)
Table of contents :
|
|
|
solution the day before examination
)..)
since early childhood.,
the eyeballs being fixed, the eyebrows raised, and the lids drooping.
and in other diseases associated with facial edema such as coast
erysipelas:
a triangular face with a broad forehead and prominent frontal bones.,
caused by ptosis and weakness of the facial muscles..
sequence, consisting of a flattened nose, receding chin, wide interpupillary
space, large, low-set ears, and less commonly other anomalies..due
to fat storing in Bichat boil
: deepened eyes, thinning of hypoderma => evidence of sternocleiomastoideal
muscles and bone prominences.
: vague look, increase of connectival tissues => false fat.
: offensive breath; bad breath
position
position
position : the patient assumes an upright or a semivertical
position by using two or more pillows to support his head and chest from
the recumbent position, or he sits upright in a chair. Used when the patient
has difficulty in breathing except in the upright position (orthopnea).
or disk
herniation,
spontaneous
pneumothorax,
gastric colic, biliary
colic
or renal colic
or rib fracture,
in which the infant lies quietly with the legs flexed at the knees and
the hips flexed and externally rotated
while sitting in bed, in which he supports himself with his hands in a
plane posterior to his pelvis. A sitting position assumed by the patient
with respiratory insufficiency, in which his hands are placed anterior
to the frontal plane
or diabetes
mellitus,
and cerebral tumor.
|
|
|
|
|
|
|
| Olympus pediatric fiberoptic and video bronchoscopes | BF-N20 | 2.2 | 55 | none | 30 |
| BF-XP40 | 2.8 | 60 | 1.2 | 35 | |
| BF-3C40 | 3.6 | 60 | 1.2 | 45 | |
| BF-3C160 (video) | 3.8 | 60 | 1.2 | 5.0 | |
| Pentax pediatric fiberoptic bronchoscope (Pentax; Asahi Optical; Tokyo, Japan) | FB-7P | 2.4 | 60 | none | 3.0-3.5 |
| FB-10V | 3.4 | 60 | 1.2 | 4.5 |
(OGIB)
takers
results in significantly better visibility of small bowel mucosa because
of fewer intraluminal bubblesref
by means of a specially designed endoscope inserted through the uterine
cervix
=> thoracoscopy / pleuroscopy :
the diagnostic examination of the pleural cavity through an endoscope.
=> mediastinoscopy : examination
of the mediastinum (e.g. for lymph node biopsy) by means of an endoscope
inserted transcutaneously through an anterior incision in the suprasternal
(jugular) notch, permitting direct inspection and biopsy of tissue in the
anterior superior mediastinum.
=> fiber optic cholecystoscopy :
=> laparoscopy / abdominoscopy / celioscopy
/ peritoneoscopy (examination of the interior
of the abdomen) was introduced by Fevers in 1933.
Local anaesthesia (general in babies). Injection of 2-8 L of previously
heated gas (air, CO2 (not flammable and easily absorbed preventing
gaseous embolism), Ar or N2O) through Veress
needle
(inserted blindly or after small incision of muscular fasciae with Hasson
trocar)
creates a pneumoperitoneum (intraabdominal pressure = 10-15 mmHg)
into which the laparoscope can be moved without risk of injuring
organs. 5-10 mm cannulas with antireflux valves are inserted through 0.5
cm-wide incisions, then 10-mm CCD cameras (0°-30°-45°-90°
: the greatest the angle, the higher the light intensity required), 2-10
mm cold light optics, trocars, mechanical suturers
(15-33 mm), and other disposable or sterilizable devices (25-35 mm in length
: dissectors, divaricators) are inserted into cannulas : they don't hurt
muscles and the blade is retracted immediately after peritoneum cut. The
device also presents a light source, an optic fibre camera, needles, endo-loops,
endo-knots,
electrobistoury and cautery. The distance between surgeon and monitor
should be 3 times the transverse diameter of the monitor and the latter
should be placed lower than surgeon's eyes. 2 monitors are placed at both
sides of the patient to allow vision to both the surgeons and his collaborators.
Threads are shorter (7 cm) and laces longer (20 cm) than in open surgery
to allow easier maneuvers : endoski needles are used
=> arthroscopy : examination of the
interior of a joint with an arthroscope
or abdominal
aortic aneurysm.
=> radiography
from enteroclysm
=> bowel
obstruction,
mediastinal baritosis
as they can be expulsed with cough or aspirated or reabsorbed from tissues)
(pretreatment with corticosteroid and antihistamines is recommended)
or creatininemia > 177 mmol/L (> 2 mg/dL),
recent AMI)
or pulmonary hypertension
: patients should be observed for a possible severe reaction during and
for at least 30-60' after administration. Patients with previous allergic
reaction to a contrast medium should be pre-treated as follows
(40 mg p.o.) or methylprednisolone
(32 mg p.o.)
(40 mg p.o.) or methylprednisolone
(32 mg p.o.) + cimetidine
(300 mg p.o.) or ranitidine
(150 mg p.o.)
50 mg i.v. (alternatively, it can be administered p.o. 2 hours before examination)
: serum creatinine needs to be measured in all patients before the injection
of a contrast medium. We suggested measuring serum creatinine before all
intraarterial injections or in the presence of risk factors for kidney
disease. The likelihood of missing a case of abnormal kidney function is
low with this less costly approachref1,
ref2ref
has an estimated plasma half-life of 1.5 to 4.9 hours, and 90% is eliminated
in 12 hoursref.
The decrease in renal function does not occur immediately after the administration
of contrast medium. Usually the serum creatinine level increases only after
24 to 48 hours and peaks on the second or third day after exposure to a
contrast mediumref.
On the basis of these data, it is safe to administer metformin until the
night before the procedure, thus averting hyperglycemiaref1,
ref2
and cholangiocarcinoma)
diagnosed after 36-43 yearsref).
It has poor sensitivity on ileum, where 75% of small bowel diseases are
located. Side effects : orthostatic
systemic arterial hypotension
in patients aged > 60 years..
: lymph nodal pointing due to sinusal engorgement; rarefied uptake due
to interposition of lymphomatous tissue among sinusal structures; foamy
look due to multiple central filling defects (instead metastases usually
cause peripheral filling defects in marginal sinus) => lymph node skipping
assessed with echography => signs of lymphostasis (perilymphatic contrast
agent extravasation, dilatation upstream
or less frequently to delineate pulmonary arteriovenous malformations,
pulmonary varices, or pulmonary vessel anatomy. Contrast agent introduced
via cardiac catheterism.
(=> renal atheroembolic disease) or thrombosis => arterial
thrombembolism
,
outlining the amniotic cavity and fetus,
and distinguishing vascular from nonvascular structures.
X-rays
suggests meningiomas
(they irritate osteoblasts in internal plate), Albright syndrome, or Paget
osteodystrophy
suggests
(palisade look), metastases, multiple
myeloma,
or xanthomatosis,
rhynopharyngeal
cancers,
eosinophilic
granuloma,
diploic pseudohydrocele (involutive fractures)
and choroid plexuses
(useful as deviation marks space-occupying lesions),
oligodendroglioma,
craniopharyngioma,
tuberculous
meningitis,
solitary tuberculoma, or neurotoxoplasmosis
X-ray
enlarge conjugation foramen
X-ray / mammography detects only 65-70% of breast
cancers
- small tumours can be obscured by other breast structures. Moreover, only
10-20% of women who have a biopsy turn out to have cancer, as overlapping
images of healthy bits of tissue can sometimes look like a possible tumour.
X-ray :
).
Double contrast on right side suggests left atriomegaly...
X-ray has to be practiced in both orthostatic
(also to confirm persistence of disease in follow-up)
(parenchymal densities, air trapping with residual volume and flattened
diaphragm better contrasted during expiration, increased radiotransparency
of retrosternal space due to pneumomediastinum
and sequelae (fibrosis, bronchiectasis,
bronchial thickening, ...))
from breast
carcinoma
or lung carcinoma
or pneumonitis;
no acute bronchitis !)
on skin
(including lobitis))
(dysventilatory Fleischner's
striae)
from breast
carcinoma
or lung carcinoma
=> vanishing lung
with gastric air boil
X-ray (with double contrast enhancement)
is practiced for
and nutcracker
esophagus,
cervical
or mediastinic
lymphadenitis,
...) undergo differential diagnosis with physiological anatomical stictures
!),
mouse
tail => scoliotic or sigmoid esophagus in megaesophagus,
esophageal
cancers)
and occlusions
: even if there are preferential ways for gases on the right side (small
curve, upper knee of duodenum, parietocolic gutter), when it occurs on
the left side it may be confused with the normal gastric radiotransparency
(although the latter is usually thicker).
(persisting stellate images)
(dyshomogenous due to presence of blood lakes (differential diagnosis with
liver
metastases);
progressive filling from periphery to center after administration of contrast
media at CT/MRI)
: differential diagnosis with wheel image and pulsating arterial flow at
echocolordoppler; at contrast-enhanced MRI/CT the central scar contrasts
later, when surrounding parenchyma has already undergone wash-out; as no
biliary canaliculi occur the hepatobiliary MRI contrast media mark cholestasis
(whiter than surrounding parenchyma), confirmed by increased [gGT]plasma
: differential diagnosis with contrast-enhanced spiral CT : dyshomogeneous
contrast due to mixed arterial and portal vascularization, no central scar
: differential diagnosis with contrast-enhanced CT/MRI : best contrasted
during arterial phase due to intratumoral arterial neoangionesis,
while the surrounding parenchyma (including regenerative nodules) contrasts
only after HCC has washed out and the eventual tumor capsule can be seen
with a gray intensity intermediate between those of parenchyma and HCC;
eventual neoplastic portal thrombosis is contrasted in the arterial phase,
too)
: differential diagnosis by using contrast-enhanced CT/MRI : best contrasted
during arterial phase due to lack of hepatic artery vascularization (excepted
metastases from neuroendocrine tumors,
they usually rely on portal blood) : the exact number of metastases changes
the prognosis of CRC allowing metastasectomy when they are in limited number
.
,
scleroderma,
asbestosis),
silicosis,
lymphangitis
carcinomatosa,
pulmonary
metastases
and HHV-5 / CMV
saturation of arterial blood (SaO2) using an oximeter
(a photoelectric device),
methemoglobin,
and reduced hemoglobin.
or tachycardia;
an area of skin is abraded until capillary bleeding occurs and a coverslip
or chamber containing balanced salt solution is applied. This permits direct
observation of inflammatory cells migrating into the site; polymorphonuclear
leukocytes predominate at about 10 hours; macrophages predominate at about
4 days.|
|
|
| air |
0.0004
|
| fatty tissue |
1.38
|
| water |
1.54
|
| brain |
1.58
|
| blood |
1.61
|
| kidney |
1.62
|
| liver |
1.65
|
| muscle |
1.70
|
| lens |
1.84
|
| bones, calculi, calcified tumors |
7.8
|
after i.v. injection of UCA)
and in 4 views of the abdomen (right upper quadrant (RUQ) (subcostal, Morison's
pouch), left upper quadrant (LUQ) and suprapubic views) for hemoperitoneum
in patients with potential truncal injuries. Other protocols image the
paracolic gutters (Douglas' pouch) but studies have not shown significant
benefit from extending the scan to include these. It doesn't look for chronic
diseases. A negative scan does not rule out intra-abdominal injury, but
the presence of a sufficient amount of blood to be detectable on US would
denote a severe injury that needs urgent surgery.)
))
using its deformation caused by the intraluminal pressure generated by
the probe. A high strain region at the lumen vessel wall boundary has 88%
sensitivity and 89% specificity for identifying vulnerable plaques. There
are higher strain values in fatty than fibrous plaques (P < 0.001).
The presence of a high strain region at the lumen plaque interface has
a high predictive value for identifying macrophages. There are high strain
values of 1% in soft plaques with increased strain up to 2% at the shoulders
of the plaque, while calcified material shows low strain values (0-0.2%).
The radial strain in the tissue is obtained by cross-correlation techniques
on the radio frequency (rf) signal. The strain is colour-coded and plotted
as a complimentary image to the IVUS echogram.
(e.g. calcifications)
(e.g. asynergias/dyssynergias post-AMI :
after i.v. injection of air microbubbles,
therapy should be administered at wk 12-16 and hence a targeted screening
should be practiced before that age..
Flows are better evaluated with parallel probe :)
for > 3' (hypocapnia induces vasoconstriction : slowing is physiological
in babies while it marks latent damage in adults)),
which may cause photic translation signal
(waves synchronous with lightnings) or desynchronization (loss of
a
rhythm) in some patients.
They are amplified by about 1 million folds and registered on paper moving
at a constant rate (15 mm/s; conventional amplitude : 1 mm = 10 mV)
or in digital format subjected to post-processing (e.g. averaging to improve
signal-to-noise ratio of spikes and sharp-waves (computed EEG).
or benzodiazepines
,
cerebral
hemorrhage,
cerebral
tumor,
brain
ascess).
If intermittent it has lower predictive value. When carotid artery stenosis
is suspected but no slow waves are detected, compression of the contralateral
carotid artery causes hypoxia
and appearance of slow waves (due to side effects this maneuver is practiced
only in the set of neurosurgery),
toxic
encephalopathies,
obstructive
hydrocephalus,
median line or posterior cranial fossa lesions, generalized
epilepsy).
If limited to one only hemisphere, they can be caused by organic lesions
to deep structures (thalamic or periventricular),
toxic
encephalopathies,
infectious
encephalopathies,
or cerebral damage due to nonfluctuating encephalopathy,
Huntington
disease)),
extraaxial lesions (meningioma,
subdural
hematoma))
(during crises or in individuals genetically predisposed to crises) but
also normally present in 2% of healthy subjects.
: epileptiform discharges in 90%
(20-70% of cortical spikes doesn't appears at EEG due to attenuation by
CSF and dura mater), and other nonspecific alterations (excessive focal
or generalized slow waves, rarely asymmetries of frequency or voltage).
Alterations can be usually seen even in intercritical periods, but don't
correlate with frequency and likelihood of relapse of crises. Video-EEG
may help to diagnose patients with post-critic amnesia or bed-time crises,
but muscular or movement artifacts may prevent diagnosis, apart from post-critical
slowing of brain waves if not present elsewhere. Crises without consciousness
impairment sometimes have a normal a
wave rhythm.,
highly malignant, rapidly growing cerebral
tumor,
herpetic
encephalitis),
cerebral
tumor
(tumor is electrically silent), complicated migraine
during attacks, traumatic
encephalopathy,
subdural
hematoma
: focal
slow arrhythmic or polymorphic activity, persisting during various
sleep stages, expecially when associated with loss of set faster waves.
Deep lesions may cause hemispheric or bilateral slow activity. Bilateral
paroxysmal burst of rhythmic d waves with frontal
predominance were once attributed to deep subfrontal lesions of median
line or posterior fossa, but are actually unspecific. Lateral intermittent
focal bursts of rhythmic delta waves suggest deep supratentorial lesion
(periventricular or diencephalic). Alteration is greater if lesion is deeper.
: generalized
slow arrhythmic or polymorphic activity
or hypothermy
: decreased voltage
: photic
epilepsy
: focal critical activity,
diffuse, accentuated in frontal regions and not reactive to external stimuli
between day 2 and 15 : generalized
slow arrhythmic or polymorphic activity, mostly in frontal or
frontotemporal regions (unilateral or asymmetric bilateral), with periodic
sharp-wave complexes (PSWC) in one or both frontotemporal regions (occasionally
in other regions and sometimes generalized)
: severe diffuse slow wave and low voltage activity
: mild alterations:
focal alterations
: generalized periodic synchronous (pseudorhythmic) discharge pattern (periodic
sharp wave complexes (PSWC))
: decreased alpha wave frequency and activity, increased theta and delta
activity in fronto-temporal regions and alterations in sleep elements.
: long-latency event-related evoked potential (ERP) (150 ms after
stimulus) (e.g. P300 or P3 waves) is useful for the testing of essential
brain functions
: no alterations in initial stages => generelized slowing (localized in
patients with focal cognitive defiiencies)
: focal or independent bilateral slowing associated with normal alpha rhythm,
cataract
or opacities of aqueous humor or vitreous body, glaucoma,
retinopathies,
optic
neuritis),
spinocerebellar degenerations, Parkinson's
disease,
bilateral glaucoma,
retinal degenerations, bilateral optic
neuritis)
and other ponto-cerebellar angle tumors : enlenghtnement of I-III interspike,
conservation of wave I with deformation or loss of subsequent waves or
loss of all BAEP waves.
or Wallenberg's
syndrome):
50% has alterations (20% even in absence of symptoms and signs referred
to the brainstem) : lack of amplitude reduction of waves IV and V > increased
III-V latency > increased I-III latency. Anyway many patients have normal
hearing despite decreased ability to localize sounds in space.
at wrist (leading electrode at Erb's point in supraclavicular fossa)
at knee => PV (lumbar posterior roots and fasciculus gracilis) and
N22
(gray matter of lumbar spinal cord) => P31 (caudal portion of medial
lemniscus) => N34 (rostral brainstem) => P38 (parasagittal
primary sensory cortex)
at ankle
(90%), Pelizaeus-Merzbacher
disease,
adrenoleukodystrophy,
metachromatic
leukodystrophy (MLD) or leukoencephalopathy / sulfatide lipidosis,
adrenomyeloneuropathy, syringomyelia,
progressive myoclonic
epilepsy,
photic
epilepsy,
late infantile ceroido-lipofuscinosis
,
motoneuropathies, cerebral
palsy
(increased amplitude in some muscular groups due to aberrant corticospinal
projections), Parkinson's
disease
(increased amplitude); absent in multiple
sclerosis.)
while recording the M wave of its muscle (little finger abductor muscle)
to note any changes in the wave. Repeated electrical shocks are applied,
: decrease < or > 12%
: decrease < or > 12%
: decrease > 12% (corrected by admnistration of prostigmine)
: initially mild decrease in amplitude followed by increase (not corrected
by admnistration of prostigmine)
(occasionally),
digitalis glycosides intoxication, hyperkalemia,
b-blockers)
or
bundle
branch block.
Relative to the hexaxial reference
system,
(lack of r waves and presence of Q waves in inferior leads : DII, DIII,
and aVF)
in elderlies
in children (valvular aortic stenosis and infantile aortic coarctation)),
even in absence of pulmonary hypertension
(?)
.....
.
.......
uncontrolled by dopamine replacement therapy have uninterpretable ECG tracings
because of artifact from the neurostimulators operating in an unipolar
configuration. To assess the effect on the artifact the neurostimulators
can be de-activated consecutively using a telemetry programmer. A satisfactory
tracing for ECG monitoring during the procedure is achieved with the left
stimulator only turned off. Deactivation can result in a rapid return of
pathological involuntary movements (which settled rapidly on re-activation)
predominantly opposite-sided respect to the switched off neurostimulator
which itself may preclude the patient from undergoing any invasive cardiological
procedures except under general anaesthesia and neuromuscular blockade.
)
(oxytocin challenge test (OCT)) 5 UI in 500 mL. Begi with 4 drops/min
and then add +4 drops/min until 3 uterine contractions/10' are achieved
(interrupt if not achieved with 40 drops/min, > 4 contractions/10' or uterine
hypertone). Then maintain for 30'.,
third trimester hemorrhage, cervical isthmic insufficiency
: monitoring every 2 days after day 280; each day after day 287
(from every 2 days to more times a day)
(every 4 days since wk 38)
: massive uterine contractions with width = 10-15 mmHg every 1 hr. After
wk 30, spreading, rate and intensity increase.
However the length of a contraction does provide useful information in
the interpretation of FHR abnormalities (see cardiotocography
(CTG)).
Sphygmomanometers may be filled with;
methods include ..
is the liquid used.is
the liquid used.
thermometer : one for use in determining
temperature of the human body.;
sometimes employed as a means of diagnosing underlying pathologic processes,
such as breast tumors..
decays :
for palliative bone
metastastic
pain relief
for palliative bone
metastastic
pain relief
(b-decay) and imaging (g-decay)
(positive tumor markers)
(Dicopac®) for Schilling test
(Dicopac®, Rubratope®) for Schilling test
for cancer teletherapy
for NIS-expressing
tissues and tumors
for pulmonary ventilation scintigraphy
and CNS perfusion scintigraphy
(negative tumor marker)
(blood cells)
(positive tumors
marker) competes with Fe for transferrin in RES cells, PMNs, and lymphocytes.
Tomogram is taken 2-4 days after i.v. injection. Renal and intestinal excretion.,
Pneumocystis
carinii
granulomas, bronchogenic
carcinoma,
Hodgkin's
disease (HD)
and lymphomas,
sarcoidosis
(panda's sign due to captation by salivary glands and l
sign due to captation by mediastinic lymph nodes).
(positive tumors
marker)
(it can be obtained by a radioisotope generator from the decay of 99Mo,
whose t1/2 = 2.8 days, allowing these generators to be
used for approximately 1 week; positive tumor marker; 99Tc is
itself an unstable and radioactive nucleus, but has t1/2 = 213,000
years, so that the tiny amounts of 99Tc radioactivity resulting
from the nuclear transformations of the 99mTc atoms of a mCi-sized
patient dose of 99mTc are ignored in practical situations).
Stannous
dichloride (SnCl2) is used as a reducing agent in the preparation
of 99mTc radiopharmaceuticals
(AcuTect®) for deep
vein thrombosis (DVT)
(99mTc-EHDP) for bone scintigraphy
(99mTc-MDP) (Osteolite®) for bone
scintigraphy
scanning (the product is not suitable to study the haematopoietic activity
of the bone marrow) : 185-500 MBq. Images may be acquired 45-60 min after
administration.
(99mTc-HMDP / HDP) (Osteoscan HDP®) for bone
scintigraphy
(99mTc-ADP) for bone scintigraphy
tissue (e.g. : parathyroid carcinoma, breast carcinoma) compared with normal
tissues : accordingly, it has been used successfully to visualize primary,
metastatic, and recurrent tumor. Increased vascular supply, disruption
of the eventual blood-tissue barrier, high-grade cancer, and viability
of tumor cells are decisive factors related to increased uptake
transport activity : as it is exported from cells as other chemotherapeuticals
are, 99mTc-MIBI uptake is the major prerequisite for distinguishing
between drug-resistant and sensitive cells)
transport activity and myocardial perfusion.
: for cancer brachytherapy
(positive tumor marker)
(nuclear oncology)
(positive tumor marker) for cancer
brachytherapy
: a neutron transforms to a proton and a b particle.
The additional proton changes the atom to 137Ba. The nucleus
ejects the b particle. However, the nucleus
still has too much energy and ejects a g photon
to become more stable. It is used for cancer
brachytherapy.
(positive tumor markers)
highly expressed in metabolically active tissues. It is used for :
(negative tumor markers))(widespread
bone metastases can occasionally give rise to a uniform distribution of
the radiopharmaceutical resulting in a superficially normal appearance
on the bone scan. The scans are recognizable by the high ratio of bone
to soft tissue activity, the absence of focal lesions in the axial skeleton,
and there are usually no renal images. These "superscans" can occasionally
be misinterpreted as normal. An index of image quantitation related to
the ratio of bone to soft tissue uptake is shown to be capable of clearly
distinguishing these patients from patients in other categories. The condition
is thought to be more frequently associated with prostatic
carcinoma
than with other aetiologies)
(when radiolabeled autologous
leukocytes are not available)
(linear pattern)
: rosary crown-shaped along ribs at osteochondral junction
(when echography is doubtful)
: 99mTcO4
=> ileus from irritation of small bowel mucosaref.
The therapeutic outcome of PSE is predicted more accurately using a normalized
spleen/liver uptake ratio [(spleen uptake at 192 h/liver uptake at 192
h)/(spleen uptake at 1 h/liver uptake at 1 h)] than a conventional splenic/hepatic
uptake ratio at 1 h and 192 href.
A reasonable estimate of the spleen:liver uptake ratio may be obtained
using planar imaging, but to estimate the spleen volume and the absolute
splenic uptake of platelets SPECT imaging is needed, in spite of the present
technical limitations of SPECTref.
(localized activity). Sensitivity = 83-87%; specificity = 55-81%)
due to interposition of lymphomatous tissue between sinuses. Also used
for study of lymphedema.
Labeling with 131I and 32P
is used for lymph node irradiation in lymphomas,
pelvic tumours, and limb melanomas after transcutaneous irradiation
=> g-rays => detection by g-camera
(radioimmunoscintigraphy (RIS) and radioimmunoguided surgery
(RIGS))
(cheap)
(CEA-Scan©; source : Immunomedics))
and soft tissue infections, e.g. diabetic patients suspected of having
osteomyelitis secondary to foot ulcers. It has sensitivity = 51% (a perforating
ulcer of the foot may result in a false-negative conclusion) and
specificity = 67% (coxarthrosis or hyperostosis can lead to false-positive
results)
(LymphoScan®) is under investigation as a staging agent
and for revealing residual disease in patients with NHL; it also provides,
with a different radioisotope attached and in a humanized antibody form,
a therapeutic option for patients with NHL
in rheumatoid
arthritis.
However, because blood tests to assess overall cell death (both apoptosis
and necrosis) following myocardial ischemia are widely available, it is
unclear whether annexin-V imaging will provide any substantial diagnostic
advantage of ischemia-reperfusion
injury (IRI).
But in theory, PS externalization may provide a more sensitive marker of
early myocardial death because apoptosis appears to precede necrosis following
the cessation of coronary perfusion, and because PS externalization is
one of the earliest apoptotic markers. If validated by clinical trials,
annexin-V imaging following cardiac transplant rejection would be a major
advance as it may obviate the need for multiple invasive biopsies. Another
potential cardiac application would be in monitoring the cardiac toxicities
of chemotherapeutic agents such as anthracyclines and anti-HER2 antibodies.
These techniques could also be applied to assess disease processes in other
organs where apoptosis is involved; some examples are brain and kidney
ischemia, kidney and liver transplants, and toxin-related liver damage.
In addition, because chemotherapy and radiotherapy for cancer work in part
by inducing apoptosis, this type of imaging may provide a faster assessment
of the efficacy of a given treatment regimen. One problem with these studies
is that annexin V will also bind to PS exposed in necrotic tissues and
to PS exposed on activated platelets, which would be present in the central
region of the infarct and in developing thrombi. Cell lysis by complement
activation will also cause PS exposure. So, although the label cannot be
considered an exclusive marker for apoptosis, this is not necessarily a
drawback in some situations, as tissue damage represents the summation
of apoptosis and necrosis. A second potential problem is the level of sensitivity.
Whereas this technique is informative when numerous cells are dying with
similar kinetics (as happens in response to a single insult), it may be
less useful in settings characterized by low levels of apoptosis or with
asynchronous death, as PS exposure is promptly followed by phagocytosis
by tissue macrophages. Ultimately, clinical studies will be needed to assess
how well these approaches allow us to see death in the livingref1,
ref2
as an imaging agent in NHL for early detection, staging, remission assessment,
monitoring for metastatic spread and tumour recurrence, and assessment
of CD20 expression prior to (radio)immunotherapy. Rituximab was purified
from Mabthera solution (Roche), photo-activated at 302 nm by UV irradiation
and radiolabelled with 99mTc. The effectiveness of the labelling
method was evaluated by determination of the number of free thiol groups
per photoreduced antibody, radiochemical purity and in vitro stability
of 99mTc-rituximab. On average, 4.4 free thiol groups per photoreduced
antibody were determined. Radiolabelling yields > 95% were routinely observed
after storage of the photo-activated antibody at -80°C for 195 days.
The direct binding assay showed preserved ability of 99mTc-rituximab
to bind to CD20, with an average immunoreactive fraction of 93.3%. The
internalisation rate was proven to be low, with only 5.3% of bound 99mTc-rituximab
being internalised over 4 h at 37°C. 99mTc-rituximab of
high radiochemical purity and with preserved binding affinity for the antigen
can be prepared by photoreduction and the method shows good reproducibilityref.
(OncoScint CR/OV 103©; source
: Cytogen Corporation)
pendetide (ProstaScint©)
in rheumatoid
arthritis
(expensive)
(sentivity = 90% for supratentorial tumours), chronic subdural hematoma,
parenchymatous hemorrhages or triangular regressing ischemic areas undergoing
recovery (red infarction)). Nowadays replaced by CT scan except when contrast
agent is contraindicated.
(shift from L-T4
to L-T3
therapy 4 weeks before examination or practice administration of rhuTSH,
to allow the TSH elevation required for NIS
gene expression),
which masks parathyroids.
or the most hyperperfused areas in diffuse hyperplasia (secondary
hyperparathyroidism
or tertiary
hyperparathyroidism)
in ectopic (mediastinic or deep) parathyroids not detected by echography
or CTexpression
may play an important role in the false-negative results of parathyroid
scintigraphy. If the lipophilic cationic radiotracers used in parathyroid
scintigraphy are transported by the same mechanism as the anticancer drugs,
they will be quickly eliminated from the parathyroid glands containing
P-glycoprotein or MDR-related protein expression and the uptake in images
will be negative. In parathyroid glands with no P-glycoprotein or MDR-related
protein expression, the radiotracers remain in the cells, making it easier
to detect them by scintigraphy,
head and neck radiotherapy
,
anticancer
chemotherapy,
neuroleptics,
candidiasis,
HHV-1
/ HSV-1,
HHV-5
/ CMV,
thyrotoxicosis,
Cushing's
disease,
myasthenia
gravis,
CTD,
polymyositis,
sarcoidosis,
stroke,
ALS,
paralytic
poliomyelitis,
cervical scars or tumors
,
opiates, nicotine, L-DOPA,
while it is decreased in GERD.
: 99mTc-milk (in babies) or 99mTc-orange
juice (in adults) => supine => 16" per frame for 60' (reflex is usually
episodic). Eventually provocative test by increasing endoabdominal pressure
or p.o. lipid-rich meal (e.g. eggs), functionpyloric and other sphincters,
intestine, bilioduodenogastric reflux, bile extravasation after endoscopic
cholecystectomy, congenital biliary tract anomalies, acute cholecystitis
(differential diagnosis with chest X-ray). When injected in orthostasis
the contrast agent usually distributes according to a gravitary gradient
Noise in kidneys or brain occurs only if the patient has right => left
cardiac shunt. It is used to assess pulmonary
thrombembolism
(sometimes the resulting precapillary
pulmonary arterial hypertension
reverses the gradient of distribution of the contrast agent !) and before
lung
volume reduction surgery.
: captopril
renographic test (CRT) (25-50 mg p.o.) eliminates the AT-II-dependent
compensation to RAS => hypoafflux (anyway if renal failure preexisted,
the decrease in captation cannot be significant). Basal value is taken
just before CRT or alternatively the day after if CRT resuts pathological.
Positive predictive value of pressure outcome after revascularization =
95%.
and hydroureteronephrosis
: diuretic renal
scintigraphy (DRS) (furosemide
0.5 mg/kg i.v.). The eventual presence of an obstruction prevents the washout
of pelvic radioactivity.
rejection (edema leads to irregular tracing)
=> scars (defective captation)
(sensitivity = 90%; specificity = 95%) (defective captation)
and allows delivery of a lower radioactive dose to children than retrograde
cystography
from epididymo-orchitis,
and abscess, or tumor
and myositis,
or osteomyelitis.-expressing
tumors (e.g. :
(90-95%)
(80-90%)
(70-80%)
(50-60%)
or neurotensin receptor 2-expressig
tumours (eg. pancreas
adenocarcinoma
and Ewing's sarcoma)-expressing
tumours (eg. breast
carcinoma)or
VIPR2-expressig
tumours,
Y2,
or Y5-expressing
tumours (eg. prostate
adenocarcinoma
and breast
carcinoma)-expressing
tumours (> 90% of medullary
thyroid carcinomas (MTCs),
a high percentage of small
cell lung cancers (SCLC),
stromal ovarian, gastrointestinal adenocarcinomas, neuroendocrine
tumors,
and malignant glioma).
The normal organ uptake is essentially confined to the stomach (and to
a lower extent, to the gallbladder and, in premenopausal women, to normal
breast tissue) as a result of receptor specific binding, and to the kidneys
as excretory organs.
(Diamox®) challenge test is used to assess cerebral
perfusion reserve. The exam may be useful in identifying CNS territory
at risk in patients experiencing TIA's and for patients being considered
for carotid ligation surgery. It may also be useful as a screening tool
in asymptomatic patients. Acetazolamide is a carbonic anhydrase inhibitor
that causes an increase in cerebral CO2. This results in vasodilatation
and increased flow in normal cerebral vessels. The increase in blood flow
is dose dependent and ranges from an increase of 30-50% after I.V. administration
of the agent. In an area of reduced blood flow, where there has already
been maximal vasodilatation (and thus loss of cerebrovascular reserve)
there can be no augmentation of flow. Contraindications to the exam include
cardiovascular instability, renal or hepatic insufficiency, and a history
of allergy to sulfa drugs. To perform the study, a baseline exam is compared
to a SPECT exam performed 25 minutes after the I.V. administration of 1
gm of acetazolamide given over 2 minutes (peak pharmacologic action is
seen about 20-25 minutes after IV administration and the agent has a half-life
of about 90 minutes- blood flow returns to normal between 2-3 hours after
injection) [12,16]. Areas of limited flow reserve will have decreased tracer
activity on the challenge exam compared to the baseline study. A decrease
of 10 to 20% in activity on the Diamox® exam compared to
baseline is considered abnormal. The exam has also been performed using
both 99mTc-HMPAO and 123I-IMPwhich
permits same day imaging without moving the patient- thus the image slices
from the 2 studies should align perfectly. Same day 99mTc-HMPAO
protocols have also been established using a low dose (5 mCi) for the baseline
exam, and 20 mCi for the challenge exam. Diamox® is extremely
safe, the major side effect being a headache (the agent can induce migraine
headaches in patients with a history of migraines), but cerebral steal
is a potential complication. The challenge test is not without limitations.
Due to the nonlinear uptake properties of HMPAO and ECD, which underestimate
perfusion in regions of increased flow, there can be limited contrast for
flow differentiation. Additionally, acetazolamide has been shown to increase
cerebral blood flow by only about 30% to 50% above baseline in normal older
patients (range 5 to 70%). This is in contrast to coronary pharmacologic
stress examinations in which coronary blood flow is increased by 300-400%.
The limitations of a weak stress agent and a low contrast imaging agent
help explain the low sensitivity for detecting significant (over 70%) stenoses.
Generous cerebrovascular collaterals via the circle of Willis are another
limitation of the exam
>> D3 receptors
(location, extension, severity)
exclusion in acute precordialgia
by virtue of the pair of g-rays that are emitted
when the positrons encounter electrons in tissues after administration
of a natural biochemical substance into which positron-emitting isotopes
have been incorporated,
GLUT3,
SGLT-1,
SGLT-2,
and SGLT-3
: it is phosphorylated by glucokinase into the anionic 6-phospho-FDG, which
cannot be further metabolized by fructoisomerase and accumulates within
cells. It is used to study glucose-dependent tissues :;
diagnostic value for lung cancers).
Renal excretion.
(from Sr-82/Rb-82 generator) (Cardio-Gen-82©)
(threshold for practicability : FPG > 200 mg/dl)
: influenza vaccine produces lymphatic activation even in HIV patientsref.
The primary clinical use of FDG-PET is in oncology, particularly for staging.
This technique is most likely to be required in older age groups—the same
patients who are most likely to have had recent influenza vaccine (indeed
the UK government is encouraging this). The situation could therefore easily
arise where an FDG-PET study is done on, say, a patient with carcinoma
of the breast or lymphoma, who had had recent immunisation. Uptake identified
in axillary lymph nodes might then be falsely assumed to be due to tumour.
Clearly this would have a major effect on staging and subsequent therapy.
No time-scale is known for the duration of this activation. It might be
very sensible for PET centres to check with their patients for recent immunisations,
and delay imaging if this has occurredref.| n according to B0 |
|
|
|
|
|
| 1H | 6.4 | 14.9 | 38.3 | 63.9 | |
| 13C | 1.6 | 3.7 | 9.6 | 16 | |
| 19F | 6 | 14 | 36 | 60 | |
| 23Na | 1.7 | 4 | 10.2 | 16.9 | |
| 31P | 2.6 | 6 | 15.5 | 25.9 |
plaques).
within minutes, whereas historically it required hours before the findings
were visible on standard MRI : when water is trapped into neurons its diffusion
is largely impaired by biological membranes
studies, and is thought to have a higher pathological specificity than
conventional T2-weighted imaging|
|
|||
|
|
 |
 |
|
| CSF
flowing with velocity > 10 cm/s |
(intermediate/grey) | long (dark) | long (bright) |
| dura mater |
(dark) | (dark) | |
| gray matter | (isointense) | intermediate (grey) | intermediate (grey) |
| white matter | (bright) | short (bright) | short (grey) |
| fat |
(bright) | short (bright) | intermediate (grey) |
| cortical bone |
(dark) | long (dark) | short (dark) |
| cancellous bone | varying shades of gray, to white | dark or black | |
| red bone marrow | (grey) | (grey) | |
| yellow bone marrow | (bright) | (grey) | |
| air | (dark) | long (dark) | short (dark) |
| bloodflowing
with a velocity > 10 cm/s |
(dark) | long (dark) | short (dark) |
| hyperacute internal hemorrhage
(0-12 hours) : oxyhemoglobin |
long (grey/dark) | long (bright) | |
| acute internal hemorrhage
(12-72 hours) : deoxyhemoglobin |
long (grey/dark) | short (dark) | |
| early subacute internal hemorrhage
(3-7 days) : intracellular methemoglobin |
(intermediate/grey) | short (bright) | short (dark) |
| late subacute internal hemorrhage
(7-15 days) : extracellular metahemoglobin |
short (bright) | long (bright) | |
| chronic internal hemorrhage
(> 15 days) : hemosiderin |
(intermediate/grey) | long (grey/dark) | short (dark) |
| oedema | (bright/grey) | long (grey/dark) | long (bright) |
| some complex proteinaceous solutions (mucocele,
colloid cyst, Rathke's
cleft cyst,
epidermoid cyst, cholesterol granuloma) |
(bright/grey) | short (bright) | long (bright) |
| vertebral body | (intermediate/grey) | (intermediate/grey) | (intermediate/grey) |
| intervertebral disc | (light grey) | (grey) | (bright) |
| ligaments and tendons | (gray/dark) | (grey/dark) | |
| calcification (tuberous
sclerosis,
neurocysticercosis,
TORCH virus infections, dystrophic calcification and pediatric AIDS) |
(dark) | long (dark) | short (dark) |
| fine calcifications (hydration layer effect around calcium phosphate complexes). | short (bright) | ||
| urine |
(intermediate/grey) | long (dark) | long (bright) |
| hyaline cartilage | (grey) | (bright) | |
| muscles | (grey) | (grey) | |
| soft tissue | varying shades of gray | dark or black | |
| bile | long (dark) | ||
| acute infarction | intermediate (grey) | ||
| acute infection | intermediate (grey) | ||
| primary brain tumor |
intermediate (grey) | ||
| metastatic disease | intermediate (grey) | ||
| iron in the basal ganglia with white matter disease such as multiple
sclerosis
and in leukodystrophies |
(intermediate/grey) | short (dark) | |
.
or permanent cardiac stimulator
of ferromagnetic material (considered sure 6 weeks after implantation)
(some kinds)
(5-10 mg) and gadolinium (Gd) chelate. The combination of Gd and furosemide
is the key for achieving a uniform distribution of gadolinium in the collecting
system and for avoiding susceptibility artifacts (T2*-effects) in the urine.
T1 -weighted excretory MRU provides impressive urograms of both non-dilated
and obstructed collecting systems in patients with normal or moderately
impaired renal function. MRU has replaced IVU in pediatric uroradiology
and is also recommended for the assessment of renal transplants
-specific
media : iron oxide (negative enhancement pattern in T2*wi and
T2wi => black normal parenchyma)
(orally or rectally administered)
and pancreatic secretions
in obstructive
uropathies
efficacy : intravascular production of reactive oxygen species is associated
with photoconsumption of O2 and consequent evolution of paramagnetic
deoxyhemoglobin.
and migraine.
+)
in a Forsmann Ag- species (e.g. rabbit (Oryctolagus
cuniculus))
anti-Forsmann Ag Abs are produced.
Copyright © 2001-2005 Daniele Focosi.
All rights reserved
| Terms of use | Legal
notices
|
|
|
|
|
