However, L-EUS and histological TN staging at surgery showed moderate agreement (κ = 0.54).

CONCLUSION: L-EUS could be a useful adjunct as a diagnostic tool in the evaluation of patients with suspected ampullary tumors.

Degeneration of the Arnold's prefrontopontocerebellar tract in a case of locked-in syndrome over a 23-year period

A 52-year-old woman has been under observation for a complete locked-in syndrome of vascular origin, since 1984. Her cognitive functions today are still normal. When first diagnosed, a CT-scan was made and 23 years later performed, a cerebral MRI was performed. A focal, bilateral and symmetric atrophy of the dorsomedial prefrontal gyri was clearly shown, contrasting with the non-atrophy of the precentral gyri (motor area), others prefrontal areas, frontopolar gyri and temporal cortices. Degeneration of the corticopontine projection, the first step in the corticopontocerebellar circuit, could explain this selective atrophy. This unique observation leads to the precise in vivo anatomical location of the Arnold tract.

Meniscopexy for internal derangement of temporomandibular joint

The term internal derangement was first adopted to describe any pathologic entity that interfered with the smooth function of the temporomandibular joint (TMJ). The term is currently used exclusively to describe alterations in disc-fossa relations. Internal derangement of the TMJ does not always cause pain, although when the disc becomes displaced, noises and locking can occur and ligamentous, capsular or retrodiscal pain may dominate the clinical picture. Meniscopexy of TMJ was done in ten patients where clinical features suggest true internal derangement of the TMJ refractory to conservative treatment with restricted movement and pain identified as arising primarily from the joint. Magnetic resonance imaging was done to identify the cause of problem.

Cytotoxic T-cells as imaging probes for detecting glioma

Tumor vaccination using tumor-associated antigen-primed dendritic cells (DCs) is in clinical trials. Investigators are using patients’ own immune systems to activate T-cells against recurrent or metastatic tumors. Following vaccination of DCs or attenuated tumor cells, clinical as well as radiological improvements have been noted due to migration and accumulation of cytotoxic T-cells (CTLs). CTLs mediated tumor cell killing resulted in extended survival in clinical trails and in preclinical models. Besides administration of primed DCs or attenuated or killed tumors cells to initiate the generation of CTLs, investigators have started making genetically altered T-cells (CTLs) to target specific tumors and showed in vivo migration and accumulation in the implanted or recurrent tumors using different imaging modalities. Our groups have also showed the utilization of both in vivo and in vitro techniques to make CTLs against glioma and used them as imaging probes to determine the sites of tumors. In this short review, the current status of vaccination therapy against glioma and utilization of CTLs as in vivo imaging probes to determine the sites of tumors and differentiate recurrent glioma from radiation necrosis will be discussed.

Multiple progressive focal nodular hyperplasia lesions of liver in a patient with hemosiderosis

Focal nodular hyperplasia (FNH) is the second most common benign lesion of the liver. It is a solitary lesion and usually does not enlarge. We present the magnetic resonance imaging findings of multiple progressive FNH lesions in a patient with hemosiderosis using Gadolinium-EOB-DTPA (Eovist) as a hepatobiliary contrast agent. The possible mechanisms underlying the occurrence and progression of FNH lesions and the potential value of Eovist in characterizing the lesions were discussed.

Imaging considerations in intraductal papillary mucinous neoplasms of the pancreas

With the widespread use of cross-sectional imaging, particularly computed tomography (CT) and magnetic resonance imaging (MRI), and the continuous improvement in the image quality of these techniques, the diagnosis of incidental pancreatic cysts has increased dramatically in the last decades. While the vast majority of these cysts are not clinically relevant, a small percentage of them will evolve into an invasive malignant tumor making their management challenging. Mucinous cystic neoplasms and intraductal papillary mucinous neoplasms (IPMN) are the most common pancreatic cystic lesions with malignant potential. Imaging findings on CT and MRI correlate tightly with the presence of malignant degeneration in these neoplasms. IPMN can be classified based on their distribution as main duct, branch duct or mixed type lesions. MRI is superior to CT in demonstrating the communication of a branch duct IPMN with the main pancreatic duct (MPD). Most branch duct lesions are benign whereas tumors involving the MPD are frequently associated with malignancy. The presence of solid nodules, thick enhancing walls and/or septae, a wide (> 1 cm) connection of a side-branch lesion with the MPD and the size of the tumor > 3 cm are indicative of malignancy in a branch and mixed type IPMN. A main pancreatic duct > 6 mm, a mural nodule > 3 mm and an abnormal attenuating area in the adjacent pancreatic parenchyma on CT correlates with malignant disease in main duct and mixed type IPMN. An accurate characterization of these neoplasms by imaging is thus crucial for selecting the best management options. In this article, we review the imaging findings of IPMN including imaging predictors of malignancy and surgical resectability. We also discuss follow-up strategies for patients with surgically resected IPMN and patients with incidental pancreatic cysts.

Spinal Cord Injuries

Spinal Cord injury (SCI) is one of the most devastating and demoralizing ailment for both the patient and the medical practitioner. However, with the better understanding of the pathophysiology, better imaging modalities and emphasis on immobilization and rehabilitation has provided a ray of hope to such patients. The initial care aims at immobilization and evacuation by the classical log roll method and focuses on life-saving procedures. Basic imaging should be augmented with an MRI in doubtful cases. Immobilization either external or internal should be followed by early efforts for rehabilitation. The use of steroids during the acute phase has become controversial. The focus of latest studies has shifted to neuroprotective and regenerative agents.

A case of solitary rectal diverticulum presenting with a retrorectal mass

Colonic diverticula are common whereas but rectal diverticula are very rare, with only sporadic reports in the literature since 1911. Most patients with rectal diverticula are diagnosed incidentally, inflammatory processes may have developed at the time of the diagnosis. We report the case of a 42-year-old woman presenting with a retrorectal mass that was detected incidentally. She was suspected of having a rectal diverticulum by transrectal ultrasonography and magnetic resonance imaging. However, the colonoscopic findings were unremarkable. A rectal diverticulum was confirmed intraoperatively, and a transanal diverticulectomy was performed.

Transient splenial lesion of the corpus callosum in a case of benign convulsion associated with rotaviral gastroenteritis

Transient magnetic resonance (MR) signal changes in the splenium of the corpus callosum (SCC) arise from many different conditions, including encephalopathy or encephalitis caused by infection, seizures, metabolic derangements, and asphyxia. Few case reports exist on reversible SCC lesions associated with rotavirus infection. A benign convulsion with mild gastroenteritis (CwG) is frequently associated with rotaviral infections. This entity is characterized by normal laboratory findings, electroencephalogram, neuroimaging, and good prognosis. We report a case of a 2.5-year-old Korean girl with rotavirus-associated CwG demonstrating a reversible SCC lesion on diffusion-weighted MR images. She developed 2 episodes of brief generalized tonic-clonic seizure with mild acute gastroenteritis without any other neurologic abnormality. Stool test for rotavirus antigen was positive. Brain MRI done on the day of admission showed a linear high signal intensity and decreased apparent diffusion coefficient values on the SCC. The lesion completely disappeared on follow-up MRI 6 days later. The patient fully recovered without any sequelae.

Magnetic resonance imaging assessment of arrhythmogenic right ventricular cardiomyopathy/dysplasia in children

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a genetically determined disease that progresses continuously from conception and throughout life. ARVC/D manifests predominantly in young adulthood. Early identification of the concealed cases in childhood is of utmost importance for the prevention of sudden cardiac death later in life. Magnetic resonance imaging (MRI) is routinely requested in patients with a confirmed or suspected diagnosis of ARVC/D and in family members of the patients with ARVC/D. Although the utility of MRI in the assessment of ARVC/D is well recognized in adults, MRI is a low-yield test in children as the anatomical, histological, and functional changes are frequently subtle or not present in the early phase of the disease. MRI findings of ARVC/D include morphologic changes such as right ventricular dilatation, wall thinning, and aneurismal outpouchings, as well as abnormal tissue characteristics such as myocardial fibrosis and fatty infiltration, and functional abnormalities such as global ventricular dysfunction and regional wall motion abnormalities. Among these findings, regional wall motion abnormalities are the most reliable MRI findings both in children and adults, while myocardial fibrosis and fat infiltration are rarely seen in children. Therefore, an MRI protocol should be tailored according to the patient's age and compliance, as well as the presence of other findings, instead of using the protocol that is used for adults. We propose that MRI in children with ARVC/D should focus on the detection of regional wall motion abnormalities and global ventricular function by using a cine imaging sequence and that the sequences for myocardial fat and late gadolinium enhancement of the myocardium are reserved for those who show abnormal findings at cine imaging. Importantly, MRI should be performed and interpreted by experienced examiners to reduce the number of false positive and false negative readings.

Magnetic resonance imaging: Review of imaging techniques and overview of liver imaging

Magnetic resonance imaging (MRI) of the liver is slowly transitioning from a problem solving imaging modality to a first line imaging modality for many diseases of the liver. The well established advantages of MRI over other cross sectional imaging modalities may be the basis for this transition. Technological advancements in MRI that focus on producing high quality images and fast imaging, increasing diagnostic accuracy and developing newer function-specific contrast agents are essential in ensuring that MRI succeeds as a first line imaging modality. Newer imaging techniques, such as parallel imaging, are widely utilized to shorten scanning time. Diffusion weighted echo planar imaging, an adaptation from neuroimaging, is fast becoming a routine part of the MRI liver protocol to improve lesion detection and characterization of focal liver lesions. Contrast enhanced dynamic T1 weighted imaging is crucial in complete evaluation of diseases and the merit of this dynamic imaging relies heavily on the appropriate timing of the contrast injection. Newer techniques that include fluoro-triggered contrast enhanced MRI, an adaptation from 3D MRA imaging, are utilized to achieve good bolus timing that will allow for optimum scanning. For accurate interpretation of liver diseases, good understanding of the newer imaging techniques and familiarity with typical imaging features of liver diseases are essential. In this review, MR sequences for a time efficient liver MRI protocol utilizing newer imaging techniques are discussed and an overview of imaging features of selected common focal and diffuse liver diseases are presented.

Magnetic resonance imaging for acute pancreatitis

Acute pancreatitis is characterized by acute chemical injury of the pancreatic parenchyma and peripancreatic tissue. The increased frequency of death in acute pancreatitis is directly correlated with the degree and progress of pancreatic necrosis. Moreover, the occurrence of some local complications in acute pancreatitis, such as pancreatic hemorrhage, peripancreatic abscess or large pseudocyst, and pseudoaneurysm, could influence the choice of treatment for these patients. Magnetic resonance imaging (MRI) can be used to help evaluate the presence and degree of pancreatic necrosis, and is crucial for identifying complications of acute pancreatitis and predicting prognosis. The purpose of this article is to describe MRI techniques for acute pancreatitis, to review the spectrum of pancreatic and peripancreatic patterns, as well as to survey various complications secondary to acute pancreatitis on MRI. The role of MRI in the initial evaluation and staging of acute pancreatitis is emphasized.

Role of three-dimensional imaging integration in atrial fibrillation ablation

Atrial fibrillation is the most common arrhythmia and in symptomatic patients with a drug-refractory form, catheter ablation aimed at electrically disconnecting the pulmonary veins (PVs) has proved more effective than use of antiarrhythmic drugs in maintaining sinus rhythm during follow-up. On the other hand, this ablation procedure is complex, requires specific training and adequate clinical experience. A main challenge is represented by the need for accurate sequential positioning of the ablation catheter around each veno-atrial junction to deliver point-by-point radiofrequency energy applications in order to achieve complete and persistent electrical disconnection of the PVs. Imaging integration is a new technology that enables guidance during this procedure by showing a three-dimensional, pre-acquired computed tomography or magnetic resonance image and the relative real-time position of the ablation catheter on the screen of the electroanatomic system. Reports in the literature suggest that imaging integration provides accurate visual information with improvement in the procedure parameters and/or clinical outcomes of the procedure.

Comparison of manual and automated determination of hippocampal volumes in MCI and early AD

MRI-based hippocampal volume analysis has been extensively employed given its potential as a biomarker for brain disorders such as Alzheimer's disease (AD), and accurate and efficient determination of hippocampal volumes from brain images is still a challenging issue. We compared an automated method, FreeSurfer (V4), with a published manual protocol for the determination of hippocampal volumes from T1-weighted MRI scans. Our study included MRI data from 125 older adult subjects: healthy controls with no significant cognitive complaints or deficits (HC, n=38), euthymic individuals with cognitive complaints (CC, n=39) but intact neuropsychological performance, and patients with amnestic mild cognitive impairment (MCI, n=37) or a clinical diagnosis of probable AD (AD, n=11). Pearson correlations and intraclass correlation coefficients (ICCs) were calculated to evaluate the relationship between results of the manual tracing and FreeSurfer methods and to estimate their agreement. Results indicated that these two methods derived highly correlated results with strong agreement. After controlling for the age, sex and intracranial volume in statistical group analysis, both the manual tracing and FreeSurfer methods yield similar patterns: both the MCI group and the AD group showed hippocampal volume reduction compared to both the HC group and the CC group, and the HC and CC groups did not differ. These comparisons suggest that FreeSurfer has the potential to be used in automated determination of hippocampal volumes for large-scale MCI/AD-related MRI studies, where manual methods are inefficient or not feasible.

Magnetically labeled mesenchymal stem cells after autologous transplantation into acutely injured liver

AIM: To evaluate tracking of magnetically labeled mesenchymal stem cells (MSCs) after intraportal transplantation.

METHODS: Mononuclear cells were isolated from bone marrow aspirates of pigs by density gradient centrifugation, cultured and expanded, after which, they were incubated with super paramagnetic iron oxide (SPIO). Prussian blue staining was performed to highlight intracellular iron. To establish swine models of acute liver injury, 0.5 g/kg D-galactosamine was administrated to 10 pigs, six of which were injected via their portal veins with SPIO-labeled MSCs, while the remaining four were injected with unlabeled cells. Magnetic resonance imaging (MRI) was performed with a clinical 1.5T MR scanner immediately before transplantation and 6 h, 3 d, 7 d and 14 d after transplantation. Prussian blue staining was again performed with the tissue slices at the endpoint.

RESULTS: Prussian blue staining of SPIO-labeled MSCs had a labeling efficiency of almost 100%. Signal intensity loss in the liver by SPIO labeling on the FFE (T2*WI) sequence persisted until 14 d after transplantation. Histological analysis by Prussian blue staining confirmed homing of labeled MSCs in the liver after 14 d; primarily distributed in hepatic sinusoids and liver parenchyma.

CONCLUSION: MSCs were successfully labeled with SPIO in vitro. MRI can monitor magnetically labeled MSCs transplanted into the liver.

MRI for diagnosis and evaluation of inflammatory bowel disease

As a non-invasive and ionizing radiation-free cross-sectional imaging technique, magnetic resonance imaging (MRI) has shown a bright future in following up patients with inflammatory bowel disease (IBD), especially child and young adult patients. The application of new techniques in MRI makes it possible to obtain MRI images that are richer in information and to evaluate the activity of IBD more objectively and quantitatively. This improvement is of great significance for clinical decision-making and evaluation of drug efficacy in IBD patients.

Non-invasive methods for liver fibrosis prediction in hemochromatosis: One step beyond

Advances in recent years in the understanding of, and the genetic diagnosis of hereditary hemochromatosis (HH) have changed the approach to iron overload hereditary diseases. The ability to use a radiologic tool (MRI) that accurately provides liver iron concentration determination, and the presence of non-invasive serologic markers for fibrosis prediction (serum ferritin, platelet count, transaminases, etc), have diminished the need for liver biopsy for diagnosis and prognosis of this disease. Consequently, the role of liver biopsy in iron metabolism disorders is changing. Furthermore, the irruption of transient elastography to assess liver stiffness, and, more recently, the ability to determine liver fibrosis by means of MRI elastography will change this role even more, with a potential drastic decline in hepatic biopsies in years to come. This review will provide a brief summary of the different non-invasive methods available nowadays for diagnosis and prognosis in HH, and point out potential new techniques that could come about in the next years for fibrosis prediction, thus avoiding the need for liver biopsy in a greater number of patients. It is possible that liver biopsy will remain useful for the diagnosis of associated diseases, where other non-invasive means are not possible, or for those rare cases displaying discrepancies between radiological and biochemical markers.

Pediatric nonalcoholic fatty liver disease: A clinical and laboratory challenge

The true prevalence of pediatric nonalcoholic fatty liver disease (NAFLD) is unknown. Challenges in determining the population prevalence of NAFLD include the type of test (and the reference intervals used to define normal and abnormal), the type of population (general population, hospital series), the demographic characteristics of the population sampled, and the nature of the study design. The natural history of pediatric NAFLD remains uncertain. The issue of when to perform a liver biopsy in children with suspected NAFLD remains controversial. Children with NAFLD but normal alanine aminotransferase are rarely investigated. However, evidence of alterations in glucose metabolism parameters should prompt a better understanding of the natural history of pediatric NAFLD not only in terms of the progression of liver disease but also regarding its potential relationship with other health outcomes such as type 2 diabetes mellitus and cardiovascular disease. This evidence could make liver biopsy mandatory in the majority of cases at risk of progressive and severe hepatic and extrahepatic disease. This conclusion, however, raises the question of the feasibility of liver biopsy assessment in an extremely large at risk population, and of the cost/effectiveness of this policy. There is a considerable, continuous interest in reliable, noninvasive alternatives that will allow the prognosis of pediatric NAFLD to be followed in large community or population-based studies.

Role of diffusion-weighted magnetic resonance imaging in the diagnosis of extrahepatic cholangiocarcinoma

AIM: To determine the clinical value of diffusion-weighted imaging (DWI) for the diagnosis of extrahepatic cholangiocarcinoma (EHCC) by comparing the diagnostic sensitivity of DWI and magnetic resonance cholangiopancreatography (MRCP).

METHODS: Magnetic resonance imaging examination was performed in 56 patients with suspected EHCC. T1-weighted imaging, T2-weighted imaging, MRCP and DWI sequence, DWI using single-shot spin-echo echo-planar imaging sequence with different b values (100, 300, 500, 800 and 1000 s/mm²), were performed. All cases were further confirmed by surgery or histopathological diagnosis. Two radiologists jointly performed the analysis of the DWI and MRCP images. Apparent diffusion coefficient (ADC) value and signal-noise ratio were calculated for EHCC. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value were tested using DWI with a b value of 500 s/mm² and MRCP images, respectively.

RESULTS: Histopathological diagnosis confirmed that among the 56 cases, 35 were EHCC (20 hilar and 15 distal extrahepatic), 16 were cholangitis, and 5 were calculus of bile duct. Thirty-three out of the 35 EHCC cases were detected by DWI. EHCC exhibited differential levels of high signal intensity in DWI and low signal intensity in the ADC map. The mean value for ADC was (1.31 ± 0.29) × 10^-3 mm²/s. The detection rate of EHCC was significantly higher by DWI (94.3%) than by MRCP (74.3%) (P < 0.05). There was a significant difference in sensitivity (94.3% vs 74.3%), specificity (100% vs 71.4%), accuracy (96.4% vs 73.2%), positive predictive value (100% vs 81.3%), and negative predictive value (91.3% vs 62.5%) between DWI and MRCP in diagnosing EHCC.

CONCLUSION: DWI has a high sensitivity for the detection of EHCC as it shows the EHCC lesion more unambiguously than MRCP does. DWI can also provide additional clinically important information in EHCC patients when added to routine bile duct MR imaging protocols.

Distinction between Intradural and Extradural Aneurysms Involving the Paraclinoid Internal Carotid Artery with T2-Weighted Three-Dimensional Fast Spin-Echo Magnetic Resonance Imaging

OBJECTIVE

The precise intra- vs. extradural localization of aneurysms involving the paraclinoid internal carotid artery is critical for the evaluation of patients being considered for aneurysm surgery. The purpose of this study was to investigate the clinical usefulness of T2-weighted three-dimensional (3-D) fast spin-echo (FSE) magnetic resonance (MR) imaging in the evaluation of unruptured paraclinoid aneurysms.

METHODS

Twenty-eight patients with unruptured cerebral aneurysms in their paraclinoid regions were prospectively evaluated using a T2-weighted 3-D FSE MR imaging technique with oblique coronal sections. The MR images were assessed for the location of the cerebral aneurysm in relation to the dural ring and other surrounding anatomic compartments, and were also compared with the surgical or angiographic findings.

RESULTS

All 28 aneurysms were identified by T2-weighted 3D FSE MR imaging, which showed the precise anatomic relationships in regards to the subarachnoid space and the surrounding anatomic structures. Consequently, 13 aneurysms were determined to be intradural and the other 15 were deemed extradural as they were confined to the cavernous sinus. Of the 13 aneurysms with intradural locations, three superior hypophyseal artery aneurysms were found to be situated intradurally upon operation.

CONCLUSION

High-resolution T2-weighted 3-D FSE MR imaging is capable of confirming whether a cerebral aneurysm at the paraclinoid region is intradural or extradural, because of the MR imaging's high spatial resolution. The images may help in identifying patients with intradural aneurysms who require treatment, and they also can provide valuable information in the treatment plan for paraclinoid aneurysms.

Different imaging techniques in the head and neck: Assets and drawbacks

In this review, the gold standard imaging techniques for the head and neck and the latest upcoming techniques are presented, by comparing computed tomography (CT), magnetic resonance imaging and positron emission tomography-CT, as well as ultrasound, depending on the examined area. The advantages and disadvantages of each examination protocol are presented. This article illustrates the connection between the imaging technique and the examined area. Therefore, the head and neck area is divided into different sections such as bony structures, nervous system, mucous membranes and squamous epithelium, glandular tissue, and lymphatic tissue and vessels. Finally, the latest techniques in the field of head and neck imaging such as multidetector CT, dual-energy CT, flash CT, magnetic resonance angiography, spectroscopy, and diffusion tensor tractography using 3 tesla magnetic resonance are discussed.

Prevalence of stroke in Restless Legs Syndrome: Initial Results Point to the Need for More Sophisticated Studies

BACKGROUND

Recent studies suggest a potential relationship between Restless Legs Syndrome (RLS) and hypertension and heart disease. Acute clinical stroke has been linked to the immediate onset of RLS, and epidemiological studies suggest the possibility that RLS may also lead to stroke.

METHODS

MRI scans from 26 RLS cases and 241 controls from the population based MEMO-Study (Memory and Morbidity in Augsburg Elderly) were assessed for the presence of clinical stroke, silent infarction, subcortical lesions and cortical atrophy. T1, T2, proton density images were obtained and infarcts and their characteristics were determined by visual inspection. RLS status was assessed according to the minimal criteria of the International RLS Study Group. Scans from the 26 RLS patients and a subset of 26 age and sex matched controls were reexamined by a separate rater using the same methodology. Descriptive statistics, logistic and linear regression models were used to determine the risk of the three types of CNS changes associated with RLS case status.

RESULTS

Among the 267 participants there was no difference in the prevalence of cardiovascular diseases or risk factors between RLS patients and the 241 controls. The prevalences of cerebrovascular events of all types, were greater in RLS patients, as were the amounts of cortical atrophy and the volume of subcortical lesions. However, these differences were not statistically significant. When age, sex and co-morbidities were taken into account in a logistic regression model, there was a statistically non-significant greater risk for stroke (Odds Ratio 2.46 with 95% CI 0.97-6.28, p = .06) associated with RLS case status.

CONCLUSIONS

Future similar studies need to be performed on younger patients without other potential vascular risk factors, using Flair images and computerized programs for detection of cerebral ischemia. Improved methods for detection may allow for a reasonable sample size.

Magnetic resonance imaging for local complications of acute pancreatitis: A pictorial review

Acute pancreatitis is a common disease characterized by sudden upper abdominal pain and vomiting. Alcoholism and choledocholithiasis are the most common factors for this disease. The choice of treatment for acute pancreatitis might be affected by local complications, such as local hemorrhage in or around the pancreas, and peripancreatic infection or pseudoaneurysm. Diagnostic imaging modalities for acute pancreatitis have a significant role in confirming the diagnosis of the disease, helping detect the extent of pancreatic necrosis, and for diagnosing local complications. Magnetic resonance imaging (MRI) might be indicated in acute pancreatitis for detecting and characterizing local complications of acute pancreatitis that involve necrotic, hemorrhagic, infectious, vascular, and pseudocyst disorders. The general MRI sequences for pancreatitis require the combined use of T1-weighted, T2-weighted sequences, and magnetic resonance cholangiopancreatography. For imaging of pancreatic necrosis, the combination of T1-weighted and T2-weighted findings with dynamic contrast-enhanced imaging gives a comprehensive evaluation of the extent of necrosis and full range of inflammatory extension. For imaging of infectious complications, dynamic contrast-enhanced examinations might help differentiate pancreatic cellulitis or abscesses, from pancreatic fluid collection or simple pseudocysts. For vascular abnormalities, the combination of cross-sectional pancreatic parenchyma imaging with MRA represents a single diagnostic modality for the full evaluation of peripancreatic artery and vein involvement, such as arterial pseudoaneurysms and venous thromboses. The purpose of this pictorial review is to examine the MRI appearances of various local complications of acute pancreatitis and to discuss the practical setup of MRI in local complications of acute pancreatitis.

Phase-contrast MRI and 3D-CISS versus contrast-enhanced MR cisternography for the detection of spontaneous third ventriculostomy

PURPOSE

To compare the diagnostic efficacies of phase-contrast MRI (PC-MRI) and three-dimensional constructive interference in steady-state (3D-CISS) sequence for the detection of spontaneous third ventriculostomy (STV) on the basis of contrast-enhanced MR cisternography (MRC).

PATIENTS AND METHODS

Eleven obstructive hydrocephalus patients with clinically-radiologically suspected STV and ten controls were examined by PC-MRI, 3D-CISS and MRC. PC-MRI and 3D-CISS sequence were applied to view the third ventricle and basal cisterns. Following injection of 0.5-1ml intrathecal Gd-DTPA injection, postcontrast MRC images were obtained in three planes. Presence of STV was scored as follows: grade 0, no existence of STV; grade 1, STV present. Results of PC-MRI and 3D-CISS were compared with the MRC findings.

RESULTS

In PC-MRI, five patients were assessed as grade 0 and six cases grade 1. As a result of 3D-CISS sequence, eight cases were evaluated as grade 0 and three cases grade 1. Based on MRC, nine cases were assessed as grade 0 and two cases grade 1. False positivity was found in four cases by PC-MRI and in one case by 3D-CISS. The sensitivity, specificity and accuracy of PC-MRI and 3D-CISS sequence regarding demonstration of STV, were 100, 100, 56, 89, 64, and 91% respectively.

DISCUSSION

PC-MRI and 3D-CISS are helpful in confirming the STV. PC-MRI and 3D-CISS should be the first preference. If PC-MRI and 3D-CISS give negative results, then MRC is not required. MRC should be performed on patients who demonstrate suspected STV findings on PC-MRI and 3D-CISS sequences. MRC may prevent false positive results.

End-systolic and end-diastolic left atrial volume assessment by two-dimensional echocardiography: a comparison study with magnetic resonance imaging

BACKGROUND

The left atrial volume (LAV) is an important indicator of the severity of certain diseases, and measuring LAV through the cardiac cycle may enable the evaluation of various left atrium (LA) functional parameters. The results of two-dimensional (2D) echocardiographic LAV measurement methods vary, and no technique is accepted as being optimal.

OBJECTIVE

This study compared the accuracy of end-systolic and end-diastolic LAV measurements by 2D echocardiography with those obtained by magnetic resonance imaging (MRI).

METHODS

Fifty consecutive patients who underwent both echocardiography and MRI due to clinical reasons with nonselective cardiac disease were studied. LAVs by 2D echocardiography were obtained with the prolate ellipsoid (PE), biplane area-length (AL), and modified Simpson's (MS) methods.

RESULTS

End-systolic and end-diastolic LAVs calculated by each method correlated significantly with MRI results (P < 0.0001). The prolate ellipsoid method provided LAVs that most correlated with MRI results, and the biplane area-length and modified Simpson's methods provided LAVs with small mean differences (<5 ml) compared to MRI results.

CONCLUSION

All three methods of 2D echocardiographic LAV measurement provide valuable LAV data, suggesting the possibility of evaluating various LA functional parameters.

Bilateral symptomatic petrous apex effusion

Petrous apex effusions can present with aural fullness, hearing loss and dizziness. Although they can be followed-up when asymptomatic, clinical management of symptomatic patients is controversial. In this study, we present clinical and radiological findings of a 24-year-old patient with bilateral petrous apex effusion. She had been complaining of bilateral aural fullness and dizziness for 2 years. Radiological examinations revealed bilateral petrous apex effusion. After medical treatment, her symptoms gradually disappeared. In all previous published studies, unilateral petrous apex effusions were reported. To our best knowledge, this is the first patient with trapped fluid in bilateral petrous apex.

A review on dural tail sign

“Dural tail sign” (DTS) which is a thickening of the dura adjacent to an intracranial pathology on contrast-enhanced T1 MR Images, was first thought to be pathognomonic of meningioma, however, many subsequent studies demonstrated this sign adjacent to various intra- and extra-cranial pathologies and in spinal lesions. In this paper we outline the history, accompanying pathologies and the differentiation and probable pathophysiology of DTS. We also discuss whether we can predict tumoral involvement of the dural tail before surgery and whether the dural tail adjacent to a tumor should be resected.

Intestinal amyloidosis: Two cases with different patterns of clinical and imaging presentation

The involvement of the small bowel in systemic forms of amyloidosis may be diffuse or very rarely focal. Some cases of focal amyloidomas of the duodenum and jejunum without extraintestinal manifestations have been reported. The focal amyloidomas consisted of extensive amyloid infiltration of the entire intestinal wall thickness. Radiological barium studies, ultrasound and computed tomography (CT) patterns of diffuse small bowel amyloidosis have been described: the signs are non-specific and may include small-bowel dilatation, symmetric bowel wall thickening, mesenteric infiltration, and mesenteric adenopathy. No data are available about the positron emission tomography (PET)/CT and magnetic resonance imaging (MRI) patterns of intestinal amyloidosis. We report two cases of small bowel amyloidosis: the former characterized by focal deposition of amyloid proteins exclusively within blood vessel walls of the terminal ileum, the latter characterized by diffuse intestinal involvement observed on MRI and PET/CT studies.

Magnetic resonance imaging staging of nasopharyngeal carcinoma in the head and neck

Magnetic resonance imaging (MRI) is the modality of choice for staging nasopharyngeal carcinoma in the head and neck. This article will review the patterns of primary and nodal spread on MRI with reference to the latest 7th edition of the International Union Against Cancer/American Joint Committee on Cancer staging system.

The role of endorectal magnetic resonance imaging in predicting extraprostatic extension and seminal vesicle invasion in clinically localized prostate cancer

Purpose

We aimed to assess the clinical value of endorectal magnetic resonance imaging (MRI) in predicting extraprostatic extension and seminal vesicle invasion in patients with clinically localized prostate cancer.

Materials and Methods

A total of 54 patients who underwent radical prostatectomy for clinically localized prostate cancer were retrospectively analyzed. The findings of endorectal MRI, performed at least 3 weeks after biopsy, were compared with the pathological results of radical prostatectomy specimens. The sensitivity, specificity, and accuracy of the detection of extraprostatic extension and seminal vesicle invasion were calculated.

Results

The sensitivity, specificity, and accuracy of the endorectal MRI findings were 50.0%, 82.6%, and 77.8% for the detection of extraprostatic extension, respectively, and 75.0%, 92.0%, and 90.7% for the detection of seminal vesicle invasion, respectively. The sensitivity of endorectal MRI in the detection of extraprostatic extension improved as the Gleason score increased.

Conclusions

Endorectal MRI findings demonstrated modest sensitivity for predicting extraprostatic extension, whereas specificity was relatively high. In addition, endorectal MRI showed better sensitivity for detecting high-grade tumors.

New progress in CT and MRI examination and diagnosis of small intestinal tumors

Precise examination and diagnosis of small intestinal tumors is difficult because of the curved course and overlapping canal of the small intestine. Traditional technology for intestinal canal examination and endoscopy cannot exhibit the intestinal wall and extra-luminal structure well. With the development and advancement of multi-slice spiral computed tomography and magnetic resonance imaging (MRI), computed tomography enteroclysis (CTE) and magnetic resonance enteroclysis (MRE) are widely used in the examination and diagnosis of small intestinal tumors. CTE and MRE, with three-dimensional imaging capabilities and excellent soft-tissue contrast, can analyze the abnormalities of peripheral intestinal structure as well as the tunica mucosa. In addition, these two technologies can clearly reveal the localization, appearance, degree of mesenteric infiltration and remote tumor metastasis, which increases our cognition of the imaging diagnosis for intestinal tumors. Here we review recent progress in imaging (CT and MRI) examination and diagnosis of small intestinal tumors.