Radiology notes: Imaging guidelines and recommendations

CT lung cancer screening: American College of Chest Physicians guidelines from JAMA: 
  1. Smokers and former smokers 55-74 with 30yr+ pack year history who smoke or quit smoking< 15 years ago.
  2. Smokers betwen 55-74 with less smoking history or severe co-morbities that would preclude treatment or limit life expectency should not be screened.
  3. Chest xrays no longer recommended due to low sensitivity/specificity.
  4. Within the benefit group estimated 3 lung cancer deaths avoided for every 1000 screenings for 6 years. 20% of individuals require follow-up with a 1% prevalence of lung cancer.

Pulmonary nodules: Evaluated per Fleischner Society Criteria 

AAA Screening: 1 screening ultrasound is recommended for male smokers aged 65-75 or persons with a family history of AAA. Per Medicare Preventive Services Guidelines

1st trimester US screening/fetal viability: Transvaginal scanning is preferred as transabdominal US frequently may not appropriately see the fetal pole requiring follow-up. If transabdominal ordered please state may perform transvaginal exam if necessary.

Pelvic US: Transvaginal US is preferred, particularly in overweight patients. Exceptions are women under 18 who are not sexually active or if there is concern for vaginal atrophy. Transabdominal US can be preferred for evaluating large masses in the adnexa. If ordering transabdominal it is helpful to add, transvaginal may be performed if indicated.

Mammography: For dense breasts the literature has shown some support for at least biannual bilateral breast ultrasound, and given recent stories in the WSJ and recent laws recommending telling all patients they have dense breast these will likely be requested more and more. Upside is a few more breast cancers will likely be found. Downside will be a lot more false positives with follow-up imaging and negative biopsies. The Society of Breast Imaging position is that there is no proven benefit to general screening and that more research is needed to decide who will benefit (likely people with family history).  However given the current climate this will likely become mainstream practice for dense and heterogeneously dense breasts.

Thyroid nodules: Evaluated per the Radiologists in Ultrasound Consensus Criteria

PE Studies: CT angiography (PE protocol CT chest) is now the gold standard and is far superior to V/Q scans. If a PE study failed due to poor contrast injection then it is usually best to give lovanox and repeat the CTA chest the next day. V/Q studies are indicated in a patients with poor renal function. In patients with normal renal function if only part of the contrast was administered do to blown IV, immediate reinjection at another site can be performed. Catheter pulmonary angiography is only rarely performed these days, and only after CTA.

Hip/Pelvic injury: In older patients, particularly osteopenic patients if patient is unable to walk/severe pain and has negative radiograph order a CT pelvis as non-displaced fractures can be missed.

Urograms: CT urograms are superior to IVP for almost everything except perhaps stricture evaluation and give far more information. In a CT urogram non-contrast CT is performed looking for stones. Then two injections of contrast are given. The 1st fills the collecting systems allowing evaluation of ureters and bladder. The second is given immediately prior to the scan and looks for masses in the kidneys/other organs.

Osteomyelitis: Obtain radiographs 1st. MRI with contrast is in general better and can allow for evaluation for abscess/fluid collections. Triphasic bone scan can sometimes be better for patients who cannot remain still for the phalanxes of the toes (frequently have motion on MRI as our scanner does not have motion correction).

MR compatibility:  Typical orthopedic appliances placed greater than 6 weeks ago are safe, although they will cause metal artifact. Orbit screening is important for welders or others at risk for metal in the orbits. Pacemakers are typically not safe although an MRI compatible device was recently released. Most shunts and cardiac stents placed in the recent past are MRI compatible. Obtain make/model information and MRI technologist can check compatibility. Neural stimulators, audiotory stimulators, and sacral stimulators are not compatible. Xanax can be considered for claustrophobia for outpatients.

Trauma CT/Acute abdomen: Standard of care is IV contrasted CT in acute trauma as many liver & splenic lacerations and acute aortic injury/dissection cannot be seen without contrast. For routine abdomen pain IV contrast is standard of care with oral contrast preferred, particularly for appendicitis/colitis. For renal colic non-contrast CT is preferred.

Pediatric x-rays: If no fracture is seen and patient has significant focal pain recommend splinting with 10 followup and repeat radiograph if pain persists to exclude Salter-Harris I fracture. On elbows if no fracture is seen, but there is an effusion, assume a fracture is present.

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