Spontaneous cervical epidural hematoma masquerading as an abscess on magnetic resonance imaging scan.

OBJECTIVE: The aims of the study are to describe a case of spontaneous spinal epidural hematoma (SSEH) without any predisposing factors and magnetic resonance imaging (MRI) features of epidural abscess and to highlight the importance of high clinical suspicion. CLINICAL FEATURES: A 75-year-old male presented to the emergency department after a severe neck pain. He progressively showed sensory and upper motor signs on the left side of the body. The MRI scans were suggestive of cervical epidural abscess with peripheral enhancement of the lesion. INTERVENTIONS AND OUTCOMES: He underwent a multiple level (C3-T1) laminectomy when he was found to have an SSEH. There has been no history of trauma or other predisposing factor, and presence of arteriovenous malformation was ruled out by MR angiography. CONCLUSIONS: The MRI features of SSEH may be misleading and mimic other spinal lesions such as abscess. Presence of tapering superior and inferior margins, spotty Gadolinium enhancement in the mass, along with abrupt clinical onset of pain and neurologic deficit, should raise the suspicion toward epidural hematoma. Enhancement in the hyperacute stage of the hematoma itself might indicate continued bleeding and, in the case of deteriorating neurologic status, will necessitate decompression.

MR imaging in the triage of pregnant patients with acute abdominal and pelvic pain.

PURPOSE: To retrospectively assess the performance of MR imaging in the evaluation and triage of pregnant patients presenting with acute abdominal or pelvic pain. METHOD AND MATERIALS: MRI studies of pregnant patients who were referred for acute abdominal pain between 2001 and 2007 were included. MR images were retrospectively reviewed and compared with surgical and pathologic findings and clinical follow-up data. Analysis of imaging findings included evaluation of the visceral organs, bowel and mesentery, appendix (for presence of appendicitis), ovaries (detection and adnexal masses were evaluated), focal inflammation, presence of abscesses, and any other abnormal findings. RESULTS: A total of 118 pregnant patients were included. MR findings were inconclusive in 2 patients and were positive for acute appendicitis in 11 patients (n = 9 confirmed by surgery, n = 2 improved without surgery). One patient with inconclusive MR had surgically confirmed appendicitis; the other patient with inconclusive MR had surgically confirmed adnexal torsion. Other surgical/interventional diagnoses suggested by MR imaging were adnexal torsion (n = 4), abscess (n = 4), acute cholecystitis (n = 1), and gastric volvulus (n = 1). Two patients with MR diagnosis of torsion improved without surgery. One patient with MR diagnosis of abscess had biliary cystadenoma at surgery. The rest of the MR diagnoses above were confirmed surgically or interventionally. MR imaging was normal in 67 patients and demonstrated medically treatable etiology in 28 patients: adnexal lesions (n = 9), urinary pathology (n = 6), cholelithiasis (n = 4), degenerating fibroid (n = 3), DVT (n = 2), hernia (n = 1), colitis (n = 1), thick terminal ileum (n = 1), rectus hematoma (n = 1). Three of these patients had negative surgical exploration and one had adnexal mass excision during pregnancy. Other patients were discharged with medical treatment. The sensitivity, specificity, accuracy, positive predictive values (ppv), and negative predictive values (npv) of MR imaging for acute appendicitis, and surgical/ interventional diagnoses were 90.0% vs. 88.9%, 98.1% vs. 95.0%, 97.5% vs. 94.1%, 81.8% vs. 76.2%, 99.1% vs. 97.9%, respectively. CONCLUSION: MR imaging is an excellent modality for diagnosis of acute appendicitis and exclusion of diseases requiring surgical/interventional treatment. Therefore MR imaging is useful for triage of pregnant patients with acute abdominal and pelvic pain.

Do neck levels negative on initial CT need to be dissected after definitive radiation therapy with or without chemotherapy?

BACKGROUND: The extent of the adjuvant neck dissection after radiotherapy with or without chemotherapy remains undefined. We investigated whether we could limit neck dissection to levels with positive lymph nodes on CT scan before treatment. METHODS: Twenty-one patients' initial diagnostic CT scans were reviewed retrospectively and neck levels were scored positive for malignancy if the respective lymph nodes met any of the following: maximum axial diameter >1 cm; oval/round shape; hypodensity; presence of extracapsular penetration; and irregular enhancement. Patients were treated with radiation alone (71%) or with radiation plus chemotherapy (29%). Neck dissection consisted of radical (8 heminecks), modified radical (4 heminecks), or selective (13 heminecks). RESULTS: One hundred two neck levels were dissected. Of these, 56 levels (54.9%) were negative on initial CT scan. None of them was found to contain cancer. CONCLUSIONS: After radiation with or without chemotherapy, neck dissection of an initially negative neck level may not be necessary. Neck dissection may target only initially positive levels.

Patterns of locoregional failure after exclusive IMRT for oropharyngeal carcinoma.

PURPOSE: To assess the patterns of failure after intensity-modulated radiotherapy (IMRT) for oropharyngeal squamous cell carcinoma (SCC). METHODS AND MATERIALS: We analyzed patients treated at the University of Texas Medical Branch between May 2002 and February 2006 who met the following criteria: (1) definitive IMRT without chemotherapy for oropharyngeal SCC; (2) no pretreatment radical surgery; (3) minimal follow-up of 1 year. The location of each nodal/primary failure was co-registered to the pretreatment planning computed tomography scan and then expanded by 5 mm to a planning target volume (PTV) of the failure (PTV-f). We then investigated whether the prescription dose to the PTV-f had been appropriate for the amount of disease present before treatment and whether the PTV-f had been adequately covered. RESULTS: A total of 50 patients were eligible. With a median follow-up of 32.6 months (range, 12.1-58.6), three local and six regional failures were observed in 8 patients. All but one failure, that had been neglected, were recorded within 14 months of the treatment end. Of the nine failures, four developed in the neck treated electively to the lowest dose level; in all of them, we could retrospectively identify initial positive lymph nodes that might have justified the subsequent failure. The remaining five failures developed in proximity of the high-dose volume. In all but one, the volume of region of interest receiving >/=95% of the dose of the PTV-f was >95%, suggesting adequate coverage. In 1 patient, about 20% of PTV-f was outside the 95% isodose, so that marginal underdosing could not be ruled out. CONCLUSIONS: A potential cause could be identified in all the failures in the lowest dose level. The implications and possible remedies are discussed. Most failures around the high-dose region were "true failures" with no apparent technical cause.

Gadolinium-based contrast exposure, nephrogenic systemic fibrosis, and gadolinium detection in tissue.

OBJECTIVE: The objective of our study was to retrospectively review one institution's cases of nephrogenic systemic fibrosis (NSF), evaluate possible associated factors, determine the prevalence of NSF, and search for gadolinium in skin samples obtained from patients with NSF. MATERIALS AND METHODS: A retrospective review of our dermatopathology database from 1997 to 2007 was performed to search for patients with NSF. The records of patients with NSF were reviewed for factors suspected to be associated with NSF such as acidosis, low hemoglobin levels, low serum calcium levels, inflammatory conditions, serum antibodies, pharmaceutical erythropoietin, angiotensin-converting enzyme inhibitors, gadolinium-based contrast agents (GBCAs), renal failure, and dialysis. The biopsy samples from NSF patients and from control subjects were examined with energy-dispersive X-ray spectroscopy to detect gadolinium. Retrospective chart reviews of patients evaluated at our local dialysis center and our dermatology clinic were conducted to identify patients who underwent MRI, who had NSF managed exclusively by our tertiary referral centers, or both from 1997 to 2007. RESULTS: Seven cases of NSF were found in the dermatopathology database. Two of the seven patients were also followed up at our outpatient dialysis clinic. No other cases of NSF were discovered within the dialysis clinic's population exclusively followed within our institution. All seven dermatopathology database NSF patients developed symptoms of NSF after receiving GBCAs during renal failure and showed concomitant proinflammatory conditions. No other proposed risk factors were uniformly present in these NSF cases. All four NSF patients with chronic renal failure developed NSF after hemodialysis, with one patient dialyzed 12 hours after receiving a contrast dose. Gadodiamide was the only GBCA that all seven NSF patients received before symptom onset. Symptom onset was from 3 weeks to 18 months after GBCA exposure, with cumulative GBCA doses ranging from 0.16 to 0.43 mmol/kg. Gadolinium was detected in six of seven NSF patients' skin biopsies. Seven of eight random control specimens obtained from three healthy control subjects, three patients with renal insufficiency who had not been exposed to gadodiamide, and two patients without renal disease who had been exposed to gadodiamide were negative. Seventy-two dialysis clinic patients underwent 127 contrast-enhanced MR examinations from 1997 to 2007. Eighteen patients received gadopentetate, none of whom developed NSF. Sixty-three patients received gadodiamide, two of whom developed NSF (prevalence of NSF in patients exposed to GBCA, 2.8%; odds ratio, 0.82 [95% CI, 0.04-18.10]; likelihood ratio, 1.16 [95% CI, 1.06-1.26]). Nine patients received both contrast agents. CONCLUSION: An association with GBCAs in the development of NSF is suggested in the setting of renal insufficiency, but other factors seem to play a role. Dialysis did not prevent the development of NSF. Gadolinium was detected in skin samples from NSF patients.

Magnetic resonance imaging of the chest, abdomen, and pelvis in the evaluation of pregnant patients with neoplasms.

This article illustrates the magnetic resonance (MR) technique and MR imaging (MRI) findings of various neoplasms in chest, abdomen, and pelvis in pregnant patients. MRI can provide useful information about characterization and staging of maternal neoplasms without exposing the fetus to ionizing radiation and can be considered as a first-line cross sectional imaging method as an adjunct to ultrasonography.

Localization of appendix with MDCT and influence of findings on choice of appendectomy incision.

OBJECTIVE: The purpose of this study was to show the relation between McBurney's point and the appendix in patients undergoing 3D MDCT and to investigate the effect of this information on a surgeon's choice of appendectomy incision. MATERIAL AND METHODS: Among 142 adults undergoing consecutive MDCT studies, 100 patients (35 women, 65 men; mean age, 52.1 years) with an identifiable appendix on abdominopelvic MDCT examinations were selected for the study group. The presence of intraabdominal mass or a history of abdominal surgery were the exclusion criteria. Three-dimensional reconstruction of the CT data was performed with a surface shaded display algorithm. The locations of the base of the appendix and McBurney's point were marked on a single 3D image that allowed display of the skin surface markings for each patient. The superoinferior and mediolateral distances from the level of the appendix to the level of McBurney's point were measured, and the radial distance was calculated from these measurements. A surgeon experienced in emergency abdominal surgery reviewed 3D CT images and one axial image showing the appendix, and his choice of incision for each patient based on the CT information was recorded. The influence of the superoinferior and mediolateral distances of the appendix from McBurney's point on the surgeon's decision was analyzed with a multivariate logistic regression model. RESULTS: The appendix was exactly at McBurney's point in only 4% of the patients. In 36% of the cases, the appendix was within 3 cm, in 28% of cases it was 3-5 cm, and in 36% of the cases it was more than 5 cm away from McBurney's point. Mean +/- SD superoinferior, mediolateral, and radial distances between the appendix and McBurney's point were 33.0 +/- 24.1, 20.8 +/- 19.3, and 42.1 +/- 26.7 mm, respectively. After reviewing the images, the surgeon would have altered his incision site in 35% of the cases. The surgeon preferred a higher incision in 28% and a lower incision in 7% of the cases. Both positive and negative superoinferior displacement away from McBurney's point were significant factors regarding the surgeon's decision to alter the incision (p = 0.005), and the superoinferior distance was more than 3 cm in 94% of the cases in which the surgeon would have altered the incision. CONCLUSION: The location of the appendix varies widely among individuals, and McBurney's point has limitations as an anatomic landmark. Three-dimensional MDCT findings can be useful to surgeons customizing appendectomy incisions. Additional information about the location of the appendix in the CT report (if possible, together with a 3D image showing the location of the appendix) may be beneficial for surgeons performing appendectomy.

Mimicks of pancreatic malignancy in patients with chronic pancreatitis: correlation of computed tomography imaging features with histopathologic findings.

Differentiation of chronic pancreatitis and pancreatic carcinoma can be a clinical and radiologic dilemma. Several patients with chronic pancreatitis can undergo unnecessary major abdominal surgery for benign lesions. This pictorial review illustrates the computed tomographic findings and histopathologic features of lesions mimicking pancreatic neoplasm in patients with chronic pancreatitis. Several benign lesions can simulate pancreatic malignancy in patients with chronic pancreatitis. Knowledge of the computed tomographic appearance of these benign entities is important to prevent unnecessary surgeries.

Prospective analysis of uncomplicated bone bruises in the pediatric knee.

To determine the incidence of uncomplicated knee bone contusions in pediatric patients. MRI studies were obtained using either high-field (1.5 T) or mid-field strength magnets (0.2-0.3 T), identifying 48 pediatric patients suitable for study. Contusion location, size, and any ligamentous or meniscal injuries were recorded. Exclusionary criteria did not include plain film findings, the interval between injury to imaging, or history of patellar dislocation [Fulkerson (2002) 30:447-456]. Uncomplicated bone bruises were those occurring in the absence of other internal derangements of the knee, such as meniscal and ligament tears. Consensus imaging findings by two reviewing radiologists revealed a 25% incidence of uncomplicated bruises (12/48 patients). These bone bruises involved the lateral and medial knee compartments 56 and 44% of the time, respectively. Bruises of the lateral compartment were larger (2.4 cm) than those found in the medial compartment (1.8 cm). Given the high incidence of symptomatic but uncomplicated contusions identified in this study of a pediatric population, we suggest appropriate joint rest and follow-up without other intervention as a primary course of treatment.

Odontoid osteomyelitis masquerading as a C2 fracture in an 18-month-old male with torticollis: CT and MRI features.

Odontoid osteomyelitis is a rare entity and can be confused with other disease processes, requiring imaging to clarify the diagnosis. The following describes a pediatric case and the associated MR and CT findings.

Revisiting MRI for appendix location during pregnancy.

OBJECTIVE: The purpose of this study is to determine the location of the appendix in pregnant patients by MRI and to investigate the possibility of gradual upward displacement of the appendix during pregnancy. CONCLUSION: The gradual upward displacement of the appendix during pregnancy was confirmed. MRI can be used for determination of the appendix localization in pregnant patients. Further studies with a larger number of patients will be helpful to answer this clinically relevant question.

Bilateral retinal detachment in a patient with Vogt-Koyanagi-Harada syndrome.

We present a 38-year-old woman with bilateral serous retinal detachments and bilateral panuveitis on fundoscopic exam. CT of the orbits and MRI scans revealed bilateral ocular choroidal thickening and bilateral retinal detachments; however, no other CNS or meningeal lesion was detected. This patient met the clinical criteria for Vogt-Koyanagi-Harada (VKH) Syndrome. Review of VKH syndrome as well as the radiographic findings will be discussed.

Magnetic resonance imaging of maternal diseases causing acute abdominal pain during pregnancy: a pictorial review.

Evaluation of acute abdominal pain in a pregnant patient is a clinical challenge. In these patients, magnetic resonance imaging (MRI) can allow a systematic cross-sectional evaluation of the entire abdomen and can provide clinically useful information in a short enough time for emergent diagnosis. This pictorial essay demonstrates MRI findings of various maternal diseases that can present as acute abdominal pain in pregnant patients. Familiarity with these findings is important for the radiologist to make an accurate and prompt diagnosis.

Right-lower-quadrant pain and suspected appendicitis in pregnant women: evaluation with MR imaging--initial experience.

PURPOSE: To determine if there is a role for magnetic resonance (MR) imaging in evaluation of pregnant women with acute right-lower-quadrant pain in whom acute appendicitis is suspected. MATERIALS AND METHODS: Informed consent and institutional review board approval were obtained. Images obtained with a 1.5-T MR imager and medical records of 23 pregnant women (age range, 19-34 years; mean age, 24.7 years) who presented with acute right-lower-quadrant pain were retrospectively reviewed. MR protocol included use of transverse, coronal, and sagittal noncontiguous T2-weighted single-shot fast spin-echo (SE) sequences; transverse fat-suppressed T2-weighted fast SE sequences; transverse T1-weighted gradient-recalled-echo sequences; and transverse and coronal short inversion time inversion-recovery sequences performed through the lower abdomen and pelvis. MR findings were evaluated by two radiologists and compared with surgical and pathologic findings and clinical follow-up data. RESULTS: Appendix was detected in 20 (86.9%) of 23 patients. Seven patients underwent surgery; four had acute appendicitis, and three had ovarian torsion. Two patients with pelvic abscesses not related to appendicitis underwent percutaneous drainage. Fourteen patients were treated medically. Dilated thick-walled appendix and periappendiceal inflammation were detected in three (75%) of four patients with acute appendicitis. In one patient with appendicitis, the appendix could not be visualized, but inflammation was present in the right lower quadrant. In three patients with ovarian torsion, MR imaging demonstrated right adnexal mass or inflammation. MR imaging was used to correctly identify pelvic abscesses and healthy appendix in two patients. A healthy appendix was depicted in 17 (89.5%) of 19 patients without acute appendicitis. CONCLUSION: MR imaging shows promise for evaluation of pregnant women in whom acute appendicitis is suspected by enabling diagnosis of other possible causes of right-lower-quadrant pain, including ovarian torsion or pelvic abscesses, and demonstrating a healthy or unhealthy appendix.

Aeration following intact canal wall mastoidectomy.

This study examines the prevalence and extent of re-aeration of the mastoid cavity following intact canal wall (ICW) mastoidectomy. Temporal bone computed tomography scans from patients with prior unilateral ICW mastoidectomy were identified. Three-dimensional volume reconstruction of the temporal bone was performed to measure aeration bilaterally. Thirty-five scans were analyzed; 16 (46%) showed good aeration in the operated ear and 19 showed poor aeration. The aeration (volume) in the surgical ears and the contralateral ears was significantly less than that in subjects without a history of ear disease. Those with poor aeration were more likely to require additional surgery. For temporal bone pairs with greater volume in the operated ear, the average difference was 1.3 cm3. Surgical creation of a mastoid cavity does not produce a large increase in aeration as compared with the contralateral ear. Following surgery, mastoid opacification may presage recurrent disease. Routine use of mastoidectomy in an attempt to improve aeration is not advocated.

Neuropathological and ultrastructural features of amebic encephalitis caused by Sappinia diploidea.

Here we present the neuropathological, ultrastructural, and radiological features of Sappinia diploidea, a newly recognized human pathogen. The patient was a 38-year-old man with visual disturbances, headache, and a seizure. Brain images showed a solitary mass in the posterior left temporal lobe. The mass was composed of necrotizing hemorrhagic inflammation that contained free-living amebae. Immunofluorescence microscopy showed that the organism was not a species of ameba previously known to cause encephalitis. Trophozoites had a highly distinctive double nucleus, and transmission electron microscopy confirmed that they contained 2 nuclei closely apposed along a flattened surface. The 2 nuclei were attached to each other by distinctive connecting perpendicular filaments. This and several other unique structural features led to the diagnosis of S. diploidea encephalitis. The patient was treated postoperatively with a sequential regimen of anti-amebic drugs (azithromycin, pentamidine, itraconazole, and flucytosine) and is alive after 5 years. Guidelines to recognize future cases of S. diploidea encephalitis are as follows. 1) It presented as a tumor-like cerebral mass without an abscess wall. 2) It had central necrotic and hemorrhagic inflammation that contained acute and chronic inflammatory cells without granulomas or eosinophils. 3) It contained trophozoites (40-70 microm diameter) that contained a distinctive double nucleus. 4) Cyst forms in the host were not excluded or definitely evident. 5) Trophozoites engulfed host blood cells and were stained brightly with Giemsa and periodic acid-Schiff. 6) Trophozoites often were present in viable brain parenchyma on the periphery of the mass without inflammatory response. 7) The prognosis after surgical excision and medical treatment was favorable in this instance.

Diabetes insipidus as a consequence of neurologic involvement in Behcet's syndrome.

OBJECTIVE: To describe a case of central diabetes insipidus that was associated with Behçet's syndrome. METHODS: We present a case report, including clinical, laboratory, and radiologic data. The pertinent literature is reviewed relative to diabetes insipidus and Behçet's syndrome, and a discussion about a possible association is presented. RESULTS: A 32-year-old man presented with diplopia and severe headaches and was found to have transverse sinus thrombosis. He reported having recurrent mouth and genital ulcers for 3 months before the current consultation. On the basis of the clinical picture, Behçet's syndrome was diagnosed. During hospitalization of the patient, polyuria and polydipsia developed, along with hypernatremia and hypotonic urine, indicative of diabetes insipidus. After desmopressin treatment was initiated, considerable improvement in clinical status and laboratory data was evident and persisted during follow-up. CONCLUSION: Behçet's syndrome, probably through vasculitic mechanisms, may result in central diabetes insipidus. This case report emphasizes that Behçet's syndrome should be considered in the differential diagnosis of diabetes insipidus.

Lower cervical dermal sinus tract and associated intraspinal abscess causing meningitis in a child.

Congenital dermal sinus tracts are frequently a cause of recurrent meningitis. We present a case of a rare lower cervical dermal sinus and an associated intraspinal abscess causing meningitis.