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SPLENOSIS

Splenosis is defined as the autotransplantation of splenic tissue resulting from the spillage of cells from the pulp of the spleen after splenic injury or splenectomy. Splenic implants are generally numerous, can be located anywhere in the peritoneal cavity, are supplied by arteries from the surrounding tissue rather than a hilar artery, have no particular shape, and have neither a hilus nor a normal capsule. Splenic implants located in the peritoneal cavity may be confused with renal neoplasms , abdominal lymphomas ,and endometriosis . If splenic rupture is associated with a diaphragmatic tear, the implants may seed the pleural cavity or pericardium , which causes intrathoracic splenosis.

Radiology:

CT – non enhanced shows round ,oval or irregular shaped multiple  masses .

CECT – Homogenous enhancement of all these masses

Ferumoxides-enhanced MRI as a novel technique for diagnosing splenosis

Radionuclide Imaging: Scintigraphy using Technetium-99m heat-damaged erythrocytes (RBC) or Indium 111-labeled platelets is more sensitive and specific for splenic uptake, making these tests the current diagnostic tools of choice.

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Gastric Ca vs Gastric Lymphoma

CHARACTER                                     CARCINOMA                                 LYMPHOMA

A. WALL THICKNESS               <1 cm                                                > 4 cm

B.MURAL THICKENING          LESS  HOMOGENOUS          MORE HOMOGENOUS

C.PERIGASTRIC FAT                   AFFECTED                               PRESERVED

D.ADENOPATHY  EXTENT       ABOVE RENAL VEIN       BELOW RENAL VEIN

E.LN SIZE                                        MEDIUM                                  LARGE

     CARCINOMA                                                      LYMPHOMA

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GI duplication cysts

  • Gastrointestinal duplication cysts are relatively common congenital anomalies which are composed of fluid-filled sacs lined by a layer of epithelium and smooth muscle from the alimentary tract.
  • They frequently share a common blood supply and muscular wall from the adjacent portion of the intestine. The most common locations are: Distal ileum (34%), esophagus (19%), stomach (9%), jejunum (9%), and appendix (6%), duodenum (5%).
  • The most common type of duplication cyst is spherical in shape, and almost never communicates with the alimentary tract. The more rare tubular type commonly communicates with the GI tract, frequently resulting in superinfection.
  • The distal 1/3 of the esophagus is the most common location for esophageal duplications. These duplications commonly contain gastric or pancreatic tissue. Gastric-mucosa containing intestinal duplications can ulcerate, causing hemorrhage and even perforation.
  • Narrowing mediastinal lesions to a particular region of the mediastinum greatly refines the differential. For middle mediastinal masses: Bronchogenic cyst, esophageal duplication, neurenteric cyst, lymphangioma, mature cystic teratoma (dermoid).

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SLIDES SHOW ESOPHAGEAL DUPLICATION CYST

 

Radiologic Findings:

  • CXR or KUB: May appear as a mediastinal or abdominal mass. Look for displacement of trachea, bronchi, esophagus, other structures. May contain air-fluid levels if communication with GI tract (very rare, tubular type).
  • CT: Thin walled, non-enhancing, density anywhere from fluid to soft tissue. Mass located adjacent to alimentary tract.. Oral contrast very helpful in delineating margins of duplication.
  • Nuclear medicine: Tc-99m Pertechnetate scintigraphy will demonstrate intestinal duplications containing gastric mucosa.

 

 

References:

  1. Kirks et al, Practical Pediatric Imaging.
  2. Brandt, Helms et al. Fundamentals of Diagnostic Radiology. 2006, 3rd Ed.
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EYE OF THE TIGER SIGN

Image

EYE OF THE TIGER sign is the MRI changes seen in Globus Pallidus in Pantothenate kinase associated neurodegenration. .The Globus Pallidus in T2W MRI shows medial high signal and lateral low signal.

Pantothenate kinase associated neurodegenration

  • Most common form of neurodegeneration with iron accumulation in the brain.
  • Mutation of pantothenate kinase 2 gene is the etiology
  • Best imaging manifestation is the “eye of the tiger sign” owing to the symmetric bilateral T2 hypo intensity adjacent to medial foci of increased T2 signal.
  • T2 hypo intensity is secondary to iron deposition within the brain
  • Clinical manifestations are rapid onset dystonia, dysarthria, rigidity and choreoathetosis.
  • Classically presents with a young child with postural deficits and gait problems.

 

 

 

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Renal Artery Stenosis

 

 

 

 

 

 

Left intrarenal doppler spectrum with dampened tardus/parvus waveform

 

 

Right intrarenal doppler spectrum normal

 

Left renal artery occlusion

 

Patent right renal artery

 

Figure

Volume-rendered image (posterior view) shows bilateral focal narrowing of the proximal main renal artery (arrows) with poststenotic dilatation. 

 

Figure

Digital subtraction angiogram shows an approximately 30% stenosis of the right main renal artery (arrow)

 

FigureCoronal maximum-intensity projection image shows two calcified plaques (arrows) projecting over the proximal right main renal artery

 

MRA showing right renal artery stenosis

 

 

ARTERIOGRAM

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RENAL VEIN THROMBOSIS

Normal color doppler ,Renal vasculature

 

 

USG shows diffusely hyperechoic kidney with loss of cortico-medullary differentiation

Color Doppler shows absent renal vein doppler signal

 

CT Scan axial section shows hypoattenuating thrombus in the left renal vein

Figure

CT scan Excretory phase shows enhancement of collaterals around ureter

MRA showing low signal thrombus partially obstructing the tumour

Most common cause is membranous nephropathy , Nephrotic synrome

Tumour Thrombus

FigureM – Mass , Arrow – Thrombus

Most common cause of tumour thrombus is Renal Cell Carcinoma

 

 

 

 

 

Reference :

a.Radiographics

b.Dr.Manjunath’s blog

c.Image consult

d.Medscape

 

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Renal Papillary Necrosis – Differential Diagnosis

D/D

A.In early ischaemic stage :During the early ischemic stage of renal papillary necrosis, corticomedullary or parenchymal phase multi–detector row CT shows a poorly marginated area of decreased enhancement at the tip of the medullary pyramid.

.1. Pyelonephritis also may be visible as a circumscribed area of reduced enhancement at CT during the corticomedullary and parenchymal phases, but the lesions in pyelonephritis are typified by lobar or segmental involvement instead of being limited to the medullary pyramid.

2.Moreover, during the late parenchymal phase, the margins of the lesions show the intense venous hyperemia that characterizes inflammatory disease.

3.Attenuation coefficients and locations may help differentiate ischemic lesions from cysts, abscesses, and hematomas.

B.In cases of advanced disease:  causes of cystic lesions in the areas of renal medullae or sinuses should be considered in the differential diagnosis. Other possible causes include

1.hydronephrosis,

2. congenital megacalices

3. parapelvic cyst

 4.caliceal diverticula.

In particular, the location of the arcuate artery relative to cystic lesions may be helpful for differentiation

Cavities produced by renal papillary necrosis can be differentiated from those in hydronephrosis by an irregular cavity contour and by extension of the cavity to arcuate arteries. Moreover, in hydronephrosis all calices are blunt tipped, whereas in papillary necrosis one or more calices may extend beyond the levels of others

FigureArrowheads indicating arcuate arteries

Like the cavities in renal papillary necrosis, pelvocaliceal diverticula may manifest as contrast material–filled fluid collections adjacent to calices. However, these two entities can usually be distinguished on the basis of location: Pelvocaliceal diverticula are not found in papillae but, rather, adjacent to the caliceal fornices or, less commonly, to an infundibulum or the renal pelvis

http://radiographics.rsna.org/content/26/6/1827.full