Chapter 25 - Abdomen and Pelvis Flashcards
Usual cause of ascites with attenuation values averaging +45 HU (p.673)
ACUTE BLEEDING
Two most gravity dependent portions of the peritoneal cavity? (p.673)
MORISON POUCH and PELVIS
UTZ appearance of simple ascites (p.673)
ANECHOIC
Exudative; hemorrhagic and neoplastic ascites often contains _______ in UTZ. (p.673)
FLOATING DEBRIS
Septations in ascites are associated with an ___ or ____ process.
(p.673)
INFLAMMATORY or MALIGNANT PROCESS
MR finding of Serous Ascites: in T1WI? In T2WI? In GRE?
p.673
T1WI: low signal intensity
T2WI: markedly increased in signal intensity
GRE: commonly bright due to fluid motion
_____refers to gelatinous ascites that occurs as a result
of intraperitoneal spread of mucin-producing cells resulting from rupture of appendiceal mucocele; intraperitoneal spread of benign or mucinous cysts of the ovary; or mucinous adenocarcinoma of the colon or rectum (p.673)
PSEUDOMYXOMA PERITONEI
(JELLY BELLY)
CR: punctate or ringlike calcifications scattered through the peritoneal cavity.
CT: mottled densities; septations and calcifications
US: intraperitoneal nodules that range from hypoechoic
to strongly echogenic within the fluid
Pneumoperitoneum is most commonly caused by _______ or __________. (p.673)
DUODENAL or GASTRIC ULCER PERFORATION
3 other additional causes pneumoperitoneum (p.673)
- TRAUMA
- RECENT SURGERY OR LAPAROSCOPY
- INFECTION OF THE PERITONEAL CAVITY WITH GAS-PRODUCING ORGANISMS
This refers to free air within the peritoneal cavity (p.673)
PNEUMOPERITONEUM
Post-operative pneumoperitoneum usually resolve in ___ to ___ days (p.673)
3 to 4 days
Failure of progressive resolution of post-operative pneumoperitoneum or an increase in air; suggests
________ (p.673)
LEAK OF BOWEL ANASTOMOSIS or SEPSIS
______ chest radiographs are the most sensitive
for free air or pneumoperitoneum. (p.674)
UPRIGHT Chest Radiograph
2 xray views that may be used with very ill patients to demonstrate air outlining the liver (p.674)
- LEFT LATERAL DECUBITUS view
2. CROSS-TABLE LATERAL view
Four signs of pneumoperitoneum on Supine radiographs
p.674
1. gas on both sides of the bowel wall (RIGLER SIGN) 2. gas outlining the falciform ligament 3. gas outlining the peritoneal cavity (FOOTBALL SIGN) 4. triangular or linear localized extraluminal gas in the right upper quadrant
A good place to look for pneumoperitoneum on CT?
p. 674
PERITONEAL RECESS BETWEEN THE LIVER
AND THE DIAPHRAGM
2 modalities sensitive in detecting abdominal calcifications
than conventional radiographs (p.674)
CT and US
Aneurysms of the aorta are manifest by luminal diameter
exceeding ___ cm as measured between calcifications
in the aortic wall (p.675)
3 cm
Ringlike calcified aneuryms most commonly involve
the ___ or ____ arteries (p. 675)
SPLENIC or RENAL arteries
____ are calcfied thrombi in the veins most common visualized in the lateral aspects of the pelvis. (p._____)
PHLEBOLITHS
- round or oval calcifications up to 5 mm in size
that commonly contain a central lucency - may be mistaken for urinary tract calculi
Calcified Lymph nodes result most commonly from
granulomatous diseases such as _____ or ____ (p.675)
TUBERCULOSIS or HISTOPLASMOSIS
-calcified lymph nodes are usually mottled
and 10 to 15 mm in size
Most commonly calcified lymph node group?
p.675
MESENTERIC NODES
Most calcified gallstones contain ________
and have a _____ appearance with a dense outer rim
and more radiolucent center. (p. 675)
CALCIUM BILIRUBINATE;
LAMINATED appearance
Term for calcifications in the gallbladder wall
p.675
PORCELAIN GALLBLADDER
This term is a suspension of radiopaque crystals within
the gallbladder bile. (p.675)
MILK OF CALCIUM BILE
- layering of the suspension can be
demonstrated on ERECT radiographs
Urinary calculi which assumes the shape
of the renal collecting system (p. 675)
STAGHORN CALCULI
RENAL CALCULI versus GALLSTONES
(p. 675)
RENAL CALCULI: more POSTERIOR in position;
GALLSTONE: more ANTERIOR in position
3 most common areas of ureteral narrowing?
p.675
- URETEROPELVIC JUNCTION
- PELVIC BRIM
- VESICOURETERAL JUNCTION
Colonic calcium deposition often due
to an undigestible material such as fruit pit
ENTEROLITHS
Calcified adrenal glands are associated with adrenal
hemorrhage in the __ ; ___ and ____. (p.676)
- NEWBORN
- TUBERCULOSIS
- ADDISON DISEASE
- calcification is mottled in the location of the
adrenal glands on either side of the first lumbar
vertebra
The calcification due to pancreatic calculi are usually
___ and of varying size (p.676)
COARSE
Calcification in the wall of a cyst is ___ or ____ - shaped
p. 676
CURVILINEAR or RING-SHAPED
- ECHINOCOCCUS CYSTS commonly calcify
and may be found in any intra-abdominal
organ as well as within the peritoneal cavity.
Most characteristic tumor calcification in uterine
leiomyomas. (p.____)
COARSE POPCORN CALCIFICATIONS
Calcified injection granuloma from quinine;
bismuth; and calcium salts of penicillin
is commonly evident in the ______. (p. 676)
BUTTOCKS
__________ causes characteristic rice-grain
calcifications in muscles. (p. 676)
CYSTICERCOSIS
Neoplastic ascites is associated with ___ (p. 673)
INTRAPERITONEAL TUMORS
Normal gas in the abdomen is predominantly
________ (p. 677)
SWALLOWED AIR
Normal air-fluid levels are in the _____ and _____;
but never in the _______. (p.677)
STOMACH and SMALL BOWEL;
but never in the COLON
DISTAL TO THE HEPATIC FLEXURE
Normal air-fluid levels in the small bowel
should not exceed ____ in length. (p.677)
2.5 cm
Small bowel is dilated when it exceeds _____.
The colon is dilated when it exceeds ____ in diameter.
The cecum is dilated when it exceeds ____ in diameter.
(p.677)
2.5 to 3.0 cm in diameter;
5 cm in diameter;
8 cm in diameter
Small bowel is more ___ in the abdomen
and is characterized by ________ (p.677)
CENTRAL;
VALVULAE CONNIVENTES
Large bowel is more ______ in abdomen
and is characterized by ______. (p.678)
PERIPHERAL;
HAUSTRA
\_\_\_\_\_ has the largest normal diameter of the large bowel (p.678)
CECUM
- always dilates to the greatest extent
irrespective of the site of obstruction
____; _____ and ______ are used interchangeably
and refer to stasis of bowel contents because of
decreased or absent peristalsis (p.678)
ADYNAMIC ILEUS; PARALYTIC ILEUS
and NON-OBSTRUCTIVE ILEUS
_____ typically demonstrates diffuse symmetric;
predominantly gaseous; distension of bowel (p.678)
ADYNAMIC ILEUS
- small bowel; stomach and colon
are proportionally dilated without
an abrupt transition
_____ refers to a segment of intestine that becomes
paralyzed and dilated as it lies next to an inflamed
intraabdominal organ. (p.678)
SENTINEL LOOP
- in essence; it is a short segment of adynamic ileus
that appears as an isolated loop of distended intestine
that remains in the same general position on serial
images
-alerts one to the presence of an adjacent inflammatory
process
A sentinel loop in the RUQ suggest ___; ____ and___.
p.678
- ACUTE CHOLECYSTITIS
- HEPATITIS
- PYELONEPHRITIS
A sentinel loop in the LUQ suggest ___; ____ and___.
p.678
- PANCREATITIS
- PYELONEPHRITIS
- SPLENIC INJURY
A sentinel loop in the LOWER QUADRANTS suggest \_\_\_ (give 5). (p.678)
- DIVERTICULITIS
- APPENDICITIS
- SALPINGITIS
- CYSTITIS
- CROHN DISEASE
______ is a manifestation of fulminant colitis
characterized by extreme dilation of all or a portion
of the colon. (p. 678)
TOXIC MEGACOLON
- absent peristalsis
- large bowel loses all tone and contractility
- bowel wall becomes like wet blotting paper
- risk of perforation is extreme
Most common cause of toxic megacolon
p.678
ACUTE ULCERATIVE COLITIS
Most striking finding in Toxic Megacolon
p. 678
DILATION OF THE TRANSVERSE COLON
UP TO 15 cm IN DIAMETER
Toxic megacolon diagnosis is suggested when the
diameter of the colon exceeds ___ cm
and the mucosa appears abnormal. (p.678)
exceeds 5 cm
TRUE OR FALSE. Barium enema is absolutely contraindicated in TOXIC MEGACOLON because of the risk of perforation.
(p.678)
TRUE
___ means stasis of bowel contents above a focal
lesion. (p.678)
MECHANICAL BOWEL OBSTRUCTION
- obstruction may be due to obturation
(occlusion by a mass in the lumen);
stenosis due to intrinsic bowel disease;
compression of the lumen by extrinsic disease
3 goals in imaging mechanical bowel obstruction.
p. 678
- Confirm the presence of obstruction
- Identify its level
- Demonstrate its cause
Radiographs can confirm the presence of bowel
obstruction _____ hours before the diagnosis
can usually be made clinically. (p.678)
6 to 12 hours before
Type of obstruction which means that the lumen
is totally occluded. (p.678)
COMPLETE OBSTRUCTION
Type of obstruction which means some bowel
contents pass through. (p.678)
PARTIAL OBSTRUCTION
Type of obstruction which refers to blockage of the
luminal contents without interference of blood supply.
(p.678)
SIMPLE OBSTRUCTION
Type of obstruction which means that the blood supply
to the bowel wall is impaired. (p.678)
STRANGULATION OBSTRUCTION
- most strangulation obstruction
are closed-loop obstructions.
Type of obstruction which means blockage
of a bowel loop segment at both ends.
(p.678)
CLOSED-LOOP OBSTRUCTIONS
______ is the term applied to necrotizing fasciitis
of the perineum; perianal and genital regions
(p.679)
FOURNIER GANGRENE
In the western world; ___ account for 75%
of the small bowel obstruction (p.679)
POST-SURGICAL ADHESIONS
In developing nations; 80% of small bowel
obstruction is caused by ____ (p.679)
INCARCERATED HERNIA
- but only 10% is caused by adhesions
DIAGNOSIS.
Radiographic findings: (p.679)
1. DILATED LOOPS OF SMALL BOWEL (> 3 cm)
disproportionate to more distal small or colon
2. SMALL BOWEL AIR-FLUID LEVELS that exceed
2.5 cm in width
3. AIR-FLUID LEVELS AT DIFFERING HEIGHTS
(> 5 mm) within the same loop (dynamic air-fluid
levels)
4. TWO OR MORE AIR-FLUID LEVELS
5. SMALL BUBBLES OF GAS TRAPPED BETWEEN FOLDS
IN DILATED ; FLUID-FILLED LOOPS PRODUCING THE
STRING OF PEARLS sign
small bowel obstruction
___ is a row of small gas bubbles oriented horizontally
or obliquely across the abdomen (p.679)
STRING OF PEARLS sign
CT DIAGNOSTIC FINDING of small bowel obstruction
p.679-680
demonstration of a transition site between
small bowel loops dilated with fluid or
air and collapsed bowel loops distal to
the obstruction
____ sign is strong CT evidence of bowel obstruction.
p.680
SMALL-BOWEL FECES sign
DIAGNOSIS.
CT FINDINGS: (p.680)
1. CIRCUMFERENTIAL WALL THICKENING
(>3mm)
2. EDEMA OF THE BOWEL WALL
(Target or Halo appearance of the bowel wall)
3. LACK OF ENHANCEMENT OF THE BOWEL WALL
(most specific sign)
4. HAZINESS OR OBLITERATION OF THE MESENTERIC VESSELS
5. INFILTRATION OF THE MESENTERY WITH FLUID OR
HEMORRHAGE
Strangulation Obstruction
DIAGNOSES (2).
4 CT signs: (p. 680)
1. Radial distribution of dilated small bowel
with mesenteric vessels converging toward a
focus of torsion
2. U-shaped or C-shaped dilated small bowel loop
3. BEAK sign at the site of torsion seen as fusiform tapering
of a dilated bowel loop
4. WHIRL sign to tightly twisted mesentery seen with volvulus
- presence of a whirl sign in patient with small bowel obstruction
correlates strongly with the need for surgery.
SMALL BOWEL VOLVULUS and
CLOSED-LOOP OBSTRUCTION
_____ is a major cause of small bowel obstruction
in children but is less common in adults. (p.680)
INTUSSUSCEPTION
- in adults; it is often chronic; intermittent
or subacute and is usually caused
by a polypoid tumor ; such as lipoma
Other 4 causes of Intussusception aside from
polypoid tumor or lipoma? (p.680)
- Meckel Diverticulum
- Lymphoma
- Mesenteric nodes
- Foreign bodies
ILEOCOLIC INTUSSUSCEPTION is usually
____ in children but is caused by a __ in adults
(p.680)
IDIOPATHIC; MASS
COLOCOLIC INTUSSUSCEPTION is ____ in adults
but ____ in children. (p.680)
COMMON; RARE
Barium study finding of Intussusception?
p.680
COILED SPRING APPEARANCE
- barium trapped between the intussusception
and the receiving bowel
CT finding of intussusception (p.681)
TARGET-LIKE INTESTINAL MASS
Ultrasound finding of intussusception (p.681)
DONUT configuration of alternating hyperechoic and hypoechoic rings representing alternating mucosa; muscular wall and mesenteric fat tissues in cross section
___ is a cause of mechanical small bowel obstruction
that should be suspected in any elderly woman
with small bowel obstruction (p.____)
GALLSTONE ILEUS
-bowel obstruction is caused by a large gallstone
that erodes through the gallbladder wall and
passes into the intestine; creating a cholecystoduodenal
fistula.
GALLSTONE IN GALLSTONE ILEUS most commonly
lodges in the ____. (p. 681)
DISTAL ILEUM
- causative gallstones are typically single;
faceted and 2 to 5 cm in size
Components of the RIGLER TRIAD (p. 681)
1. DILATED SMALL BOWEL LOOPS (80% of cases) 2. AIR IN THE BILIARY TREE OR GALLBLADDER (67%) 3. CALCIFIED GALLSTONE IN AN ECTOPIC LOCATION (50%)
When the cecum exceeds __ cm in diameter;
it is at high risk for perforation with attendant risks
of peritonitis and septic shock. (p.681)
10 cm
Most colonic obstructions occur in the ___ colon.
p. 681
SIGMOID
- bowel lumen is narrower;
stool is more formed
RADIOGRAPHIC FINDING diagnostic in large bowel
obstruction. (p.681)
DILATION OF THE COLON FROM THE CECUM
TO THE POINT OF OBSTRUCTION
- colon distal to the obstruction is devoid of gas
Air-fluid levels distal to the ______ are strong evidence of obstruction unless the patient has had an enema
(p.681)
HEPATIC FLEXURE
Sigmoid volvulus is most common in the ___
and in individuals on ____ diets. (p.681)
- sigmoid colon twists around its mesentery;
resulting in a closed-loop obstruction
ELDERLY; HIGH-RESIDUE diets
Radiographic diagnosis when a large-gas filled loop
without haustral markings arises from the pelvis
and extending high into the abdomen and often to the diaphragm. (p.681)
SIGMOID VOLVULUS
Radiographic sign in SIGMOID VOLVULUS where the
apex of the distended sigmoid colon may
extend cephalad to the transverse colon. (p.681)
NORTHERN EXPOSURE SIGN
Barium enema (in SIGMOID VOLVULUS) demonstrates obstruction that tapers to a beak at the point of the twist; usually approximately \_\_\_ cm above the anal verge. (p.681)
15 cm
DIAGNOSIS.
5 CT FINDINGS: (p.681-682)
1. Inverted; dilated U-shaped sigmoid colon
2. Absence of gas in the rectum
3. Transition zones between dilated and
collapsed bowel occur at the point of twisting
4. Oblique lines created by the orientation
of the transition zones create the X-MARKS
THE SPOT SIGN appreciated on the sequential
images
5. A single beak-shaped transition point corres-
ponding to the beak sign seen on barium enema
- as a closed loop-obstruction the bowel is prone
to ischemia and perforation; signs of which must
be carefully sought.
SIGMOID VOLVULUS
___ causes 1% to 3% of large bowel obstruction
in adults and occurs most frequently in the
30 to 60 years age group (p.682)
CECAL VOLVULUS
- a closed-loop obstruction that may result
in ischemia; necrosis and perforation - most common type: the twist and invert
with the cecum displaced to the left upper quadrant.
____ refers to a folding of the cecum to a position
anteromedial to the ascending colon; rather like folding the toe of a sock back on itself (p._____)
CECAL BASCULE
DIAGNOSIS.
Four classic radiographic findings: (p.682)
1. Coffee bean-shaped loop of gas-distended bowel having haustral
markings directed toward the left upper quadrant
2. Apex of the cecum in the left upper quadrant
3. Cecal distension greater than 10 cm in diameter
4. Collapse of the distal colon
- proximal small bowel dilatation may or may not be present
CECAL VOLVULUS
DIAGNOSIS.
Seven CT findings: (p.682)
1. Cecum in the upper mid and left abdomen
2. Volvulus in the RLQ seen as an area of swirling of the bowel and mesenteric fat (WHIRL SIGN)
3. Appendix is displaced to the left upper quadrant
4. Two transition points are present; one for the entering loop and one for the exiting loop
5. when the loops are completely wound around each other an X-MARKS THE SPOT sign is present formed by the crossing
configuration of the transition zones
6. cecum is distended more than 10 cm
7. distal large bowel is decompressed
CECAL VOLVULUS
____ is the most common cause of large bowel obstruction
in elderly and bedridded patients. (p.682)
FECAL IMPACTION
___ is a rare inflammation of the wall of the colon caused by fecal impaction. (p.682)
STERCORAL COLITIS
____ is clinical disorder of acute colonic distension with abdominal pain and distension but without the presence of mechanical obstruction (p.682)
COLONIC PSEUDOOBSTRUCTION (OGILVIE SYNDROME)
- radiographs demonstrate dilatation of the colon most commonly from cecum to splenic flexure
- CT demonstrates the same findings with additional evaluation for wall thickening associated with colitis or findings of colonic ischemia
DIAGNOSIS.
10 CT findings: (p. 683)
1. Circumferential or nodular thickening (>5 mm) of the bowel wall with infiltration of low-density edema or high-density blood; resulting from mucosal injury.
2. thumbprinting resulting from this nodular infiltration of the bowel wall
3. dilatation of the bowel lumen (>3cm) for small bowel; >5cm for colon; > 8cm for cecum)
4. PNEUMATOSIS INTESTINALIS
5. Edema or hemorrhage into the mesentery
6. engorged mesenteric vessels
7. Thrombosis of mesenteric arteries or veins
8. poor enhancement of the bowel wall along its mesenteric border; which is evidence of ischemia
9. poor or absent mucosal enhancement with thinning of the bowel wall; which is evidence of bowel infarction
10. ascites; which is commonly present
bowel ischemia
____ refers to the presence of gas within the bowel wall (p. 683)
PNEUMATOSIS INTESTINALIS
- it may occur as a benign entity without clinical significance or may be an important finding of bowel ischemia
- RADIOGRAPHIC SIGN; not a disease
4 causes of Pneumatosis Intestinalis (p.683)
- BOWEL NECROSIS; usually associated with other radiographic and clinical signs of bowel ischemia
- MUCOSAL DISRUPTION; caused by ulcers; mucosal biopsies; trauma; enteric tubes; or inflammatory bowel disease
- INCREASED MUCOSAL PERMEABILITY related to immunosuppression in AIDS;organ transplantation or chemotherapy
- PULMONARY DISEASE resulting in alveolar disruption and dissection of air along interstitial pathways to the bowel wall.
TRUE OR FALSE. Pneumatosis in asymptomatic patients is very likely benign and incidental. (p.____)
TRUE
TRUE OF FALSE. Pneumatosis in seriously ill patients with abdominal pain or distension is more likely to be a sign of bowel ischemia. (p.____)
TRUE
____ appears on radiographs or CT as cystic air bubbles (few mms to several cms) or linear streaks of air within the bowel wall; esp in its most gravity-dependent aspect (p.683)
PNEUMATOSIS
meaning of the acronym FAST? (p.683)
FOCUSED ABDOMINAL SONOGRAMS FOR TRAUMA
- may be used to detect the presence of intraperitoneal fluid to triage trauma patients for CT
DIAGNOSIS. CT findings: (p.683) 1. HEMOPERITONEUM 2. SENTINEL CLOT 3. ACTIVE BLEEDING 4. FREE AIR WITHIN THE PERITONEAL ACTIVITY 5. FREE CONTRAST WITHIN THE PERITONEAL ACTIVITY 6. SUBCAPSULAR HEMATOMAS 7. INTRAPARENCHYMAL HEMATOMAS 8. LACERATIONS 9. ABSENCE OF ORGAN ENHANCEMENT 10. INFARCTIONS
traumatic injury
_____ acute blood within the peritoneal cavity measuring 30 to 45 HU (p.683)
HEMOPERITONEUM
____ a focal collection of clotted blood (>60 H) that maybe seen in the peritoneal cavity adjacent to an injured organ (p.683)
SENTINEL CLOT
Active bleeding in abdominal trauma is seen as extravasated contrast (85 to 370 H); seen during ___ phase of scanning with MDCT. (p. 683)
ARTERIAL
____ an insensitive sign of bowel injury provided that diagnostic peritoneal lavage has not been performed (p.683)
FREE AIR WITHIN THE PERITONEAL CAVITY
____ this may result from oral contrast leaking from injured bowel or IV contrast leaking from a ruptured bladder. (p.___)
FREE CONTRAST WITHIN THE PERITONEAL CAVITY
______ appear as crescent-shaped collections confined by the capsule of the injured organ (p.683)
SUBCAPSULAR HEMATOMAS
____ this appears as an irregularly shaped low-density areas within a contrast-enhanced solid organ (p.683)
INTRAPARENCHYMAL HEMATOMAS
___ this appears as jagged linear defects defined by lower-density blood within a contrast-enhanced injured organ in abdominal trauma (p. 683)
LACERATIONS
___ reflects damage to the organ’s arterial supply in abdominal traumas. (p.683)
ABSENCE OF ORGAN ENHANCEMENT
_____ are seen as zones of decreased contrast enhancement that extend to the capsule of a solid organ in abdominal traumas. (p.683)
INFARCTIONS
The abdomen and pelvis contain more than __ lymph nodes that may be involved in a wide variety of neoplastic and inflammatory diseases.(p. 684)
230
____ measurements of lymph node size are preferred to determine abnormal enlargement. (p. 684)
SHORT-AXIS
3 Morphologic patterns of PATHOLOGIC lymphadenopathy include ___; ___ or ____. (p. 684)
- SINGLE ENLARGED NODES
- MULTIPLE SEPARATE LOBULATED ENLARGED NODES
- BULKLY CONGLOMERATE MASSES OF LYMPH NODES
Calcifications in enlarged nodes may be seen with __ ; ___; ___ and ___. (p. 684)
- INFLAMMATORY ADENOPATHY
- MUCINOUS CARCINOMAS
- SARCOMAS
- TREATED LYMPHOMA
TRUE OR FALSE. Normal nodes are oblong in shape.(p.684)
TRUE
Most pathologically enlarged nodes have CT densities ____ than skeletal muscle. (p.684)
SLIGHTLY LESS
Low-density nodal metastases are commonly seen with __;___ and ___. (p.684)
- NON-SEMINOMATOUS TESTICULARCARCINOMA
- TUBERCULOSIS
- occasionally LYMPHOMA
Radiographic sign wherein masses of retroperitoneal nodes may silhoutte segments of the normally echogenic wall of the aorta. (p.685)
SONOGRAPHIC SILHOUTTE SIGN
Radiographic sign which refers to entrapment of mesenteric vessels by masses of enlarged lymph nodes in the mesentery. (p.685)
SANDWICH SIGN
LYMPH NODE MRI SIGNAL CHARACTERISTICS: in T1WI? In T2WI? (p.___)
T1WI: low signal intensity compared to surrounding fat;
T2WI: high signal intensity compared to muscle
______ is responsible for 20% to 40% of all lymphoma and is characterized histologically by the presence of REED-STERNBERG CELL. (p.685)
HODGKIN LYMPHOMA
- has a bimodal age distribution most commonly affecting patients aged 25 to 30 years and older than 50 years
____ is responsible for 60% to 80% of lymphoma.(p.685)
NON-HODGKIN LYMPHOMA
- a heterogeneous group of disorders with a confusing array of changing names and classifications
- particularly common in immunocompromised patients
Solid organ involvement of Non-Hodgkin lymphoma primarily affects the following organs (6). (p. 685)
- SPLEEN
- LIVER
- PANCREAS
- KIDNEYS
- ADRENAL GLANDS
- TESTES
DIAGNOSIS.
5 manifestations: (p.685)
1. Solitary or multiple homogeneous well-defined nodules;
2. Confluent masses;
3. Mild uniform contrast enhancement of nodules and masses;
4. Diffuse involvement producing only organomegaly;
5. Organ invasion from adjacent tissue.
Non-Hodgkin’s Lymphoma
5 GI involvement of Non-Hodgkin Lymphoma (p.685)
- Wall involvement deep to the mucosa that may be missed at endoscopy;
- Circumferential wall thickening;
- Luminal dilatation; narrowing or cavitation
- Nodules; polyps and ulcers
- Impaired peristalsis
____ is a spectrum of lymphoid hyperplasias and neoplasias in patients who have received solid organ transplants and immunosuppresive therapy. (p.685)
POSTTRANSPLANTATION LYMPHOPROLIFERATIVE DISORDER
(PTLD)
- the disorder results from an Epstein-Barr virus-induced proliferation of B lymphocytes that is usually opposed by functioning T cells.
Extranodal involvement in solid organs with discrete solitary; multiple or infiltrative masses is most common in what condition. (p.685)
POSTTRANSPLANTATION LYMPHOPROLIFERATIVE DISORDER
(PTLD)
- GI involvement is similar to NHL and includes wall thickening; luminal narrowing;eccentric extraluminal mass; luminal ulceration and stranding in the mesentery.
- Treatment is reduction of immunosuppresive therapy
____ is an uncommon primary tumor of the peritoneal membrane (p.685)
PERITONEAL MESOTHELIOMA
- all are closely associated with asbestos exposure
- US demonstrate the sheetlike superficial masses
- prognosis is poor; with most patients dying within 1 year of diagnosis
One-third of all mesotheliomas arise from the ______ with most of the remainder arising from the ____. (p.685)
PERITONEUM; PLEURA
Cake-like thickening of the omentum (p.686)
OMENTAL CAKE
- In PERITONEAL mesothelioma; CT demonstrates nodular; irregular peritoneal and omental thickening and masses; which merge to large plaques
Peritoneal metastases are most commonly associated with these four carcinomas.(p.686)
OVARIAN, COLON, STOMACH and PANCREAS CARCINOMA
MNEMONIC: PM PaCOS
Three preferential sites for tumor implantation of peritoneal metastases (p.686)
- PELVIC CUL-DE-SAC
- RIGHT PARACOLIC GUTTER
- GREATER OMENTUM
DIAGNOSIS. 5 CT findings: (p.686) 1. Tumor nodules on peritoneal surfaces 2. Omental Cake 3. Tumor nodules in the mesentery 4. Thickening and nodularity of the bowel wall due to serosal implants 5. Ascites; that is commonly loculated
PERITONEAL METASTASES
____ occurs when the primary sites of hematopoiesis in the bone marrow fail as a result of myelofibrosis or when hemolytic anemias overwhelm blood cell production (sickle cell disease and thalassemia) (p.686)
EXTRAMEDULLARY HEMATOPOIESIS
- bilateral; relatively symmetric and enhance mildy; and homogeneously postcontrast
The most obvious manisfestations of EXTRAMEDULLARY HEMATOPOIESIS are homogeneous well-marginated paraspinal masses that favor the _____ spine. (p.686)
THORACIC spine
____ are benign cystic lesions that arise from lymphatic vascular channels. (p.686)
LYMPHANGIOMAS
- cystic mass contains septations and multiple loculations
- lesions occur in the omentum; mesentery; mesocolon and retroperitoneum
CT finding in Lymphangiomas (p.686)
Fluid density mass with enhancing wall and septa
- US shows better multilocular nature of the mass
____ arise in the retroperitoneal tissues outside of the retroperitoneal organs. (p.686)
PRIMARY RETROPERITONEAL NEOPLASMS
Most common sarcoma of the retroperitoneum (p.686)
LIPOSARCOMAS
-containts distinct fat density (other example: TERATOMAS)
______ is rare condition manifest by formation of a fibrous plaque in the lower retroperitoneum that encases and compresses the aorta; inferior vena cava and ureters. (p.686)
RETROPERITONEAL FIBROSIS
- 2/3 of cases are idiopathic.
- the fibrotic plaque is usually located over the anterior surfaces of the L4 and L5 vertebrae.
- plaques are typically of low signal intensity on both T1WI and T2WI;
- plaques that shows high signal intensity on T2WI should be considered suspicious for malignancy as a cause
____ an ergot prescribed for migraine headache; causes 12% of RETROPERITONEAL FIBROSIS cases. (p.686)
METHYSERGIDE
TRUE OR FALSE. On US; retroperitoneal fibrosis is easily confused with lymphoma (p.___)
TRUE
TRUE OR FALSE. Wooden foreign bodies are usually not visualized on conventional radiographs. (p.686)
TRUE
- CT shows high attenuation of the wooden object.
_______ are a rare but dreaded complication of surgery. (p.687)
RETAINED SURGICAL SPONGES (gossypiboma)
- retained sponges may be asymptomatic; causes an abscess; or abscess; or generate a granulomatous response; inducing fibrosis and calcification
_____ occur within the peritoneal cavity because of spillage of contaminated material from perforated bowel or as a complication of surgery; trauma; pancreatitis; sepsis; or AIDS (p.____)
ABSCESSES
_____ is the most common site for abscess formation.(p.688)
PELVIS
DIAGNOSIS. 7 Radiographic findings: (p.688) 1. Soft tissue mass 2. Collection of extraluminal gas 3. Displacement of bowel 4. localized or generalized ileus 5. elevation of the diaphragm 6. pleural effusion 7. Atelectasis or consolidation at the lung bases
ABSCESSES
Most SPECIFIC sign of ABSCESS; but is UNCOMMON (p.688)
A FOCAL COLLECTION OF EXTRALUMINAL GAS
- CT shows a loculated fluid collection; often with internal debris and fluid-fluid levels.
_________ within the fluid collection is strong evidence of abscess. (p.688)
GAS
Gas within the fluid collection is evidenced by echogenic foci producing ___ or ___ artifacts. (p.688)
COMET-TAIL or REVERBERATION artifacts
A ___ of the abdominal wall is a protrusion of bowel; omentum; or mesentery through a defect in the wall of the abdomen or pelvis. (p.____)
HERNIA
_____ refers to hernias that are not reducible. (p.688)
INCARCERATION
____ refers to hernias associated with bowel obstruction and bowel ischemia. (p.688)
STRANGULATION
____ hernias entrap only a portion of the bowel wall without compromising viability. (p.688)
RICHTER
____ hernias are most common in children and adults (p.688)
INGUINAL
_____ hernias extend throughout the internal inguinal ring in the inguinal canal LATERAL to the inferior epigastric vessels.
(p.688)
INDIRECT INGUINAL hernias
___ hernias occur medial to the inferior epigastric vessels directly into the inguinal canal through a weakness in its floor (p.688)
DIRECT INGUINAL hernias
____ hernias are complications of surgery with herniation through the surgical incision.(p.688)
INCISIONAL HERNIAS
____ hernias occur in association with surgically created stomas. (p. 688)
PARASTOMAL hernias
____ hernias occur through defects in the lumbar musculature posterolaterally below the 12th rib and above the iliac crest.
(p.688)
LUMBAR hernias
____ hernias occus in the lower abdominal wall lateral to rectus abdominis and inferior to the umbilicus through a defect in the aponeurosis of the transverse abdominis and internal oblique muscles. (p.688)
SPIGELIAN hernias
A CD4+ T-cell count below ____ cells/mm3 is diagnostic of AIDS. (p.689)
below 200 cells/mm3 (normal is 800 to 1000 cells/mm3)
AIDS is characterized by multiple opportunistic infections and aggressive malignancies; most commonly ____ and ___. (p.689)
KAPOSI SARCOMA (KS) and AIDS-related lymphoma.
- infection by multiple organisms at multiple sites
_____ are the most useful modalities for evaluating the solid visceral organs; adenopathy and the peritoneal cavity. (p.690)
CT and US
______ causes pneumonia in nearly 80% of patients with AIDS. (p.690)
Pneumocystis carinii
______ is a cause of bulky abdominal adenopathy; hepatosplenomegaly and focal lesions in the liver and the spleen. (p.690)
ATYPICAL MYCOBACTERIUM
___ and ___ are common causes of esophagitis as well as gastric antritis and duodenitis. (p.690)
CANDIDA ALBICANS and CYTOMEGALOVIRUS
____ and ____ are protozoans; previously found only in animals; that infect the GI tract and causes severe diarrhea. (p.690)
CRYPTOSPORIDIUM and ISOSPORA BELLI
___ and ___ are causes of AIDS-related cholangitis. (p.690)
CRYPTOSPORIDIUM and CYTOMEGALOVIRUS
_______ occurs as the most common malignancy associated with AIDS and may also occur in organ transplant patients.
(p.690)
KAPOSI SARCOMA
______ are extremely aggressive neoplasms that respond poorly to therapy and commonly involve the extranodal sites. (p.690)
AIDS-related Lymphomas
- median survival is only 5 to 6 months
- extranodal involvement is found at presentation in most patients (CNS in 27%)
_____ is serous fluid in the peritoneal cavity (p.673)
ASCITES
Ascites is most commonly caused by _____ (p.673)
- CIRRHOSIS
- HYPOPROTEINEMIA
- CONGESTIVE HEART FAILURE
Exudative ascites results from inflammatory processes such as _____ (p.673)
- ABSCESS
- PANCREATITIS
- PERITONITIS
- BOWEL PERFORATION
Hemoperitoneum results from _____ (p.673)
- TRAUMA
- SURGERY
- SPONTANEOUS HEMORRHAGE
Neoplastic Ascites is associated with ___ (p. 673)
INTRAPERITONEAL TUMORS
Conventional Radiographic diagnosis of ascites requires that at least ___ mL of fluid be present. (p.673)
at least 500 ml of fluid
DIAGNOSIS.
Six radiographic findings: (p.673)
1. Diffuse increase in density of the abdomen
(gray abdomen)
2. indistinct margins of the liver; spleen and psoas muscles
3. medial displacement of gas-filled colon; liver and spleen away from the properitoneal flank stripe
4. bulging of the flanks
5. increased separation of gas-filled small bowel loops
6. dog’s ears appearance of symmetric densities in the pelvis
due to fluid spilling out of the cul-de-sac on either of the bladder
ASCITES
DISGNOSIS.
CT finding: (p.673)
Fluid density in the recesses of the peritoneal cavity
ASCITES
Type of ascites with attenuation values near water
-10 to +10 HU) (p.673
SEROUS ASCITES
Type of ascites with attenuation values usually above +15 HU (p.673)
EXUDATIVE ASCITES
