Two Insects, Two Bites, One Patient: A Lyme Disease and Jamestown Canyon Co-infection.

Lyme disease (LD) is the most common tick-borne illness across the United States, caused by the bacterium Borrelia burgdorferi sensu lato and transmitted to humans by the bite of infected Ixodes ticks. Jamestown Canyon Virus (JCV) is an emerging mosquito-borne pathogen found mostly in the upper Midwest and Northeastern United States. Co-infection between these two pathogens has not been previously reported since it would require the host to be bitten by the two infected vectors at the same time. We report a 36-year-old man who presented with erythema migrans and meningitis. While erythema migrans is a pathognomonic sign of early localized Lyme disease, Lyme meningitis does not occur in this stage but in the early disseminated stage. Furthermore, CSF tests were not supportive of neuroborreliosis, and the patient was ultimately diagnosed with JCV meningitis. We review JCV infection, LD, and this first reported co-infection to illustrate the complex interaction between different vectors and pathogens and to emphasize the importance of considering co-infection in people who live in vector-endemic areas.

"Double Trouble": Severe Meningoencephalitis Due to Borrelia burgdorferi and Powassan Virus Co-Infection Successfully Treated with Intravenous Immunoglobulin.

BACKGROUND Powassan virus (POWV) is an emerging tick-borne flavivirus transmitted to humans by ticks. While infection is asymptomatic in some people, others develop life-threatening encephalitis with high mortality rates. Co-infection between POWV and Borrelia burgdorferi is rare despite the fact that both pathogens can be transmitted through the same tick vector, Ixodes scapularis. It is unclear if co-infection leads to more severe clinical presentation and worse outcome. CASE REPORT A 76-year-old Wisconsin man was admitted for meningoencephalitis complicated by hypoxemic and hypercapnic respiratory failure requiring endotracheal intubation. The patient had no known tick bites but lived in a heavily wooded area. Extensive work-up for infectious, autoimmune, and paraneoplastic causes was positive for Borrelia burgdorferi and Powassan virus infection (POWV). Following treatment with ceftriaxone for neuroborreliosis and supportive care for POWV infection, the patient failed to improve. Intravenous immunoglobulins (IVIG) were started empirically, and the patient attained gradual neurological improvement and was successfully extubated. CONCLUSIONS Treatment for POWV infection is supportive, and at this time there are no approved targeted antivirals for this disease. At this time, it remains unclear if co-infection with 2 pathogens leads to a more severe clinical presentation and higher mortality. In the absence of contraindications, IVIG might be beneficial to patients with POWV infection who are not improving with supportive care.

Measurement of Prostate Volume with MRI (A Guide for the Perplexed): Biproximate Method with Analysis of Precision and Accuracy.

To review the anatomic basis of prostate boundary selection on T2-weighted magnetic resonance imaging (MRI). To introduce an alternative 3D ellipsoid measuring technique that maximizes precision, report the intra- and inter-observer reliability, and to advocate it's use for research involving multiple observers. We demonstrate prostate boundary anatomy using gross pathology and MRI examples. This provides background for selecting key boundary marks when measuring prostate volume. An alternative ellipsoid volume method is then proposed using these boundaries in an attempt to improve inter-observer precision. An IRB approved retrospective study of 140 patients with elevated serum prostate specific antigen levels and/or abnormal digital rectal examinations was done with T2-weighted MRI applying a new (Biproximate) technique. Measurements were made by 2 examiners, correlated with each other for inter-observer precision and correlated with an expert observer for accuracy. Correlation statistics, linear regression analysis, and tests of means were applied using p ≤ 0.05 as the threshold for significance. Inter-observer correlation (precision) was 0.95 between observers. Correlation between these observers and the expert (accuracy) was 0.94 and 0.97 respectively. Intra-observer correlation for the expert was 0.98. Means for inter-rater reliability and accuracy were all the same (p = 0.001). We conclude that using more precise reproducible landmarks with biproximate technique, precision and accuracy of total prostate volume is found to be demonstrated.

Fusobacterium necrophorum subsp. necrophorum Liver Abscess with Pylephlebitis: An Abdominal Variant of Lemierre's Syndrome.

Liver abscess associated with suppurative portal vein thrombosis (pylephlebitis) secondary to Fusobacterium necrophorum has been rarely reported. It is considered to be an abdominal variant of Lemierre's syndrome associated with significant morbidity and mortality. We report a case of 69-year-old man who developed liver abscess and pylephlebitis due to F. necrophorum with an unclear source of infection. We discuss the pathogenesis, diagnosis, and treatment strategy for this entity, with a review of previously published cases of pyelephlebitis due to F. necrophorum in regard to their clinical presentation and outcome.

MRI in differentiating malignant versus benign portal vein thrombosis in patients with hepatocellular carcinoma: Value of post contrast imaging with subtraction.

PURPOSE: To evaluate MR imaging parameters including quantitative multiphasic post-contrast enhancement with subtraction and qualitative diffusion weighted imaging (DWI) in differentiating benign versus malignant portal venous thrombosis (PVT) in patients with hepatocellular carcinoma (HCC). METHOD: Radiology reports over a 6-year period ending February 2016 were searched for key words indicating presence of both HCC and PVT on abdominal MRI. 39 patients were identified with PVT characterized as benign or malignant based on pathologic data or serial imaging growth criteria. Image review was performed by two subspecialized radiologists blinded to the diagnosis and medical chart. Signal intensity for regions of interest were recorded within the portal vein thrombus as well as the portal vein on pre-contrast and dynamic post-contrast phases without and with subtraction. Qualitative parameters for DWI and presence of PV expansion were also evaluated. RESULTS: Percent enhancement generated high area under the curve (AUC) for both readers on all non-subtraction phases: arterial (0.95/0.98), portal venous (0.97/0.97) and delayed phase (0.96/0.99) and subtraction phases: arterial (0.91/0.96), portal venous (0.94/0.99) and delayed phases (0.96/0.97). Statistically significant differences were observed between benign and malignant PVT for both readers for PV expansion (p= <0.001/0.006). No qualitative DWI parameter reached statistical significance for both readers. CONCLUSIONS: Post-contrast and subtraction MRI can reliably distinguish malignant from benign PVT in patients with HCC using subtracted or non-subtracted images and at arterial, portal venous, or delayed phase timing.

Precision and accuracy of magnetic resonance imaging for lobar classification of benign prostatic hyperplasia.

PURPOSE: To validate the application of a magnetic resonance imaging (MRI)-based lobar classification of benign prostatic hyperplasia (BPH) for use in research and clinical management. METHODS: Two radiologists with 5 and 11 years post-fellowship experience were trained in the lobar classification of BPH using an internally developed atlas of prostate anatomy with example MRI images edited by a third senior radiologist designated as the "administrator" of the study. A study population of 140 patients referred to a tertiary academic medical center with known or suspected prostate cancer was selected by the administrator to test the interrater reliability (IRR; precision) of the classification as well as accuracy of the two readers compared to the administrator as the "gold" standard. The intrarater reliability of repeat readings of the administrator was also examined. Percentage of agreement, proportion of agreement, and Cohen's κ were applied. This was a retrospective IRB-approved study. RESULTS: IRR (precision) between the two interpreting radiologists was 64% agreement, corresponding to unweighted κ of 0.52. Composite proportion of agreement across all BPH types (categories) for interpreting radiologists was 0.67. Observer accuracy was 62% agreement, unweighted κ 0.49, for observer 1 and 67%, unweighted κ 0.58, for observer 2. Intrarater reliability for the administrator was 87% agreement, unweighted κ 0.81 with composite proportion of agreement across all categories of 0.87. CONCLUSIONS: MRI lobar classification of BPH is a reproducible and reliable tool for research and clinical applications.

Splenic Rupture as the First Manifestation of Babesia Microti Infection: Report of a Case and Review of Literature.

BACKGROUND Babesiosis is an emerging, tick-borne zoonosis caused by intraerythrocytic protozoa of the genus Babesia. Babesia microti is the main pathogen causing human disease and is endemic in the northeastern and upper midwestern parts of the USA. Severity of infection ranges from mild, self-limited, febrile viral-like illness accompanied by nonspecific symptoms to life-threatening infection complicated by severe hemolytic anemia, disseminated intravascular coagulation (DIC), acute respiratory distress syndrome (ARDS), and renal or/and hepatic failure. Splenic rupture (SR) is a very rare but life-threatening complication of severe B. microti infection. CASE REPORT A 79-year-old female farmer from Wisconsin, USA was admitted during summer with hemorrhagic shock secondary to spontaneous splenic rupture. She was transfused with 3 units of packed red blood cells (PRBC) and underwent emergent splenectomy. Postoperatively, she recovered well and was discharged on postoperative day 4. However, she was re-admitted on postoperative day 10 for febrile hemolytic anemia. Further exposure history was obtained and was significant for multiple tick bites 8 weeks preceding the index hospitalization. She was promptly diagnosed with babesiosis and Lyme disease co-infection. She responded favorably to 10 days of azithromycin and atovaquone and 21 days of oral doxycycline. CONCLUSIONS Despite its rare occurrence, SR due to B. microti infection is a dreaded complication that can rapidly progress to hemorrhagic shock and death. In contrast to other complications of babesiosis, SR is not correlated with parasite burden or immune status of the affected host. Babesiosis should be considered as part of the differential diagnosis in patients from endemic areas presenting with atraumatic splenic rupture.

Aggressive angiomyxoma: case report and review of the literature.

A 47-year-old female presented to clinic with a 5-year history of a left buttock mass. The patient's hemoglobin was low (9.7 g/dL); laboratory analysis was otherwise unremarkable. Ultrasound of the left gluteal region demonstrated a heterogeneous vascular solid lesion. Magnetic resonance and computed tomography imaging showed an enhancing mass extending from the left ischioanal fossa through the levator ani muscle into the pelvis. Biopsy revealed bland-appearing spindle-shaped cells positive for estrogen and progesterone receptors, consistent with an aggressive angiomyxoma. The mass was surgically excised without complication. To date, follow-up imaging has not demonstrated evidence of tumor recurrence.

Lipiduria presenting following right hemicolectomy: A case presentation and brief review of the literature.

Lipiduria, also known as lipuria, refers to the presence of lipids within the urine. When lipids are present in macroscopic quantities, lipiduria can be visualized as a fat-fluid level on computed tomography imaging. Although the general differential diagnosis of lipiduria is broad, reported etiologies of lipiduria diagnosed by computed tomography have primarily included chyluria, urine-induced lipolysis, and trauma. We report a case of lipiduria occurring coincidentally with resolution of perivesical fat necrosis in a patient after partial right hemicolectomy for B cell lymphoma.

Contrast Enhanced MRI in the Diagnosis of HCC.

Hepatocellular carcinoma (HCC) is the 6th most common cancer worldwide. Imaging plays a critical role in HCC screening and diagnosis. Initial screening of patients at risk for HCC is performed with ultrasound. Confirmation of HCC can then be obtained by Computed Tomography (CT) or Magnetic Resonance Imaging (MRI), due to the relatively high specificity of both techniques. This article will focus on reviewing MRI techniques for imaging HCC, felt by many to be the exam of choice for HCC diagnosis. MRI relies heavily upon the use of gadolinium-based contrast agents and while primarily extracellular gadolinium-based contrast agents are used, there is an emerging role of hepatobiliary contrast agents in HCC imaging. The use of other non-contrast enhanced MRI techniques for assessing HCC will also be discussed and these MRI strategies will be reviewed in the context of the pathophysiology of HCC to help understand the MR imaging appearance of HCC.

Low dose pedal magnetic resonance angiography at 3 tesla with time-resolved imaging of contrast kinetics: a feasibility study.

OBJECTIVES: To assess the feasibility of low-dose time-resolved imaging of contrast kinetics (TRICKS) magnetic resonance (MR) angiography of the pedal vasculature at 3.0 Tesla (T) using a head coil. MATERIALS AND METHODS: Eleven healthy volunteers were imaged using TRICKS MR angiography at 3.0 T with both feet positioned in a head coil. A dose of 7 mL was used for each of 3 acquisitions: images were obtained of each foot in the sagittal plane, and then both feet were imaged simultaneously in the transverse plane. The following parameters were used for acquisition: (TR/TE 4.7 milliseconds/ 1.3 milliseconds, field of view = 28 cm, Flip angle = 30 degrees, 384 x 256 matrix, section thickness = 1.6 mm, Bandwidth = 19.23). The dorsalis pedis, plantar arch, distal posterior tibial, lateral tarsal, and medial plantar arteries were graded for visualization, artifact, and overall image quality on a 4-point scale (1 = worst; 4 = best). RESULTS: Superior visualization trended towards separate sagittal acquisitions when compared with that of bilateral transverse acquisitions for most of the individual vessels of the foot. Overall, separate sagittal acquisitions (average score = 2.9) were superior to bilateral transverse acquisitions (average score = 2.6). The average image quality score reflecting the amount of artifact was 2.6 for studies obtained using bilateral transverse acquisitions and 3.1 for studies obtained using separate sagittal acquisitions. CONCLUSION: Low-dose gadolinium multi-injection TRICKS and bolus-chase MR angiography at 3.0 T provides an effective and easily reproducible technique for imaging of the pedal vasculature in volunteers and has great potential for clinical application.

Thymic hyperplasia in thyroid cancer patients.

OBJECTIVE: Although there is a well-recognized association between thymic hyperplasia and benign thyroid disorders, the prevalence of thymic hyperplasia in patients with malignant thyroid diseases has not been previously reported. We performed this study to determine the prevalence and morphologic features of thymic hyperplasia on CT scans of thyroid cancer patients. CONCLUSIONS: Thymic hyperplasia is commonly observed on CT scans of thyroid cancer patients and almost always demonstrates a characteristic pyramidal configuration. This characteristic appearance should not be mistaken for metastatic disease.

The morphology of an infarct in nonarteritic anterior ischemic optic neuropathy.

OBJECTIVE: The mechanism by which nonarteritic anterior ischemic optic neuropathy (NAION) causes an infarct in the optic nerve is controversial. We studied the three-dimensional anatomic configuration of a NAION infarct to better elucidate its pathophysiology. DESIGN: Case report with clinicopathologic correlation. METHODS: Serial sections of the optic nerve from a previously reported patient diagnosed with NAION 20 days before death were studied. Every fourth slide was stained with hematoxylin-eosin, photographed, and digitized. NIH Image 1.62 was used to reconstruct the nerve in all three dimensions, and the infarct morphology was analyzed. MAIN OUTCOME MEASURES: Morphology of the reconstructed optic nerve infarct. RESULTS: The area of axonal loss within each section of the optic nerve was identified and reconstructed. The loss was in the superior part of the nerve, encircling the central retinal artery at its greatest extent. Remaining areas of the nerve appeared healthy, and, notably, the periphery of the uninvolved inferior portion of the nerve was normal. Three-dimensional analysis revealed two distinct areas of infarct at the posterior extent of the lesion which coalesced toward the center of the lesion and finally tapered as the infarct reached the optic nerve head. Sagittal reconstructions gave the appearance of a two-pronged fork posteriorly connecting to a single "handle" anteriorly. There was no obvious correlation between the configuration of the infarct and any single vascular territory. The total length of the nerve involved by the infarct was approximately 1.5 mm. CONCLUSIONS: The morphology of this NAION infarct is not consistent with disease of large or small vessels and, more likely, represents a form of compartment syndrome that causes tissue ischemia.