Full story parathyroid imaging Dr Ahmed Esawy

Dr. Ahmed Esawy
MBBS M.Sc. MD
Dr Ahmed Esawy

ULTRASOUND
NUCLEAR IMAGING
(Isotope scanning / SPECT/CT)
CT/MRI imaging
Dr Ahmed Esawy

• 4 glands: sup / inf, right / left
• superior most often behind mid thyroid, deep and medial
• inferior at lower tip, 20% in upper thymus
• supernumerary glands - 3-5% ( Also more than four parathyroid glands
may be present and ectopic localisation may be seen.)Dr Ahmed Esawy

Parathyroids are NOT related to the thyroid (except they are neighbors in the
neck).
Parathyroid glands make a hormone, called "Parathyroid Hormone".
You can easily live with one (or even 1/2) parathyroid gland.
Everybody with a bad parathyroid gland will eventually develop bad
osteoporosis--unless the bad gland is removed.
Dr Ahmed Esawy

Variations in localization of parathyroid glands.
Dr Ahmed Esawy

Ectopic Locations (5-15%):
•Thyrothymic ligament
•Tracheoesophageal groove
•Retro esophageal space
•Retropharyngeal/high cervical
•Carotid sheath
•Intrathyroid
•Ant/post superior mediastinum
•Retropharyngeal
•Intrathymic
•Aorto-pulmonary window
Dr Ahmed Esawy

Distribution of the ectopic sites of parathyroid
Dr Ahmed Esawy

HOME MASSEGE
The main imaging tests for the
evaluation of this pathology are the
ultrasound and the scintigraphy
with Tc 99m Sestamibi (MIBI).
In some cases a CT can be helpful,
especially with glands of ectopic
localization. Dr Ahmed Esawy

WHERE SHOULD I LOOK FOR PARATHYROID
GLANDS?
Dr Ahmed Esawy

normally not seen sonographically
Normal parathyroid glands are very small,
measuring approximately
6 mm in the craniocaudal dimension
and 3-4 mm in the transverse dimension
with shape like a flattened disk
Dr Ahmed Esawy

• Usually the pathological parathyroid gland appears as a hypoechoic
(“black”) nodule behind the thyroid in close contact with the thyroid
capsule. Upon use of the doppler feature no flow is present within the
parathyroid gland.
• The size Problems with localisation may occur when the parathyroid
glands are not in contact with the thyroid tissue or other tissues which
may be used to contrast it against.
• If the parathyroid gland is localised in the mediastinum it may also be
difficult to localise using ultrasonography.
• Large goitres, and goitres with hypodense areas may also make
localication of parathyroid glands difficult
• Usually the parathyroids may be visualised with ultrasonography if they
are more than 8-10 mm in diameter.
• To be able to do biopsies it is recommended that a parathyroid
scintigraphy (sestamibi-scintigraphy) is performed before the
ultrasonography is performed.
Dr Ahmed Esawy

Normal anatomy of the parathyroid glandsDr Ahmed Esawy

4 glands: sup / inf, right / left
superior parathyroid glands : posterior to
middle/upper portion of the thyroid lobe
Inferior parathyroid glands: posterior, inferior to the
inferior pole of the thyroid lobe
In summary: posterior or inferior to the thyroid lobe
Dr Ahmed Esawy

normally the size of a grain of
rice
Dr Ahmed Esawy

Parathyroid glands location. Sc: subctuaneous tissue E: esophagus. C: carotid artery
Ms: músculo
Dr Ahmed Esawy

Parathyroid glands location. Sc: subctuaneous tissue. Ms: músculoDr Ahmed Esawy

2—Sonogram of 25-year-old woman with possible thyroid enlargement (thyroid
was
normal). Note subtle isoechoic parathyroid gland inferior to lower pole of thyroid
(arrows). Normal parathyroid glands are uncommonly seen on sonography
because of their small size.
Dr Ahmed Esawy

PARATHYRIOD PATHOLOGY
Dr Ahmed Esawy

The ONLY purpose of the parathyroid
glands is to regulate the calcium level in
our bodies within a very narrow range
Dr Ahmed Esawy

Control of mineral metabolism by
parathyroid hormone (PTH)
Dr Ahmed Esawy

Parathyroid disorder
• Congenital Parathyroid Gland
Cyst
agenesis ,hypoplasia
supernumerary glands
congenital ectopias
• Hyperparathyroidism (HPT)
isolated
syndromic
Familial isolated hyperparathyroidism (FIHP)
Multiple endocrine neoplasia type 1 (MEN1)
• Hypoparathyroidism
• Cancerous forms of parathyroid disease
Dr Ahmed Esawy

Hereditary Hyperparathyroidism Syndromes
Familial hyperparathyroidism includes a group of disorders in which primary
hyperparathyroidism (PHPT) is inherited, usually as an autosomal dominant
trait. These include:
multiple endocrine neoplasia type 1 (MEN1),
MEN2A,
MEN4,
familial hypocalciuric hypercalcemia (FHH or FBHH),
neonatal severe hyperparathyroidism (NSHPT),
autosomal dominant moderate hyperparathyroidism (ADMH),
hyperparathyroidism-jaw tumor syndrome (HPT-JT),
familial isolated hyperparathyroidism (FIHPT) .
PHPT is a rare condition in children and young adults; and when present, it
is often in the context of a hereditary hyperparathyroidism syndrome
FIHPT Syndrome
Dr Ahmed Esawy

Hyperparathyroidism
SECONDARY PRIMARY PHPT
ACQUIRED
HEREDITARY
FAMILIAIL
TERTAIRY HP
Dr Ahmed Esawy

Hyperparathyroidism
isolated syndromes
Dr Ahmed Esawy

PRIMARY
Hyperparathyroidism
ACQUIRED
Adenomas
Hyperplasia
carcinomas
HEREDITARY / FAMILIAIL
multiple endocrine neoplasia type 1 (MEN1), MEN2A, MEN4,
familial hypocalciuric hypercalcemia (FHH or FBHH),
neonatal severe hyperparathyroidism (NSHPT),
autosomal dominant moderate hyperparathyroidism (ADMH)
hyperparathyroidism-jaw tumor syndrome (HPT-JT),
familial isolated hyperparathyroidism (FIHPT)
Dr Ahmed Esawy

1ry hyperparathyroidism
acquired
Caused by
• single Adenoma 80%
• Double Adenoma 5-10%
• Four-Gland Hyperplasia 5-10%
also MEN, ectopic
• Parathyroid carcinoma 1% elevated PTH
• Women are affected two or three times more frequently than men
• The patient usually present with signs symptoms of
hyperparathyriodism
Dr Ahmed Esawy

PTH→ +ve osteoclasts→bone resorption, Ca reabsorption from tubules, Ca
absorption from the gut → ↑ serum and urinary Ca and ↓ serum P with ↑ urinary P.Dr Ahmed Esawy

typical situation of a patient with parathyroid
disease--one of the parathyroid glands grows
into a tumor and makes too much hormone
Other three may be normal
Dr Ahmed Esawy

Causes of Secondary
hyperparathyroidism
- Hypocalcemia (rickets, osteomalacia or renal failure
,intestinal malabsorption)  2ry HPT.
- Hyperplasia of parathyroid gland (osteosclerosis 
rugger jersey spine, subperiosteal erosion is the
prominent feature. Brown tumours are rare, vascular
calcification common.
Dr Ahmed Esawy

Tertiary hyperparathyroidism
►Occurs in pts. with 2ry HPT who develop
autonomous parathyroid adenoma.can
develop after long-standing secondary HPT
in Chronic kidney failure /transplantation
►HPT fails to respond to ttt of underlying
cause.
Dr Ahmed Esawy

Sonography in Primary
Hyperparathyroidism
Dr Ahmed Esawy

Ultrasound has a central role in patients with primary
hyperparathyroidism. It may be used pre-and peroperatively
for
1) Localisation of parathyroid glands
2) Indentifying number of supposed pathological glands
3) Identifying thyoid pathology and thus be a part of pre-
operative planning of the extent of surgery
4) Performing biopsies from the thyroid and sometimes also
the parathyroid glands
Dr Ahmed Esawy

Algorithm for
preoperative
localization and
surgical treatment of
primary
hyperparathyroidism.
Dr Ahmed Esawy

parathyroid
adenomas
Dr Ahmed Esawy

WHAT DO PARATHYROID ADENOMAS LOOK LIKE?
Small adenoms is oviod .large adenomas is oblong (often parallel to long axis
of neck) may be lobulated or bullous
homogeneous solid mass
hypoechoic to the thyroid gland ,extrathyriodal mass with well defined
margins.
DOPPLER show Hypervascularized, except when they are small sized or very
deep located.
Doppler show polar arterial structure
The "vascular arch" is a typical finding. It must be distinguished from glands
presenting a central hilar vascularity.
Dr Ahmed Esawy

Most parathyroid adenomas are located posterior or
immediately inferior to the thyroid lobe and medial to
the carotid.
Most parathyroid adenomas are single 5 % multiple
Peak incidence 3rd -5th decade
3% have an ectopic location
The main imaging test for the evaluation of this pathology
are the ultrasound and the scintygraphy with Tc 99m
Sestamibi. In some cases a CT can be helpful, especially
with glands of ectopic localization.
Dr Ahmed Esawy

US
• Effective, noninvasive and inexpensive
• Limitations are operator dependent, restriction to lesions in the neck
• Often combined with sestamibi
Dr Ahmed Esawy

ADENOMA OF THE LEFT INFERIOR PARATHYROID GLAND. Images at the
top: cervical ultrasound, axial (panel A) and longitudinal (panel B) scans. Image at the
bottom: axial CT image. Lesion was unnoticed on CT.
Dr Ahmed Esawy

ADENOMA OF THE LEFT INFERIOR PARATHYROID GLAND. It is located
caudal to the inferior pole of the left thyroid lobe. Axial scan (panel A), longitudinal scan
(panel B y C) y longitudinal scan with color Doppler imaging ( panel D)
Dr Ahmed Esawy

ADENOMA OF THE UPPER RIGHT PARATHYROID GLAND 84-year-old male.
Routine analysis Ca 14 mgr/dl and PTH: 200 Ultrasound, axial scan (panel A) and
longitudinal scan (panel B): hypoechoic rounded nodule adjacent to the posterior margin
of the superior pole in the right thyroid lobe Parathyroid scintigraphy (C) was positive
(arrow). The patient had normal ultrasound and scintigraphy done 2 years beforeDr Ahmed Esawy

Normal appearance of parathyroid adenoma on ultrasoundDr Ahmed Esawy

ARE PARATHYROID ADENOMAS ALWAYS
HYPOECHOGENIC?
Occasionally adenomas with atypical appearances are
found: cystic, heterogeneous , hyperechogenic ( or
with calcifications.
Dr Ahmed Esawy

Atypical large size parathyroid adenomasDr Ahmed Esawy

Atypical parathyroid adenoma. Ultrasound: axial (A) and longitudinal (B) scan
Dr Ahmed Esawy

WHAT SIZE SHOULD THEY HAVE?
Average measure between 0.8 and 1.5 cm.
Smaller sizes are less frequent: microadenomas
Macroadenomas: differential diagnosis with carcinoma must be
made
Dr Ahmed Esawy

Parathyroid microadenoma. Ultrasound:Axial (A)and longitudinal (B) scan
Dr Ahmed Esawy

Parathyroid Adenoma
Minimally invasive surgery requires localization of
the abnormal gland
US: solid, homogeneous hypoechoic, flat or soft
feeding vessel enters pole/ arcs along edge
Tech 99m Sestamibi for localization if US
unsuccessful
rapid serum PTH levels intraoperative
Dr Ahmed Esawy

Sagittal view of the left neck showing the thyroid gland with multiple nodules within
the gland. The nodule at the inferior edge of the gland appears to be just outside the
gland and has a demarcating capsule.Dr Ahmed Esawy

Transverse view demonstrating the nodule in the region just inferior to the left lobe of
the thyroid bed, with an echogenic curv
Dr Ahmed Esawy

An arc of prominent vessels surrounding and leading into the nodule is
demonstrated Parathyroid adenoma
Dr Ahmed Esawy

Left inferior parathyroid adenoma
Dr Ahmed Esawy

Right inferior parathyroid adenoma
Dr Ahmed Esawy

Parathyroid adenoma. The lesion is postero-inferior to the thyroid
with a thin highly reflective capsule
Dr Ahmed Esawy

Parathyroid adenoma of the same echogenicity as the thyroid
parenchyma. The parathyroid mass can only be separated from the thyroid
by the highly reflective capsule.
Dr Ahmed Esawy

Very large right superior parathyroid adenoma associated
with brown tumour of the left clavicle.
Dr Ahmed Esawy

44-year-old woman with hyperparathyroidism due to right inferior parathyroid
adenoma. Resected gland weighed 629 mg, nearly 15 times weight of a normal
gland (40–50 mg).
A, Sonogram shows typical hypoechoic adenoma (arrows) deep in relation to
lower pole of thyroid.
B, Color Doppler sonogram shows peripheral feeding vessel (arrow) characteristic
of parathyroid adenomas. Also note typical arc or rim vascularity
Dr Ahmed Esawy

55-year-old woman with primary hyperparathyroidism due to large left superior
adenoma.
A, Sonogram shows hypoechoic nodule suspected of being parathyroid medial
to common carotid artery (arrow).
B, Graded compression sonogram increases conspicuity of adenoma (arrows).Dr Ahmed Esawy

25-year-old woman with Hashimoto’s thyroiditis.
A and B, Sonograms show how prominent central compartment lymph nodes
(arrows) may mimic adenomatous parathyroid glands.
C, Color Doppler sonogram may aid in differentiating between lymph nodes and
adenomas: Lymph nodes are supplied by a central hilar vessel (arrow), whereas
vessels that supply adenomas typically enter either pole.
Dr Ahmed Esawy

67-year-old woman with hyperparathyroidism and left tracheoesophageal
groove adenoma that could easily be mistaken for posterior thyroid nodule.
Peripheral, polar vascularity seen on color Doppler sonogram helps to identify
this as
adenoma. Subsequent parathyroidectomy preformed at time of total
thyroidectomy revealed this to be a supernumerary hyperplastic parathyroid
Dr Ahmed Esawy

52-year-old woman with hyperparathyroidism and right superior parathyroid adenoma.
A, Early-phase 99mTc-sestamibi SPECT image shows physiologic uptake in salivary
glands and thyroid gland, with focus of more intense uptake overlying superior pole of
right thyroid lobe (arrow).
B, Two-hour delayed SPECT image shows radiotracer retention in adenoma (arrow) but
clearing of tracer from overlying thyroid
Dr Ahmed Esawy

A 55-year-old woman with parathyroid adenoma. A, B. Coronal images from a
technetium-
99m sestamibi parathyroid scan (A, early phase; B, delayed phase) demonstrate a
single area of increased uptake in the right lower neck. C, D. Gray-scale sonograms
(C, axial scan; D, longitudinal scan) demonstrate a large well-defined hypoechoic
Dr Ahmed Esawy

A 73-year-old woman with parathyroid adenoma with characteristic feeding vessels.
A longitudinal sonogram shows a hypoechoic solid mass with multiple feeding
vessels from the lower pole margin of the thyroid gland.
Dr Ahmed Esawy

A 63-year-old man (A) and a 34-year-old woman (B) with suspicious parathyroid
incidentalomas (PTIs).
A. An axial sonogram depicts an oval, well-defined hypoechoic solid PTI (arrow).
The lesion was proven to be a parathyroid lesion by a fine needle aspiration-
parathyroid hormone (FNA-PTH) assay. B. An axial sonogram shows an enlarged
thyroid gland with heterogeneous parenchymal echogenicity and a flat hypoechoic
nodular lesion (arrow) located posterior to the gland. Many lymphocytes were found
up on cytologic examination and an FNA-PTH assay found low level of parathyroid
hormone. A flat nodular lesion, suspected to be a PTI, was proven to be an
enlarged perithyroidal lymph node associated with chronic thyroiditis.Dr Ahmed Esawy

A 51-year-old woman with very large nonfunctioning parathyroid cyst.
A. An axial sonogram shows the parathyroid cyst (PC) (6.2 cm, 58.1 mL) below the
right lower pole of the thyroid gland. The PC recurred two 2 months after simple
aspiration. B. An axial sonogram shows the transisthmic approach of an 18-gauge
needle (arrow) into the PC. C.An axial sonogram shows the PC after it was filled with
instilled ethanol via an 18-gauge needle (arrow) after the complete evacuation of the
cystic fluid. D. An axial sonogram shows the PC with a much smaller size (2.5 cm, 3.3
mL) 1 month after ethanol ablation. T, trachea; C,common carotid artery.
Dr Ahmed Esawy

parathyroid adenoma
Dr Ahmed Esawy

Transverse gray scale images of very large
(A) and small (B) parathyroid adenomas in
typical extrathyroidal locations. Adenomas
typically
appear homogeneously hypoechoic with
well-defined margins.
The adenomas measure 1.8 × 1.5 cm (A)
and 0.7 × 0.5 cm (B).
Dr Ahmed Esawy

Enlarged Extrathyroidal Feeding Artery
Parathyroid adenoma imaged without (A) and with (B) power Doppler
sonography showing the presence of a large extrathyroidal feeding vessel with a
polar insertion.
Dr Ahmed Esawy

Large parathyroid adenoma without (A) and with (B) power Doppler sonography
showing the presence of an extrathyroidal feeding vessel inserted at the pole of the
long axis of the adenoma
Dr Ahmed Esawy

Parathyroid adenoma in longitudinal (A) and transverse (B) views showing a rim of
peripheral vascularity
Dr Ahmed Esawy

Parathyroid adenoma adjacent to the carotid artery imaged in the transverse plane
without (A) and with (B) power Doppler sonography. The
peripheral vascular pattern of the adenoma easily distinguishes it from the carotid artery
and jugular vein.
Dr Ahmed Esawy

Longitudinal images of right (A) and left (B) lobes of the thyroid showing asymmetry
of vascularity at the inferior aspect of the gland secondary
to the presence of a left inferior parathyroid adenoma. The adenoma is shown on the
right in B, and diffuse hyperemia is shown in the adjacent thyroid gland and
surrounding tissues.
Dr Ahmed Esawy

Transverse images without (A) and with (B) compression, which improves
visualization of the adenoma. The relationship between this deep
adenoma and the longus colli muscle is also demonstrated
Dr Ahmed Esawy

Transverse images without (A) and with (B) compression, showing dramatic
improvement of visualization of a very small adenoma
Dr Ahmed Esawy

Transverse images without (A) and with (B) compression, showing dramatic
improvement of visualization of a small adenoma
Dr Ahmed Esawy

Hyperparathyroidism (QPTH, 243 pg/mL) and 752- mg left superior parathyroid adenoma at minimally invasive
parathyroidectomy in a 47-year-old woman. A, Sagittal sonography
shows a 1.4-cm hypoechoic superior parathyroid adenoma (asterisk) deep to the mid pole of the left thyroid lobe.
B, Immediate and delayed Tc 99m sestamibi SPECT. The immediate
study (left) shows asymmetric (left greater than right) thyroid uptake. The delayed study (right) shows mild focal
residual uptake posterior to the mid pole of the left thyroid lobe
Dr Ahmed Esawy

Hyperparathyroidism (QPTH, 281 pg/mL) and 322-mg left superior parathyroid
adenoma at minimally invasive parathyroidectomy in a 66 year old man. A,
Sagittal sonography shows an elongated hypoechoic parathyroid adenoma
(arrows) deep to the upper pole of the left thyroid lobe. B, Immediate and
delayed Tc 99m sestamibi SPECT. The immediate study (left) shows perhaps
slightly asymmetric right lobe tracer uptake. The delayed study (right) shows no
convincing tracer retention
Dr Ahmed Esawy

Longitudinal view of a thyroid nodule without (A) and with (B) power Doppler
sonography. Although the thyroid nodule (calipers) has
peripheral vascularity, it lacks a well-defined extrathyroidal feeding artery with
polar insertion. The hyperechogenicity and location within the thyroid
gland are also helpful for differentiating this nodule from a parathyroid adenoma.
Dr Ahmed Esawy

Classic parathyroid adenoma
identified on ultrasonography
Sagittal ultrasonographic image shows a
hypoechoic, well-defined mass (A) just
below the inferior pole of the right thyroid
gland (*). B, Transverse ultrasonographic
image with color flow Doppler shows the
increased peripheral arch of vascularity of
the mass frequently seen with adenomas
Dr Ahmed Esawy

Large parathyroid adenoma without (B) and with (A) power Doppler sonography.
In addition, a hypoechoic intrathyroidal nodule is shown,
superficial to the adenoma. An extrathyroidal feeding vessel inserted at the pole of
the long axis of the adenoma is shown, distinguishing it from the thyroid nodule.
Dr Ahmed Esawy

Longitudinal images of a parathyroid adenoma deep to the thyroid gland without
(A) and with (B) power Doppler sonography. The hyperechogenicity
of this pathologically proven adenoma was unusual and seen only in this adenoma.
An extrathyroidal feeding artery inserts at the pole of the long axis of the adenoma.
Dr Ahmed Esawy

A, Longitudinal gray scale image showing a deep hypoechoic structure in the
expected location of the longus colli muscle. B, Power Doppler image showing the
presence of an extrathyroidal feeding artery and peripheral vascularity of a deep
adenoma apposed just superficial to the longus colli muscle. Compression was used
in both images.
Dr Ahmed Esawy

A and B, Transverse
gray scale images of a
retrocarotid
parathyroid adenoma
without (A) and with
(B) compression. C
and D, Same adenoma
in longitudinal images
without (C) and with
(D) power Doppler
sonography. The edge-
shadowing artifact of
the carotid artery
obscures the adenoma,
which is only visible
with compression and
adjustment of the
acoustic window. An
extrathyroidal feeding
artery is also shown.
Dr Ahmed Esawy

a, b Neck ultrasonography of a 31-year-old female patient with primary
hyperparathyroidism shows evidence of double adenoma involving the right and left
inferior parathyroid glands. The left inferior parathyroid lesion was predominantly cystic. c,
d Tc-99m sestamibi scintigraphy and SPECT revealed only the right inferior parathyroid
adenoma and the left inferior lesion seen on ultrasonography was not seen. e High-power
photomicrograph (×100, H&E stain) of the left inferior parathyroid lesion, which was
negative on scintigraphy and SPECT, shows acinar dilatation (arrowheads) and
haemorrhage Dr Ahmed Esawy

Atypical ultrasound features of
parathyroid tumours
Atypical ultrasound features of parathyroid lesions pose a diagnostic challenge.
Awareness of these features would help improve lesion detection.
Teaching points
1.Cystic change is significantly related to the size, weight and measured
parathyroid hormone levels.
2.Cystic change in parathyroid tumours indicated a slightly higher risk of
malignancy.
3.Heterogeneous parathyroid adenomas are larger in size and heavier, and they
have higher PTH levels.
4. Awareness of atypical ultrasound features will improve preoperative clinical
prediction
Dr Ahmed Esawy

a Neck ultrasonography of 48-year-old male patient with primary hyperthyroidism
showed a predominantly cystic right inferior parathyroid lesion with internal
septations
Dr Ahmed Esawy

a Neck ultrasonography of a 21-year-old female patient with primary
hyperthyroidism
showed haemorrhagic and cystic degeneration in the right superior parathyroid
adenoma
Dr Ahmed Esawy

Neck ultrasonography of a 55-year-old male patient showed a right inferior
parathyroid lesion with hypoechoic and hyperechoic components.
Dr Ahmed Esawy

Neck ultrasonography of a 42-year-old male patient with parathyroid carcinoma showed
a heterogeneous, more rounded left inferior parathyroid lesion with areas of cystic
degeneration and ill-defined microlobulated margins
Dr Ahmed Esawy

Neck ultrasonography showed a calcified right inferior parathyroid adenoma in a 27-
year-old male patient with primary hyperparathyroidism. An echogenic rim around the
lesion could be seen inspite of calcification
Dr Ahmed Esawy

SHOULD I NECESSARILY FIND ANYTHING?
False negative:
- Minimally enlarged adenoma
- Adjacent lesions in an enlarged or multinodular
thyroid
- Ectopic parathyroid adenoma
Dr Ahmed Esawy

False negative: parathyroid adenoma in multinodular goiter
Dr Ahmed Esawy

Retroesophageal adenomaDr Ahmed Esawy

INTRATHYROIDAL ADENOMA Ultrasound shows a very vascularized and welldefined
hypoechogenic solid nodule (mid third of left thyroid lobe)
Dr Ahmed Esawy

Visualization of an Ectopic
Parathyroid
Adenoma in the Patient with the Use
of Scintigraphy, PET-MRI, and PET-
CT.
metabolically
active mass behind the left sternoclavicular
joint.
Dr Ahmed Esawy

Ectopic Parathyroid Adenoma Localized by Tc-99m Sestamibi SPECT/CT
Localization Prior to Re-operation is Useful
Anterior static Sestamibi images, done immediately, and at 20 minutes and 3 hours
show a focal lesion superior and lateral to the right thyroid lobe.
Dr Ahmed Esawy

Ectopic Parathyroid Adenoma Localized by Tc-99m Sestamibi SPECT/CT
Localization Prior to Re-operation is Useful
SPECT/CT in
tomographic, CT
and fused images
in the axial,
sagittal and
coronal plane,
showing focal
increased uptake
lateral to the right
hyoid bone (white
arrow).
Dr Ahmed Esawy

Normocalcemic primary hyperparathyroidism
(NPHPT) is a condition characterized by elevation of
the parathyroid hormone (PTH) in the presence of
normal serum calcium and the absence of secondary
causes, such as renal insufficiency, vitamin D
deficiency, use of medications such as
hydrochlorothiazide and lithium,
as well as hypercalciuria and malabsorption states.
Dr Ahmed Esawy

Is it a Parathyroid Adenoma?
hypoechoic oval nodules near thyroid in 2.3%
FNA – 24% parathyroid
58% thyroid
11% lymph node
8% nondiagnostic
Dr Ahmed Esawy

Parathyroid adenomas not
important unless biochemically
active
Dr Ahmed Esawy

IF THERE IS A NODULE, IS IT NECESSARILIY AN
ADENOMA?
False positive:
- Cervical Lymph node
- Thyroid nodule
- Anatomical structures
Prominent blood vessel
Esophagus
Longus colli muscle
Dr Ahmed Esawy

False positive: lymph nodeDr Ahmed Esawy

Extrathyroidal lymph node without (A) and with (B) color Doppler sonography.
Although the gray scale image shows a lesion that is indistinguishable from a
parathyroid adenoma, the color Doppler image shows central hilar vascularity. This
node proved to contain metastatic thyroid adenocarcinoma.
Dr Ahmed Esawy

False positive: adenopathyDr Ahmed Esawy

FALSE POSITIVE: Thyroid noduleDr Ahmed Esawy

False positive: normal anatomic structuresDr Ahmed Esawy

IF THE NODULE IS SMALL, COULD IT BE A
NORMAL PARATHYROID?
Normal parathyroid glands are usually not visualized.
The average size is 5x3x1mm, and
they are isoechogenic to normal thyroid. )
Dr Ahmed Esawy

Normal parathyroid gland
Dr Ahmed Esawy

PARATHYRIOD
CT IMAGING
Dr Ahmed Esawy

PARATHYROID ADENOMA
Definition: Benign neoplasm of the parathyroid
parenchymal cells, including chief cells and/or oncocytic
cells.
May be associated with hyperparathyroidism-jaw tumor
syndrome (HPT-JT):
Autosomal-dominant disorder
Characterized by:
– Parathyroid adenoma or carcinoma
– Fibro-osseous lesions of the jaw (e.g., ossifying fibroma of
mandible or maxilla): 30% of cases
– Renal cyst, hamartoma, carcinoma: 20% of cases
Dr Ahmed Esawy

On CT adenoma appear as well-defined
nodules usually hyperenhanced in relation to
the thyroid gland.
Dr Ahmed Esawy

A: Early Sestamibi scan
(thyroid + parathyroid)
B: Late Sestamibi scan
(left lower parathyroid)
C: SPECT showing
parathyroid
D: Low dose CT
E: Fused image
F: Ultrasound showing 8mm
parathyroid adenoma
(between calipers)
Dr Ahmed Esawy

SPECT/CT of
mediastinal
parathyroid
adenoma
Top Row: Sestamibi
scan
Middle Row: low
dose CT
Bottom Row: fused
images
Dr Ahmed Esawy

40-year-old woman who presented with recurrent hypercalcemia and hyperparathyroidism
after resection of both left-sided glands. Contrast-enhanced CT
scan shows brisk enhancement of 8-mm soft-tissue nodule (arrow) in mediastinum
that correlated anatomically with focus of radiotracer retention in mediastinum on prior
sestamibi SPECT. This was found to be a hyperplastic right inferior parathyroid glandDr Ahmed Esawy

The role of four-
dimensional
(4D) CT
Higher sensitivity than ultrasound, but involves radiation
•4D-CT is derived from 3D CT scanning, with added
dimension from changes in perfusion of contrast over time,
which allows to characterize hyperfunctioning parathyroid
glands
Dr Ahmed Esawy

The role of four-dimensional (4D) CT is to enable
accurate localization of the parathyroid adenoma in
eutopic and ectopic locations and to depict
multiglandular disease.
Characteristic contrast enhancement pattern for a
parathyroid adenoma is peak enhancement at the
arterial phase, washout of contrast material from the
arterial to delayed phase, and low attenuation on the
non–contrast enhanced images.
The morphologic imaging findings of parathyroid
adenomas include central low attenuation change,
lobulated margins, and a polar vessel sign.Dr Ahmed Esawy

Images in a 73-year-old man with a
left carotid space parathyroid
adenoma; 4D CT study shows a
parathyroid lesion with typical
enhancement characteristics and
morphology. (a) Nonenhanced
phase axial image shows an oval
lesion (arrow), lateral to the
pyriform sinus of the hypopharynx
and anterior to the left common
carotid artery (CCA). The mass has
low attenuation. (b) Arterial phase
axial image reveals the lesion
(arrow) is vividly enhancing. There
is a central nonenhancing region.
(c) Delayed phase axial image
shows
washout of contrast material with
decreasing attenuation (arrow)
compared with the arterial phase.
Note that other structures such as a
level IB lymph node (LN),
submandibular gland (SMG), and
muscles do not have
marked washout of contrast
material from the arterial to the
delayed phase. (d) Coronal
reformatted image in the arterial
phase demonstrates oval lesion
(arrow) that is separate from the
thyroid gland (Thy).
Dr Ahmed Esawy

a 52-year-old woman with a large left parathyroid adenoma. (a) Coronal arterial
phase 4D CT image shows a lesion measuring up to 4 cm in craniocaudal dimension
(straight arrows), inferior to the left thyroid lobe and extending between the left
common carotid artery (CCA) and brachiocephalic artery (BC).
There is an enlarged inferior thyroid artery that terminates at the superior pole of
the lesion (curved arrow). Note the contralateral normal inferior thyroid artery
(arrowhead).
(b) Arterial phase axial image shows the lesion (arrow) enhances and has similar
attenuation as sequestered thyroid tissue (arrowhead). (c) Axial image in the
nonenhanced phase is helpful in differentiating between high attenuation thyroid
tissue (arrowhead) and the lower attenuation candidate lesion (arrow).
Dr Ahmed Esawy

Images in a 78-year-old woman
with left-sided multiglandular
disease. (a) Arterial and (b)
delayed phase axial 4D CT
images at the level of the
thyroid isthmus show a lesion
(arrow) posterior to the
superior left thyroid lobe, which
has early vivid enhancement
and rapid washout of contrast
material. (c) Arterial and (d)
delayed phase axial CT images
at the thoracic inlet show a
second rounded lesion (arrow)
inferior to the left thyroid lobe,
which has a similar
enhancement pattern to the
first lesion. Note a significant
streak artifact (*) caused by
the beam hardening from the
clavicles and contrast material
in the veins, especially
on the arterial phase image.
Lesions in or close to these
artifacts could be missed.
Dr Ahmed Esawy

Images in a 74-year-old woman with thyroid nodule mimicking a parathyroid adenoma
at 4D CT. (a) Axial nonenhanced image shows a low-attenuation candidate lesion
(arrow) at the posterior aspect of the left lower thyroid lobe. Subsequent arterial phase
images were technically poor because the patient had aortic regurgitation and arterial
phase imaging was performed too early. Since the radiologist was at the scanner, two
additional contrast-enhanced phases were performed.
(b) An early delayed phase axial CT image at 40 seconds from the start of contrast
material injection shows the lesion (arrow) enhances more relative to the thyroid
gland, and (c) a routine delayed phase axial CT image at 100 seconds from the start of
contrast material injection shows washout of contrast material (arrow). This
was reported as a parathyroid lesion but was found to be a thyroid nodule at surgery.
Dr Ahmed Esawy

Images in a 69-year-old woman with a right parathyroid adenoma. (a) Axial, (b)
coronal, and (c) sagittal arterial phase 4D CT images show a vividly enhancing lesion
(straight arrow) posterior and inferior to the lower pole of the right thyroid lobe. This
lesion contains a central nonenhancing focus best seen on the axial image. There is a
characteristic tortuous polar vessel at the superior aspect of the lesion (curved arrow)
seen on axial and sagittal images. Note that a left level VI lymph node (arrowhead)
seen on the axial and coronal images is in the same location as the parathyroid
adenoma but is not enhancing on arterial phase and has no
associated vessels.
Dr Ahmed Esawy

Images in a 45-year-old woman with a
right carotid space parathyroid adenoma.
There was a prior history of unsuccessful
neck exploration. (a) Axial arterial phase
4D CT image shows a lesion (arrow) in
the right carotid space, anterior to the
common carotid artery. The lesion does not
have vivid arterial enhancement,but there
is a characteristic polar artery that courses
around the lesion (arrowhead). (b) Axial
delayed phase image shows washout of
contrast material (decreasing attenuation)
in the lesion (arrow).
(c) Sagittal reformatted arterial phase
image shows the lesion has a lobulated
superior margin (arrowhead).
The polar vessel and lobulated contour
help to differentiate it from a lymph node.
(d) Axial gadoliniumenhanced
T1-weighted fat-suppressed magnetic
resonance image of the neck demonstrates
contrast
enhancement of the lesion (arrow), but the
morphologic feature of peripheral artery
and the lobulations could
not be seen because of the lower
resolution.
Dr Ahmed Esawy

Images in a 47-year-old woman with multiglandular disease in the retropharynx.
She had a history of an unsuccessful neck exploration, but the superior parathyroid
glands were unable to be identified. (a) Arterial and (b) delayed phase axial 4D CT
images show the two lesions (arrows) in the retropharyngeal space at the level of
the pyriform sinuses with early vivid enhancement and rapid washout of contrast
material. (c) Arterial phase image reformatted in the coronal plane shows bilateral
lesions (arrows) in the retropharyngeal space. The larger right lesion has a polar
vessel, which is tortuous (arrowhead). This is a characteristic ectopic location for
the superior parathyroid gland.
Dr Ahmed Esawy

Images in a 61-year-old woman with multiglandular disease in the posterior
mediastinum arising from the superior parathyroid glands. (a) Axial CT image shows a
candidate lesion (arrow) composed of cystic (*) and solid components in the posterior
mediastinum. (b) Coronal 99mTc sestamibi images at 10 minutes (left) and 2 hours
(right) show two focal areas of uptake and focal persistent tracer activity, respectively,
below the level of the left thyroid gland (arrows), corresponding to the abnormality
seen at CT. Note that the cystic component on the right seen at CT does not have
activity. At surgery the patient had bilateral parathyroid lesions that had descending
into the posterior mediastinum. Despite the mediastinal location, this is more
characteristic of superior parathyroid adenomas because these adenomas fall posterior
and inferior to the tracheoesophageal groove when enlarged. Inferior parathyroid
adenomas are found along the thyrothymic ligament and are located in the anterior
mediastinum. Dr Ahmed Esawy

ultrasound (US). ( a ) US
image in the longitudinal
plane, rotated clockwise 90°
to match the CT sagittal
reconstructed projection,
demonstrates the parathyroid
adenoma
(1.1 × 0.5 × 0.5 cm) ( thick
arrow ) along the inferior
aspect of the left lobe of the
thyroid ( thin
arrow ). ( b ) US image in the
transverse plane demonstrates
the parathyroid adenoma (
arrow ) inferior
to the left lobe of the thyroid
lateral to the trachea (T) and
medial to the carotid (C) that
correlates
with the position of the
parathyroid adenoma
documented on 4D-CT
Case 1 Dr Ahmed Esawy

Same patient before
technetium-99 m sestamibi
(Tc-99 m MIBI). ( a )
Transverse, sagittal, and
coronal
static images of the neck and
chest 30 min following the
intravenous injection of 25
mCi of Tc-99 m MIBI
demonstrate uptake in
parathyroid adenoma ( black
arrow ). ( b ) SPECT/CT
images,
obtained after the initial set
of immediate postinjection
images, demonstrate type E
parathyroid gland ( red arrow
)

Same patient before 4D-CT. ( a ) Axial postcontrast computed tomography (CT)
scan reveals an enhancing parathyroid adenoma (0.8 × 0.5 × 0.9 cm) underlying
the posterior surface of the left thyroid lobe ( arrow ). ( b ) Sagittal reconstructed
maximal intensity projection (MIP) image demonstrates that the parathyroid
adenoma is along the inferior aspect of the left thyroid lobe ( arrow )
Case 1
Dr Ahmed Esawy

Another patient US. ( a ) US image in the transverse plane demonstrates a parathyroid
adenoma (3.2 × 1.3 × 0.9 cm) ( arrow ) in the paraesophageal region inferior to the left
thyroid lobe lateral to the trachea (T) and medial to the carotid (C) that correlates with
the position of the parathyroid adenoma documented on 4D-CT. ( b ) US image in the
longitudinal plane demonstrates the parathyroid adenoma ( thin arrow ) inferior and
posterior to the left thyroid ( th ). Incidental note is made of a multinodular thyroid. The
dominant nodules in the right (0.8 cm) and left lobe of the thyroid (1.4 cm) ( thick
arrows ) were documented as colloid nodules on US-guided biopsy prior to the MIP
Case 2
Dr Ahmed Esawy

Same Another patient
technetium-99 m sestamibi
(Tc-99 m MIBI). ( a )
Transverse, sagittal, and
coronal
static images of the neck and
chest 30 min following the
intravenous injection of 30
mCi of Tc-99 m MIBI
demonstrate avid focal tracer
in left paraesophageal region
in the tracheoesophageal
groove ( arrow ).
( b ) SPECT/CT images,
obtained after the initial set
of immediate postinjection
images, demonstrate type C
parathyroid adenoma ( red
arrow )

Same Another patient CT. ( a ) Axial noncontrast CT shows a soft tissue attenuation
parathyroid adenoma separate and posterior to the left thyroid lobe ( arrow ) along
the paraesophageal region. ( b ) Following contrast administration, the parathyroid
adenoma enhances avidly during the arterial phase of the contrast bolus. ( c ) On the
later phase of the study, contrast has washed out quickly from the adenomatous
parathyroid ( arrow ). ( d ) Coronal reconstructed MIP images demonstrate the
parathyroid adenoma relative to the thyroid gland and adjacent structures. ( e )
Sagittal reconstructed MIP images demonstrate the parathyroid adenoma relative to
Case 2
Dr Ahmed Esawy

CT. ( a ) Axial noncontrast CT
shows a soft tissue
attenuation parathyroid
adenoma (0.9 × 0.5 × 1.9
cm) in the etroesophageal
region ( arrow ). Note that
the patient has had total
thyroidectomy.
( b ) Following contrast
administration, the
parathyroid adenoma shows
early enhancement ( arrow ).
( c ) Following contrast
administration, the
parathyroid adenoma shows
early washout ( arrow ). Note
the left common carotid
artery ( arrowhead ).
( d ) Sagittal reconstructed
MIP images demonstrate the
parathyroid adenoma
anterior to the C5 and C6
vertebral bodies ( arrow )
Case 3Dr Ahmed Esawy

39-year-old woman with left superior
adenoma showing typical MRI signal characteristics.
A, T2-weighted MR image shows increased T2 signal in
adenoma (arrow) relative to thyroid gland and
surrounding soft tissues.
B, Axial T1-weighted MR image shows typical
intermediate T1 signal (arrow) seen in adenomas
C, Gadolinium-enhanced T1-weighted image with fat suppression shows intense
enhancement typical of adenomas (arrow). These imaging characteristics can be
indistinguishable from those of lymph nodes and thus must be interpreted in clinical
context and in concert with other imaging techniques
Dr Ahmed Esawy

A, Unenhanced CT scan at the level of the lower poles of the thyroid gland shows no discrete
adenoma. B, Immediate first-pass image following contrast administration shows a tiny, avidly
enhancing adenoma in the right paraesophageal region (anterior to *). C, Second pass at 60
seconds shows some washout of enhancement, which is clearly less than on the immediate
postcontrast scan. D, Last pass delayed image at 90 seconds shows little enhancement of the
adenoma, which is still readily identifiable. On another patient:
E, Coronal reconstructed CT
image from immediate first-
pass enhanced CT scan
shows a large adenoma
below the inferior pole of the
left thyroid lobe (arrow).
Dr Ahmed Esawy

F, Coronal maximum intensity projection image in anterior projection shows the
adenoma (arrow). G, Coronal maximum intensity projection image in the
posterior projection shows the adenoma (*) posterior to the common carotid
artery.
Dr Ahmed Esawy

Selective arteriography in conjunction with
venous sampling for PTH
•Requires catheterization of multiple veins
in the neck and mediastinum, from which
blood samples are obtained with rapid PTH
measurement in angio suite
•Parathyroid adenomas have increased
vascularity, demonstrating a characteristic
blush on arteriography
•Indicated for patients requiring re-
exploration with negative or discordant
imaging studies
Bilateral cervical angiography :
circumscribing
Vessels also correlating strongly with PTA
Dr Ahmed Esawy

Parathyroid Adenoma FNAB
• role of FNA for Dx
• don’t do it!
• single vessel enters the end of the gland,
easily damaged at biopsy
• induces fibrosis/necrosis which can make
resection more difficult and mimic cancer at
pathology
Dr Ahmed Esawy

There is only ONE way to treat parathyroid
problems--Surgery.
Mini-Surgery is now available that almost
everyone can/should have. You should educate
yourself about the new surgical treatments
available. Do not have an "exploratory"
operation to find the bad parathyroid tumor--
this old fashioned operation is too big and
dangerous.
Dr Ahmed Esawy

parathyroid
hyperplasia
Dr Ahmed Esawy

WHAT DOES IT MEAN IF THERE ARE MUTIPLE
NODULES?
Multiglandular disease: if more than one gland is
enlarged the condition is parathyroid
hyperplasia. Anatomo-pathologically is not possible to
distinguish between adenoma and hyperplasia.
The concept of "multiple adenoma" is controversial and
generally not accepted.
Dr Ahmed Esawy

Multiple nodules: if more than one gland is
enlarged the condition is parthyroid
hyperplasia. Anatomo-pathologically is not
possible to distinguish between adenoma and
hyperplasia.
Dr Ahmed Esawy

15-year-old girl with hyperparathyroidism
due to parathyroid hyperplasia.
A–D, Sonograms show four slightly enlarged
parathyroid glands (arrows): right superior
(A), right inferior (B), left superior (C), and
left inferior (D). Patient subsequently
underwent four-gland exploration and
subtotal parathyroidectomy, leaving portion
of right superior gland. Largest of resected
hyperplastic glands weighed only 322 mg.
Relatively small size of typical hyperplastic
glands decreases sensitivity of sonography.
Dr Ahmed Esawy

Parathyroid HyperplasiaDr Ahmed Esawy

76-year-old woman with left juxta-thyroid parathyroid hyperplasia. A, Arterial
phase image shows the hyperenhancing parathyroid lesion (arrow), which has
higher attenuation than the adjacent thyroid gland (arrowhead). B, Venous phase
image shows decreased attenuation of the parathyroid lesion (arrow),
representing rapid washout of contrast. The adjacent thyroid gland (arrowhead)
has higher attenuation than during the arterial phase.
Dr Ahmed Esawy

WHAT IS THE VALUE OF THE MIBI SCINTIGRAPHY IF
POSITIVE? WHAT IS THE
VALUE IF NEGATIVE?
MIBI Scintigraphy consists of an early stage (10-15 minutes)
and a late stage (2-3 hours). Adenomatous/hyperplastic tissue
presents uptake of Tc-99m which persists at late stage. It has a
sensitivity of 88% similar to the ultrasound to detect solitary
parathyroid adenomas. Its sensitivity is slightly higher than
ultrasound in parathyroid hyperplasia.
The main advantage over ultrasound is the detection of ectopic
glands in mediastinum
Dr Ahmed Esawy

Parathyroid Hyperplasia
Dr Ahmed Esawy

FALSE NEGATIVE
-Multiglandular disease: parathyroid hyperplasia
-Some lesions have an early wash-out: uptake in the
early stage but not late.
Dr Ahmed Esawy

Scintigraphic: false negativeDr Ahmed Esawy

FALSE POSITIVE:
-The most frequent are thyroid nodules (follicular
adenomas, colloid nodules,carcinomas…)
-Lymph node, remnant thymic, ectopic thyroid tissue...
Dr Ahmed Esawy

Scintigraphic: false positive
Dr Ahmed Esawy

Nuclear imaging
Dr Ahmed Esawy

Parathyroid Imaging and Localization Using
SPECT/CT
Dr Ahmed Esawy

Early phase (A) and delayed phase (B) of planar 99mTc-sestamibi scan showing
normal parathyroid findings
Dr Ahmed Esawy

Intravenous injection of 25mCi of 99mTechnetium
•AP and oblique views of thorax and neck with gamma camera immediately after
injection and at 1h and 4h or SPECT (single photon emission computed
tomography)
•Limitations with coexistence of thyroid pathology or other metabolically active
tissue can be overcome with double-tracer subtraction technique
Dr Ahmed Esawy

the clinical value of SPECT/CT in the management
of parathyroid patients. Using SPECT/CT requires
additional imaging time and, therefore, appropriate
planning and organization
Using SPECT/CT has improved the overall accuracy
rates of parathyroid examination
Dr Ahmed Esawy

(A) SPECT/CT image showing possible adenoma, but thyroid uptake creates difficulty.
(B) Misregistration, which may have resulted from patient movement between SPECT
and CT acquisitions. This study was subsequently reprocessed.
Dr Ahmed Esawy

Adenoma in left inferior gland, visible in delayed phase of planar 99mTc-sestamibi
scan.
Dr Ahmed Esawy

Early phase (A) and delayed phase (B) of planar 99mTc-sestamibi scan showing high
uptake in parathyroid, consistent with adenoma
Dr Ahmed Esawy

Transverse (A),
fused coronal (B), and fused
sagittal (C) SPECT/CT
images
showing higher uptake in
neck,consistent with
parathyroid adenoma,
which helped to support
information given by
planar scan.
Dr Ahmed Esawy

SPECT/CT coronal(A) and transverse (B) images that helped to confirm position of
adenoma. Both images show high-uptake area consistent with parathyroid adenoma.
Early phase (A)
and delayed
phase (B) of
planar 99mTc-
sestamibi scan
showing high-
uptake area on
left side of
neck consistent
with
parathyroid
adenoma
Dr Ahmed Esawy

Early phase (A) and delayed phase (B) of planar 99mTc-sestamibi scan showing
irregular uptake within thyroid gland.
Dr Ahmed Esawy

Coronal (A),transverse (B), and
sagittal (C)SPECT/CT images
showing uptake within neck
area. Even though fused images
helped with anatomic
localization,disease within
parathyroid gland could not be
excluded
Dr Ahmed Esawy

Planar 99mTcsestamibi scan showing uneven thyroid uptake on
600-s anterior view. Scan was acquired 20 min after injection.
Dr Ahmed Esawy

Parathyroid Imaging - Tc-99m Sestamibi
45 min Anterior 45 min LAO
2 HR 2 HR
submandibular
gland
thyroid lobe
adenoma
Delayed
views
Dr Ahmed Esawy

Right inferior pole
parathyroid adenoma
15 min Ant 1 hr Ant 1 hr RAO
adenomaDr Ahmed Esawy

15 min Ant 1 hr Ant
Right superior parathyroid
adenoma

Right inferior parathyroid
adenoma - 54F
15 min Ant 1 hr Ant 1 hr RAO

Tc-99m sestamibi positive
for intense uptake LIP
Immed Ant Delay Ant
Dr Ahmed Esawy

preoperative localization
is cost effective by reducing in patient stay and
reducing the incidence of complications. It is also
likely that this will improve the patient experience for
this procedure. We favor subtraction imaging with
the support of high-resolution ultrasound for
optimum preoperative localization
Dr Ahmed Esawy

Two patient studies using subtraction imaging and pinhole collimator. The first
patient (A) has a normal iodine scan. The sestamibi scan demonstrates an
abnormal area of accumulation at the lower pole of the right lobe of the thyroid,
without the need for subtraction. The subtraction scan confirms this site of
abnormality.
The second patient (B) has an ectopic gland below the left lobe of the thyroid.
Dr Ahmed Esawy

The patient has a normal iodine scan. The subtraction image allows the localization of
the parathyroid adenoma to be made with greater confidence than on the sestamibi
scan alone
Dr Ahmed Esawy

The iodine scan demonstrates a multinodular thyroid. The subtraction scan shows
increased uptake of sestamibi in the right lobe of the thyroid within the upper and
lower poles, corresponding to 2 adenomas.
Dr Ahmed Esawy

The iodine scan has a normal appearance. The sestamibi subtraction scan
demonstrates 3 abnormal areas of uptake, 2 in the right lobe of the thyroid
and 1 below the left lobe. The patient had four gland hyperplasia, the upper
pole of the left lobe was missed
Dr Ahmed Esawy

99mTc-sestamibi images viewed at 20 minutes and 2 hours after injection of
sestamibi (dual-phase technique) using pinhole collimation. The early image on the
left shows the distribution of sestamibi in the thyroid and parathyroid tissue, with a
small area of slight increased uptake seen at the lower pole of the right lobe of the
thyroid. This is seen more clearly at 2 hours when the thyroid activity has “washed
out.”
Dr Ahmed Esawy

Parathyroid Carcinoma
Rare (<1%) of enlarged parathyroids
Clues: peroperative Ca++ and PTH extremely
high – nonspecific
Local invasion at surgery
Dx: external path or metastases (up to 30% at
presentation)
Dr Ahmed Esawy

In some settings biopsies are performed of the
parathyroid glands. The latter may be used to confirm
that the tissue identified is actually parathyroid tissue
through staining for parathyroid hormone (PTH).
None except local irritation by scanning. If biopsies are
performed, pain, bleeding, and infection may be seen in
rare cases.
Dr Ahmed Esawy

Clinical Features Associated with Malignancy in Parathyroid Neoplasms
• Serum calcium level >14 mg/dl
• Serum parathormone levels 2 to 3 times normal
• Severe metabolic manifestations: nephrolithiasis, bone disease, etc.
• Palpable neck mass
• Difficulty in surgical dissection owing to adherence to surrounding
structures
Dr Ahmed Esawy

Parathyroid carcinoma.
Radiology
Imaging procedures are of similar utility as
in parathyroid adenomas
Dr Ahmed Esawy

Parathyroid carcinoma in a patient with severe
hyperparathyroidism.
A, Axial T2-weighted MR image shows a demarcated
2.5-cm mediastinal mass (*) that represents a
parathyroid carcinoma. B, Axial T2-weighted MR image
of another patient with hypercalcemia shows a
nonhomogeneous mass in the right tracheoesophageal
groove. The margins are slightly unsharp. This is a
parathyroid carcinoma. C, Axial T2-weighted MR image
shows a large mass in the right tracheoesophageal
groove in this patient with severe hypercalcemia. At
surgery, this was a parathyroid carcinomaDr Ahmed Esawy

SECONDARY NEOPLASMS
Definition: Contiguous involvement from tumors
in adjacent structures or metastatic neoplasms
from distant sites involving the parathyroid gland.
Dr Ahmed Esawy

Hypoparathyroidism
Dr Ahmed Esawy

Hypoparathyroidism is decreased function of the parathyroid glands with
underproduction of parathyroid hormone. This can lead to low levels of
calcium in the blood,
Dr Ahmed Esawy

Causes of Hypoparathyroidism
►Acquired
►Idiopathic / Inherited
Dr Ahmed Esawy

CAUSES OF ACQUIRED HYPOPARATHYRIODISM
Surgical hypoparathyroidism Removal of, or trauma to, the parathyroid glands due
to thyroid surgery (thyroidectomy), parathyroid surgery (parathyroidectomy) or
other surgical interventions in the central part of the neck
Autoimmune invasion and destruction is the most common non-surgical cause. It
can occur as part of autoimmune polyendocrine syndromes.
Hemochromatosis
Magnesium deficiency
Dr Ahmed Esawy

IDIOPATHIC HYPOPARATHYROIDISM
A form occuring at an early age (genetic origin) with autosomal recessive mode of transmission
“multiple endocrine deficiency –autoimmune-candidiasis (MEDAC) syndrome”
“Juvenile familial endocrinopathy”
“Hypoparathyroidism – Addisson’s disease – mucocutaneous candidiasis (HAM) syndrome
Idiopathic (of unknown cause), occasionally familial (e.g. Barakat syndrome (HDR
syndrome) a genetic development disorder resulting in hypoparathyroidism, sensorineural
deafness and renal disease)
Absence or dysfunction of the parathyroid glands is one of the components of chromosome 22q11
microdeletion syndrome (other names: DiGeorge syndrome, Schprintzen syndrome, velocardiofacial
syndrome).
Circulating antibodies for the parathyroid glands and the adrenals are frequently present.
Other associated disease:
Pernicious anemia
Ovarian failure
Autoimmune thyroiditis
Diabetes mellitus
DiGeorge syndrome, a disease in which hypoparathyroidism can occur due to a total absence of the
parathyroid glands at birth. Familial hypoparathyroidism occurs with other endocrine diseases,
such as adrenal insufficiency, in a syndrome called autoimmune polyglandular failure syndrome
type 1 (APS-I).
A defect in the calcium receptor leads to a rare congenital form of the disease
Dr Ahmed Esawy

Radiographic features
musculoskeletal
focal (25%) and generalised (10%)
Osteosclerosis  pelvis, inner table of the skull, prox. femur, v.bodies.
dense metaphyseal bands
skull vault thickening
diffuse idiopathic skeletal hyperostosis-like changes
subcutaneous periarticular calcification (around shoulders and hips)
CNS
intracranial calcifications: most commonly basal ganglia but also subcortical
white matter, corona radiata and thalamus, cerebrum & cerebellum
head and neck
cataract
Dr Ahmed Esawy

Markers
parathyroid hormone (PTH) level: low
serum phosphate level: high
serum calcium level: low
Dr Ahmed Esawy

dense metaphyseal bandsDr Ahmed Esawy

diffuse idiopathic skeletal hyperostosis
Dr Ahmed Esawy

Pseudo hypoparathryoidism
Pseudohypoparathyroidism (normal PTH levels but tissue insensitivity to the hormone,
associated with mental retardation and skeletal deformities)
- Hereditary, dominant. Ccc by hypocalcemia & hyperphosphatemia not responding
to parathormone End-organ resistance ??, defective cAMP in kidney and bone.
Radiological features: as above.
1. Short stature, large skull.
2. Short metacarpals, metatarsal & phalanges esp. 4th and 5th metacarpals.
3. Teeth hypoplasia & defective enamel.
4. Basal gang., cerebellum & skin calcification by CT.
5. Deformities (chr. tetany): Coxa vara, valga
Cone shaped epiph.
Bowing of bones.
Pseudo pseudo hypoparahyroidism
- Same skeletal manifestations of pseudohypoparathyroid but with normal blood
chemistry.
Dr Ahmed Esawy

brain showed calcification in the basal
ganglia, thalamus and cerebral white matter
Dr Ahmed Esawy

Short metacarpals, metatarsal & phalanges esp. 4th and 5th metacarpals
Dr Ahmed Esawy

Patients with pseudopseudohypoparathyroidism have
similar clinical and radiological features
as pseudohypoparathyroidism but without alterations in
parathyroid hormone levels and calcium metabolism. There
is often a family history of pseudohypoparathyroidism
Pseudohypoparathyroidism (PHP) is a condition
where there is end-organ resistance to parathyroid
hormone / parathormone (PTH).
Dr Ahmed Esawy

bilateral basal ganglia and subcortical calcification.Dr Ahmed Esawy

Brain CT scan shows bilateral calcification in basal ganglia, periventricular
demyelination and mild dilatation of lateral ventricles
Dr Ahmed Esawy

T2-weighted views of brain MRI shows high-intencity signals in periventricular
white matter and midbrain
Dr Ahmed Esawy

GIOTRE
DIFFUSE FOCAL/NODULAR
MULTINODULAR
UNINODULAR
NON-TOXIC TOXIC
Structural / Anatomy
Functional /biochemical
Dr Ahmed Esawy

NODULAR GIOTRE
UNINODULAR
MULTINODULAR
MNG
INACTIVE
COLD
TOXIC NODULE
TOXIC NODULE
TOXIC MULTINODULAR GIOTRE INACTIVE
COLD
MALIGNANT BENIGNDr Ahmed Esawy

NODULAR GIOTRE
BENIGN
ADENOMA
NEOPLASM
COLLIOD
Cyst
Complex cyst
Focal thyrioditis
MALIGNANT
As function: biochemical
- hot (toxic)
- cold (N :TSH)
cold nodule in a toxic thyroid (as may
occur in Grave’s disease)
Dr Ahmed Esawy

Parathyroid adenoma
detected by 201Tl/99mTc-
pertechnetate subtraction
imaging (A to C) and by
99mTc-sestamibi
subtraction imaging with
123I (D). A, 99mTc-
pertechnetate
concentrated within the
thyroid gland. B, 201Tl
concentrated within
thyroid and parathyroid
glands. C, Computer
techniques allow
technetium concentrated
in the thyroid gland to be
subtracted from thallium
that accumulates within
thyroid and parathyroid
tissue. After thyroid
subtraction, a parathyroid
adenoma is noted as a
focus of increased thallium
uptake (arrows). D,
99mTc-sestamibi
subtraction imaging with
123I shows an adenoma
below the inferior pole of
the left lobe of the thyroid
gland
Dr Ahmed Esawy

Full story parathyroid imaging Dr Ahmed Esawy

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