- 16% of all hepatic hemangiomas
- More common among small (<1 1="1" 42="42" cm="cm" hemangioma="hemangioma" hemangiomas="hemangiomas" in="in" incidence="incidence" less="less" li="li" of="of" than="than">
- Immediate homogeneous enhancement at arterial phase and hyperintensity persists in delayed phases. Enhancement equal to aorta in all phases.
- High T2 signal intensity may be helpful for differentiation from other arterial enhancing nodules (but it can also be seen in islet cell tumor metastasis) 1>
December 21, 2012
December 11, 2012
- Metastatic neuroblastoma. Given her age at five years old, this needs to be in differentials
- Ewing's sarcoma
- Telangiectatic osteosarcoma
- Osteomyelitis. Great mimics of aggressive-looking bone tumor. Symptoms may overlap with round-cell tumor, including fever
Facts: Ewing's Sarcoma
- Malignant round-cell tumors of the bone with neural cell origin
- Tumors of children and young adults, most between 10-20 years old. Less than 2% occur in children less than 5 years old
- Most common sites = femur >> pelvis
- Pelvic Ewing's -- bad prognosis because there is no anatomic barrier to tumor spread, close proximity to viscera and neurovascular bundles, prone to recur
November 30, 2012
- Rotational ankle fractures are classified according to force direction applied to the foot, while the injured foot can be in a different position (supination/pronation, adduction/external rotation)
- AO/Weber classification: A, B, C fractures are differentiated by location of fibular fractures.
- Fibular fracture below the syndesmosis = AO/Weber A (usually supination-adduction)
- Fibular fracture at the syndesmosis = AO/Weber B (~ supination and external rotation)
- Fibular fracture above the syndesmosis = AO/Weber C (~ pronation external rotation)
- High fibular fracture above the syndesmosis resulting from external rotation
- Often, there is injury to the medial ankle either a tranverse medial malleolar fracture, posterior malleolar fracture or disruption of the deltoid ligament
- Disruption of the syndesmosis and interosseous ligament up to the fibular fracture site
- Suspicious for this fracture if you see a 1) transverse medial malleolar fracture or 2) posterior malleolar fracture but no fibular fracture on the ankle radiographic series. In these situation, a full-length fibular radiograph should be taken
November 26, 2012
Facts: Aim of Cancer Screening
- We expect cancer screening program to lower cancer-related mortality by a means of 1) earlier detection of disease destined to be fatal and 2) early Rx of screen-detected cancers
- A cancer screening program should 1) increase incidence of cancer detected at an earlier stage and 2) decrease incidence of cancer presenting at a late stage
- Breast cancer rate from 1976 through 1978 (mammography was uncommon) ~ baseline incidence
- Breast cancer rate from 2006 through 2008 ~ current incidence
- Confounding effects of menopausal hormone therapy were minimized by not including transitory increase in incident breast cancers from 1990 through 2005. Underlying incidence of breast cancer assumed to rise by 0.25% annually
- Number of cases of early-staged breast cancer rises from 112 to 234 cases per 100,000 women
- Number of cases of late-staged breast cancer decreases from 102 to 94 cases per 100,000 women
- "With an assumption of a constant underlying disease burden, only 8 of the 122 additional early-stage cancers diagnosed were expected to progress to advanced disease." This was estimated that breast cancer was overdiagnosed. In 2008, the overdiagnosis would account for 31% of all breast cancer diagnosed
- Bleyer A and Welch HG. Effect of three decades of screening mammography on breast cancer incidence. N Eng J Med 2012;367:1998
- Kalager M et al. Effect of screening mammography on breast cancer mortality in Norway. N Eng J Med 2010;363:1203
- Autier P et al. Breast cancer mortality in neighbouring European countries with different levels of screening but similar access to treatment: trend analysis of WHO mortality database. BMJ 2011;343:d4411
- Kaunitz AM. Screening mammography: does overdiagnosis overshadow prevention of advanced breast cancer? Journal Watch Women's Health November 21, 2012
November 20, 2012
- Rare, benign disorder of unknown etiology comprises of eosinophilic granuloma (unifocal), Hand-Schuller-Christian disease (multifocal) and Letterer-Siwe disease (disseminated variant) - these are different manifestations of a same disease
- Clonal proliferation of Langerhans cells
- Peak incidence 5-10 years but there is a shift toward younger children
- Vertebral involvement in 8-25% of cases
- Thoracic > cervical, lumbar
- Vertebral body >> posterior elements
- Solitary, well-defined osteolytic lesion with scalloped borders eventually progresses to collapse and a classic "vertebra plana"
- Typically single vertebral body involved. Disc spaces spared
- Soft tissue mass suggests more aggressive course
- Ewing sarcoma
- Leukemia, lymphoma, metastatic neuroblastoma
Hosalkar HS, Greenberg JS, Wells L, Dormans JP. Isolated Langerhans Cell Histiocytosis of the T12 vertebra in an adolescent. Am J Orthop 2007;36: E21-E24.
November 10, 2012
- Also known as papillary cystadenoma lymphomatosum
- 14-30% of all parotid tumors
- Almost always in older adults (peak incidence at 6th-7th decades of life)
- Most commonly found within parotid gland (esp. tail). Occasionally in minor salivary glands.
- MRI, although has high specificity and sensitivity for diagnosis, still cannot differentiate all malignant parotid tumors from benign ones. Tissue sampling is required for definitive diagnosis
- Well-circumscribed solid mass, homogeneous enhancement and without calcification
- If calcification is present in a benign-appearing parotid mass, pleomorphic adenoma should be considered first
- US: multiple anechoic internal areas
- MRI: low T1, high T2 signal intensity
- Salivary scintigraphy: Accumulation of Tc-99m pertechnetate due to high mitochondrium
Hatch RL, Shah S. Warthin tumor: a common, benign tumor presenting as a highly suspicious mass. J Am Board Fam Med 2005;18: 320-322.
November 1, 2012
Facts: Fatty Liver
- Most common abnormality of the liver seen on cross-sectional imaging
- Common patterns: diffuse fat accumulation, diffuse fat accumulation with focal sparing, and focal fat accumulation in an otherwise normal liver
- Unusual patterns may mimick neoplasm, inflammation or vascular conditions
- Pathology: triglyceride acculation within cytoplasm of hepatocytes
- Term "fatty liver" is preferred over "fatty infiltration of the liver" because triglyceride accumulation occurs within hepatocytes but rarely other cell types. Infiltration of fat into parenchymal does not occur
- US: 1) Liver echo greater than renal cortex and spleen with attenuation of sound wave, 2) loss of definition of diaphragm, 3) poor delineation of intrahepatic architecture (to avoid false-positive diagnosis, all three findings should be fulfilled). Sensitivity 60-100%. Specificity 77-95%.
- CT: Liver attenuation 10 HU less than that of spleen, or less than 40 HU. Sensitivity 43-95%. Specificity 90%.
- MRI: Signal intensity loss on opposed-phase images in comparison with in-phase images. Sensitivity 81%. Specificity 100%.
- Diffuse deposition: most common
- Focal deposition and focal sparing: characteristically in specific areas (adjacent to falciform ligament or ligamentum venosum, porta hepatis, in GB fossa). Suggestive findings of fatty pseudolesions rather than true masses are:
- Fat content
- Characteristic location
- Absence of mass effect on vessels and other liver structures
- Geographic configuration (not round or oval)
- Poorly delineated margin
- Contrast enhancement similar to or less than that or normal liver parenchyma
- Multifocal deposition
- Perivascular deposition
- Subcapsular deposition
Hamer OW, Aguirre DA, Casola G, et al. Fatty liver: imaging patterns and pitfalls. Radiographics 2006;26: 1637-1653.
August 31, 2012
|Ultrasound image of the kidney shows a crescentic heterogeneous hypoechoic lesion in the perinephric space (arrows). The kidney is marked by the calipers.|
|Axial unenhanced CT images confirm a thick left perinephric hematoma (stars) and several fragmented stones in the lower pole of the left kidney.|
- ESWL (Extracorporeal Shock Wave Lithotrypsy) is a common and standard treatment for renal/proximal ureteric calculi in majority of patients
- Most common complication = microscopic hematuria
- Perinephric hematoma and infection (including pyelonephritis) can occur
- Incidence of hematoma varies depending on method of diagnosis. By US, incidence is about 0.1-0.6%. By CT/MRI, incidence rises to 20-25% of cases.
- No clear correlation between number of shockwaves or intensity given and incidence of hematoma
- Most perinephric hematoma resolves spontaneously within 2 years and the renal function is preserved. They are mostly treated conservatively
- Crescent-shaped collection surrounding the affected kidney
- Hypoechoic on US, hyperattenuating on non-contrast CT and no enhancement after IV contrast
- Displacement or compression of adjacent renal parenchyma
- Differentiate from subcapsular hematoma by appearance and pressure effect to underlying kidney.
- "Page" kidney occurs when (usually) subcapsular hematoma causes chronic renal parenchymal compromise and then hypertension
Labanaris AP, Kuhn R, Schott GE, Zugor V. Perirenal hematomas induced by extracorporeal shock wave lithotripsy (ESWL). Therapeutic management. TheScientificWorldJOURNAL 2007;7:1563-1566.
August 21, 2012
- 8-10% of all childhood malignancies
- Malignant tumor composed of immature ganglion cells. Most (2/3) arise from abdomen or pelvis and the rest is extra abdominal
- Typically seen in children under age of 5 years
- Treatment determined by stage of tumor at presentation. Regionally limited disease is potentially resectable, but locally extensive or disseminated disease is usually not resectable
- Current imaging staging evaluation: 1) CT or MRI of primary tumor, 2) skeletal survey, 3) bone scintigraphy or MIBG for bone metastasis, and 4) bone marrow aspiration and biopsy for marrow disease
- CT alone has low sensitivity (43%) but high specificity (97%) for detection of stage 4 disease. CT accuracy = 81%. MRI is more sensitive (83%) but less specific (88%) and slightly more accurate (85%).
- Sharply marginated, fusiform paraspinal mass
- Oriented along direction of sympathetic chain
- 40% contain calcifications
- Heterogeneous enhancement
- Differentiation from ganglioneuroblastoma (usually 5-10 years old) and ganglioneuroma (usually > 10 years old) not possible by imaging. Basically, they are tumors of sympathetic ganglia
1. Siegel MJ. Pediatric Body CT. 2008
2. Siegel MJ, Ishwaran H, Fletcher BD, et al. Staging of neuroblastoma at imaging: report of the radiology diagnostic oncology group. Radiology 2002;223:168-175.
August 11, 2012
- AKA supracondylar process of the humerus
- Congenital osseous/cartilagenous projection arising from the anteromedial surface of the distal humerus
- Found in 1% of population
- Associated with ligament of Struthers, which connects the process to the medial epicondyle (fibers of pronator teres may arise from this structure)
- Median nerve and brachial artery pass below this arch and may be compressed
- Fracture is possible but rare
August 1, 2012
- SFV, as understood by vascular surgeons and radiologists, is a continuation of the popliteal vein. After joining the deep femoral vein, it becomes common femoral vein
- Superficial femoral vein is actually a "deep" vein
- Most vascular surgeons and radiologists understand that SFV is a deep vein, but many physicians in other specialty or general practitioners do not
- Based on a survey of multispecialty groups, only 24% of physicians would give anticoagulants to patients having "acute thrombosis of the superficial femoral vein". There is a misperception of many physicians that SFV is superficial vein, therefore it would not be treated as deep vein thrombosis
- Current consensus developed by experts in phlebology officially established “femoral vein” as the vein that originates from the popliteal vein and courses in the femoral canal and bluntly discarded “superficial femoral vein” as an “unauthorized term" … because it is a deep vein
- SFV is not in the official Terminologica Anatomica
- The other vein is "deep femoral vein" or "profunda femoris vein"
- Supported by International Interdisciplinary Consensus Committee on Venous Anatomical Terminology convened on September 8–9, 2001 (Nomenclature of the veins of the lower limbs: an international interdisciplinary consensus statement. J Vasc Surg 2002; 36:416-422)
- Supported by Society of Interventional Radiology
Hammond I. The superficial femoral vein. Radiology 2003;229;604-666 (link)
July 21, 2012
- Bacterial infection of urine associated with ureteral obstruction, AKA infected hydronephrosis. Accumulation of pus in the renal pelvis and calices of the kidney
- Common causes are ureteric obstruction by stone and ureteropelvic junction (UPJ) obstruction
- Septic patients with high fever, flank pain and tenderness
- Any febrile patients with hydronephrosis should be suspected of having pyonephrosis
- Ultrasound: echogenic urine and debris in the hydronephrotic kidney
- Prompt drainage essential
July 12, 2012
July 11, 2012
- Acute disseminated infection of mycobacterium tuberculosis via bloodstream, or progression of active TB (rupture of caseating lymph node or cavity into blood vessel)
- Primary site may be intra- or extrapulmonary, or may not be recognizable
- Life-threatening infection. Mortality 13-50%
- Any age, any immune status but poor immune individuals are at increased risk
- Only 30% have positive sputum examination
- Up to 60% have negative skin test
- Chest radiograph (CXR) can be normal in early disease
- CXR usually shows abnormality up to 10 days or more after clinical illness has started. CT can show it earlier
- "Miliary" nodules are tiny (<2 mm), discrete, about the same size. They may coalesce into patchy and more irregular opacities
- Nodules may take 2-3 months to fade even with adequate therapy
- No correlation between number or size of nodules and clinical health
- Lymph node enlargement, hepatosplenomegaly may be seen
July 1, 2012
- Avulsion of pelvic bones usually found in young, skeletally immature athletes.
- Forceful contraction of the attached muscle while the athlete actively engages in kicking, running or jumping.
- Three major locations: ASIS (sartorius attachment), anterior inferior iliac spine (AIIS, rectus femoral attachment) and ischial tuberosity (hamstrings and adductor attachment).
- 50% of cases at ischial tuberosity, 23% ASIS, 22% AIIS (of all pelvic avulsions).
- Localized swelling and tenderness at the site of avulsion fracture. Limited motion from pain.
- Plain radiography usually sufficient for diagnosis.
- Comparison view helpful to ensure that abnormality is not a secondary center of ossification.
- Pitfalls: secondary ossification center, osseous mass seen as a delayed presentation mimicking neoplasm.
May 31, 2012
- Subdural blood collection that has similar attenuation with the gray matter
- Acute SDH appears as a high density collection with declining density with time. It passes "isodense" state mostly in subacute phase (2-6 weeks after initial trauma)
- Isodense SDH poses diagnostic dilemma because it is not apparently seen on CT
- In acute setting this can be seen in anemic patients (acute isodense SDH). Experimental data showed that Hb 8-10 g/dl will be isodense to the adjacent brain
May 21, 2012
Prostate Cancer: Facts
- Most commonly diagnosed non-skin cancer in men in USA, estimated lifetime risk 15.9%
- Most cases have good prognosis even without treatment
- Lifetime risk of dying of prostate cancer 2.8%
- PSA-based screening programs detect many cases of asymptomatic prostate cancer but evidence suggests that many of them will not progress or will progress slowly that it would have remained asymptomatic for the lifetime
- "Overdiagnosis" of prostate cancer based on PSA is between 17-50%
- Screening resulted in none or minimal reduction in prostate cancer mortality (0 to 1 prostate cancer deaths avoided per 1000 men screened)
- "False positivity" near 80% (cutoffs value 2.5-4 ug/L)
- Applies to men in general US population. Although older age is the strongest risk factor for development of prostate cancer, neither screening nor treatment trials show benefit in men older than 70 years
- Decision to initiate or continue PSA screening should be understood by patients about possible benefits and harms of screening
- The American Urological Association, the American Academy of Family Physicians and the American College of Physicians: currently updating their guideline
- The American Cancer Society: men at average risk beginning at age 50 years and black men or men with a family history of prostate cancer beginning at age 45 years
May 11, 2012
- Chest x-ray remains an initial screening examination in patients who has sustained blunt chest trauma
- In the appropriate clinical setting and with a CXR demonstrating mediastinal widening or other signs of mediastinal hemorrhage, thoracic aortography or helical chest CT is indicated
- CTA is emerging as a very sensitive and specific examination for aortic injury and has replaced aortography in many trauma centers
- Mediastinal widening has been defined as a transverse diameter of 8 cm from the left side of aortic arch to the right margin of the mediastinum (even on AP portable CXR)
- Mediastinal widening is 90% sensitive but 10% specific for aortic injury
- Approx 7% of patients with aortic injury have normal initial CXR
- If no mediastinal hematoma seen on CT, probability of significant aortic injury is very low
May 1, 2012
- Several possible mechanisms but at present it is believed to be an incomplete ischemia mainly related to cerebral small vessel arteriolosclerosis
- Pathology: partial loss of myelin, axons, oligodendroglial cells; mild reactive gliosis, astrocytic gliosis, stenosis of arterioles from hyaline fibrosis
- Important substrates for cognitive impairment and functional loss in the elderly
- Very common in elderly with hypertension, diabetes, hyperlipidemai
- Ill-defined hypodensities on CT
- T1 hypointensities, T2/PD/FLAIR hyperintensities. FLAIR best to demonstrate severity of disease
- When the largest lesion is adjacent to ventricles, it's called periventricular white matter changes
- On diffusion tensor MRI, there is elevation of diffusivity and reduced fractional anisotrophy (FA) meaning impaired white matter integrity
Xiong YY, Mok V. Age-related white matter changes. J Aging Res 2011
April 21, 2012
- Small round/oval defect in the lower third of the sternum
- Incomplete fusion of multiple ossification centers
- Usually asymptomatic and of no clinical significance
- Prevalence 6.7% in autopsy population
- Mostly incidentally found on chest CT
- Usually solitary
- Mostly in the body of the sternum. Rare in the manubrium
April 10, 2012
- Self-limited benign osteogenic tumor consisting of a vascular mass (nidus) surrounded by reactive bone sclerosis
- Male predominance (male:female = 2:1). Teenagers and young adults (90% of cases between 5-30 years old)
- Characteristic pain referring to the nearest joint, worse at night. Pain is relieved by aspirin or NSAIDs
- Treatment options: surgical excision, CT-guided percutaneous resection or destruction of the nidus
- Location: cortex, medulla or periosteum (anywhere but cortex most common)
- Long bones of lower extremity (esp femoral neck) most commonly affected. Almost never seen in flat bones and craniofacial bones
- Central lucent area (nidus) surrounded by sclerotic bone (nidus may be subtle and has variable degree of calcification)
- CT is helpful to identify the nidus (as in our case)
- MRI can be misleading because reactive bone marrow edema and soft tissue involvement may mimic malignancy
March 31, 2012
- Defect within the lower uterine cavity in patients with history of cesarean section in expected location of a hysterectomy incision
- Based on a study utilizing hysterosalpingograms, 60% of women with prior C-section had this anatomic defect
- Knowledge of this anatomic defect avoids misdiagnosing it as other pathology
- Often benign clinical significance. Some reports of ectopic scar pregnancy and abnormal uterine bleeding associated with this pathology
- Focal outpouching (most common feature) and thin linear defect
- Location: lower uterine segment (most common) > uterine isthmus, upper endocervical canal
- Prominent cervical glands (tubular, symmetric structure from both walls of endocervical canal)
- Postmyomectomy diverticula (unilateral, from site of resection, correlated with surgical history and location of diverticula)
- Gartner's duct cyst (long, tubular structure parallel to uterine cavity)
- Adenomyosis (location of defect anywhere along uterine cavity)
March 21, 2012
- Well-differentiated adenocarcinoma of the lung
- Lepidic growth meaning spread of neoplastic cells in peripheral air space without destroying lung architecture
- On CT, it can be a nodule, mass, consolidation (segmental or lobar), multi centric or diffuse disease
- Important CT feature is internal radiolucencies but this is overlapping with other diseases
- Lucencies can represent air bronchiologram, bubbles of pseudocavitation, cavitation, serpentine, alveologram or thin-walled cystic lesions
- Bubbly lucencies or pseudocavitation is believed to be non-involved lobules, paracicatricial emphysema and fibrosis with honeycombing and localized bronchiectasis.
March 11, 2012
- Requires a breach through all layers of hollow viscus that would allow escape of intraluminal content into the peritoneal cavity
- Results in peritonitis, either localized or generalized
- Plain radiography sensitivity ranges from 50% to 98% depending on the technique (upright chest, upright abdomen, left lateral decubitus, supine abdomen) and additional postural maneuver
- Recent study of 1,723 patients with GI perforation shows that radiography (either upright chest, upright abdomen or both) has positivity rate of almost 90%. 10% of radiographs did not show free air despite patients having GI perforation. Highest positivity rate was seen with gastric and duodenal perforation (94%), but lowest with appendiceal perforation (7%)
March 1, 2012
- Hemangioendothelioma and angiosarcoma are a group of primary malignant vascular tumors of the bone, which are extremely rare
- Common locations: femur, tibia, pelvis and vertebra
- Age group: between 4th and 5th decade
- Imaging appearance: lytic lesion without sclerotic border, multilocular, bone expansion and laminated periosteal reaction
- Common differential diagnosis = aneurysmal bone cyst, simple bone cyst
- A 50 years old female presented with pain and swelling at left foot with no history of trauma. On clinical examination local tenderness at heal was present.
- Radiograph taken in oblique (fig 1) positions, showed a well defined, lobulated lytic lesion with a few internal septa in the anterior part of Calcaneum. The lesion extends and breaches the medial and superior cortex of calcaneum
- MRI study of foot and ankle using 1.5T Siemens Magnetom Essenza machine, which included T1, T2, PD and T2 fat suppressed axial, sagittal and coronal sequences were performed. On PDW sagittal and T1 coronal images the lesion appears well defined, lobulated , with few internal septas in the anteroinferior part of calcaneum and breaches the medial and superior cortex and involves the adjacent myofascial planes. The lesion is hyperintense on PDW images [figure 2 A] and hypointense in T1W coronal images [figure 2 B] Tibiotalar joint shows minimal joint effusion.
- On histopathological examination of the material obtained after intraoperative curettage of calcaneum findings were in favor of tumor of vascular origin.
- On the basis of the clinical, radiological and histopathological findings, presumptive diagnosis of Calcaneal Hemangioendothelioma was considered.
- Hemangioendothelial sarcoma includes hemangioendothelioma and angiosarcoma, which encompasses a group of primary malignant vascular tumors in bone that vary from the malignant capillary and cavernous blood vessel formation to the proliferative endothelial sarcomas. Hemangioendothelioma is a tumor of blood vessels, in which endothelial cells are seen as predominant cell
- Primary malignant vascular tumors in bone are extremely rare(less than 1% of all bone tumors). It can occur in all age groups; however most of the patients are between 4th and 5th decades of life. Most commonly affected bone is Femur (16%), followed by Tibia(14%), pelvis(12%), vertebra(10%). Other rare sites are foot, hand, forearm bones and clavicle. The patient may not experience any specific symptoms or signs. Patient may present with Pain or occasionally swelling. Hemangioendothelioma shows multicentricity of lesions in the bones of the same extremity. On Radiographs, the solitary lesion is well circumscribed, lytic with no surrounding sclerosis or matrix mineralization, which shows internal septa which may be scant or incomplete. Occasionally it may show multilocular appearance. The tumor causes expansion, thinning and erosion of the cortex and often associated with a mild laminated periosteal reaction.
- On MR imaging, the lesion appears well defined, multilocular which is hyperintense on T2W and PDW images and hypointense on T1W images with internal septa. The lesion involves the surrounding soft tissue and involvement of multiple bones can occur.
- The etiology of unicameral bone cysts of the calcaneum is an enigma, just as it is with these lesions in other bones. Popular theories regarding the origin of bone cysts have been related to the long bones and the juxtaposition of the cyst to the growth plate
- Most commonly considered differential diagnoses are Simple Bone Cyst, Aneurysmal Bone Cyst. That can be differentiated by moth eaten erosion pattern and irregular margins of Hemangioendothelial sarcoma.
1. Ackerman LV, Spujat HJ. Tumors of bones and cartilage. Atlas of tumor pathology. Armed Forces Institute of Pathology, Washington, DC, 1962
2. Jaffe HL, Lichtenstein L. Solitary unicameral bone cyst with emphasis on the roentgen picture. Arch Surg 1942;44:1004-1025
3. Smith RW, Smith CF. Solitary unicameral bone cyst of the calcaneum: a review of twenty cases. J Bone Joint Surg Am 1974;56:49-56.