4. FREE AIR
SENSITIVITY OF IMAGING STUDIES
COMPUTED TOMOGRAPHY 99%
LATERAL UPRIGHT CHEST RADIOGRAPH 98%
AP UPRIGHT CHEST RADIOGRAPH 80 - 90%
SUPINE ABDOMEN RADIOGRAPH ?
5. PNEUMOPERITONEUM
SENSITIVITY OF IMAGING STUDIES
RADIOLOGIC DEMONSTRATION DEPENDS ON:
– VOLUME OF FREE AIR
– TIME INTERVAL BEFORE IMAGING
– TYPE OF IMAGING
– CONDUCT OF IMAGING EXAMINATION
AS LITTLE AS ONE CC CAN BE DEMONSTRATED
10% OF PATIENTS WITH PERFORATED ULCERS
DO NOT DEMONSTRATE PNEUMOPERITONEUM
26. RETROPERITONEAL GAS
CAUSES
IATROGENIC
– SURGERY
– DIAGNOSTIC PROCEDURE
TRAUMA
– PENETRATING
– RUPTURED VISCUS
RETROPERITONEAL DUODENUM, COLON, RECTUM
PERFORATED BOWEL
SECONDARY TO TUMOR, INFECTION, OBSTRUCTION,
NECROSIS
CAUDAL EXTENSION OF PNEUMOMEDIASTINUM
GAS WITHIN ABSCESS
27. RETROPERITONEAL GAS
IMAGING
LITTLE CHANGE IN POSITION OR SHAPE WHEN
COMPARING SUPINE, UPRIGHT, DECUB
RADIOGRAPHS
BUT FREE INTRAPERITONEAL GAS IS FREELY MOBILE
TENDS TO STAY IN ONE RETROPERITONEAL
COMPARTMENT
DUODENAL PERFORATION…..RUQ ANTERIOR PARARENAL
SPACE
SIGMOID DIVERTICULITIS….. LLQ
PERIRENAL ABSCESS…………. PERINEPHRIC SPACE
OFTEN FORMS LINEAR, CURVILINEAR GAS
COLLECTIONS
29. RETROPERITONEAL GAS
IMAGING
BENEATH DIAPHRAGM CAN SIMULATE
PNEUMOTHORAX
LARGE VOLUME OF GAS CAN OUTLINE
RETROPERITONEAL STRUCTURES
KIDNEY, LIVER MARGIN, PSOAS, FLANK STRIPE
RETROPERITONEAL GAS CAN EXTEND
CEPHALAD TO MEDIASTINUM
FASCIAL PLANES OF BODY WALL AND EXTREMITIES
INTO PERITONEAL CAVITY
62. ABSCESS
SUSPECT AN ABSCESS WHEN RADIOGRAPHS
SHOW A GAS COLLECTION THAT IS ABNORMAL
BECAUSE OF PERSISTENCE ON MULTIPLE
VIEWS
GET HISTORY, PX, LAB DATA BY
CONSULTATION WITH ORDERING MD.
CONFIRM WITH CROSS-SECTIONAL IMAGING
69. PANCREATIC GAS
-only 3 causes
GAS IN PANCREATIC BED
– ABSCESS
– POST PANCREATIC DRAINAGE
PROCEDURE
PERCUTANEOUS OR SURGICAL
– PUESTOW PROCEDURE
– PSEUDOCYST
– PANCREATIC FISTULA