Bone scans and Q scans when and how to order

1
Bone scans and Q scans when and how to order?

• Dr Stewart Redman
• Consultant Radiologist
• R.U.H. Bath

2
Overview

• Bone scans
• Radiation dose
• Q scans
• PET/CT and other scans

3
Bone Scans - Principles

• Gives a picture of bone turnover rather than
  structure
• Whole body imaging - so good at picking up occult
  lesions
• Single lesion characterisation consider MRI first

4
Background

• Patients injected with phosphate labelled
  technetium.
• Taken up by osteoblasts and incorporated into
  bone.
• Highlights areas of abnormal bone metabolism.

5
R.U.H. Department

• Ground floor R.U.H. South
• We perform 3,500 scans per year
• 1,300 of these are bone scans
• 10 20 of these are referred from GPs

6
Referral Process

• Standard Radiology form.
• Fax or send to the Nuclear Medicine Department at
  the R.U.H.
• Non urgent waiting times around 4 weeks.
• Shorter waits have caused DNA rate to rise from
  1 to 10

7
Scan Process

• Injected in department.
• Usually then sent away for 3 hours while
  osteoblasts go to work.
• Lie on scanning bed for around 20minutes.
• Sometimes need focused views also.
• Reasonably tolerated

8
RUH Cameras
GE Starcam
Dual headed camera Gamma camera with CT
Single headed camera
Philips Medical/ GE / Siemens
Dual headed camera
9
Indications

• Pattern and activity of arthopathy
• Presence and extent of metastases
• Infected or loose prosthesis
• Shin splints or stress fracture
• Reflex sympathetic dystrophy
• Further characterise lesions found on MRI
• Hypertrophic osteo-arthropathy

10
Limitations

• Resolution is poor
• Purely lytic lesions can be missed
• Myeloma
• Occasionally purely lytic metastases

11
Case 1

• 40 year old man referred with chronic non
  specific pain around the right knee
• X-rays and MRI of the knee normal

12
Normal bone scan
13
Case 2

• 78 year old man with a past history of localised
  prostate cancer and a right hip replacement 3
  years ago.
• Presents with pain in pelvis, hip and right thigh.

14
Pattern of multiple metastases
15
Case 3

• 77 year old woman
• Fell onto left hip 3 weeks previously
• On going left hip pain
• No fracture on X-ray
• Past history of Breast Cancer 38 years ago with
  recurrence 28 years ago

16
Highly suspicious for metastases
17
Confirmed on MRI
18
Case 4

• 22year old woman
• Right shin pain
• Came on while marathon training

19
Stress Fracture
BLOOD POOL
20
Case 5

• 56 year old woman
• Increasing pain on walking
• ? Stress fracture of L 2nd metatarsal
• X-ray NAD

21
Uptake at TMTJs
22
Case 6

• 48 year old man
• Pain in right lower ribs
• History of Crohns disease and some weight loss
• X-ray NAD
• ?metastases

23
Fractured rib
24
Case 7

• 59 year old woman
• History of Rheumatoid and fibromyalgia
• Pain all over difficult to distinguish cause
• ?Active inflammatory joint disease

25
Scattered joint based uptake
26
Radiation Doses (in MSv)

• 0.05 Chest x-ray
• 0.8 Q scan
• 1-2 Annual radiation doses
• 3 Bone scan
• 4 CT-PA
• 8 CT abdo/pelvis

27
Radiation Dose

• Bone scan dose might equate to 1 in 6000 lifetime
  risk of causing a fatal cancer.
• 1 in 5 lifetime risk of fatal cancer.

28
Lung perfusion (Q) scan

• Currently only able to perform a perfusion scan
• Patient injected with labelled albumin aggregates
• These lodge in the pulmonary capillaries
• 10 minutes later 6 images acquired

29
Indications

• Useful for excluding PE in
• Young patients
• No chronic lung disease
• CXR normal
• Postpartum

30
Limitations

• Abnormal result often needs a CT scan to clarify
  the cause

31
Wells Clinical Prediction Rule for Pulmonary
Embolism
32
Risk score interpretation (probability of PE)

• gt6 points high risk (78.4)
• 2 to 6 points moderate risk (27.8)
• lt2 points low risk (3.4)

33
Ambulatory Care

• Assessed using the clinical criteria
• If low probability D-Dimer and if negative
  discharge
• If medium or high CXR
• If this is normal consider Q scan
• If abnormal for CTPA
• If positive liase with DNs

34
Case 1

• 34 year old female
• 2 days post partum
• Short of breath
• CXR - NAD

35
Normal Q scan
36
Case 2

• 28 year old female
• Presents with chest pain and shortness of breath
• Normal CXR

37
High probability of PE
38
PET/CT scans

• Patients injected with labelled glucose
• Malignant cells have a high metabolic rate
• Currently main indications are in staging cancer
  particularly pre-operatively

39
The process

• Mobile scanner visits the BRI once a week
• Patients are injected and asked to rest for 1hour
  while the glucose is taken up
• Scanner slightly more claustrophobic than a CT
  but less than an MRI
• The PET scan takes 20 minutes
• Followed by CT which takes a few seconds

40
A mobile PET/CT scanner
41
Case 1

• 74 year old woman presented with weight loss and
  haemoptysis
• Patient had an x-ray and a CT scan which showed a
  LUL mass with no spread
• Indication for PET/CT to confirm staging
• Planned management primary resection.

42
Case 1
43
Some of the other tests we perform

• Renal MAG 3, DMSA
• Cardiac Myoview, MUGA
• G.I. Octreotide, MIBG, White Cell Scan, Red
  Cell Scan, Meckels scan

44
Thankyou Any questions?