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Mimicker: Inguinal Mesh Plug

Depending on the inguinal hernia repair method chosen, a mesh plug can be used for reinforcement. One such method uses a polypropylene (Prolene) plug

    • The post-operative appearance of an inguinal mesh plug can masquerade as an inguinal mass or lymphadenopathy

Imaging Findings

    • On CT, mesh plugs can have a slightly nodular or smooth outline. The density is similar to sightly lower than muscle. Mesh plugs have also been reported as a ring-like density with central fat attenuation, potentially mimicking epiploic appendicitis if on the left
    • On MRI, mesh plugs are typically T1 hypointense and demonstrate variable T2 weighted signal
    • Due to a granulomatous reaction, mesh plugs can be FDG avid

Helpful hints in preventing misdiagnosis

    • Mutliplanar reformations can be useful in demonstrating the conical morphology of the mesh plug, although they can appear ovoid
    • Postsurgical changes including skin thickening and suceptabliity artifact can also be helpful imaging features
Ryan Schwope mesh plug
Left inguinal mesh plug with a lobular contour
Ryan Schwope mesh plug cor
Left inguinal mesh plug. Note conical morphology on this coronal MPR.


The British Journal of Radiology, 77 (2004), 261–265
J Comput Assist Tomagr. 2008Jul-Aug;32(4):529-32.
American Journal of Roentgenology. 2010;195: 701-706.

Suspected Type I Rotatory Atlatoaxial Subluxation in Asymptomatic Patients

type I Atlantoaxial Rotatory Subluxation

In an earlier post on rotatory atlatoaxial subluxation, we discussed the Fielding and Hawkins classification, and its application to symptomatic patients (e.g., those with torticollis). Here, we discuss the challenge of making a diagnosis of rotatory atlatoaxial subluxation in unselected patients.

That is, what do you do if your neck or c-spine CT scan is obtained with the head turned, and you see what looks like a Type I rotatory atlatoaxial subluxation?

The patient below was referred to our institution in a cervical collar for management of atlantoaxial rotatory subluxation.

normal head rotation

30-year-old man: Thick reconstructions centered at C1-C2 from a CTA obtained with the head rotated to the left. There is apparent type I atlantoaxial rotatory subluxation.


Let’s take a look at what we know:

  • Normal maximum rotation of the head on body is between 60–80°.
  • Normal maximum rotation of C1 on C2 makes up for about half of that: 30–45° (although some sources say it can be up to 50°).
  • Cutoff for abnormal C1-C2 rotation: >45° or >56°, depending on source.

Looking at our image above, our rotation of C1 on C2 is about 30 degrees, which puts it in the normal range. But, what if the number was higher? How well do we do as radiologists in correctly identifying this as normal?

One study that was helpful came from the forensic field. Pathologists had noted that CTs of cadavers, which are impossible to position “correctly,” were resulting in a lot of over-calling of atlantoaxial rotatory subluxation. When they looked at their data they found:

  • 19 cases where the C-spine was stable on autopsy. In those 19, 13 had suspected rotatory subluxation based on on CT (false positives)
  • The C1-C2 angle in those 13 false positives were between 16–47°.
  • All false positives were type I.
  • 2 cases where the C-spine was unstable at autopsy. In those 2 cases, 1 had suspected rotatory subluxation on CT (true positive).
  • The C1-C2 angle in the 1 true positive was 42°.
  • There was a significant association between the false positives and degree of head rotation.

Generalizing this cadaveric study suggests that we need to be careful in calling type I atlantoaxial rotatory subluxation in asymptomatic patients who simply happen to have their head turned in the scanner. This supports the conclusions from a study in living, asymptomatic patients, where the authors showed that incomplete rotational facet displacement on CT was not sufficient to define subluxation.


Endologix Stent-graft


Most endostent devices used for endovascular repair of aortic aneurysms have the graft material sutured on the luminal side of the stent. The AFX endostent device (Endologix, Irvine, California) is different from other devices in that the graft material is sutured on the outside of the metal component, attached only at the proximal and distal ends.

Delayed CT shows the smoothly marginated contrast extending beyond the confines of the metal strut Ryan Schwopeunchanged in size and configuration when compared to arterial phase imaging


By intent, the graft material of the AFX stent-graft can separate from the metal struts where it is not directly apposed to the aortic wall.  During surveillance with contrast-enhanced imaging of patients who have reviewed this device, contrast can be detected outside of the metallic construct. Although this finding can imply a type 1 or 3 endoleak when identified with other endostents, it is a normal finding with the AFX device.

Avoiding misinterpretation as an endoleak can be achieved by confirmation of the type of endostent device used for aneurysm repair. In addition, the contrast extending beyond the metal struts does not change in configuration or size on delayed imaging.


J Vasc Interv Radiol. 2012 Nov;23(11):1544-6.

Management of Pancreatic Cystic Lesions

Thick slab MRCP image showing massive dilatation of the main pancreatic duct

Incidental cystic pancreatic lesions found on 13% of MRI abdomens

    • Wide variety of pathology both benign and malignant


  • Imaging findings and demographics are the key to diagnosis
Ryan Schwope


Cystic Pancreatic Neoplasms (Four major categories)


    1. Serous cystadenoma: Benign (very low malignant potential)


    1. Mucinous cystic neoplasm (MCN): Premalignant or malignant


    1. Intraductal papillary mucinous neoplasm (IPMN): Malignant potential (Main Duct >> Branch Duct)


    1. Unusual cystic neoplasms:
        • Solid pseudopapillary neoplasm (SPN): Low grade malignancy
        • Cystic forms of more common neoplasms (neuroendocrine)


Nonneoplastic Pancreatic Cysts


    • Pseudocyst


    • Retention cyst


    • Lymphoepithelial cyst


    • Localized ductectasia


Major Imaging Features Guiding Management


    • Number and size of cystic components: Risk of malignancy increases when size ≥ 3 cm


    • Septations and solid components: Mural nodule has a 87% Sp and 56% Sn for malignancy


    • Main pancreatic duct (MPD) dilatation and communication with the cystic lesion: MPD > 10 mm has a 77% Sp and 67-92% Sn for malignancy


Sendai Criteria

High Risk Stigmata

    • Jaundice


    • MPD ≥ 10 mm


    • Enhancing solid component

Worrisome Features

    • Size ≥ 3 cm


    • MPD 5-9 mm


    • Non-enhancing mural nodules


    • Thick enhancing cystic wall


    • Lymphadenopathy


    • Abrupt Duct Termination




    • Any worrisome features present = Endoscopic Ultrasound (EUS) and Cyst aspiration with fluid analysis


    • Any high risk stigmata present or suspicious cytology on EUS = Surgical resection


    • MCN or SPN = Surgical resection


    • Serous cystadenoma
        • 2-3 cm: F/U every 2 years
        • ≥ 4 cm: consider resection


    • IPMN:
        • Main duct and combined type: Surgical resection (but depends on location, pt. age/clinical status)
        • Branch duct type = follow if < 3 cm and contains no solid components
            • If < 2cm F/U q1yr; if growth FU q6mo
            • If 2-3 cm F/U q6mo x 2 years, then q1yr
            • Consider EUS (if mucinous then resect)
            • If growth ≥ 3 cm, resect


What the Clinician/Surgeon wants to know


    1. Number of cystic lesions


    1. Largest cystic lesion
        • Unilocular
        • Multilocular: Microcystic ( 2cm)


    1. Lesion size


    1. Lesion location: Head/Body/Tail


    1. Septations: None/Thin/Thick (> 2mm)


    1. Solid components: Present/Absent


    1. Calcifications: None/Coarse/Rim/Central


    1. Communication with MPD: Present/Absent


    1. Main pancreatic duct diameter: > 5 mm/Not dilated




    • Gandhi NS and Hecht E. “Adding Value to Clinical Care: Structured Reporting of Pancreatic Pathology”, Workshop Session Presentation, Society of Abdominal Radiology Annual Meeting, 2015






Bisphosphonate-related Osteonecrosis of the Jaw

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is associated with the use of bisphosphonates to treat severe osteoporosis, and metabolic and oncologic bone conditions, including hypercalcemia associated with malignancy. These agents inhibit osteoclasts, reducing bone resorption and osteolysis, and also possess antiangiogenic properties, reducing blood flow and necrosis. Patients with BRONJ present with pain and exposed, nonvital bone involving the maxillofacial structures. The incidence of BRONJ increases with the duration of treatment, especially with the intravenous route and concomitant steroid therapy. The osteonecrosis usually is participated by dental extraction. When spontaneous, it commonly occurs along the mylohyoid ridge. BRONJ can mimic osteomyelitis and osteoradionecrosis. A history of dental caries and the presence of periosteal elevation can help direct one towards the diagnosis of osteomyelitis. Osteoradionecrosis can be excluded if the patient has not received oropharyngeal radiation therapy. Jaw neoplasm, primary or metastatic, can potentially also mimic BRONJ. Treatment of BRONJ consists of cessation of bisphosphonate drug therapy, antibiotics for secondary infection, and surgical debridement of necrotic sequestra.

Ryan Schwope BROJN1
Figure 1: Axial CT of the facial bones. There is a mixed sclerotic and lytic lesion within the mandible (Figure 1, arrows) with foci of cortical interruption (Figure 2, arrowheads).
Ryan Schwope BROJN 2
Figure 2: Sagital CT of the facial bones. There is a mixed sclerotic and lytic lesion within the mandible (Figure 1, arrows) with foci of cortical interruption (Figure 2, arrowheads).



Ryan Schwope
CT shows a predominantly fat
attenuation, intramural uterine mass. There is rim of surrounding
calcification as well as a few foci of internal soft tissue density at the
superior aspect of the mass 

Ryan Schwope
   MR imaging showed the majority of the uterine mass as hyperintense on T1 weighted imaging (isointense to subcutaneous

Ryan Schwope
T2 weighted image with fat saturation MRI shows the uterine mass markedly hypointense (isointense to subcutaneous fat)

Ryan Schwope
Post contrast T1 weighted MRI image with fat saturation show mld enhancement of the soft tissue component  along the superior margin of the mass; the majority of the mass is markedly hypointense (isointense to subcutaneous fat)

lipoleiomyomas are rare, benign tumors with a variable reported incidence
ranging from 0.03% to 0.2%. The exact etiology of these lesions is
unclear.  It is postulated lipoleiomyomas
either arise from fatty metaplasia of the smooth muscle cells of leiomyomas, or
from misplaced embryonic fat cells in the uterus. CT is highly specific for
the diagnosis when an intrauterine mass is seen containing both macroscopic fat
and soft tissue density. MR can also be confirmatory as the mass will have high
T1 weighted signal which can be confirmed as fat by using a fat suppression. The role of imaging is also to differentiate lipoleiomyoma from an ovarian
teratoma, a much more common entity presenting as a fat-containing pelvic mass.
Lipoleiomyomas require no treatment or follow-up whereas teratomas are
frequently resected. 


Giant Cell Containing Lesions of Bone


  • Brown tumor of hyperparathyroidism
  • Hemophiliac pseudotumor


  • Giant cell reparative granuloma
  • Non-ossifying fibroma
  • Giant cell tumor
  • Aneurysmal bone cyst
  • Chondroblastoma
  • Chondromyxoid fibroma
  • Langerhans cell histiocytosis
  • Pigmented villonodular synovitis


  • Osteosarcoma
  • Clear cell chondrosarcoma
  • Metastatic carcinoma
  • Malignant fibrous histiocytoma
  • Solitary fibrous tumor metastasis

ILAR Classification of Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) is an umbrella term for a group of abnormalities characterized by chronic articular inflammation and association with HLA alleles. The International League Against Rheumatism (ILAR) has classified JIA into seven subtypes, including an unclassifiable group. These include:

  • Systemic arthritis: Arthritis in one or more joints with or preceded by fever of at least 2 weeks’ duration documented to be daily for at least 3 days, and accompanied by one or more of: evanescent erythematous rash, lymphadenopathy, hepatomegalyor splenomegaly, or both, serositis
  • Oligoarthritis: Arthritis in 4 or fewer joints in the first 6 months. Subtypes include persistent (no more than 4 joints throughout the course of the disease) and extended (more than 4 joints after the first 6 months).

  • Polyarthritis, RF negative: Arthritis affecting 5 or more joints in the first 6 months of disease. RF is negative
  • Polyarthritis, RF positive: Arthritis affecting 5 or more joints in the first 6 months of disease. Two or more tests for RF, conducted at least 3 months apart during the first 6 months, are positive. Considered the pediatric version of adult rheumatoid arthritis.
  • Psoriatic: Arthritis plus psoriasis OR Arthritis plus at least two of the following: dactylitis, nail pitting or onycholysis, psoriasis in a first-degree relative.
  • Enthesis-related: Arthritis plus enthesitis OR Arthritis or enthesitis, plus at least two of the following: presence of or a history of sacroiliac joint tenderness and/or inflammatory lumbosacral pain‡, presence of HLA-B27 antigen, onset of arthritis in a male over 6 years of age, acute (symptomatic) anterior uveitis, history of AS, ERA, sacroiliitis with IBD, reactive arthritis, or acute anterior uveitis in a first-degree relative
  • Unclassified: Arthritis that fulfills criteria in none of the above categories, or fulfills criteria in two or more of the above categories


Petty RE, Southwood TR, Baum J, Bhettay E, Glass DN, Manners P, Maldonado-Cocco J, Suarez-Almazor M, Orozco-Alcala J, Prieur AM. Revision of the proposed classification criteria for juvenile idiopathic arthritis: Durban, 1997. J Rheumatol. 1998 Oct;25(10):1991-4.

Femoral Fracture

stress fracture mri, it Stress+fracture+mri AP x-ray showing femoral
stress fracture mri, it Stress+fracture+mri AP x-ray showing femoral

Treatment with bisphosphonate therapy appears to be associated with an increased risk of atypical fractures of the femur, according to a report published Online First by Archives of Internal Medicine. “Current evidence suggests that there is an association A study in the current issue of the Journal of Orthopedic Trauma links Merck’s osteoporosis drug Fosamax to a rare type of fracture in the femur. The small, observational study looked at 70 patients who experienced low-energy femur fractures, which occur MONDAY, Sept. 22, 2014 (HealthDay News) — Trends in operative management of femoral neck fractures by orthopedic surgeons applying for board certification have changed over time, according to research published in the Sept. 3 issue of The Journal of Bone Proximal Femoral Fractures in elderly patients are a serious problem in the aging society. Recently, surgical indications have changed due to advancements in medical technology. The purpose of this study was to investigate the outcome of elderly patients Luckily, Haley suffered minimal injuries given the scenario. Her Femoral Fracture required an emergency vet visit, x-rays, fluids, hospitalization, surgical repair and medication. Because Haley has been insured with a PetFirst policy since 2007 The researchers analyzed 477 patients’ data, aged 50 years and older, who were hospitalized with a subtrochanteric or femoral shaft 39 patients with an atypical fracture, of which 32 patients or 82.1% were treated with bisphosphonates, whilst of .

Law360, New York (January 16, 2013, 2:52 PM ET) — Merck & Co. Inc. urged a New Jersey federal court Tuesday to dismiss part of a multidistrict litigation accusing it of negligence and other claims over femur fractures and similar injuries allegedly caused The occurrence of an unusual type of fracture of the femur, or the thigh bone, is very low in patients with osteoporosis, including those treated with the drug family known as bisphosphonates, according to a new study led by a team of UCSF epidemiologists. ABSTRACT Stress fractures are a common overuse problem among military trainees resulting in preventable morbidity, prolonged training, and long-term disability following military service. Femoral neck stress fractures (FNSFs) account for 2% of all stress OTTAWA, Dec. 20 (UPI) — A review of the research by Canadian health officials found a slightly increased risk of “atypical femur fracture” among those who take bisphosphonate drugs. Officials at Health Canada said this serious type of thigh bone fracture .

Another Picture of Femoral Fracture :

Image of the Day 4: Anterior Hip
Image of the Day 4: Anterior Hip Dislocation

Medical Surgical Nursing Mnemonics
Medical Surgical Nursing Mnemonics

Fracture Pelvis

Michael Porter, Equine
Michael Porter, Equine Veterinarian

Although there is no conclusive evidence that a hospitalization can lead to dementia, the American Geriatrics Society estimates that about 30% of patients over 70 who undergo surgery—either for a fractured pelvis, hip, or other health issue— come home The man was taken to hospital with suspected head injuries and fractured pelvis. Police attended and are appealing for witnesses to the accident, to help with their inquiries. Call 101 with information. His back was broken in two places. His jaw, collarbone, ribs and pelvis were fractured and his lung was punctured. Two weeks in intensive care, two months in hospital and four years of physiotherapy later, Mr Duggan still suffers every day. “The man has chest injuries, internal injuries and possibly a fractured pelvis,” Mr Elliott said. Metropolitan Fire Brigade spokesman Trevor Woodward said the fact the man had survived the crash was extraordinary. “That’s a very lucky fella,” he said. POLICE are appealing for information after an elderly woman fractured her pelvis after being knocked down by a car in Tunbridge Wells last week. The 74-year-old woman was hit by a car on Vale Road in Tunbridge Wells on November 6 at around 5.30pm (CNN)– German Chancellor Angela Merkel fractured her pelvis in a skiing accident in Switzerland over the holidays, her spokesman told reporters Monday. Merkel was cross-country skiing when the accident occurred. Spokesman Steffen Seibert did not disclose .

Anteroposterior compression pelvic fracture with an associated Denis zone II sacral fracture. The symphysis was plated with a 3.5-mm reconstruction plate, and the sacrum was fixed with iliosacral screws. Unstable pelvic fractures typically occur as a Q: My horse was sound when he was turned out one night, and the next morning he was lame in the hind end. It took quite a few diagnostics by my veterinarian before it was determined that he had suffered a slight pelvic fracture. How common is this and what (NaturalNews) If you had serious doubts about an earlier Natural News story on how a woman cured her cancer with carrot juice, as recommended to her by another who had done the same, here’s another carrot juice story that should blow your mind. [1] It was The motorist, believed to be in his 40s, suffered serious chest and leg injuries, a possible fractured pelvis and head injuries during the collision in Point Cook, in Melbourne’s west, yesterday morning. Paramedics were also concerned he may have .

Another Picture of Fracture Pelvis :

fracture is a vertical shear injury on one side of the pelvis
fracture is a vertical shear injury on one side of the pelvis

approaching North
approaching North